You should update the first post with more info....right now I can't find where you may speak on how many judges and who the judges are....right now I imagine a group of friends and their significant others, some alcohol, and self given badge that says "if there was a difference...I definitely have the ear training to tell.."..... people like to talk about whos the best drummer, and I'm like oh you play? and then they say no....and I realize their opinion suddenly doesn't matter so much....
and have you blindly tested the threshold of that THD percentage @ 20hz
blindly, do you detect 8.4% or 33% or 1.2% ?
Why, now, you assume that it's below 10% at 20hz? Based on what?
Don't play with me
You'd be better off arguing how well trained the ears where of the judges of this test.
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Here is a quote from at interview with Bruno Putzeys and Lars Risbo, owners of Prurefi:
"...a class D amplifier is simple enough that with two sine waves you can pretty much probe all there is to probe. The only real surprise we had recently was to do with the output choke. Magnetic materials have something called hysteresis, but there is precious little information about what this really does. If you test a magnetic core with a sinewave the distortion looks a little like soft clipping, perfectly benign. But what came out of tests on iron parts in loudspeakers was that hysteresis has a long term memory so you can get intermodulation between things that happen now and things that happened 10 minutes ago. With music this distortion sounds like half correlated noise.
Lars: Crackling. You hear when each magnetic domain flips.
Bruno: When you put the coil inside the amplifier’s feedback loop that distortion gets reduced along with the distortion of the power stage and everything else. We have a strong suspicion here that the most audible distortion in typical class D amplifiers may very well be that."
"...Lars: I’m going out on a limb here but maybe there is a wider class of “memory” distortion effects that are completely ignored when you do sine wave tests. Why shouldn’t similar effects occur in capacitors? And thermal effects in class AB amplifiers are also notable for being very audible without showing up on a THD plot."
As can be seen from Lars' comment, not everything may be fully known at this time. Those guys are class D experts and they know how to listen as well. At least I know how to listen too 🙂
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Based on years of measurement. Probably can't tell below 10%.10% is 20dB less so 80dB@40Hz for the first harmonic.
I agree, it all SPL-dependant, but would add it's also frequency dependent in terms of how low in freq is desired.
Cause like you've said and we all know, bass SPL is about displacement.
Especially when equal SPL across the spectrum requires that displacement has to increase at 4X per each octave lower in freq.
That's where your 10" = 21" craps out imo.
You've made a very arbitrary judgement on what SPL works at what low corner, for normal hi-fi and normal people in a normal room.
The distribution is wide.
Heck, even my "normal" isn't constant....there's before wine-thirty SPL, and post wine-thirty .....when sometimes even four 18n862's aren't enough bass 😀
Not interested in that golden ears quest.
I don't give a flying fck about that.
What I'm interested in, the ONLY thing that I'm interested in, is statistical value, related to real-world application. In the case of these blindtests: as much participants as possible, with background as various as possible, ages range as wide as possible, and male + female.
And that's what I did.
And if you're in the profound *illusion* that musicians, sound engineers, audiophiles and other ''trained ears'' would suddenly turn upside down the results and the conclusions of those blind tests... You're entirely wrong, but you're most welcome to organize your own test and lose time, energy and money doing so.
When I was younger, my ''normal'' was 140-145db in the 30-50hz range...
But for most people, like 99% of people, and I would say 99.9% of WOMEN, 115db @ 30-50hz is pretty loud enough. They don't need more. They might complain if there's more.
That's all. That's all my point.
I'm not saying 125db @ 30hz couldnt be fun for some, I'm just saying that's unusual. ''Normal'' people are not expecting that at all from a Hifi sound system.
Yeah, the full bandwidth sums the various components to greater overall SPL.
By the same reckoning, pink noise with its greater density than music, invariably measures a little higher SPL than music, when both meter at the same line level.
Imo, pink is more real world than not.
It is very revealing where music often fails. Measurements that look identical often sound different with pink.
Back to your new test...
My guess is not only were the peaks from the woofer-mid, but the average SPL too. In fact, i doubt it's a guess. 😉
Personally, I think you need to ditch the other drivers and compare the HF alone...just like the mid tests. 😀
Mark, In the cabin where I am, I'm running 4x 8w1v3 which combined have a Vd of 675cm³, which is by my standards pretty weak.
I'm used to 4x 10w7 which gives 3551cm³...
But with room gain, EQ and everything, I am still able to reach some serious SPL down to 26hz with the small 8's subs...
And, at least, I am using their capacities. Unlike the 10w7's that were basically sleeping, underused, for most of their playing time.
Hahaha!
But you know that a bunch of people here would not agree with that!
We've been through that for about 50 pages...
I may be getting worse as i age...almost 68. The neighborhood has a bet going on whether the windows blow out, or my house just fall downs first..
But ladies...uhmmm.
I've been very lucky, very blessed by, the 0.1% that like loud music 🙂
Yeah, 'normally' (lol) that's plenty.
But sometimes I want to get rowdy, and bring in a JTR Orbitshifter or two to play along.
dB v2
Or go outside with 4 Labhorns...true ball busters..at least to low mid 30's Hz..
Gotta love SPL that moves ya ! literally 😀
so now you are saying that cabin gain of your car is no different than the room gain of a persons listening room....k
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