Originally Posted by Rythmik
I am pretty sure some of you, like me, wonder why different subwoofers sound differently, or why different amplifiers sound differently (to a much lesser degree). Very often the argument is that I hear more from this sub vs I hear less from this sub. But we all know a signal is a signal. It cannot disappear. The more I look into it, the more I think the reason is "coherence". That is, the key is in the small signal buried under the loud signal. With a lesser subs (not due to passive radiator, but just poorly design subwoofer), the small signals are not coherent with loud signals. Therefore it sounds as if there is a lot of background noise. But if the coherence is preserved, then that background noise becomes clear as ambience and we can now recognize the previous thought as background noise is now correlated to the loud signals. That is why all tests we use today fail in terms of the ability to test the coherence of sound when both large and small signals are present. The coherence is more important when reverberation is in the recording and in rooms with reasonable reverberation (that is, not an anechoic room). The reason is the reverberation arrives at different time than the source that it derives from and it is always later. That is, we hear the loud signals first and then try to correlate small signals that arrive later. It is a temporal correlation. When the subwoofer is able to preserve the correlation, all the minute low level sound falls into the right place. Without the correlation, the low level sound will be like annoying background noise that you wish to get rid of. In fact we don't have to play the subwoofer loud to destroy the temporal correlation. That means the harmonic distortion figures we normally look at have little (corelation) to the temporal correlation issue.
Thanks for the detail reply.
Another thing I notice also after almost a week watching TV, maybe is the result I spend more time with your instruction in adjusting. I swear the human voice becomes clearer. Before, there were more base in the human voice that make it a little unnatural, and also make it a little harder to hear the words. Now, it's cleaner and clearer, more separation. Maybe it's also what you describe about the corelation. It is nice and these are not what I expect when I buy this.
I hope you keep the F12SE in production for a while. I have to spend money on other part of the system and I won't get to sub again any time soon. But eventually, I would buy the second one.......not just to have dual sub, more for decoration!!! I am using this as the end table on one side of the sofa. Looks like the glass top is going to cost me like $300. It will look very nice to have a pair one on each side. Sound wise, I am happy with one already.
Ha ha, I cannot stress enough, if you make your big boss like how it looks, it goes a long long way to justify spending more money!!!! Remember, the big boss is going to give you performance review any time, any day of the year, not just once a year!!!