Rythmik subwoofers?

Hi all.
I have been looking for a small sealed subwoofer to add to my Harbeth P3ESR in a 20x15 size room. In my price range of about 5 to 6 hundred dollars and the usual suspects SVS,HSU,etc,etc. I came across this Rythmik sub. Anyone familiar with this brand. It is only sold direct. This is the model I have been looking at!

Musical sub on a budget

Looking for an affordable musical that can be also used for moderate home theatre use? L12 uses our proprietary servo design to gain low frequency clarity and articulation. For home theatre use, L12 has a HT playback mode with rumble filter to limit less audible sub-sonic contents. While many of our competitors limit their best technology (such as servo) to their top level models, we wanted to make Direct Servo affordable, so we've held nothing back. As a result, you get the tight and music bass you wouldn't normally expect from a subwoofer at this price range. L12 is likely the least expensive servo subwoofer on the market.

Direct Servo Technology

You may have heard about other servo subwoofers which are generally well regarded for their accuracy. It is a well established technology, most often based around an accelerometer which measures cone movement. Our Direct Servo technology has significant advantages over other servo technologies. We use a sensing servo coil which acts like a microphone which compares the original signal to what the subwoofer is actually reproducing. The signal is then corrected instantly to compensate for any differences. Once you understand the concept, you may wonder like we do why anyone would make a subwoofer any other way.

Some of the benefits of Direct Servo include:

  • Reduction of the effects of thermal compression are eliminated under normal operation
  • Higher efficiency allowing output which would normally require a more powerful amplifier
  • Deep bass extension can be achieved using a low mass driver with superior transient response
  • Mechanical and thermal memory effects are reduced, further improving transient response
  • Much greater damping control over the cone
  • Dramatic reduction of the re-radiation of bass from inside the box

Read more about Direct Servo in our technology section.

View animation demonstrating how Direct Servo works 

This budget level sub delivers the same articulate and tuneful bass that our subs are known for and yet provides enough HT bass thanks to its sealed design. The combination of servo and a sealed enclosure is what makes this sub deliver on both quality and quantity in bass.

The quickguide for L12 can be found here. This model has a 120-240v switchable power. Price includes shipping to 48 US continental states only. Shipping to other region or country should inquire us for actual cost. Introductory discount is $30 for black oak finish, shown in the shopping cart. Shipping and duty to Canada is an additional $90.

For overseas customer, L12 is small enough to ship via postal service. Please use contact page for a postal shipping quote.

 DescriptionPrice  L12 sealed sub black oak with 300WRMS Ucd Hypex amp$569 L12 sealed sub black matte with 300WRMS Ucd Hypex amp (back order)$569 Shipping and duty of L12 to Canada$90 Postal Parcel shipping to Alaska$120 Standard Postal shipping to Hawaii$60 Postal air priority shipping to Hawaii$85

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I had a pair of f15 hp with my maggie 1.6s very musical and fast, i would buy them again.  Go for it you will not regret it. 
Rythmik are excellent subs, I use two F-12G in my two channel rig. So far very pleased with there performance.
Rythmic is overpriced had the F15 and another a 12 inch in a past life.. The best sub for music is the JBL LSR310s, buy them used and you can get it for around $250. The pro JBL sub got crazy resolution even in the deep bass.
I just had a conversation with Fritz, of Fritz speakers, looking for information on his floor standing models. After explaining my system, he recommended the Rythmic sub.A great guy to talk to. I call trying to buy his speakers and he is trying to tell me to try a sub woofer with my monitors and then goes on in detail on why the Rythmic is so good, wich is what that article says. Good luck, and if you do purchase one, I would love to hear your thoughts.
I too have spoken with Fritz a couple of times. Met him at the first California Audio Show. He's one of the most straightforward folks you'll meet in this hobby ... knowledgeable, generous, and friendly. Dave Fabrikant of Ascend Acoustics partners with Rythmik subs, selling them with his direct-to-consumer line. I also dealt with him via phone and email when I got a pair of his speakers quite a few years ago (they're still in service at my younger daughter's home). At the time of my original purchase, Dave favored (partnered) with Hsu Research; and that's what I got. BTW, once it was dialed in, the Hsu was quite good in combo with the Ascends.

Jim Salk (Salk Sound) is using the same Rythmik Servo technology in his top of the line Exotica 3 floor standers. He felt that those hypex amps powered his speakers in a way that provided the best in fast, deep bass ... going down to 20hz. Check out some of the reviews and comments over on audio circle. Based on that, and checking some of the same info noted by Yogiboy, I plan to get the F12 as my next purchase.

Finally, if you go with Ascend - since they distribute for Rythmik - there's a 45-day satisfaction guarantee, which is 15 more days than they used to offer. I have firsthand experience with that, taking delivery of a pair of the low-end, entry-level speaker line for a bedroom system I was putting together. Following my audition (about 3 weeks, if I remember), Dave took them back and gave me a full no-hassle refund. None of that 10-20% "restocking fee" BS!

Good luck and Happy Listening

I have an SVS SB2000. Although I have a dedicated listening room I’ve only yet used it in my HT setup. I can tell you that my room is a bit larger than yours, and on movies with the relevant bass this thing literally shakes my whole first floor seemingly without strain. On paper the L12 looks like it could be as potent, although its amp is 300 Watts vs. 500 for the SB2000. The L12 counters with greater hookup flexibility and more sound adjustments and is $140 cheaper. The L12 looks like a great sub and hard to see how you’d be disappointed, especially given the consistently positive feedback Rythmik subs get here on A’gon. I will say that SVS offers free shipping both ways during the 45-day trial period, so literally no risk to try. Really can’t see you being unhappy either way.

Last thought is that if a used Vandersteen 2Wq came up for sale in your price range that would probably be my first choice.  Hope this helps and best of luck. 

Another professional user of Rythmik subs is Sterling Sound, the great audiophile mastering house in NYC. They have three pair of F15's in their monitoring systems.

Planar and mini-monitor speaker lovers have long had to accept the rolled-off bottom end of their speakers, and the difficulty in successfully adding subs to them. Maggies are one such speaker of course, and the bass they do have is excellent in quality. Subs good enough to blend seamlessly with them are few, and Rythmik is one such sub. The number of Maggie and mini-monitor users happy with the mating of their speakers and Rythmik's has been slowly growing, all by word-of-mouth.

Subs have traditionally been considered almost impossible to be added to the highest-quality speakers for music reproduction, but there are now a handful, many listed by the above posters. I have had a few myself, from the legendary KEF B-139 woofer (used by Dave Wilson in his WAMM model in the 70's-80's) in a folded transmission line enclosure, HSU sonotube 10", and Infinity RS-1b servo-feedback towers with six 8" woofers each. I now own pairs of both Rythmik F15HP's, and the very, very special Rythmik/GR Research OB/Dipole subs (a pair of 12" woofers mounted in Open Baffle H-frames)---producers of the highest quality bass I have yet to hear, regardless of price.

By the way, don't be "fooled" by the fact that the Rythmik L12 has an "only" 300 watt amp versus the SVS SB2000's 500 watts. Just as with any speaker, the SPL produced by a sub is determined not just by the wattage of the amp, but also by the sensitivity/efficiency of the driver(s) the amp is powering. Rythmik's woofers, due in part to their relatively low (for a woofer) mass, are more sensitive than the woofers used in most other subs. Remember, if the Rythmik L12's woofer is only 3dB more sensitive than that used in the SVS SB2000's, the Rythmik will actually have effectively more power than the SVS. I don't know that such is the case, I am just making the theoretical argument.

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+1 rythmic.  I use 2f15s, would defiantly purchase again. I had 1 svs pb12 plus, rythmiks are much better!

I own a Rythmik F12SE and use it for a small HT set-up. I also have Salk Exotica 3's with the Rythmik woofers and amps x 4 (300 watts each). Incredible bass.

Have owned the older SVS models and they were well made. Seaton Sound is also worth checking out for subs. Super fast.
I never hear about which crossovers people use to integrate their subs. The usual 80 hz.24db per octave crossover surely is not valid for all rooms and sub placements.  What if I need a steeper rolloff, or a lower crossover frequency and want to high pass filter my mains at a frequency i select. Do these details make a difference? I want to get a pair of rythmik F12 to pair w my maggie 3.7 but obviously am interested in a crossover. Which one to get? I already have a preamp, amps , and sources.

topjetboy---The Rythmik F12 plate amp includes lots of controls (most importantly a phase control providing not a couple of settings, but a continuously variable range of 0-180 degrees, to allow time-alignment of speaker and sub electronically, without having to move the sub physically), including of course a low-pass filter for the sub itself, with a range of 40Hz to 120Hz, and 2nd and 4th order slopes---12dB and 24dB an octave respectively. The standard A370 version of the plate amp also provides high-pass filtering for the main speakers.

If you want a reasonably-priced outboard x/o that provides more flexibility, and perhaps better (more transparent) sound, Nelson Pass’ First Watt B4 is one such x/o. It provides x/o frequencies in 25Hz increments from 25Hz to 3200Hz, and 1st/2nd/3rd/4th order slopes---6dB/12dB/18dB/24dB per octave. Now THAT’S flexibility! And, it is built with discrete parts---no opamps or ic’s. The B4 retails for $1500, but I believe Reno Hi-Fi sells it for about a grand.

I had a Velodyne Spl 1200, then a JL audio fathom F110, and now a pair of 12" Salk/Rythmik subs and they are my favorite.  I liked the Fathom too but the 10" lost steam for me.  A pair of Fathom 13" would have been better for me, but I'm quite happy with the my Rythmiks.  

Jim Salk made me a custom stained burled maple finish that is gorgeous!  They're the nicest looking subs I've ever seen.  One of them uses the GR Research paper cone drivers and the other one uses Rythmik's aluminum driver.  I ordered them this way so I could see which driver I liked best in my system- then switch out the driver.  I've been listening for a month now and I really enjoy both.  The GR driver sounds soo natural and organic, plus it integrates so well you don't even know it's on until you turn it off.  

The aluminum driver has different strengths.  It plays louder when they are both set to the same volume and it digs down lower so I hear a deeper octave of bass compared to the GR!  It's got more authority and umph too, which I love.  

So for now, I'm getting the best of both worlds by keeping them both.  If I were forced to choose one, I'd go with a pair of the Rythmik's aluminum drivers.  I also have to say that I'm a bass-aholic.  To clarify, I don't like exaggerated or a heavy bass sound.  I like bass that is naturally and cleanly produced.  I don't like to miss out on bass information that is in the music, plus the subs produce ambient information that makes music sound more realistic.
Great report on the two 12" Rythmik/GR Research drivers, erndog. Both used the same basket, frame, motor, etc., the material of the cone being the only difference between the two. Rythmiks Brian Ding feels his aluminum cones greater stiffness affords less cone breakup at higher volume, while GR Researchs Danny Richie feels his paper cones lesser mass affords greater low-level resolution, the paper material also providing a more natural, organic timbre to bass instruments than does aluminum. They both agree that for music at less-than-extreme SPL, the paper cone is the way to go. Most Rythmik owners use their subs in home theater systems (or multi-media ones), GR customers in music only systems.
I've had a pair of 12" Rythmik son bs in my main system for +/- 10 years now.  These are very good subwoofers.  There may be many other very good choices out there, but the Rythmiks are certainly among them.
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Yup yogiboy, it sure will. But it will provide only one slope---2nd order, 12dB/octave. And only two x/o frequencies, one at each switch position. You’ll need to specify those frequencies when you order the x/o from HSU. I doubt you can beat it for anywhere close to a hundred bucks!

If a 1st order, 6dB/octave slope will work for you, the best filter is a single capacitor installed on the input jacks of the power amp for your main speakers---a passive x/o. The value of the capacitor will determine the corner frequency, the amps input impedance also being a factor in the equation. The formula for determining the capacitor value to achieve the desired x/o frequency can be found via a Google search. This way of filtering eliminates the need for an extra pair of interconnects---from the x/o to the amp. Plus you’ll avoid any degradation of the signal an active x/o may impart.

Bought a Rythmik L12 a couple of months ago ... it failed within 2 weeks and I sent it back for a full refund. Cheap, Chinese crap, IMHO. You get what you pay for. Ultimately bought a JL e110 (triple the price of the L12, I know), BUT it’s built like a tank, sounds way better and articulate than the L12, and is made in the USA. Just my $0.02.

Fair enough rlb. On the other hand, there are a fair number of happy Rythmik owners, including the audiophile mastering house Sterling Sound, who have three pair of F15's in their monitoring systems. All companies have a percentage of product failures, Rythmik's percentage being lower than many who offer much more expensive ones.

The L12 is a Rythmik budget model, not their top-o-the-line 12", the F12 (with aluminum-cone woofer) and F12G (paper-cone). That model is more competitive with the e110. If you can afford the three-times-as-expensive JL e110, it's curious you would buy the L12 instead of the F12.

I'm with ya on the made in the U.S.A., but Rythmik's designer/owner Brian Ding is Chinese, and has a great relationship with his parts suppliers. If made entirely in the U.S.A., Rythmik subs might retail for twice as much as they do.

I really like my dual Rythmik F12G with Magnepan 3.7i and did directly compare them to the SVS SB13 Ultra.  The SVS wasn't better imho.
@bdp24 ... just because the L12 is a budget model, doesn’t mean that it should be less reliable than the F12. Initially, I thought the L12 would be a good deal; I didn’t go for F12 because I didn’t need its bells and whistles. After the L12 failed, I decided to follow the advice of my Mother from years ago ... "if you buy the best, you’ll never be sorry." So, I researched other subs and arrived at the e110 based on its build, quality, reputation, and USA manufacture. Rythmik has a reputation for good bang for the buck. JLA has a reputation for excellent product, but at a cost. Having compared both, I’m confident I made the right decision.

1 is a pretty small sample size to determine reliability issues with a company. I bought an F12SE used about 3 years ago and have never had so much as a hiccup from it. It has been a reliable and excellent performer for me. Just my 2 cents worth. 

rlb61, pointing out that the L12 is a Rythmik budget model was not done to make the case for it therefore of course being less reliable than the F12 (or JL e110, or any other sub), but rather because you made the case for the JL e110 being a higher performer than the L12. My point was that if it was the level of performance the JL provides you desired, and you could afford the e110, why then when you got yourself a Rythmik wasn't it an F12 instead of the budget model L12? The difference between the two is not "bells and whistles"; the extra controls on the F12 are not decoration, they provide valuable performance benefits. The F12's amplifier is a higher performance and wattage design than the one installed in the L12. And the F12's driver (both aluminum and paper cone versions) is a superior design and performance unit than the one used in the L12.

A comparison between the performance of the Rythmik F12 and the JL Audio e110 is a valid one, between the L12 and e110 less so. Reliability is a separate issue.

@bdp24  ... At the time, I bought the L12 because the difference between it and the F12 seemed insignificant ... the F12 has a 400 watt amp vs the 300 watt of the L12, thereby providing an additional 1dB of sound for $400 more. Plus, I didn't think I needed the additional accoutrements of the F12. Just because I can afford more doesn't mean I have to spend more if the price to performance ratio is close. Ultimately, I chose to max out the budget for the e110.

Granted, electronics can fail, as evidenced by the L12 I had purchased. However, it doesn't leave one with a good feeling when it happens within 2 weeks of purchase and, for me, it soured the desire to purchase another Rythmik product. I'm happy for those who dig their Rythmik, but it's just not my cup of tea. Moreover, after having compared the sound quality between the L12 and the e110, I think the e110 is worth the extra dough.
I know how you feel, having a new component crap out so soon. A long time ago I bought my first ARC pre-amp and power amps, and the first time I turned them on the pre-amp made a popping sound, and I smelled something burning. My dealer (Walter Davies, the guy who went on to invent and market the great Last Record Preservative) repaired it, replacing a blown resistor. My introduction to ARC, unfortunately. Part failures dogs all manufactures, it’s just a drag when it happens to your new purchase, and it leaves a bad taste in your mouth.
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I have both a 12 and a 15 Rhythmik. First, I got the 12 and it was almost new so I just said OK, I’ll take that for for that price. Well, I was surprised when I heard how well it handled the lower 20 hz s. Not all the way down to 20 on the Rhythmik 12, though, but down to 23 hz - 24 hz with fluidity.... IN a sub, I look for ease in changing direction in note. Without dribbling and stuttering - pretty easy to please on subs.

A few months later someone wanted to sell a Rhythmik 15 so I said, Great!  Now I can see if the 15 sounds better than the 12. Well -  In a lazy relaxed manner it yielded the TUNING of the bass and tom tom - not the TUNE, as in la de da doodley dodo, but in how well the drums had been tuned and synced with each other.  I don't think many drummers still tune their drums kit but I am probably wrong on that...  The Rhythmik spoke this tuning easily and clearly, and just about the same way I remember that low register from when I played bass in front of big ass drum kits and amp walls in the 70s. Deep. Right into the back of the head. I like it. BUT, I don't like RAP.

I’d pay 50% on Rhythmik and not worry about getting rid of them if you want to change your system within a year... As soon as anyone hears them, at their price they not have heard this quality of bass before, IMHO.
I am looking for an active 18 with the passive 18 aboard.... I enjoy trying new parts and pieces in my system. I guess that is what an audiophile is? Also, obviously, listening to music is number one.
Audio is great fun,