Dear Brian, Rythmik Audio,

I wanted to thank you for such a great product and service. I completed the sub over last week and I am so completely thrilled. I was always disappointed with my Paradigm (band-pass?) sub for well over a decade. Either I was not using it or I had it turned so low so I would not be reminded of its presence with puffy thumpy bass bursts. This DS12 unit has really rejuvenated my interest in listening to my setup a lot more. I am amazed at the low bass in music that I had never heard before. Even in pieces with no bass drum electric or acoustic bass it fills in the ambience in the music, breath, body feel. I realize my JMLabs Cobalt 15¡¦s were never that great at bass but I finally feel satisfied like I am hearing a continuum in the music without that feeling that the sub is finally kicking in at the low end. I¡¦m loving the fullness at lower to moderate volumes that I never felt before.

The unit shipped so fast, you provided me with prompt e-mail replies on my enclosure questions. You provide great service and great product.

Best Regards,

Adam S.

Newark CA

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The complete blog is in http://www.btinternet.com/~richard.d.miles/DS12s/DS12s.html

Brian,

My DS12 kit arrived yesterday. I just wanted to thank you for making such high quality components available for DIY.

I really enjoyed building the enclosure for my sub. It wasn't particularly time consuming or difficult following our plans, was inexpensive and I am enormously pleased with the end result.

Most importantly, the performance of the sub has exceeded my expectations. The integration with my front speakers is perfect - I cannot tell the difference between the sub being there or not, apart from the obvious increase in low frequency energy when present in the source material. I previously thought that my Mission E83 fronts were full-range and I've measured their response down to 36Hz in room. Up to this point I've always listened to music in stereo without a sub. With the sub crossed over at 80Hz the improvement in the depth and clarity of the bass in startling, the stereo image is clearer and the extension of the sub is adding a lot of atmosphere to the sound. My Audiolab (ex-TAG McLaren Audio) processor and power amp are fast paced, I was amazed how different all my music sounded when I got it but the sub is not being left behind at all - quite the opposite in fact!

I've run some sweeps on the sub and the 3dB point is 12.5Hz, which is amazing considering the physical size of the driver and the 2 cu ft enclosure. For me this is the unique selling point of your product. Other subs I considered didn't have anything like this level of extension, and/or were physically much larger, which ruled them out of the running with my domestic situation. It also seems that you aren't trading anything in terms of sound pressure levels either and I can honestly say that I don't need any more SPL in my 16'x16'x9' room. I've never felt bass like it.

I've attached a few pictures of my finished sub. Please feel free to use them as you wish. There are many more on a build website I put together: http://www.btinternet.com/~richard.d.miles/DS12s/DS12s.html which you can use as you wish as well.

Best Regards
Richard Miles

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Brian,

just wanted to follow up to let you know that I finally finished my DS12 and it sounds absolutely amazing. It is such an improvement over my Monitor Audio FB210 I can't even believe it, and that sub cost $1000 new! The DS12 hits low bass notes with such authority and clarity that it has actually steered me towards music with more bass, just so I can listen to it and be amazed. I've given a couple of endorsements for Rythmik Audio on hometheaterforum.com, as applicable, and I will continue to do so whenever people want to embark on a DIY sub. Also your company's customer service was very helpful. I thank you for a good experience. Keep up the good work!

Sincerely,

Matt

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Brian,

I received the speaker and plate amp. While I was waiting for them to arrive, I built a baltic birch plywood 2 ft3 sealed enclosure from the plan included on your website. The only change I made was to use Lee Valley chrome cabinet legs. A few coats of high gloss paint to match, a piece of glass on top and I have a nice end table. So it blends in and nicely augments the low end dimension of my music system. I definitely feel like I received an excellent product, a great deal.

Thank you,

Cam

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The blog is in http://projectcube2007.blogspot.com/

From the Blog… I don't own any professional audio testing equipment but I wish I did: I'd LOVE to see this baby's numbers - her maiden voyage saw my 3 tests I put all my audio components through - Diva Plavalaguna from The Fifth Element (if you test speakers, you know the scene i mean), Massive Attack's Angel, and Thomas Bangalter's Rectum.

I did a side by side with 3 configurations from the T773 - the cross set to 200hz, 80hz, and 40hz with the fronts and rears set to small in order to hear the bass channeling. The only real competition to the sub however is the fronts so those were the ones i really concentrated on.

I should also point out that the Rythmik Audio AS370 12dB/Octave Amplifier I purchased has customizable settings for a low pass filter and damping factor - VERY handy when fighting cone excursion and clipping. Through my tests i set my amplifier on the DS-15 to a 14hz low pass filter and a high damping factor. The low pass filter acts exactly how one would expect it to work and the damping factor steepens the curve of filtration on the low end. While I would normally want something less harsh, on a 15" bass driver you're going to lose quality quicker than on a 4" mid range.

200hz Cross - Stereo - Playing Massive Attack's Angel provides a good indication of the speakers power handling/filtering/as well as the CD players discrete processing (the track features simultaneous, sharp, tweeter and woofer signal), since none of that is on trial here however, i concentrated on the balance between the sub and full range fronts - I wanted to see how the woofer handled the low end next to the high and mid range that i'm so used to hearing on the Studio-100s.
Though i love my fronts i never realized they rolled off like that - haha. The DS-15 handled itself beautifully, no signs cone excursion. The driver appeared to be a little over driven on the part of the crossover freq, so i tuned it down.

80hz Cross - Stereo - My fronts tend to lose a lil' bit of their bite at freqs around 40hz. The 80hz mark saw everything i dreamed of in a sub - The bass was smooth and clean and after adjusting the phase on the amplifier one couldn't tell the low end on the fronts from the bass. The mid and high end popped over the sub and sounded excellent - complete coverage of the spectrum.

40hz Cross - Stereo - This is really where i want to keep the sub, using the fronts (while still set to 'small' on the T773) full range and keeping the sub for the freqs unheard on the fronts. Where as i expected separation issues and a distorted 40 - 200hz range with the cross tuned so low, i actually received a velvety smooth low end from music that i never knew had that kind of bass. The music sounded rounder, complete, and more dynamic - listening to the full range on the fronts still sounds GREAT but the 'real kick you in the stomach' bass from the DS-15 went perfectly with it. I gotta admit, I'm a puritan and want to stay off the sub for CD playback but I don't think I'm going to be able to...

Thanks for making a great kit!! I had a blast building it and have been nothing but Blown away by the quality…

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Here are some pictures of the box that took me over a month to build. It looks just like an end table and fools everybody. That is until I turn on the music. I have owned to other subs. One was a 10 inch and the
other was a 15 inch . Both were made by Defintive tech. This sub is so very tight and firm. I would of never thought that I would be able to own a sub that hits hard and very clean and I will never ever feel like I am listening to a bass drum from a marching band. The bass is so real you feel like you are sitting right next to the real thing. Thanks so much for you help answering my questions on the phone.

Scott from Chandler, AZ

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As much as I like the price to performance ratio of SVS subs, I belive you made a good choice over the SB12's. I was lucky enough to listen to both the SB12 and the 12" Rythmik kit in the same room, (aprox 1800ft³ room closed) & the choice was rather easy to make in both our opinons. The owner sold his SB12 about a month later. Certainly not saying this is the decision everyone whould make if they had both subs in their room at the same time & was able to do side by side measuring and listening comparisions for a good period of time.

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I have been a bass nut for many years and as a result have gone through a variety of subs looking for the perfect sub with music and something that would still work in an HT application. After trying various subs from Paradigm, REL, SVS, Axiom, HSU, Velodyne and a host of others I was still not completely happy. The Velodyne DD-18 was hands down the best of the bunch but I had a hard time justifying it’s cost as it still wasn’t exactly what I wanted with music. A friend recommended I contact Brian from Rythmik and after corresponding with Brian for a week or so I took the plunge based on his advice and ordered two DS-12 kits and I’m glad I did. The DS-12 is the fastest and tightest sub I have owned to date. A musical bass note sounds like a note not just a boom or a deep rumble. With two of them working together the results are jaw dropping. The pair are as good as the Velodyne DD-18 I had and cost considerably less. If you want a sub (or subs) that can actually play a musical bass note and will still provide some solid rumble for HT, look no further then Rythmik Audio.

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After building a nice strong sealed box (1 1/2" thick mdf, internally crossbraced) and installing your DS12 woofer and amp set, I have been stunned at the output and quality of the sound. Thank you very much for putting out such a great product at such a good price.

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I spent some more time with Audyssey last night and it's really growing on me. I also spent an hour or so listening in 2 channel with only the Rythmiks active and I have to say they lived up to my expectations and then some.

In the stereo configuration that I have them in they actually seem to image better than the IB alone did and they are just as articulate. This is not a fair comparison but other than the IB, the only other decent sub that I owned was the Paradigm Seismic 12 and it was not in a good room or EQ'd and I recall it seemed to "shake the house" more than the Rythmiks do, but I never got it to sound as good with music as this set up does.

The Audyssey is certainly doing its' job and the Rythmiks are definitely up to the task.

..... These are very articulate subs. Super tight, no bloat and very "natural" sounding which is really noticable with acoustic bass, piano and the lower register of male voices.

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Well, the open baffle speakers that I’m going to build will need to be crossed over at 80 Hz, and I thought that dual 12”s in bass bins under each speaker would be a better set-up. Also, I have some room modes, and I’m hoping that two subs in different locations will help with this.

I thought that you might like to read the impressions from the person that bought my DS15. He is using it (for now) for sub-30 Hz content with his open baffle speakers. Line array of 15” bass drivers, 15” coaxial midrange, and a horn loaded compression tweeter. He likes your sub! I also included a pic with my raw DS15 next to his speakers……………………….

"Got the "little" sub up and running early this morning. This is a really nice subwoofer system. As articulate and clean as any "big" sub system I've heard. When replacing the big array setup it gives up a little resolution through the upper end of the curve, but goes down deeper for sure. Definition down low is scary. In a normal listening room a pair could replace the array's in a smaller setup and sound very, very nice. I gave them a workout with Pomp & Pipes, a pipe organ sampler with deeeeeep material. The excursion can get pretty crazy,pretty fast, but the servo kept things in check, where I think an open loop system would have given it up. Augmenting the woofer array is a pretty wild setup. You hate to cut the array off any, because it is so capable at that range. Running the Rythmik crossover as low as possible is still a little high, but you can add a just a little pop below 25Hz. A single works, two would be stellar. You are going to really like the dual 12" setup. When going for a low tuned, heavy coned driver I don't think you could pull off a seamless transition to an open baffle system without the servo loop. You normally see an open baffle system augmented by a fairly light coned driver, because of their inherent transient ability. The characteristics of a open baffle sound, lean toward a very "fast" presentation, which to me means the driver can stop and start very quickly. This makes the speaker very clean and articulate. The Rythmic sub possesses the same traits, so you are heading in the right direction with your setup. I've been thinking about your configuration and I think I'd build it with the side firing drivers. I'd do a mirrored pair and by swapping speakers side to side, you'd have different setup options. Also because of the length of the low frequency soundwaves, the radiation pattern resembles a rock dropped into water when viewed from the top. The wave propagation is evenly distributed at the subwoofer frequencies. Got the new kits ordered yet?"

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I am just about done with my Rythmik 15" and throught I would send you a picture. I still have to finish the grill but other than that it is done and sounds fantastic. I also have a Paradigm Servo 15 V1 sub which you can see sitting next to the DS15 in one of the pics. From the standpoint of excursion, the rythmik has about 3-4 mm more excursion and similar power (370 vs 400 watts). The paradigm is one of the best sounding and most musical subs I have ever heard but is somewhat limited in output because of the very aggressive limiter they put in this version. From an output perspective the Rythmik plays at least 3-5 db louder. I haven't really explored the limits of Rythmik yet but hope to in the next few days. The Rythmik sounds slightly different but is every bit as tight and refined as the Paradigm...and of course 1/4 the price (not counting the cabinet)

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In my room i've had a total of 4 subwoofers. 3 were sealed DIY projects, and the 4th is a small Velodyne dps-10. Of all 3 of my sealed DIY projects (Avalanche 15, Tumult 15d2, Rythmik servo ds12tc) the Rythmik is the indisputable sound quality champ.

IDW, you will be pleasantly surprised with the capabilities of the Rythmik kit.

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“The sub sounds great, goes DEEP like my PB12/Plus2 did, but is much more defined and musical.“

I just wanted to let you know that the sub has really opened up since our last correspondence. Actually, one afternoon of fairly robust music made the difference. I now have plenty of headroom at -5 on the sub pre-out. The sub sounds great, goes DEEP like my PB12/Plus2 did, but is much more defined and musical. It doesn't have the SPL of the twin SVS, but it has more than enough for me. And this while I haven't even started to eq it. Thanks for your help, and thanks for making servo technology available to us DIYers. (....You're helping people get very high quality bass in their homes for a price that they can justify (get past the wife!)).

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“I put on a piece of music, sat in my listening position, and WOW! It was a revelation. My first impression was "is the sub on?," because the imaging was so incredibly improved over the prior sub.“

“When I first decided that I wanted to take the plunge into high end audio, I read reviews, but being always a skeptic (and realizing that everyone has different preferences) I went and auditioned as well, and fell in love with the sound of Martin Logans. I bought a used pair of Quest Zs from a friend who was buying the new $10k summits, and was instantly enthralled. For Jazz and vocals, I had heard nothing like them. A wonderful, detailed, ethereal sound that drew me into the music. As I played other types of music, however, rock/rap/pop,I percieved a lacking in the bass/midbass region being covered by the woofer. I decided to try to integrate a midbass array and a sub, in order to fill this perceived deficiency. Being on a budget, I decided to make the array myself. Having completed this, a friend loaned me a $500 12" sub he had lying around. The brand will go unmentioned, but it was of the standard commercial variety for that price point, and ported. I integrated the sub with the system and balanced the level to match the rest of the system...but it just sounded...wrong. Boomy, bloated, one note bass, it just didn't mate at all with the panels. I was hoping it was the sub, but was somewhat fearful that the line array I had built could be to blame as well.

Having read for over a year about the success people have had with the rythmik subs in music systems, but always skeptical. I decided to build my own box, and give the kit a try. I was enthusiastic, but not expecting to be overwhelmed. I made the cabinet out of double thick 3/4" mdf, with a triple thick baffle, and then veneered it (first time veneering!) with cherry. I then stained it and coated it with polyurethane...it turned out pretty nicely I think. When the kit (the DS12-CV Servo kit) arrived a couple of days later, I took a moment to admire the build quality and amp...and then assembled the sub. I placed it next to my array (not ideal positioning perhaps...but I just wanted to hear it!) and attached it, with an 80Hz crossover point, set to the 14HZ/High Dampening settings. I put on a piece of music, sat in my listening position, and WOW! It was a revelation. My first impression was "is the sub on?," because the imaging was so incredibly improved over the prior sub. I looked over at the sub, and saw the cone moving...but there was no indication of any sound coming from it whatsoever. It matched beautifully with the soundstaging and imaging of the panels (which is quite impressive.) Equally as well, it kept up perfectly with the finesse and detail from the panels, with none of the delayed resonance that I've heard from lesser subs in the past. I had a giant grin across my face, as I popped in CD after CD of ALL genres (even the ones I had said "well, martin logans just aren't good at playing this") and was amazed at the result. I had achieved what I had set out to, and much much more, and the key piece of that was the rythmik sub. My friend with the Summits came over to listen as well, and was equally as floored. The improvements were monumental. I've heard the Martin Logan subs, and the depth and descent are both great subs (that use servo technology as well) but I would be lying if I said that I thought they sounded any better than my rythmik...and they are at a much higher price point. I couldn't be happier with how this turned out, and I can very honestly say that I think my stereo now equals or bests many others that cost much much more. The upgrade bug that bites so often in this hobby is gone from me (unless it is to add another rythmik!) and I am enjoying my music collection more than ever!

On movies, at first, I was a little bit disappointed, because I was used to hearing big one note bass reverberate during a big bass hit. The more I listened, however, the more and more I appreciated what the sub was doing. It made the entire movie watching experience more engaging...as things just sounded more realistic. It's no longer a matter of listening to a movie to hear "oh listen to the sub on this part" as can be done with other "big" subs. It's WOW, this whole movie just sounds great. I've been spending a lot more time movie watching lately as well! "Chronicles of Riddick," one of my favorite action movies, has many places that sound much much better now, especially during parts where energy weapons are being fired, as there's an awesome sensation that I've never felt before, and I've watched this movie many times (including in the theater). The only way i could be happier with the sub is if I had 2 (which I will at some point in the future-the box is already built! “

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Hi Brian,

Thanks for the note. See the attached photo's. I am very satisfied with the performance of your servo sub. It quite easily beat anything I have tried before. It easily reaches 20hz. in my room and with the Velodyne SMS-1 I can achieve a frequency response with-in less than +/- 3db from 20 to 80hz. I have never heard bass response this tight and tuneful before, you have a great product. I will probably be ordering another sub after the first of the year to re-do the upstairs home theater system. The room size is the same as down stairs but with a very high cathedral ceiling so I am thinking I will need the 15" driver at a minimum or (2) of the 12" drivers. Have a great Christmas.

Regards

Dave

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I love my stereo pair of Rythmik DS12 subs.In the past I have built several ported subs but was never happy with the boominess of them. No matter how hard I tried to tune and place them properly. After listening to dozens of commercial subs at shops and friends houses, the Rythmik may be the most musical subs I have ever heard. Very fast, clean and tight, 118 lbs. each , the grills were originally 1.5" from the baffle and at higher volume the surround would hit them . So they were moved to be 2.25" from the baffle. I don't have 1000's of dollars to spend on subs ....but with these I feel like I have 1000's of dollars worth of subs. BTW, Brian Ding was a pleasure to deal with. He answered all of my emails promptly, shipping was fast, and they were packaged very well.

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“regardless of whether it's rock, classical, country or anything else I throw at the signal.... it astounds me!“

Just wanted to drop a quick note and tell you how great this combo kit sounds! I finally got to really begin to give the sub a real workout @ 100+ db and I'm totally amazed by the clarity and definition of the notes I'm hearing. With nearly 7000 songs to play, It's impossible to listen to them all but regardless of whether it's rock, classical, country or anything else I throw at the signal.... it astounds me! I can't thank you enough for putting this product on the market!!

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Rythmik/Velodyne 12" servo sub comparision

Measurements

Listening

Music notes

Movie Notes

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“The sound of both subs are incredible and you will be hard pressed to find anything comparable for less than $3000.00. Considering I spent about an average of $800 each to build them, I consider them to be a true bargain.“

“I had the chance to compare the new servo kit, with the aluminum driver, to the old kit over the weekend.

Both subwoofer enclosures are identical except for the choice of wood for the legs and I moved the position of the amp down 3/4" of an inch on the second sub to make it easier to mount the amp between the "legs". The cabinets are made from 1" HDF with four internal cross braces. The top and bottom is reinforced with 3/4" birch plywood. With the solid wood accent piece this makes the total thickness of the top 2 1/8" thick! The sub on the left is Sapeli and Santos Rosewood. The sub on the right is Sapeli and Quilted Birdseye Maple. The inside of the subs are lined with acoustic batting. The amplifier is inset flush and the woofer is inset 3/8". The total weight if the finished sub is about 120 lbs. They are finished with 12 coats of semi-gloss poly-acrylic (sanded between each coat, of course). The subs sit on 1 3/8" heavy duty spikes.

Now as far as the difference in sound between the old and new kits goes, they are very similar. I used test tones from 250 to 20 Hz to test frequency response. The old driver is a little bit more efficient (ie - a little bit more output). The new driver is a little bit more controlled at 20 Hz. I don't think that anybody will be able to tell the difference between the two subs sound unless they are placed side by side. However, there is a difference of about 2db in efficiency between the two. I prefer the sound of the old kit for movies/home Theater and the new kit for music. Of course, I'm really splitting hairs here. The sound of both subs are incredible and you will be hard pressed to find anything comparable for less than $3000.00. Considering I spent about an average of $800 each to build them, I consider them to be a true bargain.

Thanks again.”

Reply: The efficiency that Rolf referred to was more on sensitivity than the efficiency. We have since increased the gain of the preamp stage so that the sensitivity in the new kits matches the previous version of kits. Also we have changed the low damping setting to Q=1.3 (from 0.9 previously) to provide a wider range of damping control.

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"I do not believe I have ever had this level of bass definition before. No boom, no overhang, just well defined musical notes and harmonics."

“I have finally finished the cabinet for the DS12-sealed, and I just have to say WOW. Over the last several years I have been searching for a sub that would complement my 2 channel set up. In that time I have purchased several commercial subs (HSU, Paradigm, Yamaha etc.) and built two others. The first was a Dayton Titanic Mk III that I put in a 2.2 cu ft cabinet, and the second was a Dayton DVC in a 2.5 cu ft sonotube. Both of these subs performed quite well, but I felt I could do better.

At about this time I heard of your company and decided to give you a try. To make a long story short, I do not believe I have ever had this level of bass definition before. No boom, no overhang, just well defined musical notes and harmonics. Once again thank you for a fantastic product and great customer service.

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"... the subwoofer is truly excellent, tactile and clean with no blurring of the bass line."

“Just a note and a few pics - the subwoofer is truly excellent, tactile and clean with no blurring of the bass line. The shock wave from the cannon shots in Telarc's 1812 overture broke two windows and killed a deer in the meadow outside! (Just kidding but the sound was awesome!)

Closed box: walls are all 1.5" composite of MDF and Red Oak Plywood. Legs are Brazilian red wood as are the top edges. There is a single internal brace placed horizontally at about mid height. Weight approximately 100lbs - no internal stuffing or wall treatment!

Thanks for producing a great product.”

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