Originally Posted by basshead81
You can if its over 10%...however we need to consider those tests are done with sine waves and burst tones. They are much more taxing then even the most demanding electronic bass music. A 50hz compression sweep will turn 100% dut and melt a voice coil fast...the only point of that test is to see if the OEM did their home work correctly and employed the correct protection circuits. The most demanding material never exceeds 25% dut. Now when we place the sub's in room, distortion wi go down due to boundary reinforcement upping the efficiency which allows more output with less excursion = lower distortion.
That being said I was just making a point that the Rythmik is far from the cleanest sub from a distortion standpoint when outdoor burst testing @ data-bass, but has always been held with high regards for how good it sounds. That tells me what is being measured outdoors needs to be looked at carefully because it does not translate into the same experience you will get in room.
ShadyJ and I argued over this all the time because he always tried to use those certain Databass measurements to nit pick a sub.
Moral of the story, do not go to data-bass and try to read a few graphs and think you know everything about how the sub will perform. Its not that easy and half of that information needs to be taken as a grain of salt unless you truly understand the data JR is putting out there.
Rythmik makes a great product that uses Servo as one of their technologies to make a solid product. It is not magical and you can still achieve great results with other methods. Just clarifying this because you always hear "It's Servo" and I truly believe 95% of those people do not even fully understand what that means.
Back to original programming....
Any word on the new FV18 and 25?
Originally Posted by Rythmik
So it is our job to make customer understand the benefit of servo. Servo can detect the movement of cone and apply the opposite polarity of voltage to the driver (being a close-loop feedback system) to counteract the external force and therefore reduces the amount of cone movement by a factor of 3x. Any unwanted cone movement generates sound. Imagine when the acoustic energy hits the enclosure and cone. The enclosure wall remains sturdy, but the cone is relatively free to move. The cone generates sound when it moves. The ability to reduce unwanted cone movement is one of the key benefits of servo. I was in the factory to demonstrate how to test our servo amps by displaying the amplifier output on the oscilloscope. A few bays over, another team is testing another design using music signal. My display showed so much noise that I had to ask them to stop in order to show a clear waveform. This is to show you how servo rejects noise that is not in the source and the ability is present anytime the amp is on. This noise can come from another channel, it can also come from the standing wave inside the enclosure itself. In terms of the force used by our servo to counteract cone movement, it is damping force, not inertia force, not spring force. The insertia force and spring force (exhibited from other type of servo designs) actually store energy and then release it back via cone movement. Our damping force method dissipates energy as it counteract cone movement. It acheives a much better clarity.
Originally Posted by Rythmik
If we are into this type of detail, we can further differentiate the "low damping" sound that is intrinsic to a non-servo system vs "high damping" sound that is intrinsic to servo but eletrically "equalized" to "low damping" (ie, more ringing). The subtle difference is the former has low damping sound because its damping force is low. That means when external force hit the cone, the cone will response with a "low damping" high ringing type of transient reponse. The latter however is different. The external force in servo will respond with a "high damping" low ring transient response. The low damping/high ringing only applies to the signal source. That is why there is a difference between acoustically implemented "low damping" and electronically implemented "low damping" and they sound differently even though in impluse response, they measure almost the same. The disturbance from the external force will show up in measurement microphone response like random noise and it is difficult to separate that from true background noise. One thing is remember is noise and distortion is separated by a vague line. Noise strongly correlated to source signal IS distortion. Distortion after fully randomized so there is no correlation to source signal will become noise. But that is another topic.
This is very interesting. I read from other threads that "servo" is just marketing yet I do believe my FVX15 sounds tighter than the MFW-15 I had before. How do you quantify that? As far as output goes, I agree other subs can have similar output as Rythmik subs using different methods, but does 110db @ 20hz or 110db @ 50hz, sound the same on all subs? I am sure distortion plays a part of the sound equation, but I also think that servo sounds better. It is harder for me to tell to tell that difference in a movie such as Mad Max Fury Road, but it seems easier to hear with music (Steely Dan, Flim & BB's, Metallica, Kraftwerk, etc...). I am no expert by any means, have not heard every sub out there, and am a huge skeptic when it comes to marketing BS, but I do think the reviews/feedback from people who buy these subs usually are pretty consistent (tight, punchy, articulate). Some people even say output is less than other subs because they are used to loud bass not clean bass. I have a music listening friend who went from a Klipsch sub to an L12 and is amazed at how much better it sounds. So if I am sold on marketing, so be it! Time to go watch a movie!
Btw, I can't wait to hear feedback on the FV25 & FV18!