Spent some time comparing a FV12 to my other subs...

I had a chance to play with a Rythmik FV12 for a couple weeks, so I spent some time comparing it with the other subs I had, which are a couple Hsu VTF3 mk3s, Outlaw Audio LFM-1 EXs, and an Elemental Designs A3-300. I wanted to see if Rythmik's servo technology really did produce a different sound, which was something I had been skeptical about. I found that it did have its own sound signature, but it was a bit different than what I would have expected. I'll also talk a little bit about some other things I noticed when listening to the other subs so closely.


from left to right: VTF3 backside, LFM-1 EX tipped over for front firing, A3-300 sans grill, Rythmik FV12 sans grill, LFM-1 EX proper orientation, VTF3 front view

I should say that I mostly did back to back ABing, that is, I switched sound from one to the other immediately so that I could hear any change right away (also I didn't feel like constantly moving around a bunch of 80 lbs subs). For what I was after, I felt I needed to remove the factor of aural memory as much as possible, so I mostly kept them in place for this, although not exactly as pictured above. Of course, the problem is this is not a fair or rigorous comparison, since placement has such an impact on the sub's performance, in output and frequency response, but I wasn't primarily after differences in FR and output. For much of this exercise, I also had any kind of EQing turned off, including Audyssey, as I didn't want to risk obscuring the natural sound of the subs. To help compensate for these deficiencies, I positioned myself closer to them than my typical listening position, where, when measured, the swings in FR weren't quite so severe. I also gain matched them for many of the listening sessions.

Many reading this probably already understand the basic principles of Rythmik's Direct Servo technology (if you don't, you can read about it here), and how it is ostensibly superior to conventional amp-driver configurations. I figured that the subwoofer with this technology would sound more detailed, especially on recordings with subtle bass, like some orchestral and jazz recordings, so those were the first things I pulled out to compare the Rythmik to the others. Now I will admit to not having golden ears, but I could not find any significant difference in sound in these types of recordings. Over a period of days, I tried different things to bring about a difference, like changing phase, damping settings, crossovers, etc, but to no avail, although I have to admit it still could have been due to a setup issue, as I did not have any of the sub's 'dialed in' to any great degree. I had the other ears listen to the subs, and they could not hear the difference either (they didn't know which sub was on or not, and weren't able to tell).

The FV12 sounded terrific, but it just didn't sound different with this material which is where I has assumed the greatest difference would be heard, and I was perplexed. I used different CDs I had laying around, such as RCA Victor recordings of Back, Telarc Recordings of Delius, and some others recordings of Smetana's The Moldau, Night on Bald Mountain, also some of the tracks on Hsu's Test CD which have both subtle and bombastic bass. Certainly none of them were among the very best reference standard recordings, but I thought they were all decent recordings. I also used some other MP3s and WAV files I had laying around which I was familiar with (also some of the recordings on this page were useful).

I did listen to quite a bit of music with heavy synthetic bass, electronic music like Drum'n'bass, dubstep, techno, electro, etc, and didn't hear any difference there either, but I didn't expect to as that music tends to use much simpler, cleaner, and more discreet bass sounds. One thing I thought I heard (but I didn't get independent confirmation with other sets of ears) was that the Rythmik was a bit more restrained on certain parts of the music, but that might have been due to FR dips and peaks from the sub's different placements.

So I turned to film material and sound effects, but at this point not expecting anything different than what I had already experienced with music. One of the first things I played was the Trainstart wav file from Danley Sound Lab's website, and, lo and behold, I hear a difference right away. This wasn't my imagination either, as I had it confirmed by others, and while it wasn't a huge, tremendous difference, it was certainly noticeable and one could hear it right away. The recording is simply a heavy freight train passing by, with lots of different types of rumbles and low frequency crunching noises. While the other subs reproduced this recording well, the Rythmik definitely had a edge in detail for the texture of much of this low frequency grinding. I heard the same in other like recordings, such as distant thunder, and also complex drone type sounds. In certain film passages, there was a difference, such as the pods rising sequence from War of the Worlds. In that scene, there was a richer texture to the earth quaking and crunching sounds, although the Rythmik was not able to dig as deep as the Hsu or Outlaw. However, in other film scenes, I couldn't detect a clear difference, such as the plane crash from Flight of the Phoenix, although I think it would have been harder to gauge a difference in that scene, even switching back and forth immediately because the nature of the bass there changes frequently and abruptly. It's a great demo scene, but just not in the way I was using it.

Now for other aspects of the sub...

My SPL meter doesn't measure stuff below 30 hz well, so I can't tell you anything concrete about the Rythmik's extension, just my impressions. Also, keep in mind placement makes a difference in FR, and I didn't bother switching all the subs around. Anyway, to my ears the Rythmik had pretty reasonable output down to 20 hz. Although it wasn't able to hit the low 20s as easily these other larger subs, it was enough to rattle doors in my room. I didn't push it real hard at low frequencies either, as it wasn't my sub and I didn't want to risk damaging it. Anyway, it seemed to be able to dig pretty deep, deeper than any $500 sub has any right to.

Output wise, the Rythmik could really belt out a tune, although you really had to compel it to do so. To get it to really blaze, I had to raise the level on the sub out in my AVR quite a bit, and also turn the gain knob up all the way to the max. It will rock though, there is no question about that. It did not have the headroom of the Hsu or Outlaw subs, they could punch harder and louder than the Rythmik, and it was easier to get them to that point, all you had to do was turn the gain knob up a bit. Their volume control is quite a bit more sensitive than the Rythmik's as well, with the Hsu being absurdly sensitive in comparison. Just touching slightly would move the volume by 2 db, I could not get any finer control on the Hsu then that! Note that is the mk3 model, the mk4 could be different. For fine control on the Hsu volume, you really want to do that from the source or pre-amp. The controls on the Rythmik offered greater control, by comparison, at least on the gain and crossover. The internal crossover seemed to work more clearly on the Rythmik as well, as it filtered out a bit more than the Hsu and a lot more than the Outlaw. The Outlaw's internal crossover didn't filter out a whole lot in comparison, I was surprised by this, I suppose it uses a much more gradual frequency filter slope.

The Rythmik also had a damping settings switch and a 28/20/14 hz high pass filter switch. The filter seemed to work as advertised, and the damping settings made some difference on movie scenes with deep bass content, but not an enormous difference. I liked having those features, they could really save your sub from harm if you wanted to push it to its limits in ultra low frequency movie scenes.

As for the appearance and finish of the sub, some people have said the Rythmik doesn't look very good, and I don't agree. It looks like what sub should look like, a big, black box, it is typical in appearance and not bad at all. I prefer it without the grill, but that's just because I think cones look cool. The modal I had was a black Oak vinyl finish, it was nice enough, it looked like it uses the exact same vinyl finish as the Infinity Primus speakers I have and would make for a nice aesthetic match with those speakers. One thing that is slightly strange though, from what I gather, this sub does not come with feet automatically, you have to order them separately, and they are metal spiked feet which is an extra $45. This is something to remember if you intend to place the sub on a hard floor where a spill could happen. One recommendation I would make to Rythmik is have the sub come with some kind of feet, even if just cheap rubber grommets which can be upgraded to the nice metal spikes, for those who need the sub elevated off their floor surface.

Anyway, some might contend my following conclusions about the Rythmik sub. In my findings, the Rythmik sub didn't bring anything extraordinary to conventional music recordings. I believe this is because the bass in most music is simply too clean for the Rythmik to differentiate itself, even on large symphonic ensembles. On certain music with heavily textured drones, like Lustmord or stuff from Cyclic Law, I think there may be a more substantial difference, but those are some fairly esoteric recordings. On movies and sound effects, the difference is notable on certain types of sounds, trains, rumbling, hurricane winds, waves, etc. To be honest I was expecting the opposite to be true; I thought that those rumbling sounds would sound the same on any sub and that classical recordings would reveal a sub's differences. Maybe the Rythmik subs can make music sound better like their website claims, keep in mind the one I had was their lowest end offering. One might argue that I had the sub set up incorrectly, or my other equipment was holding the Rythmik back, or the recordings I was using weren't good enough for the task, or that I just didn't know what to listen for, and that could all very well be true. However, I think that the bass part of a musical note for most instruments isn't a very complex sound, and any sub that can cleanly play that back with low distortion, low overhang, dynamic linearity, and reasonably flat frequency response ought to sound pretty similar.

Bottom line, this is a terrific sub, especially for the price. I would say in some way it compared favorably to the Hsu and Outlaw subs, both of which are more expensive. In other ways, it did get bested by them, notably in extension and output, but then they are bigger subs. The problem here is I didn't have the subs which the Rythmik should be properly compared to, which are the Outlaw Audio LFM-1 Plus, Hsu VTF2 mk4, and Epik Legend, which are its true rivals. I would say the Elemental Designs A3-300 also, but that model has recently been retired from ED's line-up. Anyway, the Rythmik FV12 is a killer sub for the money, if you have $500+shipping, it is a great choice.

Thanks, only the Outlaw and Hsu subs are mine. The Rythmik and Elemental Designs sub aren't, and are not in my possession anymore, sadly, if you wanted to hear them and were in the Chicago area.

I actually did hook them all up simultaneously. In that pic, they are not hooked up or plugged, because the wiring made a unsightly spaghetti mess. Anyway, what I did was set them all up and gain matched separately them to hit 80 db at one listening position at a 50 hz test tone at a zero degree phase, with the speakers disconnected to insure no cancellation from them. I wanted to see how the bass SPL would add up, so I turned each one on down the line with a 50 hz test tone.

What I found was kind of interesting. The first four I turned on actually got louder, with each additional unit I turned on making a diminishing contribution, but the fifth made the system quieter. I switched the phase on the fifth to 180, and it added a miniscule amount to the SPL. I turned on the sixth and the SPL dropped again, so I flipped the phase on that one to 180, with no change. Then I started flipping phase switches with the previous subs, which gained some SPL at some points and lost it at others. Ultimately I was only ever able to gain an additional 11 db over a single sub. I think I could have squeezed a couple more db by playing with the phase switches some more, but I got sick of the 50 hz hum, so I stopped. The point is, to get the most out of six subs in this kind of array, you would need either some heavy duty calibration equipment, or a lot of time and patience to work out possible phase combinations to beat cancellation, and that would be only for a single listening location in your room.

The "other ears" are really family members (also family dog*), they are not audio people, but they could perceive the difference in certain sounds. Having some people over who are more appreciative of this sort of thing would have been good, but I don't personally know anyone like that, and in the time window I had these extra subs I didn't want to set up some kind of a meet, it would have been too sudden to arrange, plus my family is taking care of a foster dog right now that needs a lot of attention, and juggling that would have been too much of a hassle.

*yes, inadvertently, the family dog. Our dog does not like thunder, and retreats to the basement and just paces around constantly for the whole duration of any thunderstorm. One of the sounds I used to compare the subs with was this fireworks finale recording from Danleys website. This dog, who usually doesn't care what is played back on the home theater even if its a war movie being played at reference level, somehow became convinced of the authenticity of the fireworks recording, and began to pace around apprehensively. I had to cut the demo short to ease the dog's nerves.

cel, I don't think it actually did better with low bass. I think it might just have more articulation, period. The sounds where it shined were complex with many different frequencies overlapping, if you listen to that train sound you might see what I am talking about, there is a lot going on there. I don't profess to understand the science of subwoofers really well, but deep bass is more the Hsu's strength than the Rythmiks, I would guess that the Hsu would have less distortion in that range. All I can tell you is that the Rythmik had a certain layer of detail that was missing from the other subs in some sounds. I would attribute this to the servo technology, but, like I said, I am not a sub expert, and maybe it was due to another factor, like maybe the deep frequencies were masking the detail from higher frequency bass (I don't think it is this though). Both subs sounded good, the Hsu sounded a bit deeper and the Rythmik sounded a bit crisper, insofar as these subterranean sounds can sound crisp. In this regard one of the best contrasting scenes is the pods rising from War of the Worlds. Both subs execute the scene beautifully, in their own way.