Sheep said:
Steve, you may want to look at the Sig Servo's numbers from AVtalk. It performs on par with the Servo V2, cept with a fancy cabinet. Look around the 100Hz area on the THD graph.
IMO completely unacceptable.
SheepStar
Sheep,
Let me preface this by saying I'm not the one who brought up the Servo-15 in this thread. Be that as it may at 100Hz THD is still below 9% at
120dB!.
First of all I realize some cross there subs over as high as 100Hz, but when most people are using subs the caliber of the Servo's , Maestro's, and DD series etc. they are most likely going to be using a cross-over at around 50-80Hz. So it would pretty much be a none issue. Second of all not many people are going to be able to notice THD at the levels of around 115db-120dB especially at that frequency. The harmonics of 100Hz will be very hard to hear at anywhere near those levels.
Have you ever heard of the Klippel test?
http://www.klippel.de/aura/
Most people that take it average around -12dB to -18dB as far as their sensitivity to THD. That translates into most people not being able to audibly hear THD until it reaches somewhere around 13-26%. I don't know about you, but I was quite shocked to hear about this myself. In fact when I took the test with my $500 pair of Sony CD3000 headphones several times, I shockingly and honestly found that I averaged around a -12dB sensitivity.
If you happen to take it, make sure you do it several times because since with every question you have a 50/50 chance of getting it right, guessing can play a big part.
For more info you can see this thread where wae have been talking about it starting at around this post (and continuing for several pages):
http://forums.audioholics.com/forums/showthread.php?p=168463#post168463
Just before that post, Craig quoted Kieth Yates when he did that huge Sub shoot-out testing the Triad Platium sub. Here is what he said:
"The Platinum did a more credible job with the U-571 depth charges, which showed a compelling if less than teeth-rattling concussiveness up to a peak level of 107dB (Fig.B4). It got through Pearl Harbor's Gooding-at-the-guns passage at the same level (Fig.D4) without blunting individual gun discharges or adding a flapping/thwocking quality, a reasonably impressive achievement for a unit of this size and price.....In none of these four core movie clips did the Triad's highish measured distortion draw attention to itself; in fact, the unit steadfastly refused to honk, rattle, rasp, or otherwise let on that my torture tracks were discomfiting it. Rather than issue distress cries, it simply stopped getting louder as I slowly turned up the level"
And the graph: (pay attention to the very high levels of THD in the lower frequencies where Yates was referring to.
)
And then Craig had this to say:
"We have done more blind tests here in which people, such as yourself, claimed all sorts of things would be audible. However, when the lights went down, suddenly all these audible problems or differences disappeared.
Mr. Yates is pretty exprienced at this listening vs. measurement stuff. Or is Yates no longer a credible source ? "
Anyway, at 115dB-120dB playing 100Hz with only 8dB or so of THD, IMHO is pretty much "moot".
Steve
