So over a year ago I bought a qbomb for two 10s. The box is huge and tuned to 35hz (I've checked specs and done my tests and yes it's tuned to 35hz). I uploaded a picture of my setup banging on a facebook bass group and holy shit, I was told I was dumb that my box was way too big and that my subs were clipping blah blah blah. I ran those two 10s in this box for over a year with zero issues and it banged! Now I'm using the same box but with more beefy subs and it still sounds incredible! Moral of the story, don't listen to haters on fb or youtube
On a side jag... One of the smartest guys out there, Ol' Albert Einstein, once said he didn't need to know everything, he just needed to know where to go look for it.
Its interesting you give all the back story on Hofmann. My Dad worked on the manhattan project in Oak Ridge and possibly knew Hofmann. When AR released the AR-2 way back in the late 50s/early 60s Dad built a heathkit hifi system featuring an AR-2 that I still have today. In the mid 60s Dad built another heathkit stereo amplifier and bought a pair of AR-3s which to my ears produced the best bass out of a small enclosure I have ever heard. Of couse both speakers were acoustic suspension. He spent his entire career, post naval service, in the nuclear industry trying very hard to further the use of Nuclear Energy in a safe and useful way and held 9 patents before his death to further that cause. Sadly the beloved AR-3a speakers are filling a landfill somewhere due to a house fire that consumed everything audio related that I held dear save for the AR-2. I feel proud to have that piece of history and to know the man behind it was someone who influenced my fathers life musically and career wise. Thank you for posting this video and sharing Hofmann's genius.
This is one the very best in recent times and most interesting audio related RUclips videos I’ve ever seen. The back story on Hofmann and others was excellent! the side stories from other RUclipsrs… so good!
I like to use efficient drivers so that I can keep the power requirements reasonable. You can actually make a system that sounds good without needing a ton of power if you choose your driver's properly.
Recently found this out when my cheaper but high sensitivity PA sub beat out my DD715 in SQ matching it in SPL well 80% of it and plays just as low but actually higher this lead me to believe that when starting out in car audio a high efficieny driver is a lot better.
@@DIYAudioGuy pro Audio sub 96DB spl and a local brand called P. Audio basically cheaper Beyma woofers i can do hair tricks and play as low as 19hz in car with it on 600watts im gonna do some more testing soon and put more vids on my channel as only my DD715s vids are up at the moment.
@@EBMproductions1 please do you say hair tricks and low lows only 600w? I just blew my jl 10w1v2. (Was very old and tattered. I got 600w to play with out my gmd9605. So which subs are in your car?
That alternator upgrade is so worth it though i’m able to keep my 3000w taramps smart 3 at full blast (78v at 1.6ohm/about 3800w give or take) any time any frequency forever as long as the car is running with my 240amp alt and xspower battery along with 0 gauge runs for power and additional grounds. Box is also tuned to 29hz so it hits them lows. Also have a built in volt meter in my car and while cruising voltage is always 13.8-14.5 and at idle only drops to 12.7 on the power hungry frequencies. (Box was designed by me courtesy of your awesome videos!)
I have a 325 HO alt running a Orion HCCA SPLX 3000.1D @ 1ohm, cruising I am able to maintain 14.8-15.2. Drawback is the alternator cost more than what my car is. Im serious😂
as a child in the 90s I got an installers manual.. the pioneer bass book.. like 1993 or so.. i figured out T&S real quick and was making 2.5-5cuft ported boxes right fast.. but also was making custom external ported behind the seat truck enclosures.. running the port under the seat externally along the floor. my first in a 93 b2200 where the OEM jack was mounted
Passive radiators can actually be more efficient than ports when using high power. Passive radiators don't compress as much if you're using a small enclosure that needs a long skinny port. You can also tweak the frequency response. You can save a bit of space if you build a box that can get low, but has most of the efficiency from 50-90 Hz. Another way you can save space is by using thinner box walls and regular thin bracing. Baltic birch allows you to build thinner than MDF. I have an enclosure that's over 3 cubic feet and the box walls are 3/8" thick, but it doesn't flex due to bracing. The total material use goes down, therefore space, although it is more tedious to build. L section metal braces are the least space consuming and thick chunks of MDF the most.
just recently I've been interested in building my own sub enclosure but don't just want prefab quality and performance. very much appreciate how you make your videos educational and fun to watch. thank you so much for your hard work!
I remember when I was 14 I bought 2 KLH 15" floor speakers from best buy and I was so proud of them, they were the first brand new speakers I bought myself brand new lol.
I was going to comment about getting around Hofmann’s Law while the video was playing. You did a great job explaining how easy it is today to achieve extreme sound pressure at low frequencies without a huge box.
From my vast experience in home audio, I would add that the different bass driver sizes effects the overall character of the bass, not just the power. I was surprised to learn when I auditioned three systems for a guest some years ago, with each system using a different bass driver size (8", 10" and 12") that the different bass driver sizes (each in a large vented enclosure) produced different bass performance characteristics. And I would add that the smaller bass driver worked better in a smaller room, and as the room size increased, the larger bass driver worked better: 8" in a 100 sq ft room, 10" for up to 200 sq ft, and 12" for rooms above 200 sq ft.
First off awesome video I love math equations they tend not to lie. As a kid I had a Cerwin Vega 15 free air dual VC that I installed in a huge homemade sealed enclosure just like buds. It hammered so low so hard. No mid all lows sub 200 hz. I've never been able to duplicate that performance because I got lucky and don't remember the exact dimensions.. My dad helped me and allowed me to jam that thing in my room as a kid and this video brought back those memories. Thanks guy. Oh I forgot to mention rigidity of enclosure. Less flexibility of box = way more output... Cool side note about jumbo btw. Awesome stuff!
Keep up the good work.👍👍Very practical. And that's awesome! 5% of the world might be trying to put 12, 18's in a car our house. Your explaining how to be as efficient as possible. That's what the other 95% is trying to do. Thank you!
I had 2 12" SE subwoofers in a sealed 5 cubic² inch box. Wired at 2 ohms, and firing 1200 watts from the trunk into the cab of a 2001 Nissan Altima; that provided some clean low bass. Althoughbeit, the bass was made even better after a SoundStream crossover was installed. The complaint is that I had to sacrifice the entire trunk for a loud stereo system. 50×4 watts Pioneer head unit feeding 400 watt amplifier on high pass which powered 4 3-way Pioneer 6×9 and 2 Kenwood tweeters. I tried to run a 2000 watt SoundStream Amp, but I fried it. Alternator did not supply enough power to it. The 1200 watt Amp used to go into protect a lot in the summer time; but it did the job when it worked.
This is so interesting. Technically speaking the game has changed so much. I remember house parties with base bottoms and fans on the amp in the winter months with the windows open in the PJs and your were still sweating.
We had an Econoline van that we used to transport the equipment a real POS. He installed (2) 18 in speakers in the rear cargo doors with a 500w Sherwood amp. That thing was booming even though we didn't know what we were doing. Thanks for the hard work you do for this channel.
Watching videos like this one makes me realize i'm missing so many knowledge, that i don't even know what the heck do i seek for in terms of audio performance.
best system I ever built was four 10 Kicker comps, each in a 1 cubic foot box mounted in rear of my Dodge Dakota RT extended cab. Kenwood 1100 watt amp, really good bass, but slot ports are the next level, and I am so ready for my new system
For my solo DDX-12 the box it was in was small and high tuned so it was honestly just loud wouldn't hit low what so ever, so I decided to build a 2.5 cubic foot box tuned down to 35hz and now she slaps all the way down to 28hz with a bandwidth of 28-71hz and I don't think I'll ever go back lol
It's funny how you can get down to the nitty gritty of drivers and enclosures for car applications and try to nail it down like a boss......THEN you go and stick it in a vehicle with its own unique acoustic properties and throw a wrench in the whole thing. Recently took my buddy and I five different box configurations/designs to get it right....all because of the dang vehicle.
Great video with good information. For me personally the math is fine and not even complicated at all. The video style is very nice as well. I liked the different shots between your talking!
What, What, What??? I was lookn 4 or @ different speaker box shapes and lo and behold here I am nerding out on mathematical formulas for bass.... N yes I did watch and enjoy the whole video, thank you!!
I’m soooo glad I found this channel. Soon as get caught up I’ll join for the min amount anyway to help support the channel. I need this information so it’s worth a tip to me.
thanks for a good video, lots of information and I am patiently awaiting my new system, two 10's in slot port box..............curently have one 10 in a powered box
Good video! In my opinion - vented port sounds gives more deeper and natural bass.I have been making an experiment - 2.5`` speaker in small 0.3L box with 1`` plastic pipe - the length of a pipe was 20``. The speaker (unexpectedly for me ) played sounds below 100Hz - but there was resonances on harmonics in the port pipe and sound wasn`t clear in mid-range band.
Well! I have learned a lot from some of the most esteemed audio engineers and received a lot of answers about speakers and amplifiers that I found one way to make speakers sound so incredibly natural and wish such rich and deep bass that you have to listen to it to believe it! I'm sure that you know about the Cerwin Vega speakers and their reputation for their nice and deep (Not saying that they are the best but they have a solid low frequency even though it's a bit too cracky....if you know what I mean!) I personally made some 6½ woofers sounds even lower in bass and so incredibly softer that everyone who heard them could not believe that the bass of a 6½ was way better than a 10 inches woofer from Cerwin Vega! I did use the same reference in order to build some much bigger speakers and the results were also absolutely amazing! I wish I could have my very own company!
My home theater set up uses two 5 and 1/4-in drivers and a transmission line for the right and left speakers. I lost my subwoofer amplifier due to a lightning strike / power surge and I didn't even notice at the sub it stop playing until I had the house to myself and wanted to crank some base heavy tracks.
You really hit the nail on the head when you said the amp is the cheap part. I just got the jp63 after watching your videos and I spent $1700 on the amp. I had to buy $350 on wiring, all 0guage copper. Then the demand for amperage I have three optima batteries which are $400 each and the lto 6.0 it was another $500 once I had it shipped from Vegas. So ya over $2000 just for the equipment to run that amp. Total cost of amp was $3750. Then the sub was $1600(rs team 18) and birch box with 3” baffle and 2.25” walls was $960. Hope people understand this when they think the amp is inexpensive. I haven’t even upgraded my alternator yet either, luckily it’s a 200amp (f250superdutystock) and keeps up fine. So ya, my one sub system was $7000 and shipping that shit from Vegas to Vancouver island wasn’t cheap. $550 in total shipping for the jp63 and a jp100.4 so probably was over 7k.
great video! i always had a feeling that my jl audio 12w6v2-d4 sub sounded okay with the 1.25cu ft recommended sealed but not great. recently, i was trying to build a 2 cu ft port but since i still stuck at building ported boxes, it ended up being a 2.3 cu ft sealed box. in any case, it sounds sooooo much better loud and low. now i know why thx to your explanation and hofmann
I bought a used JL 10W7 and bought a costum box that was made for 12W7 ported specs. The hole was cut to fit a 10s. I’m so excited to get tyem installed and tuned! It will be loud and low as what you have experienced here too
I've seen your vids off and on the past few years, looking up different things. As a drummer, I've always appreciated hifi audio/quality equipment but focused more on the headphones/earbuds space. After a few incrementally improved installs over the years, and dreaming about my ideal setup, I'm going all out; h/u, 3 way active front stage, rear fill, custom sub box, some strategic sound dampening... But what in the sam hell have I done, other than NOT HIRE A PROFESSIONAL... Thanks to this gem I now know OF COURSE there's a sub box CAD? program🤦♂️ And now (at 35) I don't have to go ask my dad to do his hocus pocus voodoo math wizardry when I eventually build my box. The more I learn, the more I realize how much more I have to learn... I'll be seeing you, I'm sure LOL. Thanks for the great content. God bless!
Years ago a CD magazine told how to build a subwoofer from a 12 inch Eminence sub at the time and it was used in an expensive M and K system. Well, I built that but the sub would bottom out with only 25 watts applied to it. A couple years later found out that the sub worked much better in a 1 cubic ft enclosure instead of the gentler Q design at 3.5 cubic feet. Before I could experiment the subwoofer's foam surround fell apart. I let some years pass and in the meantime built some khorns (mid 80s) and 10 years later bought a car sub off of ebay. It happened to be a MA audio MA121XQ and it had the right parameters for the 3.5 box I had made a decade or more earlier. Tuned to 27hz or so and powered by a 300 watt amp (I just replaced it yesterday with a new Dayton 250 amp with dsp) and it doesn't bottom out and just works. Low cost too. It has 10mm xmax which seems plenty.
So here is something I have been doing for a few years that seems to work well. 10 inch sub in a box with volume for a 12. 12 sub in a box with volume for a 15 and so on. Not sure how well my idea works on paper but it usually sound pretty good to me. My current set up is pretty low budget. 7.2 surround sound. With old school sony tower speakers for my bass. internally braced because of half inch fiber board. Boxes are 2.6 cubic ft with 12 inch woofers on a 200watt rms fisher 2 ch amp. Ports are two inch abs pipe about 12 inches long. Seems to do pretty well. Nothing crazy for a set up but over all it seems to work well.
just a thought but an ole ambulance or fire rescue truck will have the "power " and space to build a really nice portable test station 🚑 they have massive electrical charging systems and well built and maintained yet cheap on the market
Not necessarily a big enclosure. It’s in the design. My enclosure is very small but has 96” long port tubing. Shakes the heck out of the windows and 17Hz. It’s more like a T-line. I prefer it over any enclosure if you want to dig below 25Hz. Light, small, loud n low. Not bulky, big and heavy like a regular ported enclosure. A pair of 10s can outperform 12s if the enclosure permits so. Because no matter how many speakers you have, you’re not going to get SPL at the frequency you want if the enclosure is not tuned properly; all you will hear is inherent noise from the cones and no actual Bass. Happens a lot with prefabs when trying to play anything below 30hz. You will start to hear some actual Bass once you are reaching the tuned frequency and above.
Knowing this and your ts parimeters and learning how to use winisd properly will allow u to find that sweet spot and build a box better then the other guy. 😁👍👍
I like my bass low, but for the enclosure that lives under my desk, I don't need it loud. So I tune for extended response and I have flat response down to about 15Hz. I don't hear that, I feel it. It does result in a port that chuffs, but I don't hear that because the desk is in the way. After that I use Sonarworks for final integration. The result is fine.
YEP ! I was penciling out equations using T/S parameters way back in 1980. The only 2 sources listing T/S parameters back then, that I knew of, was RadioShack, and SpeakerLab. I made 2 subs for my living room that were big enough to double as end tables on either side of my couch! and my first home theater was born cira 1985. These ready made sub enclosures drive me insane... generic sized, and tuned to too high of a Fq, and pray the driver you stick in it, is happy with the volume. The proverbial Kart before the horse.
I was at Kstate college back in 81 or so and I had some speakers I had bought from McGee radio out of Kansas City but didn't have the specs to build the right boxes. They were a 12 inch with alnico magnet and whizzer cone. There was a guy in Manhattan, Ks that was advertising homebuilt speaker builds. Well, he had a brother that had a computer and he could measure the parameters of the speaker. I let him do it and it turned out it took a 5 cubic ft enclosure tuned to 35 hz or so. I built the boxes and I wish I still had that pair of speakers. Worked fantastic.
12:00 Mannnn I remember the PA Electrovoice ELM12’s some were using in their vehicles. I had two recently in 2006 in a jeep Cherokee and them EV’s GOT HELLA LOUD when it was around 100-400hz which is unheard of any 12” car subwoofer being able to do. I had a 12” subwoofer as well for the lows so I had nice coverage on the low end from 36hz-400hz.
When it comes to my portable designs, I have a saying: Hoffman's law may be iron, but my batteries are lithium-ion :) You gotta love Class D and modern battery tech. Physics can't be cheated, but it can be negotiated with quite reasonably.
Interesting video. I've been trying to figure out some of this subwoofer stuff, and not sure size always is the key feature for subwoofers. I consistently see 10" and 12" subs that rarely go below 35 Hz. Yet I have an 8" JBL sub rated at 18 Hz - 800 Hz (which I'm sure to many that 900 Hz is on the high end of a sub). The box came with the sub, and though I have not tested it, I can say yes it does play lower notes than to subs that are in the 35 - 40 Hz range (I do have exceptional hearing, and proof humans can hear below 20 Hz and above 20 Khz. But I have terrible eyesight, and think one sense made up for another. I'm just glad it was my ears instead of sense of smell. lol). But I too always thought a larger subwoofer driver was needed to hit down to the 20 Hz mark, like a 15" or larger. So how are smaller subs able to achieve this ? Please, I seriously would like to know as I am somewhat confused maybe? And I am having a hard time locating anything about a driver's ability to reach to low end Hertz like a subwoofer. It seems to me you would always want a sub to go down to 20 Hertz otherwise you are cheating yourself. And one reason I ended up with the JBL I do as it is hard to find subwoofers that reach that low of Hertz. Which really surprised me.
I enjoyed watching this video and learning more about something us DIY speaker guys often quote, but don't really know that much about, Hoffmann's Iron Law. I really like your channel -- the content, and how you do your videos. Informative and entertaining... plus you're brave enough to do the car audio thing... that takes GUTS!!!! -- Tom Zarbo (AKA Zarbo Audio Projects)
I got 3x12 up front and 2x12 under the couch , my walls are 3-4ft thick stone wall and between this room and the dining room is a 7ft tunnel of stone.....basically open the door stand outside and the loudest bass in the house, the tunnel is basically the port of my sitting room speaker.
The issue with the enlarging the cabinet is you end up adding efficiency to the low end only. The problem is you rob energy from the top end to do it. Same with large port area. Yeah it's awful loud around the box tuning but it rolls off very fast above there in the range. Boxes that are too large for a driver with introduce mechanical distortion into the range around a half octave above the port tuning due to the mismatch in damping. You'll also find you run into xmax limits very quickly in an oversized cab. So in summation, Hoffman iron law gives you low end extension at the cost of high end extension. All you are doing is moving the playable band, down the range and shortening it at the same time (low bass one note wonders). I grew out of iron law boxes many years ago when I realised the bandwidth drawbacks. It's a great way to get cheap woofers loud at low frequency but you'll soon get bored with only being able to play your tuning specific decaf tracks. Everything else with transients in it or upper bass will sound muddy and 10 minutes behind everything else. You'll also get bored of wearing out woofer suspension if you are competing like this. Xx
I'm not sure if Toid was saying you don't hear it at all or your feel it more than hear it. (At 3:55 ) Because I can hear just fine to below 15Hz. I've had my fun with my big boxes, but I'm slowly starting to lean towards smaller. And I mean coming from my 14.5ft³ Full Marty to a more manageable dual 5.4ft³ UM12" boxs. Soon enough I might try Infinite Baffle in my car so I get more trunk space back and I'll use my UM18 that is collecting dust in that build.
@@JoshM7 Yep. It seems like every one that I've ever heard and owned sounds better and more efficient bass than a ported box. Bic is a company that makes a lot of them at low costs
@@billy3650 My build with Passive Radiators aren't very suited for home use as I'm using an oversized enclosure (3.6 cubic feet tuned to 19Hz) riding xmax limits on my Ultimax 10 that cause a bit of noticeable distortion in the house. In my car that distortion is masked and never audible. What I do love is the silent operation even under tuning. I'll never hear port noise in the first place. But it's still very nice. When I had it in the house it was crazy how silent it was.
One thing to note is that there can be practical limits to how big the driver can get, in a PA system you might get away with four 21" drivers on either side of a stage, not so much in a fiat 500 or a small apartment. This is another major reason why high excursion has become so common over the years. The missing link is full range drivers.
320amp otternator.... lol. Seriously though - nice video. Power is so cheap and drivers so specialized these days that we are spoiled with tiny enclosures. I remember dropping Rockford SP-412s into 3cuft each and it was a compromise!
I've got a couple of videos where I use some passive radiators, I think one of the very first projects I built for the channel was a passive project. Perhaps it's time to make a nice video on passive radiators?
@@DIYAudioGuy I saw that. I started watching some of the PR videos, but I've never heard a solid explanation on how to come up with enclosure dimensions or proper weight of the PR, etc.
Great. At 3.05 you spoke about the great passive radiator. At 0.48 you flipped around the MK Boombox. I would like to build the MK Boombox but I find it a bit to big/deep. Can’t you redesign it with two passive radiators instead for the ports? Us the same kit, but only cut and remodel the box, that are included in the kit, so we beginners DIY have something to do during winter. Keep up the great work.
A lot of people seem to build their own (or modify the kit). As far as making the kit smaller/using a PR you can just model in WinISD. You will need to relocate the amp, it takes up the full depth of the kit.
Glad you enjoyed it! I has a lot of fun digging into Dr. Hofmann's story. His dad was even more impressive. He was literally the worlds best concert pianist during his time.
You worded the evolution of CA subwoofers wrong. You said "when that happened CA subs got less efficient". What you meant was "when that happened CA subs started sounding like crap". LOL. Great video!
Unfortunately the formula does not give a full picture of how a subwoofer will perform, only the pass band efficiency. That is why I recommend this: ruclips.net/video/yZNeYBYGRKk/видео.html
I always try to get as much air movement in as small of a box as possible. I like to use driver's that don't need much volume and have a high Xmax like for example an SB23MFCL-4 with 12mm Xmax or a Ciare 12.00SW with 14mm Xmax and put them into a Tapped Horn. For both driver's i have designed Tapped Horns that go down to 13hz. A friend is currently building the one i designed for 2 of those Ciare 12s and he will build 4 of those Dual 12 TH and together they will be capable of generating 127db down to 13hz at 1meter outside according to Hornresponse. Each sub has a outside Volume of 655Liters and does 91db at 1watt. Inside and corner loaded those could probably cause some SERIOUS injury to human and the house they are placed in.
Theil/Small based there research on using existing electronic filter theory and modelling the physical attributes of the driver as electronic components. AR did were not famous for a sealed enclosure, they developed "acoustic suspension" which is a sealed enclosure but with the driver designed to specific specifications to compliment the enclosure. Theil/ Small took this further and worked out the driver and box requirements for a ported enclosure as well as refining fully the requirements for sealed enclosures and any other box design by defining the Theil/Small specifications we all use to this day. Up until these two things, ported boxes and vented boxes was a hit and miss try it and see what it sounds like affair, which lead to the ported boxes getting a bad name for boominess as they were never aligned properly.
Hello , I love the videos you have put together on boxes . Whats your stand on the so called 6th order boxes and do u feel they are worth the time to build? Thanks for all the time and knowledge you provide .
@@DIYAudioGuy the 6th order is supposed to be a dual tune port so u can play a larger variety of notes with less restriction and role off but just seems kinda impossible to be true when listening to you explain ho the ported system works. Is it true they work as they say so i can tune one at 23hz and another at 40hz ?
is there a calculator online to input the parameters and get the result? You left out the part of how to apply the law to get the most out of the enclosure, or did I miss something?
I’m going with a 2k amp to power my Fi Neo 3.5 12 inch. I would choose a high quality high efficiency amplifier with adequate buffer capacitance between the power supply and output section so that I can get away with only a big 3 upgrade. Don’t want to deal with the headaches of messing with alternators.
You just have the one sub, correct? If it's the dual 1Ω model, look into the (yet to be released) Stetson 3000.1 EVOX2 - 1Ω. With it, you could wire your single sub at 2Ω and get 1980w RMS from it, while leaving yourself with enough overhead for the possibility of getting another 3.5, wiring them to 1Ω, and getting 3000w for the pair. Being an SQ sub that's aimed at a ported box though, you might just wanna stay at 2Ω for the added control. Average music draw is ~120a, with a burping max of about double that (240a), btw. Seems like it'd be a good match for you, if it being $800 and full bridge aren't issues for you.
That Iron law sounds like one for car performance, You can make it Cheap, Fast and Durable, but you can only pick two. In much the same way, you can't do all three due to it being almost impossible
So glad you mentioned the 10 vs 12 thing. So tired of the idiots talking like their 10's outperform 12's without giving any specs of both setups. If somebody has low end 12's, they can be outdone by high powered 10's sure, but that's not the comparison that should be made. All else being equal, the 12's will always win. Some people really need a smack across the face to try and wake them up from their delusions.
Question: I’ve always bought prefab boxes but I finally saved enough to buy a ported custom box. I listen to various types of music but mostly rap. Hate to be a dummy but I have no clue what I should tune my box to. Thinking about 37hz-41hz.
It really has more to do with your taste and the sub you are using. I would tune it a bit lower, but that is just my preference. I would rather be low than loud so I tend to shoot for the lower 30's. I did have a 10 tuned to 22HZ, I enjoyed those extreme lows, but I sacrificed to much output/SPL. That is the tradeoff with a ported enclosure, you can tune it low, or loud. You have to pick.
agreed. in isolated frequency testing, i found 30-40Hz to provide the most bang for the buck. while i would love to feel the 25Hz magic, it is simply not realistic with my “budget” system and is way inefficient down there. used a deep crossover to tune as much of that signal out as possible.
![Jack Harlow - Hello Miss Johnson [Official Music Video]](http://i.ytimg.com/vi/Q86_nlRoIGw/mqdefault.jpg)
Learn more about subwoofer design here: ruclips.net/p/PL3Aot9dMXzXZ21MXAzvirExu0sfsWWSHT
Well explained. I'm a technical reading and learning geek so this stuff is right up my alley!
Thank you for another great video Brother!
@@BabyCharlotteschannel I always prefer the more technical stuff.
Thanks.
I use pa driver's as subs on class a b amps on a factory alt🤫
@@unbanmy360 Those PA drivers are very efficient.
So over a year ago I bought a qbomb for two 10s. The box is huge and tuned to 35hz (I've checked specs and done my tests and yes it's tuned to 35hz). I uploaded a picture of my setup banging on a facebook bass group and holy shit, I was told I was dumb that my box was way too big and that my subs were clipping blah blah blah. I ran those two 10s in this box for over a year with zero issues and it banged! Now I'm using the same box but with more beefy subs and it still sounds incredible! Moral of the story, don't listen to haters on fb or youtube
Absolutely! I bought this box with the intention of trashing it. I was wrong.
"Why is there so much math?"
Because math is how you understand and predict the behavior of the physical world.
That's a great way to put it!
After all, math is the only pure science followed by chemistry and biology.
@@kevinwheeler5595 What about Physics
On a side jag...
One of the smartest guys out there, Ol' Albert Einstein, once said he didn't need to know everything, he just needed to know where to go look for it.
Absolutely, save your brain power for the important stuff.
Its interesting you give all the back story on Hofmann. My Dad worked on the manhattan project in Oak Ridge and possibly knew Hofmann. When AR released the AR-2 way back in the late 50s/early 60s Dad built a heathkit hifi system featuring an AR-2 that I still have today. In the mid 60s Dad built another heathkit stereo amplifier and bought a pair of AR-3s which to my ears produced the best bass out of a small enclosure I have ever heard. Of couse both speakers were acoustic suspension. He spent his entire career, post naval service, in the nuclear industry trying very hard to further the use of Nuclear Energy in a safe and useful way and held 9 patents before his death to further that cause. Sadly the beloved AR-3a speakers are filling a landfill somewhere due to a house fire that consumed everything audio related that I held dear save for the AR-2. I feel proud to have that piece of history and to know the man behind it was someone who influenced my fathers life musically and career wise. Thank you for posting this video and sharing Hofmann's genius.
This is one the very best in recent times and most interesting audio related RUclips videos I’ve ever seen. The back story on Hofmann and others was excellent! the side stories from other RUclipsrs… so good!
Thanks!
Hofmann was obviously an intellectual GIANT!!!!!!!! Very impressive and informative video!!!
I like to use efficient drivers so that I can keep the power requirements reasonable. You can actually make a system that sounds good without needing a ton of power if you choose your driver's properly.
That's a smart strategy.
Recently found this out when my cheaper but high sensitivity PA sub beat out my DD715 in SQ matching it in SPL well 80% of it and plays just as low but actually higher this lead me to believe that when starting out in car audio a high efficieny driver is a lot better.
@@EBMproductions1 What is the PA sub?
@@DIYAudioGuy pro Audio sub 96DB spl and a local brand called P. Audio basically cheaper Beyma woofers i can do hair tricks and play as low as 19hz in car with it on 600watts im gonna do some more testing soon and put more vids on my channel as only my DD715s vids are up at the moment.
@@EBMproductions1 please do you say hair tricks and low lows only 600w? I just blew my jl 10w1v2. (Was very old and tattered. I got 600w to play with out my gmd9605. So which subs are in your car?
That alternator upgrade is so worth it though i’m able to keep my 3000w taramps smart 3 at full blast (78v at 1.6ohm/about 3800w give or take) any time any frequency forever as long as the car is running with my 240amp alt and xspower battery along with 0 gauge runs for power and additional grounds. Box is also tuned to 29hz so it hits them lows. Also have a built in volt meter in my car and while cruising voltage is always 13.8-14.5 and at idle only drops to 12.7 on the power hungry frequencies. (Box was designed by me courtesy of your awesome videos!)
For that kind of power you definitely need the alternator.
I have a 325 HO alt running a Orion HCCA SPLX 3000.1D @ 1ohm, cruising I am able to maintain 14.8-15.2. Drawback is the alternator cost more than what my car is. Im serious😂
Two years old, just saw the video, and another incredible audio treatise! Thanks for this Hofmann presentation!
That guy was absolutely amazing. A true legend, just like his father.
as a child in the 90s I got an installers manual.. the pioneer bass book.. like 1993 or so.. i figured out T&S real quick and was making 2.5-5cuft ported boxes right fast.. but also was making custom external ported behind the seat truck enclosures.. running the port under the seat externally along the floor. my first in a 93 b2200 where the OEM jack was mounted
Passive radiators can actually be more efficient than ports when using high power. Passive radiators don't compress as much if you're using a small enclosure that needs a long skinny port. You can also tweak the frequency response. You can save a bit of space if you build a box that can get low, but has most of the efficiency from 50-90 Hz. Another way you can save space is by using thinner box walls and regular thin bracing. Baltic birch allows you to build thinner than MDF. I have an enclosure that's over 3 cubic feet and the box walls are 3/8" thick, but it doesn't flex due to bracing. The total material use goes down, therefore space, although it is more tedious to build. L section metal braces are the least space consuming and thick chunks of MDF the most.
just recently I've been interested in building my own sub enclosure but don't just want prefab quality and performance. very much appreciate how you make your videos educational and fun to watch. thank you so much for your hard work!
Thanks for watching.
I've been building speakers for 40 years and during that time, one of my greatest discoveries was Hofmann's Iron Law.
Fantastic video! My Acoustic Research 12" powered sub I've had for around 20 years means so much more to me now after learning about Hofmann. Thanks!!
As best I can tell KLH is the only one of the three that still making hi-fi speakers. So you might just have yourself a rare gem right there!
I'm building a full sound system with my buddies, and we just picked up two Eminence NSW6021-6. This video will definitely help us!!
Appreciate the shout out to hoffman sr. Titan of the keyboard - one of the greatest of all time
He was a legend!
I know the law for many years. But I don't know the formula. Thanks for sharing Adudo guy !!!! 😀😀😀👍👍👍
It was a fun video to make, I'm glad you enjoyed it.
I remember when I was 14 I bought 2 KLH 15" floor speakers from best buy and I was so proud of them, they were the first brand new speakers I bought myself brand new lol.
I still have my floor standing speakers from Radio Shack, purchased in 1988.
I was going to comment about getting around Hofmann’s Law while the video was playing.
You did a great job explaining how easy it is today to achieve extreme sound pressure at low frequencies without a huge box.
for coffee☕, the part about bass reflex subwoofers, closed speakers, and Hofmann Iron Law, is very interesting 👍
Thanks for the coffee!
This is an excellent video Justin well worth anyones time kudos.
Thanks man! It was a ton of fun to make!
From my vast experience in home audio, I would add that the different bass driver sizes effects the overall character of the bass, not just the power. I was surprised to learn when I auditioned three systems for a guest some years ago, with each system using a different bass driver size (8", 10" and 12") that the different bass driver sizes (each in a large vented enclosure) produced different bass performance characteristics. And I would add that the smaller bass driver worked better in a smaller room, and as the room size increased, the larger bass driver worked better: 8" in a 100 sq ft room, 10" for up to 200 sq ft, and 12" for rooms above 200 sq ft.
Absolutely!
15, 18, 21, up to 33 being biggest home theater sub.
First off awesome video I love math equations they tend not to lie. As a kid I had a Cerwin Vega 15 free air dual VC that I installed in a huge homemade sealed enclosure just like buds. It hammered so low so hard. No mid all lows sub 200 hz. I've never been able to duplicate that performance because I got lucky and don't remember the exact dimensions.. My dad helped me and allowed me to jam that thing in my room as a kid and this video brought back those memories. Thanks guy. Oh I forgot to mention rigidity of enclosure. Less flexibility of box = way more output... Cool side note about jumbo btw. Awesome stuff!
That's awesome!
Very good stuff, i used to work on car audio back in the 90s. Im glad i only build home stuff now.
Keep up the good work.👍👍Very practical. And that's awesome! 5% of the world might be trying to put 12, 18's in a car our house. Your explaining how to be as efficient as possible. That's what the other 95% is trying to do. Thank you!
That is what I'm shooting for!
I had 2 12" SE subwoofers in a sealed 5 cubic² inch box. Wired at 2 ohms, and firing 1200 watts from the trunk into the cab of a 2001 Nissan Altima; that provided some clean low bass.
Althoughbeit, the bass was made even better after a SoundStream crossover was installed.
The complaint is that I had to sacrifice the entire trunk for a loud stereo system.
50×4 watts Pioneer head unit feeding 400 watt amplifier on high pass which powered 4 3-way Pioneer 6×9 and 2 Kenwood tweeters.
I tried to run a 2000 watt SoundStream Amp, but I fried it. Alternator did not supply enough power to it.
The 1200 watt Amp used to go into protect a lot in the summer time; but it did the job when it worked.
This is so interesting. Technically speaking the game has changed so much. I remember house parties with base bottoms and fans on the amp in the winter months with the windows open in the PJs and your were still sweating.
Parties tend to get hot.
We had an Econoline van that we used to transport the equipment a real POS. He installed (2) 18 in speakers in the rear cargo doors with a 500w Sherwood amp. That thing was booming even though we didn't know what we were doing. Thanks for the hard work you do for this channel.
Watching videos like this one makes me realize i'm missing so many knowledge, that i don't even know what the heck do i seek for in terms of audio performance.
best system I ever built was four 10 Kicker comps, each in a 1 cubic foot box mounted in rear of my Dodge Dakota RT extended cab. Kenwood 1100 watt amp, really good bass, but slot ports are the next level, and I am so ready for my new system
Man that 15” flat down to 21hz would be sooooo coool and i bet so many people wouldn’t mind the size trade to have one of those in the Ht!
Great info! I appreciate that you provide the why behind a method so we can apply it to our own ideas. Thank you!
Glad it was helpful!
For my solo DDX-12 the box it was in was small and high tuned so it was honestly just loud wouldn't hit low what so ever, so I decided to build a 2.5 cubic foot box tuned down to 35hz and now she slaps all the way down to 28hz with a bandwidth of 28-71hz and I don't think I'll ever go back lol
Love your passion and enthusiasm for science
There are so many cool things in the world! Look up Hofmann's father. Amazing man.
It's funny how you can get down to the nitty gritty of drivers and enclosures for car applications and try to nail it down like a boss......THEN you go and stick it in a vehicle with its own unique acoustic properties and throw a wrench in the whole thing. Recently took my buddy and I five different box configurations/designs to get it right....all because of the dang vehicle.
Absolutely! All of the formulas and software assume you are playing in an infinity large room.
Great video with good information. For me personally the math is fine and not even complicated at all. The video style is very nice as well. I liked the different shots between your talking!
Most people pay to much attention to watts and overlook efficiency.
Wow! This video is less than 12 mins but helped me a lot, thanks.
What, What, What??? I was lookn 4 or @ different speaker box shapes and lo and behold here I am nerding out on mathematical formulas for bass.... N yes I did watch and enjoy the whole video, thank you!!
I’m soooo glad I found this channel. Soon as get caught up I’ll join for the min amount anyway to help support the channel. I need this information so it’s worth a tip to me.
Thanks!
thanks for a good video, lots of information and I am patiently awaiting my new system, two 10's in slot port box..............curently have one 10 in a powered box
Good video! In my opinion - vented port sounds gives more deeper and natural bass.I have been making an experiment - 2.5`` speaker in small 0.3L box with 1`` plastic pipe - the length of a pipe was 20``. The speaker (unexpectedly for me ) played sounds below 100Hz - but there was resonances on harmonics in the port pipe and sound wasn`t clear in mid-range band.
Well! I have learned a lot from some of the most esteemed audio engineers and received a lot of answers about speakers and amplifiers that I found one way to make speakers sound so incredibly natural and wish such rich and deep bass that you have to listen to it to believe it! I'm sure that you know about the Cerwin Vega speakers and their reputation for their nice and deep (Not saying that they are the best but they have a solid low frequency even though it's a bit too cracky....if you know what I mean!) I personally made some 6½ woofers sounds even lower in bass and so incredibly softer that everyone who heard them could not believe that the bass of a 6½ was way better than a 10 inches woofer from Cerwin Vega! I did use the same reference in order to build some much bigger speakers and the results were also absolutely amazing! I wish I could have my very own company!
My home theater set up uses two 5 and 1/4-in drivers and a transmission line for the right and left speakers. I lost my subwoofer amplifier due to a lightning strike / power surge and I didn't even notice at the sub it stop playing until I had the house to myself and wanted to crank some base heavy tracks.
Hofmann's life sounds like my upbringing. Frequency means more than EVERYONE ELSE can fathom.
Yea, his dad was more interesting than he was. Apparently he was literately the best concert pianist on the planet during his day.
Very well-done video. I have a lot of time explaining this to people. Now I can just point them to your video.
Please share it with them!
@@DIYAudioGuy I'll be discussing speakers in a future video, and I'll link to your video when I do.
Living loud with Andy love that dude he's a cool dude
I think he has a great on-screen presence. He will have 20k subs here on YT by this time next year.
You really hit the nail on the head when you said the amp is the cheap part. I just got the jp63 after watching your videos and I spent $1700 on the amp. I had to buy $350 on wiring, all 0guage copper. Then the demand for amperage I have three optima batteries which are $400 each and the lto 6.0 it was another $500 once I had it shipped from Vegas. So ya over $2000 just for the equipment to run that amp. Total cost of amp was $3750. Then the sub was $1600(rs team 18) and birch box with 3” baffle and 2.25” walls was $960. Hope people understand this when they think the amp is inexpensive. I haven’t even upgraded my alternator yet either, luckily it’s a 200amp (f250superdutystock) and keeps up fine. So ya, my one sub system was $7000 and shipping that shit from Vegas to Vancouver island wasn’t cheap. $550 in total shipping for the jp63 and a jp100.4 so probably was over 7k.
Amps are cheap, but power is not.
great video! i always had a feeling that my jl audio 12w6v2-d4 sub sounded okay with the 1.25cu ft recommended sealed but not great. recently, i was trying to build a 2 cu ft port but since i still stuck at building ported boxes, it ended up being a 2.3 cu ft sealed box. in any case, it sounds sooooo much better loud and low. now i know why thx to your explanation and hofmann
It takes space to make bass.
I bought a used JL 10W7 and bought a costum box that was made for 12W7 ported specs. The hole was cut to fit a 10s. I’m so excited to get tyem installed and tuned! It will be loud and low as what you have experienced here too
I've seen your vids off and on the past few years, looking up different things. As a drummer, I've always appreciated hifi audio/quality equipment but focused more on the headphones/earbuds space. After a few incrementally improved installs over the years, and dreaming about my ideal setup, I'm going all out; h/u, 3 way active front stage, rear fill, custom sub box, some strategic sound dampening... But what in the sam hell have I done, other than NOT HIRE A PROFESSIONAL... Thanks to this gem I now know OF COURSE there's a sub box CAD? program🤦♂️ And now (at 35) I don't have to go ask my dad to do his hocus pocus voodoo math wizardry when I eventually build my box. The more I learn, the more I realize how much more I have to learn... I'll be seeing you, I'm sure LOL. Thanks for the great content. God bless!
I totally get that. I feel like I've just scratched the surface! There's so much more to do and so much more to learn.
Years ago a CD magazine told how to build a subwoofer from a 12 inch Eminence sub at the time and it was used in an expensive M and K system. Well, I built that but the sub would bottom out with only 25 watts applied to it. A couple years later found out that the sub worked much better in a 1 cubic ft enclosure instead of the gentler Q design at 3.5 cubic feet. Before I could experiment the subwoofer's foam surround fell apart. I let some years pass and in the meantime built some khorns (mid 80s) and 10 years later bought a car sub off of ebay. It happened to be a MA audio MA121XQ and it had the right parameters for the 3.5 box I had made a decade or more earlier. Tuned to 27hz or so and powered by a 300 watt amp (I just replaced it yesterday with a new Dayton 250 amp with dsp) and it doesn't bottom out and just works. Low cost too. It has 10mm xmax which seems plenty.
Great video! Keep up the fantastic work, love watching your content.
I'll need to bring you in for a guest spot sometime!
Thank you sir. I watched it twice!!
Awesome! Thanks for watching..
Awesome video and great history! Knew about the law but not about the person nor history. Nicely done
Thanks! I had a lot of fun putting this video together.
So here is something I have been doing for a few years that seems to work well. 10 inch sub in a box with volume for a 12. 12 sub in a box with volume for a 15 and so on. Not sure how well my idea works on paper but it usually sound pretty good to me. My current set up is pretty low budget. 7.2 surround sound. With old school sony tower speakers for my bass. internally braced because of half inch fiber board. Boxes are 2.6 cubic ft with 12 inch woofers on a 200watt rms fisher 2 ch amp. Ports are two inch abs pipe about 12 inches long. Seems to do pretty well. Nothing crazy for a set up but over all it seems to work well.
That is not a bad rule of thumb.
youre going to blow up man im so hyped, you make such quality videos there is no way youll spin tires.
I am just hyped to be here!
@@DIYAudioGuy thats why youre succeeding, in it because you love it not because you want it.
I love your channel man its great content.
Keep up the good work.
just a thought but an ole ambulance or fire rescue truck will have the "power " and space to build a really nice portable test station 🚑 they have massive electrical charging systems and well built and maintained yet cheap on the market
I thought the exact same thing! If I were going to build a bass van That is the route I would take.
Used to run a professional audio company, designing building and installing sound systems in various live pa venues... I'm learning stuff here, LOL...
You should start posting videos yourself! I bet I can learn a ton from you.
Not necessarily a big enclosure.
It’s in the design.
My enclosure is very small but has 96” long port tubing. Shakes the heck out of the windows and 17Hz.
It’s more like a T-line. I prefer it over any enclosure if you want to dig below 25Hz. Light, small, loud n low. Not bulky, big and heavy like a regular ported enclosure.
A pair of 10s can outperform 12s if the enclosure permits so. Because no matter how many speakers you have, you’re not going to get SPL at the frequency you want if the enclosure is not tuned properly; all you will hear is inherent noise from the cones and no actual Bass. Happens a lot with prefabs when trying to play anything below 30hz. You will start to hear some actual Bass once you are reaching the tuned frequency and above.
T-lines are cool!
Thank car audio gods for Hofmann!!
He was a giant.
🔴So how much bigger should the box be above the manufactured recommended size
That is a great question, join us on our next live show and we will try to give a detailed answer: bit.ly/3PYKG5P
Knowing this and your ts parimeters and learning how to use winisd properly will allow u to find that sweet spot and build a box better then the other guy. 😁👍👍
That is the goal.
Great job on the editing!! Wow! Great content
Thanks, glad you enjoyed it.
Henry Kloss was actually the driving force behind AR, KLH (KLossHenry), Advent, and Cambridge Audio.
I like my bass low, but for the enclosure that lives under my desk, I don't need it loud. So I tune for extended response and I have flat response down to about 15Hz. I don't hear that, I feel it. It does result in a port that chuffs, but I don't hear that because the desk is in the way. After that I use Sonarworks for final integration. The result is fine.
YEP ! I was penciling out equations using T/S parameters way back in 1980. The only 2 sources listing T/S parameters back then, that I knew of, was RadioShack, and SpeakerLab.
I made 2 subs for my living room that were big enough to double as end tables on either side of my couch! and my first home theater was born cira 1985.
These ready made sub enclosures drive me insane... generic sized, and tuned to too high of a Fq, and pray the driver you stick in it, is happy with the volume. The proverbial Kart before the horse.
I miss radio shack
I was at Kstate college back in 81 or so and I had some speakers I had bought from McGee radio out of Kansas City but didn't have the specs to build the right boxes. They were a 12 inch with alnico magnet and whizzer cone. There was a guy in Manhattan, Ks that was advertising homebuilt speaker builds. Well, he had a brother that had a computer and he could measure the parameters of the speaker. I let him do it and it turned out it took a 5 cubic ft enclosure tuned to 35 hz or so. I built the boxes and I wish I still had that pair of speakers. Worked fantastic.
This guy looks just like my doctor whom I have to see tomorrow morning. Hopefully I get some good news from the visit.
Good luck!
12:00 Mannnn I remember the PA Electrovoice ELM12’s some were using in their vehicles. I had two recently in 2006 in a jeep Cherokee and them EV’s GOT HELLA LOUD when it was around 100-400hz which is unheard of any 12” car subwoofer being able to do. I had a 12” subwoofer as well for the lows so I had nice coverage on the low end from 36hz-400hz.
Yea, a lot of the early car subwoofers were EV's or Eminence PA drivers.
justin dropin" that tuesday knowledge!!
Partying on a Tuesday!
When it comes to my portable designs, I have a saying: Hoffman's law may be iron, but my batteries are lithium-ion :)
You gotta love Class D and modern battery tech. Physics can't be cheated, but it can be negotiated with quite reasonably.
Interesting video. I've been trying to figure out some of this subwoofer stuff, and not sure size always is the key feature for subwoofers. I consistently see 10" and 12" subs that rarely go below 35 Hz. Yet I have an 8" JBL sub rated at 18 Hz - 800 Hz (which I'm sure to many that 900 Hz is on the high end of a sub). The box came with the sub, and though I have not tested it, I can say yes it does play lower notes than to subs that are in the 35 - 40 Hz range (I do have exceptional hearing, and proof humans can hear below 20 Hz and above 20 Khz. But I have terrible eyesight, and think one sense made up for another. I'm just glad it was my ears instead of sense of smell. lol). But I too always thought a larger subwoofer driver was needed to hit down to the 20 Hz mark, like a 15" or larger. So how are smaller subs able to achieve this ? Please, I seriously would like to know as I am somewhat confused maybe? And I am having a hard time locating anything about a driver's ability to reach to low end Hertz like a subwoofer. It seems to me you would always want a sub to go down to 20 Hertz otherwise you are cheating yourself. And one reason I ended up with the JBL I do as it is hard to find subwoofers that reach that low of Hertz. Which really surprised me.
It is all about the interaction between the enclosure and the drier.
If they go lower they go less loud (hofmann law)
I enjoyed watching this video and learning more about something us DIY speaker guys often quote, but don't really know that much about, Hoffmann's Iron Law. I really like your channel -- the content, and how you do your videos. Informative and entertaining... plus you're brave enough to do the car audio thing... that takes GUTS!!!! -- Tom Zarbo (AKA Zarbo Audio Projects)
Brave, or stupid? I will let you know when I found out!
I got 3x12 up front and 2x12 under the couch , my walls are 3-4ft thick stone wall and between this room and the dining room is a 7ft tunnel of stone.....basically open the door stand outside and the loudest bass in the house, the tunnel is basically the port of my sitting room speaker.
The issue with the enlarging the cabinet is you end up adding efficiency to the low end only. The problem is you rob energy from the top end to do it. Same with large port area. Yeah it's awful loud around the box tuning but it rolls off very fast above there in the range. Boxes that are too large for a driver with introduce mechanical distortion into the range around a half octave above the port tuning due to the mismatch in damping. You'll also find you run into xmax limits very quickly in an oversized cab.
So in summation, Hoffman iron law gives you low end extension at the cost of high end extension. All you are doing is moving the playable band, down the range and shortening it at the same time (low bass one note wonders). I grew out of iron law boxes many years ago when I realised the bandwidth drawbacks. It's a great way to get cheap woofers loud at low frequency but you'll soon get bored with only being able to play your tuning specific decaf tracks. Everything else with transients in it or upper bass will sound muddy and 10 minutes behind everything else. You'll also get bored of wearing out woofer suspension if you are competing like this. Xx
Great video brotha. Keep dropping the knowledge on us we appreciate it.
Thanks!
I'm not sure if Toid was saying you don't hear it at all or your feel it more than hear it. (At 3:55 ) Because I can hear just fine to below 15Hz.
I've had my fun with my big boxes, but I'm slowly starting to lean towards smaller. And I mean coming from my 14.5ft³ Full Marty to a more manageable dual 5.4ft³ UM12" boxs.
Soon enough I might try Infinite Baffle in my car so I get more trunk space back and I'll use my UM18 that is collecting dust in that build.
Normal human hearing is 20hz to 20khz -- some can hear more some hear less.
@@DIYAudioGuy Indeed.
Passive radiators are the best to me. Good video
Yes they are!
They cost extra but they are really nice. I almost feel like they oversimplify a build. Which is a good thing.
@@JoshM7 Yep. It seems like every one that I've ever heard and owned sounds better and more efficient bass than a ported box. Bic is a company that makes a lot of them at low costs
@@billy3650 My build with Passive Radiators aren't very suited for home use as I'm using an oversized enclosure (3.6 cubic feet tuned to 19Hz) riding xmax limits on my Ultimax 10 that cause a bit of noticeable distortion in the house.
In my car that distortion is masked and never audible.
What I do love is the silent operation even under tuning. I'll never hear port noise in the first place. But it's still very nice. When I had it in the house it was crazy how silent it was.
@@JoshM7 Do you have a trunk or hatchback? I know trunks mask a lot of distortion
One thing to note is that there can be practical limits to how big the driver can get, in a PA system you might get away with four 21" drivers on either side of a stage, not so much in a fiat 500 or a small apartment. This is another major reason why high excursion has become so common over the years. The missing link is full range drivers.
True
320amp otternator.... lol.
Seriously though - nice video. Power is so cheap and drivers so specialized these days that we are spoiled with tiny enclosures. I remember dropping Rockford SP-412s into 3cuft each and it was a compromise!
For sure! We live in interesting times!
this was a great explanation. Now, to peruse your channel for passive radiator information
I've got a couple of videos where I use some passive radiators, I think one of the very first projects I built for the channel was a passive project. Perhaps it's time to make a nice video on passive radiators?
@@DIYAudioGuy I saw that. I started watching some of the PR videos, but I've never heard a solid explanation on how to come up with enclosure dimensions or proper weight of the PR, etc.
96% of the video: I love Hofmann ❤ 4%: Basics of Bass boxes ;)
What is not to love? The guy did some awesome stuff!
Great. At 3.05 you spoke about the great passive radiator. At 0.48 you flipped around the MK Boombox. I would like to build the MK Boombox but I find it a bit to big/deep. Can’t you redesign it with two passive radiators instead for the ports? Us the same kit, but only cut and remodel the box, that are included in the kit, so we beginners DIY have something to do during winter. Keep up the great work.
A lot of people seem to build their own (or modify the kit). As far as making the kit smaller/using a PR you can just model in WinISD. You will need to relocate the amp, it takes up the full depth of the kit.
@@DIYAudioGuy Thanks. I need to learn how to use WinISD. So handy you just recently made a tutorial! Keep up the good work.
@@rikardekvall3433 There is a bit of a learning curve, but it is a great tool and the price is right.
Great job bringing the good energy, and great information.🔥💯
Glad you enjoyed it! I has a lot of fun digging into Dr. Hofmann's story. His dad was even more impressive. He was literally the worlds best concert pianist during his time.
I will be looking into him also. Thank you!
You worded the evolution of CA subwoofers wrong. You said "when that happened CA subs got less efficient". What you meant was "when that happened CA subs started sounding like crap". LOL. Great video!
🤣
Your a beast man. What a fantastic video.
Thanks
Hie ...please can you do a video of examples of how to calculate different size boxes using this formula...
Unfortunately the formula does not give a full picture of how a subwoofer will perform, only the pass band efficiency. That is why I recommend this: ruclips.net/video/yZNeYBYGRKk/видео.html
@@DIYAudioGuy ok thank you
This is a wonderful video. Good job!!
Thank you!
Good history lesson. Thanks
Glad you enjoyed it
Aloha from Hawaii! Can you make a Rotary Sub video, please.
I always try to get as much air movement in as small of a box as possible. I like to use driver's that don't need much volume and have a high Xmax like for example an SB23MFCL-4 with 12mm Xmax or a Ciare 12.00SW with 14mm Xmax and put them into a Tapped Horn. For both driver's i have designed Tapped Horns that go down to 13hz. A friend is currently building the one i designed for 2 of those Ciare 12s and he will build 4 of those Dual 12 TH and together they will be capable of generating 127db down to 13hz at 1meter outside according to Hornresponse. Each sub has a outside Volume of 655Liters and does 91db at 1watt. Inside and corner loaded those could probably cause some SERIOUS injury to human and the house they are placed in.
Theil/Small based there research on using existing electronic filter theory and modelling the physical attributes of the driver as electronic components.
AR did were not famous for a sealed enclosure, they developed "acoustic suspension" which is a sealed enclosure but with the driver designed to specific specifications to compliment the enclosure.
Theil/ Small took this further and worked out the driver and box requirements for a ported enclosure as well as refining fully the requirements for sealed enclosures and any other box design by defining the Theil/Small specifications we all use to this day.
Up until these two things, ported boxes and vented boxes was a hit and miss try it and see what it sounds like affair, which lead to the ported boxes getting a bad name for boominess as they were never aligned properly.
Awesome, thanks for filling in those gaps.
Hello , I love the videos you have put together on boxes . Whats your stand on the so called 6th order boxes and do u feel they are worth the time to build? Thanks for all the time and knowledge you provide .
Unless you are doing SPL competitions it is hard to beat a ported enclosure.
@@DIYAudioGuy the 6th order is supposed to be a dual tune port so u can play a larger variety of notes with less restriction and role off but just seems kinda impossible to be true when listening to you explain ho the ported system works. Is it true they work as they say so i can tune one at 23hz and another at 40hz ?
is there a calculator online to input the parameters and get the result? You left out the part of how to apply the law to get the most out of the enclosure, or did I miss something?
I’m going with a 2k amp to power my Fi Neo 3.5 12 inch. I would choose a high quality high efficiency amplifier with adequate buffer capacitance between the power supply and output section so that I can get away with only a big 3 upgrade. Don’t want to deal with the headaches of messing with alternators.
You just have the one sub, correct? If it's the dual 1Ω model, look into the (yet to be released) Stetson 3000.1 EVOX2 - 1Ω. With it, you could wire your single sub at 2Ω and get 1980w RMS from it, while leaving yourself with enough overhead for the possibility of getting another 3.5, wiring them to 1Ω, and getting 3000w for the pair. Being an SQ sub that's aimed at a ported box though, you might just wanna stay at 2Ω for the added control.
Average music draw is ~120a, with a burping max of about double that (240a), btw. Seems like it'd be a good match for you, if it being $800 and full bridge aren't issues for you.
Smart.
Gosh I love this video!
Good content sir!
Glad you liked it
Cool video, learned something new.
Awesome, thanks.
this is critical information!! thank you!!!
As long as we don't achieve critical mass! The results would be explosive.
@@DIYAudioGuy ⚙️🙂
That Iron law sounds like one for car performance, You can make it Cheap, Fast and Durable, but you can only pick two. In much the same way, you can't do all three due to it being almost impossible
Yep!
So glad you mentioned the 10 vs 12 thing. So tired of the idiots talking like their 10's outperform 12's without giving any specs of both setups. If somebody has low end 12's, they can be outdone by high powered 10's sure, but that's not the comparison that should be made. All else being equal, the 12's will always win. Some people really need a smack across the face to try and wake them up from their delusions.
Exactly.
Question: I’ve always bought prefab boxes but I finally saved enough to buy a ported custom box. I listen to various types of music but mostly rap. Hate to be a dummy but I have no clue what I should tune my box to. Thinking about 37hz-41hz.
It really has more to do with your taste and the sub you are using. I would tune it a bit lower, but that is just my preference. I would rather be low than loud so I tend to shoot for the lower 30's. I did have a 10 tuned to 22HZ, I enjoyed those extreme lows, but I sacrificed to much output/SPL. That is the tradeoff with a ported enclosure, you can tune it low, or loud. You have to pick.
agreed. in isolated frequency testing, i found 30-40Hz to provide the most bang for the buck. while i would love to feel the 25Hz magic, it is simply not realistic with my “budget” system and is way inefficient down there. used a deep crossover to tune as much of that signal out as possible.