I apologize for joining this discussion so late as I feel I can contribute. I am cross-posting the following from another thread so I can expand on my thoughts and get the opinions of you all.
I'm still not caught up on this thread but I feel like I have a good handle on this topic. I have spoken to Brian Ding of
Audio about this specific topic on several occasions. I sat with Brian during the JTR 2400ULF demo at the first Houston GTG. This was his first time ever hearing a JTR sub. I also built the Rasperry Pi vibration sensor (in addition to Vibsensor) to see if I could develop a standardized test to assess the tactile characteristics of a sub outdoors GP (no consistent results yet). However, I believe we may already have the measurement we need in the waterfall.
Originally Posted by Leon!
If that's the case, say for instance I go with my plan of 14hz tune (in a small room on suspended wood floor) and the deepest frequencies are overpowering like you describe once I get mid bass up to par, can I just turn on the 18hz rumble filter, or try equalization if I can figure it out? Or is it not that simple? I was just thinking easier to cut out too loud too low frequencies if I erred on the side of too low a tuning, vs. trying to add them if I don't find subsonic frequencies powerful enough if I went too high a tune. Maybe I'll split the difference and go 16hz - 18hz. Thank you both.
I disagree with some of the characterizations that a low-tuned ported sub is a risk in a sealed room, suspended floor, or even a very small, sealed, suspended room. Certain subs are definitely risks in overwhelming a room with LF energy. I do not believe the Rythmiks fall into this category. The controls on the Rythmik should allow you to dial in the TR to taste in any small room.
Damping factor control: LOW > MED > HIGH in regards to TR
Tuning Frequency: Variable on the FV(X)15s & FV18, I actually experience more relative TR from the Rythmiks with the higher tunes vs lower. However, subjective SQ increases along with extention as the tune decreases (even with content with no ULF content).
Bass Extension fliter (-12dB) & Rumble filter (-6dB): These allows the native frequency response to be shaped to accommodate different room sizes/gain profiles, similarly to Low-frequency Adjust (LFA)/Room Size Control (RSC).
While the JTR has -18dB of range in the LFA it does not have the damping factor control of the Rythmik. Don't believe the narrative that Direct Servo is a gimmick and the Rythmik website is rife with sketchy engineering. I am an electrical engineer and I get schooled by Brian Ding every time we communicate!
On the flip side, Rythmik doesn't have a low-enough damping control setting (or excursion) to compete with the violence of the JTRs. Brian could engineer it, but I didn't get the impression that he sees any benefit as their portfolio is quite extensive and there is room for both Rythmik and JTR in the marketplace. They truly both unique in their own rights.
I am cross-posting this in the other thread as I think we can prove this out with two sets of evals.
1) The Rythmik FV25 at
2) The JTR Captivators 1400, 2400ULF and 4000ULF (and possibly the 2400) coordinated here in SoCal (