Finally, some mathematics! Autistic Engineer here. Acoustic enthusiast. I just need to make sure my suspension doesn't exceed xmax and -3db too soon. Thank you.
Idk about everyone else but i trust a guy that builds my favorite thing in the world... i tune to FS and 99.9% of time it sounds great. Very helpful info!
Thanks for the tutorial 😀 Bro it is spot on 👍😎 I learned about 90% of this out of a Pop Mech from 1957 had Hofmann's Iron & other short hand notes on audio and the Loudspeaker Cookbook back in 1992. You are on fire 🔥... 👍😎 As always
I've got 4 bdc2 12s. F.s is 26. Put them in an 11 cb ft t-line slot ported box at 36hz. Box is 250 lbs empty. Subs are awesome in this box. Wicked bass without the subs doing full xmax. They barely have to move. Having a proper box makes all the difference. 👍 love your videos man. Keep em cumin
Awesome description of how enclosures work Patrick. One of the best I've heard and spot on. However I will say that experienced builders actually can make "6th" order bandpass enclosures sound pretty great and work well if the space is available. I built a c-pillar series tuned wall enclosure in my yukon with 4 Skar VXF 15s and it sounds amazing. It plays from 25-60 hz and 156db @ 38hz and actually sounds good and clean. I mostly play decaf and rebassed music when I give demos at shows and most of it is 25-35hz. I built it specifically for demos too tho. Had them in a regular ported bass reflex wall at first and gained 3db with the bandpass. Definitely could have just been luck lol but I did spend a lot of time designing the enclosure to make sure it was going to do what I wanted before I built it. Great video man.
@Thomas Shitt that's what I do like about 6th orders. There is a low tuning frequency and a high tuning frequency that are usually 1 octave apart. Say 25 and 50 or 30 and 60. So you get the roll off at each end of the band. And a peak at each tuning frequency.
@Thomas Shitt depending on the size of the box and port you can still make a ported box play a wide band but may not be as efficient as a 6th. I plan to redo mine next winter and make it a b pillar build and have much more airspace than I do now so hopefully I will get some gains from that also. The enclosure I have now is actually on the small size for a 6th but it worked out well.
Bandpass boxes can be great in certain circumstances. The vent acts as an acoustic filter too, and can help to reduce distortion, sometimes significantly. The "Enigma" build that I did years ago using a cheap bass driver showed THD less than 1% at its RMS rating all the way down to 50 Hz, rising below that because the acoustic filter effect was less effective. When designing bandpass designs, Just make sure to use suitably-sized vents so they don't result in output compression at higher volumes. And they're a great way or ensuring that the woofer is physically protected. For car audio use however, a decent sealed or vented alignment is simpler to design and should work fine for most people.
Looking at what we have available today. 4th order was good when we did not have the crossover controls we have today. READ the loud speaker cook book and info like this is also found there.
With this video, I know why my higher FS subs were crazy inefficient tuned to 35 Hz. I was forcing them to perform at a place they were already rolling off.
subs that have a high fs, generally above 75hz are exclusively closed box, or used in pro audio as mid-bass with a cut at 140/160hz and also giving more watts rms than the declared ... in your case it's just that you made a project with the wrong compromises, for example I have a pair of 3-way loudspeakers fitted with 11-inch Beyma SM110, 47.4-litre box tuned to 53.5 Hz reflex with two 7.5 cm tubular ports 13.6 cm long . calculating the offset port and the tubes correctly sized for the air movement it arrives at the f3 at 38 hz , fs of the woofers at 64 hz . many people told me on sight "the box is too big", then when they listened to them they kept silent, it is one thing to make boxes without knowing what it is doing, it is another thing to know the behavior of the box, you have to learn the graphs and interpret them
@@albertodalmaso8896I hate people saying "tHe BoX iS ToO BiG" but most of the videos I see with 1.2 net boxes for 8 inch drivers SLAM and obviously they know what they're doing
I find that a mid QTS (4.0-5.5) and a lower Fs (20-24Hz) in a smaller box than the Vas sealed box will perform well down to 30Hz. And that’s awesome. You don’t need to go down to the low Fs.
It's funny that you mention tactile transducers cuz I was actually going to put a pair underneath my front seats and run them off of my four Channels rear channels. I use my cars trunk for work, which is already under sized for my job, so I can only have a ported 8 on a separate amp. Budget limited of course. Also about enclosure building and chasing flat response...flat is BORING. People also forget to factor in cabin gain, that also gives you a free bass boost 😆 😃 😊 Your version of the sunfire true 8 sounds intriguing
The shop I worked at was a Rockford dealer we had that program for box building. It was great it worked every time. I just adjusted the measurement to fit where I needed it to.
@@RobotUnderground I'm 98% sure it was the Rockford program. It was almost 20 years ago. But it had all the Rockford speakers in it, you could add any speaker to it and test the box sealed or ported
I had some thick spiral bound Rockford Fosgate Tuner/Technician manual I stole from Myer Emco back in the mid 90s. Was a good 3 inches thick : ). Wealth of information in that about box building and speaker response, learned a lot as a 14 year old from that.
Thanks Patrick, I learned a lot from this video. Definitely helped me realize some of the mistakes I’ve made and how to get what I want out of a box and. 🤙🤙
When I was in my teens in the 70s I owned a pair of AR48S sealed home speakers. They had that bump at about 40hz and have always loved the sound of small sealed boxes and subs made for them. Power is so cheap today,and power is what these sealed subs like.
@@JasonWW2000 class d amp use 30% less power for the same output as clas ab! less power drawn is cheaper. You don't need hi power alternators.Hence power is cheap,a fullbridge class d 3000k amp can be had for 200.00,home class d subamps are cheaper too.
@@7thsoneli Yes, but an 80% efficient 3,000 watt amp is still going to draw 300 amps of current. The same 3,000 watts from a Class AB amp with 50% efficiency would draw 375 amps. So Class D is an improvement, but it still takes power to make power. For 300 amps you could probably get by on a 250A alternator and a second AGM battery and just not blast it all the time. Or maybe with box rise you might only be drawing 200A on music. The costs add up. I try to use efficient subs and efficient boxes to get the most output on a lower amount of power.
@@JasonWW2000 I agree but short of spl competition music is dynamic usual draw is less than 100 amps maybe 50,headroom is where the power is needed,not continuous. An amp like my jbl 1000 draws 113 at full power the capacitors in a good amp provide the juice for bursts. if you into spl good luck its an expensive hobby,lol
I built my box before i knew anything about box building since then ive learned my box i built is 6.5 cubic feet after bracing and sub.Tuned to 28-30 hz...I did good just by guessing what i needed, i guess i got lucky I built using all the room i could for my placement
I build every enclosure to the specs of that particular driver. If the woofers won't work well in whatever vehicle because box size, I pick different drivers. Ported box with the largest woofer(s) as will fit in available space. Before knowing anything, I used to build a nice big sealed box and got good results every time.
Me bass tube is my favorite It can't take a lot of power to the subwoofers. I can get PVC pipe with 1/2 or thicker and from 15 inch smaller. I've been making boxes from the 80's and still learning stuff.
Very good explanation of the parameters needed to design a sub box. I was listening to you and wondering why would a manufacturer recommend a smaller sealed box size then the Vas of their subwoofer? IF say the subs Fs was 23.5, would they just be tuning the box higher maybe in the 40's hz range.
Sealed boxes aren't "tuned". But with an Fs that low, you can manipulate the performance with an EQ / bass boost pretty easily in a sealed box, including one that's smaller than recommended or "normal". The compromise is sensitivity and the requirement for more power that would be a box with the volume of the Vas. Does that make sense?
@@RobotUnderground Got it. So they would be recommending a smaller sealed box only to fit more cars(smaller spaces) knowing you can compensate for it by other means. My question referred to a 13w7 I bought super cheap off craigslist "working." I built the recommended box and it pounds hard but it is blown. There is a rattle so I'll be watching you other vids to accomplish that. Thanks for response!
@@jeremynelson8496 Yes, that's what I was trying to communicate about sealed boxes. Sorry to hear about your sub. The best thing I can recommend is just buying a replacement top assembly from me. I can build you a 12", 15" or 18" that simply bolts into place. I only have D1 coils right now but for most people that's fine.
When you did the high side peak I almost spit out my coffee. I thought you were boosting 70-80Hz. Then you wrote 12k and I gained consciousness. BTW you’re right about 30-40Hz sounding great if it’s boosted. But if you have any peaks over 40Hz it sounds like crap.
the reason that big professional companies experiment with bandpass and get acceptable results is because they design a custom driver made exactly for that box. and even then after all that trouble and money, 2 ported subs in smaller boxes will keep up with them. The LAcoustics KS28 (2x18 ported) is the best design that millions of dollars has achieved.
the port boost is in most cases distortion given by the saturation of the reflex tube. venturi effect big bullshit, we speak of resonance of hemholtz . the only thing about the "port boost" that completely different calculations are used and from software that are not yet properly modulated and simulated is the increase in efficiency given by the horn loading, there you can speak of clean boost because the increase in efficiency is not only volumetric but acoustic (how to compare DBspl against DBa, only in car audio and gigantic systems is the barometric DBspl used, in 90% of cases we are talking about DBa). the volume of a closed box is not the vas value, the vas is only an indication of how yielding the suspensions are
following your reasoning, a box is built sparingly, in a good way. but as in the crossovers you can't use a filter for a 15" faital Pro and mount it on a 15" SB acoustic sub, you will get 2 completely different things also regarding the box. you don't take into account the ebp which is fundamental
Isn't Q the resonance peak width? It is for EQ filters. Low Q is very spread out, almost no resonance peak. High Q is almost always undesirable. I also wonder what happened to the "zero Q" subwoofers, they all disappeared and now you can't even find good information about what was really meant. About this too, I once saw a subwoofer that was just an actual cube of say 10" with a 10" woofer in it and a huuuge surround. I tried pushing that speaker cone and it didn't move, that's how stiff the suspension was. How the heck can something like that produce any sound?
Yes a low Q is a broad peak. The more narrow the peak the more frequency dependent it is. So it depends on the problem that you're solving That's why I liked Rockford's OEQ2 which allowed you to change which frequency you wanted to adjust. It didn't allow to adjust the Q but that was still okay. That is actually how a really good sealed box should behave but I prefer reported boxes or passive radiator instead
So if a 12" subwoofer has a FS of 29hz & a VAS of 27.1L(0.957 cu ft). If you built a 1 cuft sealed enclosure it would have a nice response down to 29hz? QTS is 0.24
how do you get a speaker with a low Fs? I like the infrasonics, not just the super-low bass. It's one reason I like big cone diameters. An 18" (actual diameter of moving) cone moves 254 square inches of air with only 56.5 inches of edge perimeter to muddy the sound, for a ratio of about 4.5:1 square inches per inch of perimeter while a 12, for example, is at 113 square inches, less than half, at a ratio of a mere 3:1, having more edge length per area to potentially muddy the sound. Super-stiff cones would be ideal for large diameters, I think, and those could hit super-low notes with far less cone travel, I theorize. The rolling bass note behind Criss Cross's "Jump" comes to mind.
You're overthinking it bud. Low Fs has to do with the relationship between how heavy the moving mass is and and how compliant the suspension is. As far as muddy, it's best to just have a high BL factor. High BL factor helps with quickness and perceived accuracy.
@@RobotUnderground I like "overthinking" stuff! Also talking with you! Thanks for talking to all of us! If, in theory, one could create a speaker "cone" that was both large enough AND responsive enough to cover the entire back portion of their car's cabin space, then there would be little to no distortion in the sound emanating therefrom, yes? Imagine a huge, flat speaker surface powered by a great number of identical motors all being fed the same signal. If one could make such a thing out of carbon fiber and Nomex honeycomb composite, (to make it light and responsive) AND if and only if one could get the motors to all act identically, then one would have the perfect speaker, would one not? (I know, it would only be mono, but just bear with me.) The stroke could be tiny, as could be the motors, as long as there were a lot of them and they behaved identically. That is my working theory why relatively-slow-moving subwoofer cones are more negatively affected by having a smaller surface area-to-edge-circumference than are the higher-frequency drivers. The air just has too much time to escape over the edges with the smaller cones. You aren't going to get the same quality of bass with a 1" subwoofer cone with an 18" stroke as you will with an 18" cone having 1 inch of stroke. Too much spillage over the edges. The small speaker would be like holding your fist 6" from someone's ear and going back and forth rapidly. (not touching them.) It would just be an object moving through the air instead of being air being moved by an object. Where there is no "edge" to the cone, but the "cone" is the entire back of the vehicle/chamber, the entire air column from speaker face to eardrum is a transmitter of the sound in completely parallel stacks of compressed and rarified air. But, what is better for low Fs? (preferably in a small box, not a moving-van-sized box, which is really just approaching infinite baffle) Do you want a heavy cone/motor and a powerful motor versus, say, an Eminence with a light cone and motor, but plenty of power? What IS the relationship between the moving mass and the suspension compliance? What do you mean by compliance? Loose and sloppy or accurate with plenty of travel? Also, I know you can do a HLCD subwoofer, but, oy vey! the box ends up being way bigger than I want, no matter how Kewl the design concept is (like Hexibase does.) For that, I'd need a VERY strong-cone very-powerful-motor driver. But could it play the 5Hz infrasonics for which I have a fascinating obsession? To answer the question on people's minds: "Why infrasonics?" A: Why big muscles? It's not about needing them. It's about wanting them and knowing if your system can do 5Hz, it ain't gonna roll off like a tantrum-throwing autistic child at 20Hz or 30Hz. it's about the ACCURACY at all the frequencies, both felt and heard. I like the Cerwin-Vega HLCD subwoofers in the club, but they seemed to hit a moment later than the audible bass note with their infrasonics. I woulda time-delayed as necessary with those to make them coincide.
@@exploranator Compliance is how soft / giving the total suspension is. Like in JL Audio subwoofers. They use a very compliant / soft spider. That's because they want to save money / make money by using cheaper materials. They will brag about having a low Mms, but having a larger Mms move is really what makes the bass. One day I'll have a knock off that's affordable and you can test them side by side. It's really just another way to make bass but it's quite fragile and requires tooling up lots of very light plastic parts. I'm making a version now with a heavier copper coil since I'm using a tighter suspension. I tested the differences in the old Rockford T1 which made the change from copper to aluminum and a softer suspension. The roll-off and performance of copper is MUCH better. It does what you're wanting it to do, in the way that want it to perform. The aluminum and lighter suspension does it, but not quite as with as much force in the low end. Mid bass, sure. But I'm not after mid bass.
my favorite enclosure I've ever made was a single type x 12 ina single reflex bandpass tuned to 70hz. that sub is loud as shit and plays everything from bass mekanik to Mellencamp fantastically, with crazy punch. could I have done that with a ported? probably, but I'd unload with the lower freqs, a sealed box wouldn't be as loud either. so to me a bandpass has its place.
@RobotUnderground all women are crazy, some know how to control it and some don't, however they are all aware that they're ALL crazy that's why they whisper to each other, & seem to have a secret language of their own. Because they DO !
I am designing a box for my daily driver and I was thinking about 6th order box but soon realised I can make ported box better for less trouble. I have 15" Alpine SWR-1542D with Fs = 23hz, Vas = 100L and Qts = 0.45. I built a sealed box with recommended net volume of 46L ( 1.625 cf ). It has F3 at 38hz. It fucking sucks. And according to WinISD it sucks in sealed box no matter what size. It simply doesn't play loud enough unless I have DSP and EQ it properly.
Correct. Sealed box will perform fine. Just would need a little bass boost at the head unit or amp. Ported box would be 3 to no more than 4cf and best when ported from 33 to 36Hz.
Bandpass isn't garbage. Put that 18 in around 3ft³ sealed and FS should raise to 40hz+. Tune the ported side to sealed resonance and that sub will play 20-60hz+. Easily. Depending on how large you make the ported section you can achieve a decently flat response
I have 2 5200s and 4 tops Havent really used them much because they are so damn heavy I really like the storm X2 12" subs though, and run those in my cars. Running them over 10 years and still as good as I remember. Crystal CMPx2 15 are in my storage and I swap them out sometimes. Maybe the 5200s have too much BL for my preference since thats the main difference I see between them and the TC3000 I like so much better
@@RobotUnderground I think the Crystal Mobile Sound subs might be built by TC as well. Ive thought about it selling them, but maybe theres a way to use them right.
@@BARBELLS-AND-BUDS Find some home audio nut that loves them. I think they suck. I have one here in the liberry only for reference if they want recone kits.
Should only be avail to RF dealers but I'll ask my contacts there if they have an old copy or something. It may be web based now which would keep pirates away.
I second this message. Only thing I disagree on is that the fs is the lowest the subwoofer will play. Fs is the subs resonate frequency not its frequency range. The rest is pretty spot on.
@@RobotUnderground my orions hccas fs is 38 and in the box they are in currently they can play as low as 22hz. You arr the one who has explain to do to your viewers again.
@@filibertofonseca8083 lol. You have no idea what you're doing. But please, go on. Make a video of your test results and please prove that you know how to overcome Hoffman's Iron Law. sites.psu.edu/speakerdesign/2013/01/24/hoffmans-iron-laws-of-speaker-building/
@@filibertofonseca8083 You can save time by using a box model program and see that by tuning the port so low, you lose the opportunity for efficiency near the Fs. The sub can and does play below the Fs but a VERY ATTENUATED SPL.
So a sub with a qts of .6 would be best in ported/vented enclosure? Just watched a video with a seemingly smart and articulate fella which terminology he spoke was having my brain fry got into the qts part but basically was saying opposite of qts value meanings smh 🤦, got a 10" mtx thunder 5500 and just wanted to build a vented enclosure that would allow to produce the most can offer as it's goin in my ext cab nissan, my biggest hurtle is slotted port size in w×d×L as everyone is measuring w×h but is the entire port channel the same or does the section towards backside running the length of enclosure have different width then the section the faces outwards from enclosure? and most importantly how does a specific tune reached whenever there's supposedly a minimum of port area/cubicft of internal volume needed to maintain air movement passing threw port ?? Shit is deep
A subwoofer always does better in a ported box. The problem can be that a woofer with a small magnet would require a very large box. When the QTS is about 5 plus or minus a little bit it can go either way sealed or ported. The Hi QTS just recommends that it does best in a ported box but really it always does better in a ported box just sometimes the box size is not reasonable depending on the VAS. The 5500 is a good little subwoofer. Don't go any larger than 1.3 ft³ and if you follow the rule of thumb for ports then you'll want about 18 square inches of port area. Then you can vary the length depending on what frequency you want to tune at. For a 10 inch like that I would recommend about 34 to 36 Hertz
Ok sweet, so would a 2"×12" slot port diameter be sufficient or 1"-1.50" w×12" ? Also is there any difference if the width changes on backside of port channel since it's shaped like L does width need to remain same entire length or is it better to have example 2" from port exit down first channel and then 2.50" width down 2nd channel which would be port entrance channel that along backside of enclosure? Since air speed is required to be kept at a certain speed supposedly to prevent noise/subwoofer unloading? You said 1.3cuft for enclosure space with port or without ? Plan to run 300watt rms which is my question regarding port width and entire channel of port width ? To be honest this is more about my ocd and challenge to self of making something that's old and entry-level at best sound sound really good for what they are, even been researching cabin gain and how to calculate and include with enclosure design? Appreciated your help bro.
All i know is my 06 maxima had the WORST F--KIN acoustics for subs. How do you find a type of car that has good acoustics, how is it measured or can u quickly tell by ear?
Other thing wrong is that high impedance rise for SPL! How would you have imp. rise at tuning? OK what about the Q value when you didn’t mention it? I mean the box volume isn’t mentioned either? So you just get a sub with 50hz FS and high BL (actually low Qts is what should go here), what about after putting it in a box? The bigger the box the lower the imp at tuning? Thank you
@@RobotUnderground I, too, am surprised at the concept of a smaller sealed than ported box, unless the port is taking up a lot of the insides of the box. Also, you would have to tune your system to your car's unique insides and also with the windows fully or partially open to get optimal results, yes?
@@exploranator A smaller, sealed box will have a higher frequency roll of.. Meaning that it won't play as low / loud as a larger and ported version. The cool thing about the sealed box is that you can EQ to taste. So if you want a solid response to 30Hz, you can just boost it with an EQ and as long as the sub can take the power and has the excursion, you'll be in good shape. I prefer a more natural and louder response of the ported box but it's not always available.
@@RobotUnderground I ordered a fi audio Neo 3.5, the largest recommended box size was a 2.5. What difference would it be if the box is 2.75? Just found your channel so you might have answered this before. Trying to learn as much as I can when I’m off work.
@@marathonbaker Even at 2.5cf, you're running it in free air basically. With a sub like that, I'd actually run it with a passive radiator in 1cf. ruclips.net/video/YlWZ3UIYOMw/видео.html
@@RobotUnderground I kind of like the big box look. I used to have the RE XXX (1st gen) and a friend had a huge box like 10cu ft for a single 15. It was a unique design, hexagon around the subwoofer cutout, 4 inch thick baffle, fiberglass inside with huge 45 degrees sides. That was probably 15 years ago but looking for a similar setup but toned down some.
@@marathonbaker Just because you like something, doesn't mean it's healthy or proper. I just follow the rules. If you don't want to, that's your business.
Hello bro Patrick, this is Hael if you remember me, I’m not against you by any mean, wanted to make sure you give bandpass a one more shot, how would you do a sealed playing as a bandpass? Have you heard any tiny subwoofer in a bandpass such as Bose or JBL? they play low and they are loud for what they are, I’m pretty sure you can’t achieve such a bandwidth and SPL with a regular sealed or even ported box! Try to have a ported box that peaks at 50hz with +6db (or even more) and still has control down at 25hz? could you do that with a sealed? A ported? Ported is the actual one note wonder if you try to match cabin gain etc., not here to argue bro and thank you for the time spent and efforts you put to help others, btw you build insanely good subs with perfectly efficient parameters!!!
I've talked a long time with several people at several brands and have come to some sobering conclusions. Your best bet is to study the work of Wayne Connelly. He helped research and develop the RATS information network for Rockford.
Awsome info totally blows my mind how much info I missed during the bass years but I have a question I just bought 2 vfl8s and I'm running a sundown 1000.1 amp prob at 3/8 the speakers are in a 2.3 net box but at the low Hertz they or it sounds like one is bottoming out any ideas box is ported tuned to 35 speaker fs is 40
@@exploranator Not bottom out, but just be more compliant than needed. The more compliant, the less resistance. The lest resistance, the less power it can handle and the SOONER and more easily it will bottom out. Play with the specs on a performance predictor like WinISD. I used BlauBox back in the 90's. You can see what happens when you're just under the Vas and just over the Vas. Then you can play with the tuning frequency to see how you can warp the response to be closer to what you want... Or at least what you think you want. Then build it and listen do it. You may not even know what you like listening to... Or at least what the prediction looks like, of the response you want.
@@travisabrahamson5092 Running the numbers for your driver and the box size and tuning that you mentioned, and taking my car's cabin gain into consideration, I end up with a dead flat response between 30 Hz and 50 Hz, which then slopes 9~12 dB to 100 Hz. Below 30 Hz it drops off 9 dB to 20 Hz. I'd probably try that in my car, if I wasn't allergic to putting 4.5 cu.ft. boxes in its trunk :-)
Dd recommends their enclosures tuned from 35 hertz to 40 hertz? You can go lower but you want feel the pressure that subwoofer gives you at what they recommend? I been owning dds since 2007 tune your box at 36 to 38 hertz and I promise you you will shatter something in your vehicle they are spl subwoofers?
WOW awesome info . I've got 6 carbon series harmony audio dual 4ohm. Amps are Harmony audio 1500.1 x3 Been considering a big 6th order . The vehicle is a 2004 Pathfinder . With the info I just gathered from you hopefully I can utilize it. What's your take on transmission line enclosures
Retraction 1.5 -2.25 per sub I was thinking 1.75 per with the subs up port front with 15² in of port area box inside measurements will be 40L/ 14H/42w @13.5 cubic feet.. port 14x8 x28L now all this is off top of the head some Numbers are subject to change. I figure with a big ass port and the bracing is going to need it should be about right size . Got 4 of these subs in a 1.5 cubic foot per sub 6.2 cubic foot box subs are inverted
@@hillbilly1036 Typically you want 16 square inches of port area per cubic foot of internal volume. Here's the RE audio flash program. drive.google.com/file/d/1pR5y2J89Z8C2l1wP9w_7-Bd8ByZeiJu9/view?usp=sharing
Ugh. Okay, Patrick. Settle my decision for me. Four, forward firing 8s getting 250 watts each, or two, up firing 12s getting 500 watts each. 2.5cu feet of max airspace available. Ported or sealed? They’re going under the rear seat of a Nissan Titan Quad Cab. I want decent kick drums for metal, and teeth chattering bass when I listen to EDM.
@@emac800 It might just activate old farts that were buried. Just make sure that the seats aren't rubbing the surrounds. We can do a reverse surround as well.
Sealed box with a 12" or 15" in the cabin. Then do a sweep. If a shop has an RTA machine, they can find it for you when you do the sweep. If not, you'll have to do it in 5hz segments to and plot with an SPL meter, and record the db readings as you go through the sweep.
This is the formula set I use to approximate the fundamental resonant frequency of a given 'cabin' or volume, and the approximate 'gain', when I do not have the time to measure a cabin, with fairly consistent results. Do the following in MS Excel: Formula process for Cabin resonant frequency: Step 1.) Define a Temperature (deg/F) in cell 'B1'. 70deg is a good average to work with, but it can be any value, you decide. Step 2.) Measure and define a Cabin 'Length' (x) in inches, in cell 'B2'. Measure from firewall to the backside of the trunk. Step 3.) Measure and define a Cabin 'Width' (y) in inches, in cell 'B3'. I measure at the widest width from window sill to window sill. Step 4.) Measure and define a Cabin 'Height' (z) in inches, in cell 'B4' I find the location of the cabin that has the highest measurement. Step 5.) Copy and paste this formula into cell 'B5': =SQRT(B2^2+B3^2+B4^2) This is the approximate maximum diagonal run (length) of your cabin, expressed in inches. Step 6.) Copy and paste this formula into cell 'B6': =((((643.855*(((((B1-32)*5)/9)/273.15)^0.5)*1.1507794)*(5280/3600)*12)/2)*(1/B5) This is the approximate fundamental resonant frequency of your cabin, expressed as Hz. Formula process for Cabin 'gain': Step 1.) Copy and paste this formula into cell 'B7': =20*LOG(B5*0.02831685) This is the approximate cabin 'gain' reference of your cabin, expressed in dB. Btw, I have another method based on the ideal gas law but the method I typed out above is a much more accurate approximation if you don't have measurement or test equipment. Good luck and lemme know if you have any questions. Let's see if Patrick approves! 😂
@@RobotUnderground it will be in a car. 2003 Volkswagen jetta. Looking at 10 cubes for the pair in the backseat. Sealed or ported through the rear deck.
@@RobotUnderground that's what I'm planning. The port would be external into the trunk space up through the rear deck so it could be removed or changed. Sealed will be the first go, ported later if I feel I want more output. The pair of them will be ran at 2 ohm on a Taramps Smart 3. Not a ton of power, but plenty for these.
Bandpass becomes much more friendly when you use 4 or more drivers and your port is big enough for you to crawl through I just got done testing a 12-15 6th order tuned 22hz and 46hz it’s flat from 20-60hz which it drops off hard above 60
I watched the part about the 5200 in SPL application. What about the great debate for the LMS ULTRA 5400 for home theatre use. Small ported 4 cubes vs passive radiator 4 cubes vs Large ported I have one sitting in the closet and haven’t pulled the trigger on building a box.
You won me over at heavy copper coil... I hope people come around and understand aluminium coils sux... There cheaper and just break cuz thats what aluminium does when electricity is going through it.. a good reference of that fact.. new homes cant have aluminium power lines in the walls just ask any fire marshal or building code inspector..
What kills me is they gripe about cca wire,but then run aluminum coils.🤷🏻♂️i hear alot of ocd in car audio.i have it too but my ocd is from lack of knowledge.its unsure ocd,from just simply not knowing,but i try to do things that i really shouldnt be trying to do.i been messing with car audio for a yr and have done took a top plate off a motor and opened the gap for a 8 layer coil.and it bout took my fingers off but screwdrivers saved em, and a close prybar.
The reason why they use aluminum coils is because it is lighter than copper and dissipate heat faster? I don't think you can find a copper 4 inch voice coil probably to heavy
Patrick if you want to get a giant laugh look up "how to make your subwoofers sound louder" video by image design , the guy has some insane concepts non based on reality by a long shot. The guy is so misinformed it's just comical instead of being irritated at his claims you just laugh at the insanity. He definitely should not be dropping dat knowledge unless your looking for misleading nonsense!
Dude I don't tune anything under 35 hz I don't like that low bass stuff I like more everyday music not rebass and bass boasted music so I tune to about 40 Hz
Do not Believe anything in this video. This is an absolute garbage video. As an example Fs is the free air resonance of the driver. And have nothing to do whit what the driver can produce installed in a box. Most subwoofers for car audio have a high Fs. So using this logic most subs cant produce anything under 40Hz.... It seems he i just making things upp. But why??
I like the bass under 30hz because I exclusively listen to romance explosions. I have to slow down the audio to get the house shaking... I'll see myself out ✌️
Finally, some mathematics! Autistic Engineer here. Acoustic enthusiast. I just need to make sure my suspension doesn't exceed xmax and -3db too soon. Thank you.
Idk about everyone else but i trust a guy that builds my favorite thing in the world... i tune to FS and 99.9% of time it sounds great. Very helpful info!
Thanks for the tutorial 😀 Bro it is spot on 👍😎 I learned about 90% of this out of a Pop Mech from 1957 had Hofmann's Iron & other short hand notes on audio and the Loudspeaker Cookbook back in 1992. You are on fire 🔥... 👍😎 As always
I've got 4 bdc2 12s. F.s is 26. Put them in an 11 cb ft t-line slot ported box at 36hz. Box is 250 lbs empty. Subs are awesome in this box. Wicked bass without the subs doing full xmax. They barely have to move. Having a proper box makes all the difference. 👍 love your videos man. Keep em cumin
Those are in free-air.
@@RobotUnderground hahaha
@@LowetheTechGuy Is what a good thing?
Awesome description of how enclosures work Patrick. One of the best I've heard and spot on. However I will say that experienced builders actually can make "6th" order bandpass enclosures sound pretty great and work well if the space is available. I built a c-pillar series tuned wall enclosure in my yukon with 4 Skar VXF 15s and it sounds amazing. It plays from 25-60 hz and 156db @ 38hz and actually sounds good and clean. I mostly play decaf and rebassed music when I give demos at shows and most of it is 25-35hz. I built it specifically for demos too tho. Had them in a regular ported bass reflex wall at first and gained 3db with the bandpass. Definitely could have just been luck lol but I did spend a lot of time designing the enclosure to make sure it was going to do what I wanted before I built it. Great video man.
@Thomas Shitt that's what I do like about 6th orders. There is a low tuning frequency and a high tuning frequency that are usually 1 octave apart. Say 25 and 50 or 30 and 60. So you get the roll off at each end of the band. And a peak at each tuning frequency.
@Thomas Shitt depending on the size of the box and port you can still make a ported box play a wide band but may not be as efficient as a 6th. I plan to redo mine next winter and make it a b pillar build and have much more airspace than I do now so hopefully I will get some gains from that also. The enclosure I have now is actually on the small size for a 6th but it worked out well.
Bandpass boxes can be great in certain circumstances. The vent acts as an acoustic filter too, and can help to reduce distortion, sometimes significantly. The "Enigma" build that I did years ago using a cheap bass driver showed THD less than 1% at its RMS rating all the way down to 50 Hz, rising below that because the acoustic filter effect was less effective. When designing bandpass designs, Just make sure to use suitably-sized vents so they don't result in output compression at higher volumes. And they're a great way or ensuring that the woofer is physically protected. For car audio use however, a decent sealed or vented alignment is simpler to design and should work fine for most people.
2 years later still watching your videos great content 🎉
I appreciate that!
Looking at what we have available today. 4th order was good when we did not have the crossover controls we have today. READ the loud speaker cook book and info like this is also found there.
I used to hook them up in tri-mode and we'd still need an inductor, so technically it'd be considered a 5th order.... Fancy pants!
Thanks RUclips I saw this channel after 2 years in this hobby and seeing 1hr youtube everyday. Interesting content unique
Glad you enjoy it!
With this video, I know why my higher FS subs were crazy inefficient tuned to 35 Hz. I was forcing them to perform at a place they were already rolling off.
Correct and that's how you burn them up... Asking them to do a job they're not made for.
Budgetbasshead just did a build with meso 6.5 metering in the 40s I think them lil CT's FS is almost 60 with 2 heating up
@@--sik801--6 I remember that
subs that have a high fs, generally above 75hz are exclusively closed box, or used in pro audio as mid-bass with a cut at 140/160hz and also giving more watts rms than the declared ...
in your case it's just that you made a project with the wrong compromises, for example I have a pair of 3-way loudspeakers fitted with 11-inch Beyma SM110, 47.4-litre box tuned to 53.5 Hz reflex with two 7.5 cm tubular ports 13.6 cm long . calculating the offset port and the tubes correctly sized for the air movement it arrives at the f3 at 38 hz , fs of the woofers at 64 hz . many people told me on sight "the box is too big", then when they listened to them they kept silent, it is one thing to make boxes without knowing what it is doing, it is another thing to know the behavior of the box, you have to learn the graphs and interpret them
@@albertodalmaso8896I hate people saying "tHe BoX iS ToO BiG" but most of the videos I see with 1.2 net boxes for 8 inch drivers SLAM and obviously they know what they're doing
Thanks man, this is exactly the video I needed
I find that a mid QTS (4.0-5.5) and a lower Fs (20-24Hz) in a smaller box than the Vas sealed box will perform well down to 30Hz. And that’s awesome. You don’t need to go down to the low Fs.
It's funny that you mention tactile transducers cuz I was actually going to put a pair underneath my front seats and run them off of my four Channels rear channels. I use my cars trunk for work, which is already under sized for my job, so I can only have a ported 8 on a separate amp. Budget limited of course.
Also about enclosure building and chasing flat response...flat is BORING.
People also forget to factor in cabin gain, that also gives you a free bass boost 😆 😃 😊
Your version of the sunfire true 8 sounds intriguing
Get out there and experiment! Fuckit! Even try some buttstuff.
The shop I worked at was a Rockford dealer we had that program for box building. It was great it worked every time. I just adjusted the measurement to fit where I needed it to.
What was the name of the program?
@@RobotUnderground I'm 98% sure it was the Rockford program. It was almost 20 years ago. But it had all the Rockford speakers in it, you could add any speaker to it and test the box sealed or ported
I had some thick spiral bound Rockford Fosgate Tuner/Technician manual I stole from Myer Emco back in the mid 90s. Was a good 3 inches thick : ). Wealth of information in that about box building and speaker response, learned a lot as a 14 year old from that.
Thanks Patrick, I learned a lot from this video. Definitely helped me realize some of the mistakes I’ve made and how to get what I want out of a box and. 🤙🤙
Glad it was helpful!
When I was in my teens in the 70s I owned a pair of AR48S sealed home speakers. They had that bump at about 40hz and have always loved the sound of small sealed boxes and subs made for them. Power is so cheap today,and power is what these sealed subs like.
I would not say power is cheap. Amps yes, but alternators and batteries are still expensive.
@@JasonWW2000 class d amp use 30% less power for the same output as clas ab! less power drawn is cheaper. You don't need hi power alternators.Hence power is cheap,a fullbridge class d 3000k amp can be had for 200.00,home class d subamps are cheaper too.
@@7thsoneli Yes, but an 80% efficient 3,000 watt amp is still going to draw 300 amps of current.
The same 3,000 watts from a Class AB amp with 50% efficiency would draw 375 amps.
So Class D is an improvement, but it still takes power to make power.
For 300 amps you could probably get by on a 250A alternator and a second AGM battery and just not blast it all the time. Or maybe with box rise you might only be drawing 200A on music. The costs add up. I try to use efficient subs and efficient boxes to get the most output on a lower amount of power.
@@JasonWW2000 I agree but short of spl competition music is dynamic usual draw is less than 100 amps maybe 50,headroom is where the power is needed,not continuous. An amp like my jbl 1000 draws 113 at full power the capacitors in a good amp provide the juice for bursts. if you into spl good luck its an expensive hobby,lol
I built my box before i knew anything about box building since then ive learned my box i built is 6.5 cubic feet after bracing and sub.Tuned to 28-30 hz...I did good just by guessing what i needed, i guess i got lucky I built using all the room i could for my placement
Well said Pat. Learned a lot. I’m a sealed box guy.
Yep I use your boxes as well I just realized that they need a little bit of bass boost to give me what I really want
I build every enclosure to the specs of that particular driver. If the woofers won't work well in whatever vehicle because box size, I pick different drivers. Ported box with the largest woofer(s) as will fit in available space. Before knowing anything, I used to build a nice big sealed box and got good results every time.
This speaks to me
Me bass tube is my favorite
It can't take a lot of power to the subwoofers. I can get PVC pipe with 1/2 or thicker and from 15 inch smaller.
I've been making boxes from the 80's and still learning stuff.
Sounds great!
im fighting this shit for years but it wont get in my brain the right way i wish i would understand it but i dont
Very good explanation of the parameters needed to design a sub box. I was listening to you and wondering why would a manufacturer recommend a smaller sealed box size then the Vas of their subwoofer? IF say the subs Fs was 23.5, would they just be tuning the box higher maybe in the 40's hz range.
Sealed boxes aren't "tuned". But with an Fs that low, you can manipulate the performance with an EQ / bass boost pretty easily in a sealed box, including one that's smaller than recommended or "normal". The compromise is sensitivity and the requirement for more power that would be a box with the volume of the Vas. Does that make sense?
@@RobotUnderground Got it. So they would be recommending a smaller sealed box only to fit more cars(smaller spaces) knowing you can compensate for it by other means. My question referred to a 13w7 I bought super cheap off craigslist "working." I built the recommended box and it pounds hard but it is blown. There is a rattle so I'll be watching you other vids to accomplish that. Thanks for response!
@@jeremynelson8496 Yes, that's what I was trying to communicate about sealed boxes. Sorry to hear about your sub. The best thing I can recommend is just buying a replacement top assembly from me. I can build you a 12", 15" or 18" that simply bolts into place. I only have D1 coils right now but for most people that's fine.
When you did the high side peak I almost spit out my coffee. I thought you were boosting 70-80Hz. Then you wrote 12k and I gained consciousness.
BTW you’re right about 30-40Hz sounding great if it’s boosted. But if you have any peaks over 40Hz it sounds like crap.
I personally like 40hz boost. Typical Q is pretty wide.
Who else is here 2024 still ❤❤❤
I came, but the video is less relevant nowadays.
the reason that big professional companies experiment with bandpass and get acceptable results is because they design a custom driver made exactly for that box. and even then after all that trouble and money, 2 ported subs in smaller boxes will keep up with them.
The LAcoustics KS28 (2x18 ported) is the best design that millions of dollars has achieved.
Unless you're Bose. Then you find a shitty little sub that nobody wanted and build a whole project around that shitty little sub array.
the port boost is in most cases distortion given by the saturation of the reflex tube. venturi effect big bullshit, we speak of resonance of hemholtz . the only thing about the "port boost" that completely different calculations are used and from software that are not yet properly modulated and simulated is the increase in efficiency given by the horn loading, there you can speak of clean boost because the increase in efficiency is not only volumetric but acoustic (how to compare DBspl against DBa, only in car audio and gigantic systems is the barometric DBspl used, in 90% of cases we are talking about DBa). the volume of a closed box is not the vas value, the vas is only an indication of how yielding the suspensions are
following your reasoning, a box is built sparingly, in a good way. but as in the crossovers you can't use a filter for a 15" faital Pro and mount it on a 15" SB acoustic sub, you will get 2 completely different things also regarding the box.
you don't take into account the ebp which is fundamental
Thank you for this. Very much!
I'm glad I could help.
Learned a lot thanks man
Glad to hear it!
Awesome video much appreciated!
Glad it was helpful!
Get those butt shakers are cool my favorite movie theater has them on every seat and it makes explosions amazing
Thanks for the information
No worries
Isn't Q the resonance peak width? It is for EQ filters. Low Q is very spread out, almost no resonance peak. High Q is almost always undesirable.
I also wonder what happened to the "zero Q" subwoofers, they all disappeared and now you can't even find good information about what was really meant. About this too, I once saw a subwoofer that was just an actual cube of say 10" with a 10" woofer in it and a huuuge surround. I tried pushing that speaker cone and it didn't move, that's how stiff the suspension was. How the heck can something like that produce any sound?
Yes a low Q is a broad peak. The more narrow the peak the more frequency dependent it is. So it depends on the problem that you're solving That's why I liked Rockford's OEQ2 which allowed you to change which frequency you wanted to adjust. It didn't allow to adjust the Q but that was still okay.
That is actually how a really good sealed box should behave but I prefer reported boxes or passive radiator instead
So if a 12" subwoofer has a FS of 29hz & a VAS of 27.1L(0.957 cu ft). If you built a 1 cuft sealed enclosure it would have a nice response down to 29hz? QTS is 0.24
Uptempo Hardcore is music genre which has really low bassline.
how do you get a speaker with a low Fs? I like the infrasonics, not just the super-low bass. It's one reason I like big cone diameters. An 18" (actual diameter of moving) cone moves 254 square inches of air with only 56.5 inches of edge perimeter to muddy the sound, for a ratio of about 4.5:1 square inches per inch of perimeter while a 12, for example, is at 113 square inches, less than half, at a ratio of a mere 3:1, having more edge length per area to potentially muddy the sound.
Super-stiff cones would be ideal for large diameters, I think, and those could hit super-low notes with far less cone travel, I theorize. The rolling bass note behind Criss Cross's "Jump" comes to mind.
You're overthinking it bud. Low Fs has to do with the relationship between how heavy the moving mass is and and how compliant the suspension is. As far as muddy, it's best to just have a high BL factor. High BL factor helps with quickness and perceived accuracy.
@@RobotUnderground I like "overthinking" stuff! Also talking with you! Thanks for talking to all of us!
If, in theory, one could create a speaker "cone" that was both large enough AND responsive enough to cover the entire back portion of their car's cabin space, then there would be little to no distortion in the sound emanating therefrom, yes?
Imagine a huge, flat speaker surface powered by a great number of identical motors all being fed the same signal. If one could make such a thing out of carbon fiber and Nomex honeycomb composite, (to make it light and responsive) AND if and only if one could get the motors to all act identically, then one would have the perfect speaker, would one not? (I know, it would only be mono, but just bear with me.) The stroke could be tiny, as could be the motors, as long as there were a lot of them and they behaved identically.
That is my working theory why relatively-slow-moving subwoofer cones are more negatively affected by having a smaller surface area-to-edge-circumference than are the higher-frequency drivers. The air just has too much time to escape over the edges with the smaller cones.
You aren't going to get the same quality of bass with a 1" subwoofer cone with an 18" stroke as you will with an 18" cone having 1 inch of stroke. Too much spillage over the edges. The small speaker would be like holding your fist 6" from someone's ear and going back and forth rapidly. (not touching them.) It would just be an object moving through the air instead of being air being moved by an object.
Where there is no "edge" to the cone, but the "cone" is the entire back of the vehicle/chamber, the entire air column from speaker face to eardrum is a transmitter of the sound in completely parallel stacks of compressed and rarified air.
But, what is better for low Fs? (preferably in a small box, not a moving-van-sized box, which is really just approaching infinite baffle) Do you want a heavy cone/motor and a powerful motor versus, say, an Eminence with a light cone and motor, but plenty of power?
What IS the relationship between the moving mass and the suspension compliance? What do you mean by compliance? Loose and sloppy or accurate with plenty of travel?
Also, I know you can do a HLCD subwoofer, but, oy vey! the box ends up being way bigger than I want, no matter how Kewl the design concept is (like Hexibase does.) For that, I'd need a VERY strong-cone very-powerful-motor driver. But could it play the 5Hz infrasonics for which I have a fascinating obsession?
To answer the question on people's minds: "Why infrasonics?"
A: Why big muscles? It's not about needing them. It's about wanting them and knowing if your system can do 5Hz, it ain't gonna roll off like a tantrum-throwing autistic child at 20Hz or 30Hz. it's about the ACCURACY at all the frequencies, both felt and heard.
I like the Cerwin-Vega HLCD subwoofers in the club, but they seemed to hit a moment later than the audible bass note with their infrasonics. I woulda time-delayed as necessary with those to make them coincide.
@@exploranator Compliance is how soft / giving the total suspension is. Like in JL Audio subwoofers. They use a very compliant / soft spider. That's because they want to save money / make money by using cheaper materials. They will brag about having a low Mms, but having a larger Mms move is really what makes the bass. One day I'll have a knock off that's affordable and you can test them side by side. It's really just another way to make bass but it's quite fragile and requires tooling up lots of very light plastic parts. I'm making a version now with a heavier copper coil since I'm using a tighter suspension. I tested the differences in the old Rockford T1 which made the change from copper to aluminum and a softer suspension. The roll-off and performance of copper is MUCH better. It does what you're wanting it to do, in the way that want it to perform. The aluminum and lighter suspension does it, but not quite as with as much force in the low end. Mid bass, sure. But I'm not after mid bass.
my favorite enclosure I've ever made was a single type x 12 ina single reflex bandpass tuned to 70hz. that sub is loud as shit and plays everything from bass mekanik to Mellencamp fantastically, with crazy punch. could I have done that with a ported? probably, but I'd unload with the lower freqs, a sealed box wouldn't be as loud either. so to me a bandpass has its place.
Are you willing to go on record that blondes aren't crazy? Just because you had one that wasn't crazy, doesn't mean the rest of us can take that risk.
@RobotUnderground all women are crazy, some know how to control it and some don't, however they are all aware that they're ALL crazy that's why they whisper to each other, & seem to have a secret language of their own. Because they DO !
I am designing a box for my daily driver and I was thinking about 6th order box but soon realised I can make ported box better for less trouble.
I have 15" Alpine SWR-1542D with Fs = 23hz, Vas = 100L and Qts = 0.45. I built a sealed box with recommended net volume of 46L ( 1.625 cf ). It has F3 at 38hz. It fucking sucks. And according to WinISD it sucks in sealed box no matter what size. It simply doesn't play loud enough unless I have DSP and EQ it properly.
Correct. Sealed box will perform fine. Just would need a little bass boost at the head unit or amp. Ported box would be 3 to no more than 4cf and best when ported from 33 to 36Hz.
Thank you.
So my fi 15s frequently is 33 hertz and I my ported box tuned to 32hertz 7.90 cubic feet sounds great
I have a ssa zcon 12" with a fs 37.0 qts .29 vas 24.4 bl 25.3 tuned at 32 hz 3 cf per ssa recommendation.
Bandpass isn't garbage. Put that 18 in around 3ft³ sealed and FS should raise to 40hz+. Tune the ported side to sealed resonance and that sub will play 20-60hz+. Easily. Depending on how large you make the ported section you can achieve a decently flat response
I think DosBox is the program you're looking for, to emulate DOS.
Someone already provided me with a program that works through the browser to emulate it
& that's why different cellos are different sizes
Correct. Different pass bands
Soooo awesome! Thank you so much!
Glad you like it!
I have 2 5200s and 4 tops
Havent really used them much because they are so damn heavy
I really like the storm X2 12" subs though, and run those in my cars. Running them over 10 years and still as good as I remember.
Crystal CMPx2 15 are in my storage and I swap them out sometimes.
Maybe the 5200s have too much BL for my preference since thats the main difference I see between them and the TC3000 I like so much better
Well there is lots of collectors and if you like money you can trade those collectors for money
@@RobotUnderground I think the Crystal Mobile Sound subs might be built by TC as well.
Ive thought about it selling them, but maybe theres a way to use them right.
@@BARBELLS-AND-BUDS Find some home audio nut that loves them. I think they suck. I have one here in the liberry only for reference if they want recone kits.
@@RobotUnderground What do you think is the best TC motor?
@@BARBELLS-AND-BUDS LMS-5400 motor using "non-linear", TC-5200 D2 8 layer coils. That's what I built for Josh Pastrana in New Mexico.
People forget that they have mid rage drivers to balance the curve.
Is there a driver like peerless STW 350 that does 20hz in 2cuft sealed
I'm sure there is. Remember that just because it can play to 20Hz, doesn't mean it's going to be at the performance level that you desire.
why not play below the fs? I had a skar zvx and the fs is 44 hz and it would play down to 25 with no issues. In a 6th order.
Does Anyone Know Where To Find The R.A.T.S Tool? I Haven't Been Able To Find It. Just A Description Of It On Rockford's Website.
Should only be avail to RF dealers but I'll ask my contacts there if they have an old copy or something. It may be web based now which would keep pirates away.
I’ve never saw a driver spec QTS of 1.4
Some from Fi are that high. It really just means that the cone is quite controlled. Not as violent at the Fs.
I second this message. Only thing I disagree on is that the fs is the lowest the subwoofer will play. Fs is the subs resonate frequency not its frequency range. The rest is pretty spot on.
Please, by all means. Show me how the sub can play below the Fs.
@@RobotUnderground I already explained it to you above.
@@RobotUnderground my orions hccas fs is 38 and in the box they are in currently they can play as low as 22hz. You arr the one who has explain to do to your viewers again.
@@filibertofonseca8083 lol. You have no idea what you're doing. But please, go on. Make a video of your test results and please prove that you know how to overcome Hoffman's Iron Law. sites.psu.edu/speakerdesign/2013/01/24/hoffmans-iron-laws-of-speaker-building/
@@filibertofonseca8083 You can save time by using a box model program and see that by tuning the port so low, you lose the opportunity for efficiency near the Fs. The sub can and does play below the Fs but a VERY ATTENUATED SPL.
So a sub with a qts of .6 would be best in ported/vented enclosure? Just watched a video with a seemingly smart and articulate fella which terminology he spoke was having my brain fry got into the qts part but basically was saying opposite of qts value meanings smh 🤦, got a 10" mtx thunder 5500 and just wanted to build a vented enclosure that would allow to produce the most can offer as it's goin in my ext cab nissan, my biggest hurtle is slotted port size in w×d×L as everyone is measuring w×h but is the entire port channel the same or does the section towards backside running the length of enclosure have different width then the section the faces outwards from enclosure? and most importantly how does a specific tune reached whenever there's supposedly a minimum of port area/cubicft of internal volume needed to maintain air movement passing threw port ?? Shit is deep
A subwoofer always does better in a ported box. The problem can be that a woofer with a small magnet would require a very large box. When the QTS is about 5 plus or minus a little bit it can go either way sealed or ported. The Hi QTS just recommends that it does best in a ported box but really it always does better in a ported box just sometimes the box size is not reasonable depending on the VAS. The 5500 is a good little subwoofer. Don't go any larger than 1.3 ft³ and if you follow the rule of thumb for ports then you'll want about 18 square inches of port area. Then you can vary the length depending on what frequency you want to tune at. For a 10 inch like that I would recommend about 34 to 36 Hertz
Ok sweet, so would a 2"×12" slot port diameter be sufficient or 1"-1.50" w×12" ? Also is there any difference if the width changes on backside of port channel since it's shaped like L does width need to remain same entire length or is it better to have example 2" from port exit down first channel and then 2.50" width down 2nd channel which would be port entrance channel that along backside of enclosure? Since air speed is required to be kept at a certain speed supposedly to prevent noise/subwoofer unloading? You said 1.3cuft for enclosure space with port or without ? Plan to run 300watt rms which is my question regarding port width and entire channel of port width ? To be honest this is more about my ocd and challenge to self of making something that's old and entry-level at best sound sound really good for what they are, even been researching cabin gain and how to calculate and include with enclosure design? Appreciated your help bro.
All i know is my 06 maxima had the WORST F--KIN acoustics for subs. How do you find a type of car that has good acoustics, how is it measured or can u quickly tell by ear?
lol. All cars are great for listening to loud and clear sound if you know what you're doing.
@@RobotUnderground i suppose, i need to get some test equipment,rta,mic,etc.
@@user-hf4eh2ts3q Start with this and an old PC or laptop, Dayton Audio DATSv3 amzn.to/3ZxE1CQ
@@RobotUnderground ill give it a look see! Thank you!
So my 15’s are fs-34.43 Qts .400 and 3 sqf per sub would I go with that or tune to 40 hz ?
3cf each at 33 to 36hz
So a good subs for the lows will have a low fs and a lot of xmax and the bl doesn’t really matter
Correct. Should have lots of BL as well.
@@RobotUnderground so is rhe VAS the largest the enclosure should be ?
@@RobotUnderground with that being said if I could take soft parts of the DS18 hooligan black basket and put them with a stronger motor I would .
@@chadbeverly4926 It wouldn't make a difference.
@@RobotUnderground oh fr ? I like their 15 but I feel like it having a BL 16.25 is low . Maybe it’s average but the 12” model has a BL of 25
Better to Use winisd to design your enclosure
Great video
Other thing wrong is that high impedance rise for SPL! How would you have imp. rise at tuning? OK what about the Q value when you didn’t mention it? I mean the box volume isn’t mentioned either? So you just get a sub with 50hz FS and high BL (actually low Qts is what should go here), what about after putting it in a box? The bigger the box the lower the imp at tuning? Thank you
How did you get your figures for box size, 4.5cf for ported and 2cf sealed? Is there a formula using these numbers?
After a while you get a feel for it but I spent hours using Blaubox and comparing how a sub performs in each enclosure.
@@RobotUnderground I, too, am surprised at the concept of a smaller sealed than ported box, unless the port is taking up a lot of the insides of the box. Also, you would have to tune your system to your car's unique insides and also with the windows fully or partially open to get optimal results, yes?
@@exploranator A smaller, sealed box will have a higher frequency roll of.. Meaning that it won't play as low / loud as a larger and ported version. The cool thing about the sealed box is that you can EQ to taste. So if you want a solid response to 30Hz, you can just boost it with an EQ and as long as the sub can take the power and has the excursion, you'll be in good shape. I prefer a more natural and louder response of the ported box but it's not always available.
What Hz do 6.5 subs like to be tuned at to use as Mid Bass, They have a 65hz , I’m thinking of using along Subs tuned at 33hz
Just cross them up at 65Hz and put them in a small, sealed box. They're worthless as subs.
@@RobotUnderground Great thanks , yeah not great for Lows
Vas on a Neo 3.5 is 26.19. Did I miss something? Doesn’t show cu ft
Most will measure in liters. It was probably a 12". That would mean the Vas is just under 1cf.
@@RobotUnderground I ordered a fi audio Neo 3.5, the largest recommended box size was a 2.5. What difference would it be if the box is 2.75? Just found your channel so you might have answered this before. Trying to learn as much as I can when I’m off work.
@@marathonbaker Even at 2.5cf, you're running it in free air basically. With a sub like that, I'd actually run it with a passive radiator in 1cf. ruclips.net/video/YlWZ3UIYOMw/видео.html
@@RobotUnderground I kind of like the big box look. I used to have the RE XXX (1st gen) and a friend had a huge box like 10cu ft for a single 15. It was a unique design, hexagon around the subwoofer cutout, 4 inch thick baffle, fiberglass inside with huge 45 degrees sides. That was probably 15 years ago but looking for a similar setup but toned down some.
@@marathonbaker Just because you like something, doesn't mean it's healthy or proper. I just follow the rules. If you don't want to, that's your business.
Me also I am a beliver that ported is king, of course it depend on situation of big wall with too many subs
For highest average system efficiency, we no longer can afford to push for lowest Fs and adding weight to the cone. But great vid anyways.
Someone needs to upload this video into a fuck'n encyclopedia.
Hello bro Patrick, this is Hael if you remember me, I’m not against you by any mean, wanted to make sure you give bandpass a one more shot, how would you do a sealed playing as a bandpass? Have you heard any tiny subwoofer in a bandpass such as Bose or JBL? they play low and they are loud for what they are, I’m pretty sure you can’t achieve such a bandwidth and SPL with a regular sealed or even ported box!
Try to have a ported box that peaks at 50hz with +6db (or even more) and still has control down at 25hz? could you do that with a sealed? A ported? Ported is the actual one note wonder if you try to match cabin gain etc., not here to argue bro and thank you for the time spent and efforts you put to help others, btw you build insanely good subs with perfectly efficient parameters!!!
I've talked a long time with several people at several brands and have come to some sobering conclusions. Your best bet is to study the work of Wayne Connelly. He helped research and develop the RATS information network for Rockford.
Awsome info totally blows my mind how much info I missed during the bass years but I have a question I just bought 2 vfl8s and I'm running a sundown 1000.1 amp prob at 3/8 the speakers are in a 2.3 net box but at the low Hertz they or it sounds like one is bottoming out any ideas box is ported tuned to 35 speaker fs is 40
Just back it off. You can probably add a 3rd or even 4th sub to the box. Look at the Vas of the driver.
@@RobotUnderground the vast 0.34
@@smokeshow973 That means you only need .34cf for the driver to reach the Fs.
@@RobotUnderground So anything bigger is allowing the speaker to bottom out?
@@exploranator Not bottom out, but just be more compliant than needed. The more compliant, the less resistance. The lest resistance, the less power it can handle and the SOONER and more easily it will bottom out. Play with the specs on a performance predictor like WinISD. I used BlauBox back in the 90's. You can see what happens when you're just under the Vas and just over the Vas. Then you can play with the tuning frequency to see how you can warp the response to be closer to what you want... Or at least what you think you want. Then build it and listen do it. You may not even know what you like listening to... Or at least what the prediction looks like, of the response you want.
So my DD 3515G that has a fs of 41hz qts of .88 and a vas of 56.8 liters, isn't going to like being tuned to 33hz in 4.5 ft enclosure?
Correct. It'll only be good for burps or as a mid bass
@@RobotUnderground Thank you , looks like I'm gunna get something else . I want it to be better than the mofo 152x I am currently running.
@@travisabrahamson5092 Running the numbers for your driver and the box size and tuning that you mentioned, and taking my car's cabin gain into consideration, I end up with a dead flat response between 30 Hz and 50 Hz, which then slopes 9~12 dB to 100 Hz. Below 30 Hz it drops off 9 dB to 20 Hz. I'd probably try that in my car, if I wasn't allergic to putting 4.5 cu.ft. boxes in its trunk :-)
Dd recommends their enclosures tuned from 35 hertz to 40 hertz? You can go lower but you want feel the pressure that subwoofer gives you at what they recommend? I been owning dds since 2007 tune your box at 36 to 38 hertz and I promise you you will shatter something in your vehicle they are spl subwoofers?
I have my ssa zcon 12" with a Fs 37.0 Qts .29 and Vas 24.4 BL 25.3 tuned at 32hz in a 3 cf enclosure and it sounds great.
WOW awesome info . I've got 6 carbon series harmony audio dual 4ohm. Amps are Harmony audio 1500.1 x3 Been considering a big 6th order . The vehicle is a 2004 Pathfinder . With the info I just gathered from you hopefully I can utilize it. What's your take on transmission line enclosures
Just a boring ported box is all you need Just make sure that you don't use round or octo-ports or any bullshit like that just build it into the box.
Yeah I prefer slot port@15-20²in of port area per cubic foot of enclosure so with the Harmony's they call for 1.5 -2.0cubes per sub so I was pp
Retraction 1.5 -2.25 per sub I was thinking 1.75 per with the subs up port front with 15² in of port area box inside measurements will be 40L/ 14H/42w @13.5 cubic feet.. port 14x8 x28L now all this is off top of the head some Numbers are subject to change. I figure with a big ass port and the bracing is going to need it should be about right size . Got 4 of these subs in a 1.5 cubic foot per sub 6.2 cubic foot box subs are inverted
@@hillbilly1036 Typically you want 16 square inches of port area per cubic foot of internal volume.
Here's the RE audio flash program. drive.google.com/file/d/1pR5y2J89Z8C2l1wP9w_7-Bd8ByZeiJu9/view?usp=sharing
Ugh. Okay, Patrick. Settle my decision for me. Four, forward firing 8s getting 250 watts each, or two, up firing 12s getting 500 watts each. 2.5cu feet of max airspace available. Ported or sealed? They’re going under the rear seat of a Nissan Titan Quad Cab. I want decent kick drums for metal, and teeth chattering bass when I listen to EDM.
two 1kw 12's will out perform the 8's.
@@RobotUnderground , thank you. You’re the best. I won’t be losing anything firing up into the seats?
@@RobotUnderground Oh… ported or sealed?
@@emac800 Sealed is fine, you can EQ to taste. I can do those for $200 each shipped.
@@emac800 It might just activate old farts that were buried. Just make sure that the seats aren't rubbing the surrounds. We can do a reverse surround as well.
hey patrick i know its a lot to explain but how do you find your cabin freq.again?
Sealed box with a 12" or 15" in the cabin. Then do a sweep. If a shop has an RTA machine, they can find it for you when you do the sweep. If not, you'll have to do it in 5hz segments to and plot with an SPL meter, and record the db readings as you go through the sweep.
This is the formula set I use to approximate the fundamental resonant frequency of a given 'cabin' or volume, and the approximate 'gain', when I do not have the time to measure a cabin, with fairly consistent results.
Do the following in MS Excel:
Formula process for Cabin resonant frequency:
Step 1.) Define a Temperature (deg/F) in cell 'B1'. 70deg is a good average to work with, but it can be any value, you decide.
Step 2.) Measure and define a Cabin 'Length' (x) in inches, in cell 'B2'. Measure from firewall to the backside of the trunk.
Step 3.) Measure and define a Cabin 'Width' (y) in inches, in cell 'B3'. I measure at the widest width from window sill to window sill.
Step 4.) Measure and define a Cabin 'Height' (z) in inches, in cell 'B4'
I find the location of the cabin that has the highest measurement.
Step 5.) Copy and paste this formula into cell 'B5': =SQRT(B2^2+B3^2+B4^2)
This is the approximate maximum diagonal run (length) of your cabin, expressed in inches.
Step 6.) Copy and paste this formula into cell 'B6': =((((643.855*(((((B1-32)*5)/9)/273.15)^0.5)*1.1507794)*(5280/3600)*12)/2)*(1/B5)
This is the approximate fundamental resonant frequency of your cabin, expressed as Hz.
Formula process for Cabin 'gain':
Step 1.) Copy and paste this formula into cell 'B7': =20*LOG(B5*0.02831685)
This is the approximate cabin 'gain' reference of your cabin, expressed in dB.
Btw, I have another method based on the ideal gas law but the method I typed out above is a much more accurate approximation if you don't have measurement or test equipment.
Good luck and lemme know if you have any questions.
Let's see if Patrick approves! 😂
👍
If you’re wondering how he erased a Sharpie on a stainless steel table.
Alcohol
You are correct. Acetone for silver sharpies
Look Hexibase channel and he goes deep to explain
He loses me sometimes as well. I have to be really sober... Plus the accent throws me off.
Omg I feel the same way just like barevids 😂😂
@@jimt5683
As a fellow Brit, I’m secondhand-offended on behalf of Sam (Barevids)! 😂
@@ScramTek sorry 😂😂
I have a Aura 1808. What do you think about them besides the 14 cu/ ft box
I've got a pair of TC sounds Pro 5100's, very similar driver from what I understand. The Vas on mine is 251 liters.
It depends on your application. Are you using it / them for a car, home theater or PA?
@@RobotUnderground it will be in a car. 2003 Volkswagen jetta. Looking at 10 cubes for the pair in the backseat. Sealed or ported through the rear deck.
@@mattnewbern4933 Just sealed is fine and then EQ to taste
@@RobotUnderground that's what I'm planning. The port would be external into the trunk space up through the rear deck so it could be removed or changed. Sealed will be the first go, ported later if I feel I want more output. The pair of them will be ran at 2 ohm on a Taramps Smart 3. Not a ton of power, but plenty for these.
UPDATE: The Fister 15"s are legit. Thanks Pat.
Yep. They move good air and cost very little in the right box.
Bandpass becomes much more friendly when you use 4 or more drivers and your port is big enough for you to crawl through
I just got done testing a 12-15 6th order tuned 22hz and 46hz it’s flat from 20-60hz which it drops off hard above 60
lol. Not true but if that's what you think, that's fine. It's your time that you're wasting, not mine.
You had me at 'bandpass is shit'.
This was literally...."all the options on the table"
Sharpie + metal... sharp metal sooper bass cat thruster
I watched the part about the 5200 in SPL application. What about the great debate for the LMS ULTRA 5400 for home theatre use.
Small ported 4 cubes vs passive radiator 4 cubes vs Large ported
I have one sitting in the closet and haven’t pulled the trigger on building a box.
Look at the BL numbers of the 5200 vs the 5400. Then compare to the Axis / TC 3000
".5 qts and lower is for sealed box"...WRONG!! .4 and lower is ported, .4‐.7 is sealed, .7 and up is IB
You can actually put any subwoofer in infinite baffle and you can put any subwoofer and a ported box.
👍👀👍
33 hertz I like a lot also
33hz=crf
"Specific applications" sounds like hair tricking to me.
Yep, donkey punch
You won me over at heavy copper coil... I hope people come around and understand aluminium coils sux... There cheaper and just break cuz thats what aluminium does when electricity is going through it.. a good reference of that fact.. new homes cant have aluminium power lines in the walls just ask any fire marshal or building code inspector..
It still depends. On a big 4" or bigger 8 layer coil, copper is most likely going to be too heavy.
What kills me is they gripe about cca wire,but then run aluminum coils.🤷🏻♂️i hear alot of ocd in car audio.i have it too but my ocd is from lack of knowledge.its unsure ocd,from just simply not knowing,but i try to do things that i really shouldnt be trying to do.i been messing with car audio for a yr and have done took a top plate off a motor and opened the gap for a 8 layer coil.and it bout took my fingers off but screwdrivers saved em, and a close prybar.
The reason why they use aluminum coils is because it is lighter than copper and dissipate heat faster? I don't think you can find a copper 4 inch voice coil probably to heavy
@@ceciljones1248 Why not just use amps that put out power to 8 ohms instead of the cheaper "Powerful but into 0.000025 ohm load" amps?
Perez Donald Martinez Timothy Davis Robert
Program is DOS box. I use Bass box Pro
Patrick if you want to get a giant laugh look up "how to make your subwoofers sound louder" video by image design , the guy has some insane concepts non based on reality by a long shot. The guy is so misinformed it's just comical instead of being irritated at his claims you just laugh at the insanity. He definitely should not be dropping dat knowledge unless your looking for misleading nonsense!
Lol just got back... great find.
It's in steps... EZ PZ
I vaguely remember watching that and wondering how many people blew their shit following his advice
Dude I don't tune anything under 35 hz I don't like that low bass stuff I like more everyday music not rebass and bass boasted music so I tune to about 40 Hz
I wanna watch movies and feel the brontosaurus' footsteps in the car.
Do not Believe anything in this video. This is an absolute garbage video. As an example Fs is the free air resonance of the driver. And have nothing to do whit what the driver can produce installed in a box. Most subwoofers for car audio have a high Fs. So using this logic most subs cant produce anything under 40Hz.... It seems he i just making things upp. But why??
This video is absolute garbage.
I like the bass under 30hz because I exclusively listen to romance explosions. I have to slow down the audio to get the house shaking... I'll see myself out ✌️
Did see the ghost? ruclips.net/video/5YxcgK0UArE/видео.html
@@RobotUnderground So. Much. Ectoplasm...