Quote:
russ.will wrote:
 Ilkka,
I'm particularly interested in your thoughts on the Rythmiks especially now I see you've expended some of your own hard earned on one. I presume you wanted to test the water yourself?
As a Monolith owner in a 1500ft^3 room (potentially about to step up to a 2500ft^3 room), Im interested in something that will at least maintain current SPL levels whilst offering deeper extension and keep a lid on distortion. In the smaller Euro room (and given the current exchange rates) the Servos look like good value, but I'm having trouble penetrating the (admittedly short of SVS levels) of hyperbole on the website.
I was leaning toward the 15" servo kit in a 3-4 cu ft sealed box as the dual 12" would just be too large at 6ft^3. I read your results, add on the min claimed boost of 3dB, add on the room gain 6-12dB/octave and I'm arriving at some scarcely believable potential in room figures considering the power outputs of the amps and the power requirements of a sealed box.
Anybodies thoughts are welcome for that matter. 
Russell |
Hi Russel and Bone,
The 12" sealed Rythmik Audio DS is generally a really good subwoofer. It has versatile settings for extension and shape of the frequency response, which both help to match the subwoofer and the room. I don't want to say a lot of subjective comments about its sound because the listening room and personal preference affect a lot to it. I can say that its sound is slightly drier than what we usually hear with other subwoofers. That might be a good or bad thing, depending what kind of sound one likes. The upper end stays really clean even when pushed really hard, but when listening to material with lots of high amplitude low frequencies (HT use), you will start to hear some amp clipping noises (ticking, crackling) at certain point. In my small room this was around 102-105 dBC measured around 2.5 meters from the subwoofer. The subwoofer will still go louder, but not without these noises. They can be hard to hear when other speakers are blasting, but if you turn them off, you will notice when the subwoofer starts to overload. Brian decided not to use any amp limiters, which helps to preserve the maximum dynamic capability of the amp. But as you can see from the THD graph, distortion grows pretty large below 30 - 40 Hz when pushed hard. If one is using one of the lesser extension settings, naturally the low end compression and distortion are lowered too. You should notice that I used the lowest extension and low-Q settings in my tests, which make the compression and THD graphs look somewhat worse when compared to subwoofers with lesser extension. So always remember to check the real output and extension from the frequency response and maximum output graphs when making any comparisons.
If one wants to match the clean (no overloading noises) output in 20 - 30 Hz range with the Monolith, one needs two of the 12" kits or one of the 15" kits (estimate since I haven't measured the 15" kit). The 15" kit should be around 3 - 5 dB louder than a single 12" kit. I would recommend using a 4 cu ft box with the 15" kit for higher deep bass sensitivity. I would recommend this as a minimum configuration for a home theater use, especially if you want to use higher than medium listening levels.