Very interesting. Open baffle seems to be bafflingly complicated. I thought I'd kock a hole in a plank and that would be job done. Ignorance was bliss!
amazing engineering here. I've wanted to build a set of open baffles, and separately a servo controlled sub. I'd love to hear this system, even through a camera mic. cameras can be surprisingly revealing, they tend to make systems sound much worse than they do in person, but then a really outstanding system will simply sound like you're listening to the recording
My journey since I started to look at loudspeakers from an engineers perspective. From low to high transient performance: Bass port cabinet > Sealed cabinet > Aperiodic cabinet > Open Baffle or dipole > H or U frame cabinet. Its rather incredible what happens once you step outside of the comfort zone (first two types) and look at what other solutions offer AND... and what them speaker drivers like. In the end, if you allow it, the driver can become a bliss and not something that is working against your goal.. Just saying :) .. Love your videos.
I like this. Competition is good for everyone. Spatial speakers use the mentioned subs and you now have a scientific reason as to why the H frame is a better design as well as difference of the drivers. I like it...gettem Danny!!
Thank you Richie! I was waiting for this video to get the lowdown on H frames for my 8x8s I showed you in my u frame and without addressing it how I expected you to I have learned so so much today! All you did was show me that deep bass never comes spontaneously without addressing the limits of 1 driver's rolloff. So since every doubling of drivers gives 6db gain I'm going to make it a 3way with my 16 woofers ~~~4 on by default then another 4 @ 55hz for next 6db then my final 8 woofers (doubling drivers engaged once again) @ 30hz to hopefully get me to 28.5hz target. Awesome
Hi Danny I was very impressed with the tip regarding two woofers and using an inductor for one. but what if you have 3 woofers... does the third woofer have a different value inductor from the second? Many thanks for the great info Craig
Thanks for all this info. I have no experience with Open Baffle speakers but plan on trying out some basic stuff on my own. Design question: has anyone tried to build an L baffle of sorts using a tube cut at an angle? In other words, imagine a driver mounted at the end of a PVC pipe just big enough to hold the driver. Cut the back of that tube at a sharp angle so that the sides of the "U" are effectively, let's say, 10" on one side, 2" on the other, and everything in between as you rotate your cross section. Multi-driver systems can just use one pipe per driver. 1. It would create the smallest baffle possible for a given driver, although it's round and likely the driver is centered on the baffle. But that means baffle step should be smoother and easier to compensate for. 2. The transition traveling around the driver is smooth, where an L frame has two strong peaks on the frequency. The angle cut tube would "smear" that across the whole frequency spectrum. That might fail to achieve the desired response but it might make it much smoother. I know speakers mounted in the center of tubes and spheres is a big no-no but also tubes create a smoother wavefront like a waveguide.
Dear Danny, Great videos & thank you. If it fits into your programs, kindly give some of your insights videos on eminance Alpha 15A , Kappallite 3015LF etc in open baffle. Especially on the one note bass in Alpha15A and your opinion.
Very interesting series Danny. I wonder though. Given the significant variation in response afforded by even seemingly minor baffle length variations, if these speakers are set too close to obstructions, too close to a back wall for instance, all of the endless trial-and-error endeavors to arrive at finely controlled response would be eaten alive by the room influences. So it seems that the box speakers, while not immune to such, provide some leniency in this regard. Once again, having a system to model this, much like I have seen finite element modeling used in my field (Chemical Engineering and don't ask why I am so intrigued by this topic, so far removed from my SME), well, that would go a long way toward not only arriving at optimal baffle configurations but would also afford some sense of room placement guidance. I have tons other thoughts about how these open baffle designs might be improved in light of my understanding reached by watching these and other videos but this message is already a chapter.
I built a pair of your W/Frame subs back in 2016. They provide a nice bottom to Magnepan 3.6 planars. For music they are fine, but often with heavey bass in movies and TV they would bottom out and often blow the covers off. To fix this, I even ordered new Rythmik drivers and modification to the A3470 PEQ from Brian to build new sealed subs. But, after setting up a new Lyngdorf MP60 2.1 processor things have changed. Before I ran the MP60's RoomPerfect correction program, it told me to do a sub adjust program first. I did this to the W/Frame subs and then I ran RoomPerfect with 13 mic positions to 100% room correction. The subs no longer bottom out and my 7.2 Magnepan system has never sounded like this. I guess I will try to return the Rythmik parts back to Brian since the W/Frame subs are completely under control. Or, I could build two additional sealed Rythmik subs and add them to the system. The MP60 has 16 outputs and I can't use Atmos with a sloped ceiling. Do you think the sealed Rythmiks would be worth the effort or would they add probems? All the Maggies and the W/Frame subs are open baffle and maybe adding sealed Rythmiks would not work.
Thanks! By now I saw many of your videos and they are all very informative. But I never heard you talking about the music which you use to check the sound. Some time ago an audio engineer told me one of his test songs is Money for Nothing by Dire Straits. What is your favorite test song?
i think ill stick to a box i like a drums to much but then again i think a old sansui speaker set sp1500 set of 4 is high fi ran by a sansui 5000a or 9090db .neat stuff to see what folks are into
I am a big open Baffle fan but as a fan of SE tube amps I have a little different philosophy. I am not a fan of servo control and arc welders for amps. My thinking goes like this. Large, efficient, high Q bass drivers wide range mid (AKA FR) and super tweeter. Since the output transformers are likely to struggle below 30 or possibly 40 Hz there is no need to try to force them down to 16Hz. Just use a sealed or IB sub for the last 8va or 8va and a half. The percussive bass is well within the range of the mains so you get the terrific OB bass sound and the sub can handle the lowest pedal tones. If you can get the sensitivity you want with a single 15 or 18 OB woofer you can even include the subs in the same stack.
@Danny Richie Hey one final question before I glue it all together! I have not cut any deeper for the woofers to sit then mounting flush on the front baffle. Do I mount the front of the baffle board @ 6" on my 12" wings to get ideal 90* cancellation? ...or... do I mount the center of the 3/4" baffle board at 6"? (Aka the front sitting @ 5 5/8")
@Danny Richie I know that you need to keep an open baffle loudspeaker a minimum of 3 feet from a wall. However, can you put a subwoofer open baffle speaker closer than 3 feet to a wall and still sound good?
Ooh I like! What is the different on the sealed vs open baffle servo sub? What does the sealed vs open baffle do for the clarity of the sound? Does the sealed give more umpf/boost to the bas? Is it necessary to have two subs or is one enough for playing music, because I need music, not for a audiophile room.
Fascinating stuff - learning a lot. Thank you! But I must ask about your listening room - it's clear from hearing the audio in this video that the acoustics are horrible. How can you hear the speaker in a room like that? Do you do measurements in that room, too?
Thanks for another super-informative video Danny. I now know more about my GR OB and sealed box subs than ever before. So many controls and although the Rythmic amp info might tell you what the control does, it’s not clear on application. You have filled many gaps. Thank you!
Question, transmission line pipe vs. Open baffles. Does a TL have any of the advantages of a open baffle sub under 100 hz.. none/ some/ many ? Thank you you for your videos, as a DIY SPEAKER builder I have learned many things form your channel. Present speakers. Vandersteen 5, magnepan 3.5, DIY project. I do not mind a short answer, if I am lucky to get one at all. Regards Andrew, Montreal, Canada
Is it worth making an open baffle bass driver without servo control? I want to do something with my GRS 12sw-4 drivers and I'm coming up with some interesting ideas, but something simple that makes me happy would... Well, make me happy! Isobaric ported boxes are intriguing me, but even with 2 drivers the box needs to be huge to be reasonable flat, like 5-6 cubes. I rattled an isobaric type setup with 3 drivers providing one driver's worth of rear wave for the ported section, but I'm thinking that may end up just as unbalanced as using two drivers. I'm thinking of a sort of W frame for the open baffle design. Just sort of imagining it, I could isolate and kill the rear waves quite well, but not sure how I'd get that low extension without expensive equipment, or if I'd be satisfied without it. Thanks for the videos. Open baffle information is scant online.
hello Danny, does a h frame really separate front and rear waves ??? Air inside the cavity will load the driver. but since the wavelengths are huge, separation of front and rear doesn't happen i guess. or may be negligible minimal.
hi danny you helped me with scan speak years ago, i want to use 2 10" scan speaks in an open baffle to make a sub for some speakers, rolling at about 100 hz, i visited you in wichita falls years ago, are you still there, i'm here in big d hope you wouldn't mind offering some advice
@@stogie525 There are theoretical advantages in inverting every other driver, however I'd trust Danny's take in that it doesn't matter much in this application. Anyway, here's the theory involved. LF drivers have inherent asymmetrical characteristics in their acoustic output front-ward, as compared to rear-ward. The various causes include; 1.) magnetic force variations, ie., inward stroke vs. outward stroke 2.) suspension non-linearities inward vs outward 3.) acoustic differences of the sound energy encountering and being impeded by the driver basket and magnet structure vs. the open front of the cone So, whether it's aerodynamics, magnetic, or related to the suspension, there's asymmetries in the front radiation relative to the rear radiation. In a two driver sub, flipping one driver around (and swapping polarity), nulls the potential differences between the two orientations. Open baffle and IB subs are oftentimes where you see this implemented for a couple reasons. One, OB and IB operate close to their physical limits ... this is where the asymmetries are more notable. Also, IBs and OBs utilize multiple identical drivers, and drivers must match for this distortion nulling advantage to occur. Danny saying it doesn't matter too much, which is consistent with my own experiments, ... but it does work. Perhaps it's because they're somewhat separated by individual baffles... as that would lessen the coupling, and thus nulling. Also, it cancels the even order distortion components, which are the least objectionable subjectively. Could be it makes motor noise off the back of the driver a bit too noticeable.
Interesting stuff! Would there be any downside to making the H frames deeper? It seems like it would naturally lower the roll off which would allow more output at the lowest frequencies.
What are the dimensions of the NX Extremes and the 3 stack sub i.e. height width depth? I could not find that info on the website but may be I missed it. Also, what is the height of the NX Otica's. Many thanks.
Hello, I found your research and explanation very good and understand👍. I 2ant to make open baffle with audax fullrange with L shape as narrow as possible, do I have to make the wings deep? I also want to make an H frame woofer. Does the size mattets and I mean the deprh? Thank you very much. Br Le
Great video series, thanks. Q1: How come the X Statik doesn't have any side wings? Q2: Despite the fact that open baffle speakers are easy on the room, they still cannot be placed near walls?
answer for Q2: For the higher frequencies, the reflected sound enables the brain to cancel out resp. to dismiss the complete reflections to at the end meet the sound as if there was no room at all, the speakers seem to disappear completely - the brain, so to say, creates a hearing-feeling like hearing in a nature ambient, reverb-free, although the ears are "hearing"=receiving a mixture of reflected and unreflected, direct radiated sound. The time-delay beetween the direct and reflected sound-waves is important here and in most rooms, a distance of about 4-5 feet e.g 1..1,5 meters away from a corner/both walls will be the optimum to achieve this effect. Siegfried Linkwitz has found out, that a dipole design, that has the same spectrum radiated in front and rear of the speaker, will be the best. Behind the listener, the sound should not be reflected, but mostly absorbed or reflected with a much higher delay (and lower energy/sound-level) than the reflected sound coming from behind the speakers resp. coming from the just mentioned corner. This is, why in smaller rooms, a dipole-design will not function properly, because the brain can not distinguish between the reflected sound from behind the speakers and the direct sound reflected from the walls behind the listener.
Hey Danny, thanks for this informative series, it has been very insightful. I’ve wondered one thing about open baffle bass and there is no one better to explain than you. I understand that traditional box subwoofers are pressure making devices and pressure is at a maximum at room boundaries and a minimum at the centre of the room where a null in bass can typically be measured. Opposingly open baffle subwoofers are velocity making devices, velocity is at a minimum at the room boundaries. Does open baffle bass have the same null in the centre of the room that box speakers have or does the different room interaction change this dynamic? Thanks.
The output levels will vary from room to room and depending on where you are in the room, but in general the room will have a more even output except at right angles to the speakers (of coarse). And the output in the center of the room is pretty solid.
Thanks for the reply. I’ve been following you online for a few years and hope to buy and build some of your stuff the new year. Here’s hoping it’s a better year for all of us.
Hello my friend...love your knowledge of speakers...i have been looking for the longest on a strange problem...i bought 2 psa s3612 subwoofer with ipal 18inch made by b&c .i had a pioneer sc55 for 10yrs and on the day i connected the subs i was scared on how powerful these sub sound,then the pioneer went off on me the same month,so i was in line to buy the denonx8500h, now connecting these same subwoofer now cause a popping noise at low frequency these are supposed to go as low as 11hrz,but it pops. I call the manufacturer and they sent me the settings on how to set my subs i did but now i watch movie and feel i am missing that punch...they now i bought this denon on ebay open box deal...manufacturer said that this is normal that the denon is sending a clipped signal causeing the subs to pop..your input if any is appreciated thks.
it is to cancel out what comes from the front with what comes from the rear. If mounted in a Wall, you cannot use this stunning feature, killing standing waves between walls. It is then like a closed box with the resonance frequency of the driver like in free air and may be without reflections in the cabinet.
The NX-Treme model will play down to mid 40's in many rooms. Some rooms will be mid to high 50's though. It just depends on the room. We recommend our open baffle servo subs with them regardless.
of course - why not? Difference is the adjustment of the cornerfrequency, a flat response and a much quicker settlement of the membrane, that will not be damped additionally by the feedback.
When you have multiple heavy drivers with such an agressive control, in a relatively light chassis, dont you get problems with keeping that chassis in place? Feels like it could start rocking about on the floor?
On your site, you have kits for "sealed servo" subs and "open baffle" subs. However, the amps and drivers seem to be the same for both. What is the difference between the two? Couldn't you also use the "sealed" driver/amp combo in a ported or open baffle configuration? Or am I missing something? Also, you are using 370 watts for a single driver sealed sub and 370 watts for a double OR triple driver open baffle sub. Doesn't that create a problem with response to spread the wattage over more drivers (e.g. damping, excursion, etc.)? Thanks for the very informative series!
@@edjackson4389 you have to wire the woofers in parallel to use an inductor (in series) for the lower only.placing an inductor in series with the series wired woofers is going to affect both of them.if you have dual voice coil woofers maybe you rewire them so the driver s can be wired in parallel and not cause too low impedance.hopes this helps.dannys suggestion of choke in one of two parallel connect drivers is also useful to correct for baffle step response on multiple midwoofer and 2,5 way designs.
Hi Danny. In your next video can you have a drawing of a W baffle (from the top)? I am having difficulty visualizing it and where the drivers would fit. Thanks!
It's a W seen from the side! The baffle not beeing a straight line, but one becoming a V, with Top and Bottom parallel, all becomes the W - I hope, I am right here.
Excellent series - Thank tyou for sharing your knowledge! When an inductor is added to the second woofer, does that cause a slight, frequency dependent phase shift of the second woofer relative to the primary woofer and if so would that result in an audible smearing of the bass notes?
Thanks for the reply to my previous question. New Question: In all the videos I've seen from you so far about upgrading, you never discuss Watts per Channel, RMS. When I moved out of my parents home some 45 years ago and got into listening to music on a "real" stereo system the only specification I thought I understood was Watts RMS. 50 Watts was more than 20 Watts and I assumed from the marketing 50 was better than 20 if your speakers could handle it. All these years that first impression has stuck. Could you discuss in one of your videos the relationship, if any, between Watts and sound quality? Also, The Manufacturers of my speakers (Polk S60) recommend between 20 Watts and 300Watts RMS. It seems counter intuitive to me that 20 Watts could be just as good as 300Watts. Is Marketing just trying to cover all the bases? So, for best sound performance I'm assuming I need a minimum of 100W, but probably 150W to 200W would be better. How wrong am I?
@@dannyrichie9743 Thanks. I actually already watched that video and now I've watched it again. I guess I had to watch it twice to overcome 45 years of wrong thinking. So, whether your Amp puts out 20W's or 300W's is only significant in terms of the size of the room you want to fill with sound? But then again that's why they have Home Theatre systems with 3 pairs of speakers and a center speaker and a subwoofer. For a 2 way system in a normal size living room you don't need a massive amount of power unless you like to make your ears bleed. :) I think I've finally got it. Thanks. This is a great channel. Keep it up.
@@iliascharis5668 I had a good sized anechoic chamber at our old location. An anechoic chamber will not be needed for measuring them. I have not measured a pair of them and I don't think they have either.
My question is, if you can only go down to 200Hz on a OB, and you still need two subs to reinforce the sound, whats the point, does they really give so much clarity compared with just using a top class driver such as Seas Excel, and wouldnt you also wish to have an open back tweeter if it makes a difference to high frequencies?
@@engjds There are several things going on here. Front to back wave separation will control low end roll off. So a wide baffle or a baffle with side wings will extend low end response. Our servo controlled woofer are loaded in an H frame and with the help of the servo control system, they will play flat to 20Hz.
@@dannyrichie9743 20Hz is a bold claim, though I do not doubt you have measured it correct, it must be very sensitive to room placement with all those additional room modes?
@@engjds Are woofers are not at all sensitive to room modes. Our woofers play flat to 20Hz and hit -3db down point in the teens. They also stop on a dime. 🙂
Another excellent video. You've mentioned in other videos that you get a lot of speakers in to upgrade. I don't imagine you are able to do videos on every speaker you've worked on. So I'm asking, Have you worked on the Polk S60? and do you have an upgrade kit for those speakers?
Cool stuff! I'm not as familiar with OB subs, but if we were comparing to a sealed enclosure, would your active damping settings correspond to Qtc values of in acoustic suspension alignments? (i.e Q=0.5, 0.7, 1.0) If so, what values would you assign to the low, medium, and high settings of your servo system?
9:25 wouldn't it be nice if such a setup could in fact play 20Hz at usable sound intensities anywhere farther than 2inches from the dust cover? :} (the 1/4 wavelength at 20Hz is ~14ft and our hearing is down in sensitivity god knows how many tens of dBs... we can't cheat physics, but they can trick us if we don't understand how things work :} )
Open Baffle loud speakers tend to be very tall. Looks like that is because of the number of drivers. Can they be shorter like the size of you H-Frame servo woofer? What are the trade-offs? I like open baffle speakers, it's just that are so big. Thoughts? Thank you for the video series.
Danny, At What frequency can cross your L shaped 6.5" woofers with the lower end servo subs? I still own the 165X woofer I can't seem to cross lower than 250Hz, is that what you are getting? Thks.
That all depends on the room size and distance as the doubling of distance represents the loss of 6db. But that level at 10Hz is a real stretch for any woofer. You should be looking at this as a solution: www.rotarywoofer.com/
@@dannyrichie9743 If I use 8 drivers each for both left and right channel (16 in total), what frequency response am I looking at from standard 1m measurement point. I intend to do away with any subwoofers and pair these to Line Force when they are available.
@@aassiimmaallii If you are wanting to go with our Line Force model (if I can make them available again) then go with a stack of six of our 12" servo subs per side. And the HX800 amp will handle a stack of six of them.
I still don't get why on the subs such a short side wing would have an impact on the lowest frequencies, shouldn't its effect be negligible in the very bottom end and be more pronunced around the 100s hz area were it is not really needed?
The space made by the wings load the driver and create pressure in the space on each side. It also further separates the front and rear output further.
@@dannyrichie9743 Thanks very much! I suppose I've been confusing baffle width gain as in baffle step related to wavelength to side power cancellation in open baffles - I was immagining it to start heppen just at the geometrical position of the wavelenght.
Denny, thank you for another great lesson! What do you think about so-called Ripol subwoofer design? I am planning to build somewhat similar compact design using two 18" proffessional drivers with low Qts & low Fs.
Careful, those often create a large un-braced panel that if not super thick and solid becomes a buzz box. And it loads the drivers pretty hard like a band pass box that is tuned too high. It is not a good idea for pure sound quality.
Also can u come up with a plan that I can buy like LX521 cause shipping is so problematic and expensive nowadays. SL made a huge name and following for being open and selling plan. All active supporting miniDSP I don’t mind not getting servo rthmik amps and subs little compromise ok fir me fir ease of goods and support available in my country of various drivers
@@dannyrichie9743 that I am aware but I prefer local diy available drivers and plate amps or dsp Incase of failure shipping back to states and return the costs might as well dump it. Please consider for people like us
So spatial audio doesn’t use servo subs am I correct but still Ron found it interesting and pleasing H frame looks kinda wired fir home minister approval
Wow. Do you really have such impressive genetics (especially that hair!) or are you just a thirty-something who follows Senior Games to get a sports fix without dealing with all the aggressive competitive nonsense?
Oops - curtains all over the place. Trying to kill the reflected part of the radiation pattern - just the opposite of what he should do. Also looks like the big wing is blocking the ipsilateral reflections, making it no longer open baffle. I am not sure what that does to the radiation pattern, and he is not going to tell us, because he is not even aware of radiation pattern.
Hi Danny - quick question. I see you have 3 different models of drivers for Servo Subs on your website. For the life of me, I am not spotting the difference between the three. Can you help point out what is likely right in front of my nose that I am missing?
The models with a FR at the end are designed for free air applications. We have them in 16 and 8 ohm versions so that they can be run in parallel. The 4 ohm woofer is designed for sealed boxes.
Very interesting. Open baffle seems to be bafflingly complicated.
I thought I'd kock a hole in a plank and that would be job done.
Ignorance was bliss!
amazing engineering here. I've wanted to build a set of open baffles, and separately a servo controlled sub. I'd love to hear this system, even through a camera mic. cameras can be surprisingly revealing, they tend to make systems sound much worse than they do in person, but then a really outstanding system will simply sound like you're listening to the recording
My journey since I started to look at loudspeakers from an engineers perspective. From low to high transient performance: Bass port cabinet > Sealed cabinet > Aperiodic cabinet > Open Baffle or dipole > H or U frame cabinet. Its rather incredible what happens once you step outside of the comfort zone (first two types) and look at what other solutions offer AND... and what them speaker drivers like. In the end, if you allow it, the driver can become a bliss and not something that is working against your goal.. Just saying :) .. Love your videos.
I like this. Competition is good for everyone. Spatial speakers use the mentioned subs and you now have a scientific reason as to why the H frame is a better design as well as difference of the drivers.
I like it...gettem Danny!!
Thank you Richie!
I was waiting for this video to get the lowdown on H frames for my 8x8s I showed you in my u frame and without addressing it how I expected you to I have learned so so much today!
All you did was show me that deep bass never comes spontaneously without addressing the limits of 1 driver's rolloff. So since every doubling of drivers gives 6db gain I'm going to make it a 3way with my 16 woofers
~~~4 on by default then another 4 @ 55hz for next 6db then my final 8 woofers (doubling drivers engaged once again) @ 30hz to hopefully get me to 28.5hz target.
Awesome
Yes to bass eq, two to three bands is what I often need for PA systems. One is better than none. 👍
1k like for you, well deserved after watching the whole series
Thank you for your explanations! Saving my money...
Hi Danny
I was very impressed with the tip regarding two woofers and using an inductor for one. but what if you have 3 woofers... does the third woofer have a different value inductor from the second? Many thanks for the great info
Craig
Thanks for all this info. I have no experience with Open Baffle speakers but plan on trying out some basic stuff on my own.
Design question: has anyone tried to build an L baffle of sorts using a tube cut at an angle? In other words, imagine a driver mounted at the end of a PVC pipe just big enough to hold the driver. Cut the back of that tube at a sharp angle so that the sides of the "U" are effectively, let's say, 10" on one side, 2" on the other, and everything in between as you rotate your cross section. Multi-driver systems can just use one pipe per driver.
1. It would create the smallest baffle possible for a given driver, although it's round and likely the driver is centered on the baffle. But that means baffle step should be smoother and easier to compensate for.
2. The transition traveling around the driver is smooth, where an L frame has two strong peaks on the frequency. The angle cut tube would "smear" that across the whole frequency spectrum. That might fail to achieve the desired response but it might make it much smoother. I know speakers mounted in the center of tubes and spheres is a big no-no but also tubes create a smoother wavefront like a waveguide.
VERY interesting - Thank you!
Dear Danny, Great videos & thank you. If it fits into your programs, kindly give some of your insights videos on eminance Alpha 15A , Kappallite 3015LF etc in open baffle. Especially on the one note bass in Alpha15A and your opinion.
I found that using thick cardboard instead of wood is one of the secrets to reduce the megaphone effect, but that's not enough on it's own.
Very interesting series Danny. I wonder though. Given the significant variation in response afforded by even seemingly minor baffle length variations, if these speakers are set too close to obstructions, too close to a back wall for instance, all of the endless trial-and-error endeavors to arrive at finely controlled response would be eaten alive by the room influences. So it seems that the box speakers, while not immune to such, provide some leniency in this regard. Once again, having a system to model this, much like I have seen finite element modeling used in my field (Chemical Engineering and don't ask why I am so intrigued by this topic, so far removed from my SME), well, that would go a long way toward not only arriving at optimal baffle configurations but would also afford some sense of room placement guidance. I have tons other thoughts about how these open baffle designs might be improved in light of my understanding reached by watching these and other videos but this message is already a chapter.
I built a pair of your W/Frame subs back in 2016. They provide a nice bottom to Magnepan 3.6 planars. For music they are fine, but often with heavey bass in movies and TV they would bottom out and often blow the covers off. To fix this, I even ordered new Rythmik drivers and modification to the A3470 PEQ from Brian to build new sealed subs. But, after setting up a new Lyngdorf MP60 2.1 processor things have changed. Before I ran the MP60's RoomPerfect correction program, it told me to do a sub adjust program first. I did this to the W/Frame subs and then I ran RoomPerfect with 13 mic positions to 100% room correction. The subs no longer bottom out and my 7.2 Magnepan system has never sounded like this. I guess I will try to return the Rythmik parts back to Brian since the W/Frame subs are completely under control. Or, I could build two additional sealed Rythmik subs and add them to the system. The MP60 has 16 outputs and I can't use Atmos with a sloped ceiling. Do you think the sealed Rythmiks would be worth the effort or would they add probems? All the Maggies and the W/Frame subs are open baffle and maybe adding sealed Rythmiks would not work.
Great series of videos. One question, do you use no rez in the front section of you H frames as well?
Thanks! By now I saw many of your videos and they are all very informative. But I never heard you talking about the music which you use to check the sound. Some time ago an audio engineer told me one of his test songs is Money for Nothing by Dire Straits. What is your favorite test song?
i think ill stick to a box i like a drums to much but then again i think a old sansui speaker set sp1500 set of 4 is high fi ran by a sansui 5000a or 9090db .neat stuff to see what folks are into
I wish i could order it already made .
I don't have time to build anything .
I am a big open Baffle fan but as a fan of SE tube amps I have a little different philosophy. I am not a fan of servo control and arc welders for amps.
My thinking goes like this. Large, efficient, high Q bass drivers wide range mid (AKA FR) and super tweeter.
Since the output transformers are likely to struggle below 30 or possibly 40 Hz there is no need to try to force them down to 16Hz. Just use a sealed or IB sub for the last 8va or 8va and a half. The percussive bass is well within the range of the mains so you get the terrific OB bass sound and the sub can handle the lowest pedal tones. If you can get the sensitivity you want with a single 15 or 18 OB woofer you can even include the subs in the same stack.
More great content Danny. Really enjoying the OB series.
@Danny Richie Hey one final question before I glue it all together!
I have not cut any deeper for the woofers to sit then mounting flush on the front baffle.
Do I mount the front of the baffle board @ 6" on my 12" wings to get ideal 90* cancellation?
...or... do I mount the center of the 3/4" baffle board at 6"? (Aka the front sitting @ 5 5/8")
Danny I have question I would like to you cover in one of your tech talk videos It is front ported speakers vs. rear ported. pros an cons
@Danny Richie I know that you need to keep an open baffle loudspeaker a minimum of 3 feet from a wall. However, can you put a subwoofer open baffle speaker closer than 3 feet to a wall and still sound good?
Ooh I like! What is the different on the sealed vs open baffle servo sub? What does the sealed vs open baffle do for the clarity of the sound? Does the sealed give more umpf/boost to the bas? Is it necessary to have two subs or is one enough for playing music, because I need music, not for a audiophile room.
Fascinating stuff - learning a lot. Thank you! But I must ask about your listening room - it's clear from hearing the audio in this video that the acoustics are horrible. How can you hear the speaker in a room like that? Do you do measurements in that room, too?
Last time I saw your open baffle rythmik subs you had the middle woofer inverted (I thought) how come you made them all the same direction?
Thanks for another super-informative video Danny. I now know more about my GR OB and sealed box subs than ever before. So many controls and although the Rythmic amp info might tell you what the control does, it’s not clear on application. You have filled many gaps. Thank you!
Is that a car battery he's using as an amp? on my way to auto zone now...
Question, transmission line pipe vs. Open baffles. Does a TL have any of the advantages of a open baffle sub under 100 hz.. none/ some/ many ? Thank you you for your videos, as a DIY SPEAKER builder I have learned many things form your channel. Present speakers. Vandersteen 5, magnepan 3.5, DIY project. I do not mind a short answer, if I am lucky to get one at all.
Regards
Andrew,
Montreal, Canada
The advantage of a TL is increased output at the tuning frequency.
Is it worth making an open baffle bass driver without servo control? I want to do something with my GRS 12sw-4 drivers and I'm coming up with some interesting ideas, but something simple that makes me happy would... Well, make me happy! Isobaric ported boxes are intriguing me, but even with 2 drivers the box needs to be huge to be reasonable flat, like 5-6 cubes. I rattled an isobaric type setup with 3 drivers providing one driver's worth of rear wave for the ported section, but I'm thinking that may end up just as unbalanced as using two drivers.
I'm thinking of a sort of W frame for the open baffle design. Just sort of imagining it, I could isolate and kill the rear waves quite well, but not sure how I'd get that low extension without expensive equipment, or if I'd be satisfied without it.
Thanks for the videos. Open baffle information is scant online.
hello Danny, does a h frame really separate front and rear waves ??? Air inside the cavity will load the driver. but since the wavelengths are huge, separation of front and rear doesn't happen i guess. or may be negligible minimal.
hi danny you helped me with scan speak years ago, i want to use 2 10" scan speaks in an open baffle to make a sub for some speakers, rolling at about 100 hz, i visited you in wichita falls years ago, are you still there, i'm here in big d hope you wouldn't mind offering some advice
Curious on how a open baffle servo Sub Would sound in a home theater application.?You’re 3 12 inch servo subs are very interesting to me.
which program do you use to simulate open baffle speakers
Where's the long wing? Interior of the center or exterior?
For open baffle subs, how much space do you need to be away from the front wall?
Love this content Danny. Thought you normally have the middle woofer facing the other way in the triple enclosure?
It can, it is about the same either way.
@@dannyrichie9743 Ahh ok, i thought there was a particular reason i.e sounded better with having the middle woofer facing the other way?
@@stogie525
There are theoretical advantages in inverting every other driver, however I'd trust Danny's take in that it doesn't matter much in this application.
Anyway, here's the theory involved.
LF drivers have inherent asymmetrical characteristics in their acoustic output front-ward, as compared to rear-ward.
The various causes include;
1.) magnetic force variations, ie., inward stroke vs. outward stroke
2.) suspension non-linearities inward vs outward
3.) acoustic differences of the sound energy encountering and being impeded by the driver basket and magnet structure vs. the open front of the cone
So, whether it's aerodynamics, magnetic, or related to the suspension, there's asymmetries in the front radiation relative to the rear radiation.
In a two driver sub, flipping one driver around (and swapping polarity), nulls the potential differences between the two orientations.
Open baffle and IB subs are oftentimes where you see this implemented for a couple reasons. One, OB and IB operate close to their physical limits ... this is where the asymmetries are more notable. Also, IBs and OBs utilize multiple identical drivers, and drivers must match for this distortion nulling advantage to occur.
Danny saying it doesn't matter too much, which is consistent with my own experiments, ... but it does work.
Perhaps it's because they're somewhat separated by individual baffles... as that would lessen the coupling, and thus nulling. Also, it cancels the even order distortion components, which are the least objectionable subjectively. Could be it makes motor noise off the back of the driver a bit too noticeable.
Servodrive is the only way for sub or bass duty
Interesting stuff! Would there be any downside to making the H frames deeper? It seems like it would naturally lower the roll off which would allow more output at the lowest frequencies.
right - downside is, that resonances will go down too, so you may need to set the crossover frequency lower too.
What are the dimensions of the NX Extremes and the 3 stack sub i.e. height width depth? I could not find that info on the website but may be I missed it. Also, what is the height of the NX Otica's. Many thanks.
Hello, I found your research and explanation very good and understand👍. I 2ant to make open baffle with audax fullrange with L shape as narrow as possible, do I have to make the wings deep? I also want to make an H frame woofer. Does the size mattets and I mean the deprh? Thank you very much. Br Le
Great video series, thanks.
Q1: How come the X Statik doesn't have any side wings?
Q2: Despite the fact that open baffle speakers are easy on the room, they still cannot be placed near walls?
answer for Q2: For the higher frequencies, the reflected sound enables the brain to cancel out resp. to dismiss the complete reflections to at the end meet the sound as if there was no room at all, the speakers seem to disappear completely - the brain, so to say, creates a hearing-feeling like hearing in a nature ambient, reverb-free, although the ears are "hearing"=receiving a mixture of reflected and unreflected, direct radiated sound. The time-delay beetween the direct and reflected sound-waves is important here and in most rooms, a distance of about 4-5 feet e.g 1..1,5 meters away from a corner/both walls will be the optimum to achieve this effect. Siegfried Linkwitz has found out, that a dipole design, that has the same spectrum radiated in front and rear of the speaker, will be the best. Behind the listener, the sound should not be reflected, but mostly absorbed or reflected with a much higher delay (and lower energy/sound-level) than the reflected sound coming from behind the speakers resp. coming from the just mentioned corner. This is, why in smaller rooms, a dipole-design will not function properly, because the brain can not distinguish between the reflected sound from behind the speakers and the direct sound reflected from the walls behind the listener.
Question, in a dual speaker Left and Right, which side is the short wall? I am thinking to the outside with the long wall to the inside.
Hey Danny, thanks for this informative series, it has been very insightful.
I’ve wondered one thing about open baffle bass and there is no one better to explain than you. I understand that traditional box subwoofers are pressure making devices and pressure is at a maximum at room boundaries and a minimum at the centre of the room where a null in bass can typically be measured. Opposingly open baffle subwoofers are velocity making devices, velocity is at a minimum at the room boundaries.
Does open baffle bass have the same null in the centre of the room that box speakers have or does the different room interaction change this dynamic?
Thanks.
The output levels will vary from room to room and depending on where you are in the room, but in general the room will have a more even output except at right angles to the speakers (of coarse). And the output in the center of the room is pretty solid.
Thanks for the reply. I’ve been following you online for a few years and hope to buy and build some of your stuff the new year. Here’s hoping it’s a better year for all of us.
Hello my friend...love your knowledge of speakers...i have been looking for the longest on a strange problem...i bought 2 psa s3612 subwoofer with ipal 18inch made by b&c .i had a pioneer sc55 for 10yrs and on the day i connected the subs i was scared on how powerful these sub sound,then the pioneer went off on me the same month,so i was in line to buy the denonx8500h, now connecting these same subwoofer now cause a popping noise at low frequency these are supposed to go as low as 11hrz,but it pops. I call the manufacturer and they sent me the settings on how to set my subs i did but now i watch movie and feel i am missing that punch...they now i bought this denon on ebay open box deal...manufacturer said that this is normal that the denon is sending a clipped signal causeing the subs to pop..your input if any is appreciated thks.
Hi, what is your opinion and experience of hole in wall baffles which are almost as an infinite baffle? thank you for your talks, most informative.
it is to cancel out what comes from the front with what comes from the rear. If mounted in a Wall, you cannot use this stunning feature, killing standing waves between walls. It is then like a closed box with the resonance frequency of the driver like in free air and may be without reflections in the cabinet.
Are the side openings facing each other or outwards? When used in stereo pair.... obviously
The open sides (short wing) of the NX-Treme faces the outside of the room.
Dannie the tower OB does it give good bass or u need the servo subs to go low with 8 woofers pee side I thought subs will not be needed
The NX-Treme model will play down to mid 40's in many rooms. Some rooms will be mid to high 50's though. It just depends on the room. We recommend our open baffle servo subs with them regardless.
Is it possible to run your open baffle subs without the servo plate amp? I mean, power them with a traditional amp.
of course - why not? Difference is the adjustment of the cornerfrequency, a flat response and a much quicker settlement of the membrane, that will not be damped additionally by the feedback.
When you have multiple heavy drivers with such an agressive control, in a relatively light chassis, dont you get problems with keeping that chassis in place? Feels like it could start rocking about on the floor?
The servo subs are in a very heavy cabinet. It doesn't move.
On your site, you have kits for "sealed servo" subs and "open baffle" subs. However, the amps and drivers seem to be the same for both. What is the difference between the two? Couldn't you also use the "sealed" driver/amp combo in a ported or open baffle configuration? Or am I missing something?
Also, you are using 370 watts for a single driver sealed sub and 370 watts for a double OR triple driver open baffle sub. Doesn't that create a problem with response to spread the wattage over more drivers (e.g. damping, excursion, etc.)?
Thanks for the very informative series!
whats the difference between h and w in terms of measurable sound characteristics
Little to nothing.
8:00 What size inductor do you recommend I try on the lower woofer? Upper and Lower woofers are 12" 4ohm. They are wired in series for an 8ohm load.
use a seperate woofer amplifier - it's cheaper than big coils with low resistance, and a huge capacitor you will need too, expensive as well.
@@ahnenpost5237 That's not what I asked. On top of that it's not cheaper
@@edjackson4389 you have to wire the woofers in parallel to use an inductor (in series) for the lower only.placing an inductor in series with the series wired woofers is going to affect both of them.if you have dual voice coil woofers maybe you rewire them so the driver s can be wired in parallel and not cause too low impedance.hopes this helps.dannys suggestion of choke in one of two parallel connect drivers is also useful to correct for baffle step response on multiple midwoofer and 2,5 way designs.
Hi Danny. In your next video can you have a drawing of a W baffle (from the top)? I am having difficulty visualizing it and where the drivers would fit. Thanks!
It's a W seen from the side! The baffle not beeing a straight line, but one becoming a V, with Top and Bottom parallel, all becomes the W - I hope, I am right here.
I was right, look here: www.gr-research.com/uploads/1/2/6/6/126601004/obsub.pdf
TCS, ABS and ESP in audio ?
Excellent series - Thank tyou for sharing your knowledge!
When an inductor is added to the second woofer, does that cause a slight, frequency dependent phase shift of the second woofer relative to the primary woofer and if so would that result in an audible smearing of the bass notes?
Thanks for the reply to my previous question. New Question: In all the videos I've seen from you so far about upgrading, you never discuss Watts per Channel, RMS. When I moved out of my parents home some 45 years ago and got into listening to music on a "real" stereo system the only specification I thought I understood was Watts RMS. 50 Watts was more than 20 Watts and I assumed from the marketing 50 was better than 20 if your speakers could handle it. All these years that first impression has stuck. Could you discuss in one of your videos the relationship, if any, between Watts and sound quality? Also, The Manufacturers of my speakers (Polk S60) recommend between 20 Watts and 300Watts RMS. It seems counter intuitive to me that 20 Watts could be just as good as 300Watts. Is Marketing just trying to cover all the bases? So, for best sound performance I'm assuming I need a minimum of 100W, but probably 150W to 200W would be better. How wrong am I?
Here you go: ruclips.net/video/YSWrT8Qk7Bc/видео.html
@@dannyrichie9743 Thanks. I actually already watched that video and now I've watched it again. I guess I had to watch it twice to overcome 45 years of wrong thinking. So, whether your Amp puts out 20W's or 300W's is only significant in terms of the size of the room you want to fill with sound? But then again that's why they have Home Theatre systems with 3 pairs of speakers and a center speaker and a subwoofer. For a 2 way system in a normal size living room you don't need a massive amount of power unless you like to make your ears bleed. :) I think I've finally got it. Thanks. This is a great channel. Keep it up.
its nice to see you in your short shorts :D
Hi Danny, what are you thoughts on products from Pure Audio Project and what would you change on them, particularly the Trio 15
Cheers
Well, bless his heart. He's trying.
Have u ever measured trio 15s??? Is an unechoic chamber needed for measurements for ob speakers???
@@iliascharis5668 I had a good sized anechoic chamber at our old location. An anechoic chamber will not be needed for measuring them. I have not measured a pair of them and I don't think they have either.
Why not 15" or 18"?
What are you playing "into the teens"? The Toccata and Fugue in D minor?
Could you tell me once again where I find the plans to build the Servo Subs box?
If you are checking out our servo subs then the plans are at the bottom of the page.
@@dannyrichie9743 I think the "W" frame plans went missing when you removed some of the sub kits.
@@joshua43214 They are still there. gr-research.com/servosubkit4.aspx
@giri kotte Sorry, new website now: www.gr-research.com/store/p22/Servo_Sub_Kit_4.html
@@dannyrichie9743 new website
hmmm, you've got me thinking about controlled servo subs now.
I have this amp on my Salk / Rythmik sub. May I ask what the Rumble Filter does and if I should use it? Thanks!!
Use the rumble filter for when you are playing vinyl and need to block any DC out of the line. It will drop anything below 20Hz.
My question is, if you can only go down to 200Hz on a OB, and you still need two subs to reinforce the sound, whats the point, does they really give so much clarity compared with just using a top class driver such as Seas Excel, and wouldnt you also wish to have an open back tweeter if it makes a difference to high frequencies?
We have open baffle drivers that play flat to 20Hz. Also, our NX Series models have a planar magnetic tweeter that is full open baffle as well.
@@dannyrichie9743 Isn't flatness more a function of front panel design than than the actual driver? a serious question as I am unfamiliar with them.
@@engjds There are several things going on here. Front to back wave separation will control low end roll off. So a wide baffle or a baffle with side wings will extend low end response. Our servo controlled woofer are loaded in an H frame and with the help of the servo control system, they will play flat to 20Hz.
@@dannyrichie9743 20Hz is a bold claim, though I do not doubt you have measured it correct, it must be very sensitive to room placement with all those additional room modes?
@@engjds Are woofers are not at all sensitive to room modes. Our woofers play flat to 20Hz and hit -3db down point in the teens. They also stop on a dime. 🙂
Another excellent video. You've mentioned in other videos that you get a lot of speakers in to upgrade. I don't imagine you are able to do videos on every speaker you've worked on. So I'm asking, Have you worked on the Polk S60? and do you have an upgrade kit for those speakers?
I've been into a handful of the Polks, but not that model.
Love those old-school NBA shorts!
Ha, they are actually almost to my knees when I stand up. They look short in the video though.
Cool stuff! I'm not as familiar with OB subs, but if we were comparing to a sealed enclosure, would your active damping settings correspond to Qtc values of in acoustic suspension alignments? (i.e Q=0.5, 0.7, 1.0) If so, what values would you assign to the low, medium, and high settings of your servo system?
Yes, it is very much like that. I don't have assigned Q settings for each one though. We are just changing the electrical Q.
9:25 wouldn't it be nice if such a setup could in fact play 20Hz at usable sound intensities anywhere farther than 2inches from the dust cover? :}
(the 1/4 wavelength at 20Hz is ~14ft and our hearing is down in sensitivity god knows how many tens of dBs... we can't cheat physics, but they can trick us if we don't understand how things work :} )
Open Baffle loud speakers tend to be very tall. Looks like that is because of the number of drivers. Can they be shorter like the size of you H-Frame servo woofer? What are the trade-offs? I like open baffle speakers, it's just that are so big. Thoughts? Thank you for the video series.
There is a shorter version. See the NX-Otica: gr-research.com/obseries.aspx
@@dannyrichie9743 The link is dead. 404.
Danny,
At What frequency can cross your L shaped 6.5" woofers with the lower end servo subs? I still own the 165X woofer I can't seem to cross lower than 250Hz, is that what you are getting? Thks.
The M165NQ drivers cross at about 160Hz in these NX Series models.
How many of these 12" drivers in open baffle setting do I need to attain 110dB@10Hz and 130dB@20Hz-200Hz?
That all depends on the room size and distance as the doubling of distance represents the loss of 6db. But that level at 10Hz is a real stretch for any woofer. You should be looking at this as a solution: www.rotarywoofer.com/
@@dannyrichie9743 mind blown.
@@dannyrichie9743 If I use 8 drivers each for both left and right channel (16 in total), what frequency response am I looking at from standard 1m measurement point. I intend to do away with any subwoofers and pair these to Line Force when they are available.
@@aassiimmaallii If you are wanting to go with our Line Force model (if I can make them available again) then go with a stack of six of our 12" servo subs per side. And the HX800 amp will handle a stack of six of them.
When are the drivers for NX series coming back in stock ?
They are due here some time in Dec.
I still don't get why on the subs such a short side wing would have an impact on the lowest frequencies, shouldn't its effect be negligible in the very bottom end and be more pronunced around the 100s hz area were it is not really needed?
The space made by the wings load the driver and create pressure in the space on each side. It also further separates the front and rear output further.
See previous video. 😁
@@dannyrichie9743 Thanks very much! I suppose I've been confusing baffle width gain as in baffle step related to wavelength to side power cancellation in open baffles - I was immagining it to start heppen just at the geometrical position of the wavelenght.
Denny, thank you for another great lesson!
What do you think about so-called Ripol subwoofer design? I am planning to build somewhat similar compact design using two 18" proffessional drivers with low Qts & low Fs.
Careful, those often create a large un-braced panel that if not super thick and solid becomes a buzz box. And it loads the drivers pretty hard like a band pass box that is tuned too high. It is not a good idea for pure sound quality.
What’s the difference between your open baffle h frame and the Rythmik gr research sub?
In actual measurement.
You can make any of the servo subs measure any way that you want.
Also can u come up with a plan that I can buy like LX521 cause shipping is so problematic and expensive nowadays. SL made a huge name and following for being open and selling plan. All active supporting miniDSP I don’t mind not getting servo rthmik amps and subs little compromise ok fir me fir ease of goods and support available in my country of various drivers
We ship our servo subs overseas all the time. And you don't have to have any MiniDSP either.
@@dannyrichie9743 that I am aware but I prefer local diy available drivers and plate amps or dsp
Incase of failure shipping back to states and return the costs might as well dump it. Please consider for people like us
@@anandshah71 Our drivers are DIY available. And we do everything we can to keep DSP products out of the signal path for high end applications.
So spatial audio doesn’t use servo subs am I correct but still Ron found it interesting and pleasing
H frame looks kinda wired fir home minister approval
Actually Spatial uses our servo subs in their top level model.
Wow. Do you really have such impressive genetics (especially that hair!) or are you just a thirty-something who follows Senior Games to get a sports fix without dealing with all the aggressive competitive nonsense?
I run in the Senior games.
Oops - curtains all over the place. Trying to kill the reflected part of the radiation pattern - just the opposite of what he should do. Also looks like the big wing is blocking the ipsilateral reflections, making it no longer open baffle. I am not sure what that does to the radiation pattern, and he is not going to tell us, because he is not even aware of radiation pattern.
Hi Danny - quick question. I see you have 3 different models of drivers for Servo Subs on your website. For the life of me, I am not spotting the difference between the three. Can you help point out what is likely right in front of my nose that I am missing?
The models with a FR at the end are designed for free air applications. We have them in 16 and 8 ohm versions so that they can be run in parallel. The 4 ohm woofer is designed for sealed boxes.