Rythmik Subwoofin' - 1st Take

My subwoofer odyssey started about 10 months ago when I bought a pair of Velodyne SPLR 8" subs and an SMS-1 controller. I planned to use them in HT apps, but tried the set-up in my new (and very difficult) listening room - just to see. The results were so astonishingly good that I posted on an A'gon thread something along the lines of "It (bass) just doesn't get much better than this".

Members Bob Reynolds, Shadome, and Drew Eckhard quickly pointed out that it does get much better. A wealth of info came my way, including data demonstrating that the SPLRs were...uhhh...unexceptional performers (that is, they suck). It was hard to reconcile the data (bad) with my listening experience (great), but I set out to do so. I wanted to find superior subs, just to get a handle on what (if anything) was missing.

The distortion/clean output and speed/tightness data (group delay)suggested lots o room for improvement, but priorities needed to be set. The big SVS subs and the JLs are impressive in both regards, but I was unsure whether I'd hear any improvement, and the $3500/pr tag on the SVS struck me as more than I wanted to ante for this experiment (The JLs are more expensive). I elected to prioritize group delay and chose Rythmik 12" subs (which also provide 100db of very clean output down to 35hz) which came in at app $1600/pr with the shiny black box upgrade accounting for $200 of that.

First: There is a difference. Instantly audible.

Second: Set-up was totally different. The SPLRs needed extensive EQ to dial in their performance. Without it, they are...uhhh..unexceptional. Once the Rythmiks were positioned for smooth response (ie, replaced the SPLRs), they were remarkably flat right to the 20hz subsonic filter. The only EQ tweaking was to optimize around the x-over point and a couple of shallow dips down below.

Bottom line: these are obviously tighter, more powerful subs which demonstrate that it's hard to judge performance in a vaccuum. The SPLRs sounded great - until these guys point up their (obvious by comparison) shortcomings. I'm tempted to say that it can't get much better, but I'm reminded what happened last time I tried that.


PS - Minimizing group delay isn't necessarily the trick to best performance. These subs (like the SVS Ultra) have variable damping(maximum damping minimizes GD) and allow the user to trade maximum clean output for "tighter/faster" bass. I started with max damping and quickly acheived ruler flat response, but there was a "mismatch" in character near the x-over point. It was only a day later that I started screwing with the damping controls and I found that the middle setting provided a better blend with my Ohm 100s. Don't know why - but that was the case for me.
Marty, thanks for posting.

Can you talk some more about the difference in EQ necessary for the two different pairs of subs? Are they in the same locations? Were you boosting the SPLR 8s?

Can you comment on the build quality of the Rythmik subs?

EQ was +6db to +10db over virtually the entire range from 25hz to 50hz for the SPLRs, plus 2 bands correcting deep suckouts between 50hz and 75hz. The balance of the EQ was to reduce one narrow bump and to fine tune correction around the x-over (75hz). Note: EQ beyond +6db required use of the SPLR's internal PEQ and the SMS-1's PEQ. Not recommended. I did it anyway.

The new subs are in the same spots and require no more than +/- 3db adjustment, except for below 25hz (I have the subsonic in line at 20hz).

Build quality looks to be first rate. The gloss finish is excellent. The only quirk: no logo on the grilles.


PS It's only been a week. If I learn more, I'll be sure to share.
I've got a Rythmik sub. It's a 12" sub, with the PEQ plate, and the GR-Research driver.

Great sub. It replaced a Velodyne DD15, and it's tighter and integrates better.
On the web site they say they go to 14hz. Do they? From what y'all are saying they are clean only to 30? Is that true

I use them in a music only system. Therefore, I don't care much about their performance below 30hz (I own exactly one disc - an SACD recording of the largest pipe organ in Europe - which registers meaningful info below 30hz.) In fact, I use a low cut filter to eliminate response below 25hz (was 20hz at the time of my OP) because nothing good happens down there in terms of music.

I haven't measured for deepest bass, but my guess is that - depending on the room, placement, damping setting, etc.:

A) The 12" Rythmiks will reproduce <20hz better (cleaner at any given SPL) than most 12" subs


B) If this is your goal, you can probably do a bit better at the price. The SVS tests better in this regard, though the Rythmik tests better for "speed" (group delay). I have never had the opportunity to do a side by side, so this is speculation on my part. Nonetheless, if I were buying subs for HT, I'd probably choose SVS, for music - I'll stick with Rythmik.


Do you have the GR Research drivers or the Rythmik drivers?