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In Reply to: RE: Just so we are clear- class A is the lowest distortion class of operation posted by Inmate51 on July 01, 2016 at 12:34:26
There is no audio Panacea, John , Pass , et al , know this better than most , if there were, everything would be class-A and be done already ..
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My personal thinking is that the most attention should be paid to that first 0.1 to 2 watts output, since that's where a lot of systems are working most of the time. As an example, even though I can crank my lowly Dynaudio/Electro-Voice speakers to fill the house, most of the time I play them at a level where people can still talk at a normal conversational level, which means my stereo is basically slackin' it.The real problem with stereo systems, even after all these decades, is still the speakers. Can y'all say "10 percent harmonic distortion"? (Oops, there's another can o' worms!)
:)
Edits: 07/02/16
Agree on the 1st watt being important......
" is still the speakers. Can y'all say "10 percent harmonic distortion"? (Oops, there's another can o' worms!)"
Mostly low order and mostly in the bass where the hearing is far less sensitive. Probably makes the sound "fuller" than one without it.
With speakers it is still the problem with materials creating bending and breakup modes, storage and release of acoustic energy etc. rather than actual harmonic distortion from the driver non-linearities (they have gotten this part pretty good over the years).
Keep in mind that this kind of distortion is not the same type as generated by electronics, which have far more high order content in the distortion.
I once helped a friend by a stereo system. She (yes she) originally wanted a home theater but after we got a nice set of stereo speakers (AudioPlan Kontrast IIIi) she decided to have a good stereo instead. We auditioned many amps and some made the speakers sound truly and fundamentally different...not just a flavor change. The worst was the integrated Denon she already had...perhaps it was broken but the sound came out so flat, hard and aggressive as well as being stuck to the speakers that she was dumbfounded that it could sound so different. In the end she bought a SET (Cary CAD-572se monos) and a tube preamp (Transcendent Sound Grounded Grid, which I built for her) because that simply sounded far better with the same speaker and wires. She went from zero to SET cultist in one step!! She has very good ears (and brain) and it showed during her evaluations.
Distortion of the speaker itself didn't change but the distortion of the signal coming through it certainly did and it was easily (and sometimes painfully) audible. My guess is that the Denon probably measured just fine by objective standards (although I cannot confirm but it was probably 10 years old) but sounded like doodoo.
Quote :"" is still the speakers. Can y'all say "10 percent harmonic distortion"? (Oops, there's another can o' worms!)"
Mostly low order and mostly in the bass where the hearing is far less sensitive. Probably makes the sound "fuller" than one without it."
And that's why bass controls turnover at 100 Hz if you're lucky. They figure if you want more bass you want that tubby tone. Not me. Most rooms cancel out the lowest octave, it is that which needs to be boosted. What's more, a sealed cabinet is much better, even though it will inherently have less bass usually, the low end is not rolling off as fast.
The method of summing the output of the port and the woofer close miced does not give reliable results. They are not in phase. From what I have "heard" even the best of them suffer in a small room because to have to give them room to shake the air.
"With speakers it is still the problem with materials creating bending and breakup modes, storage and release of acoustic energy etc. rather than actual harmonic distortion from the driver non-linearities (they have gotten this part pretty good over the years). "
In other words, rattling. Just not rattling really bad right now. But you are right. Other distortion generated by the motor of the speaker should be pretty much gone now. In the old days they never expected the cone excursion of today. If they wanted bass they had to use a 15" woofer, some of the 8" of today can outdo them on low bass. And I do not mean one note resonant cavities, I mean something like a Boston Acoustics
A-70. And plenty others. I had the chance to audition a pair of Canton 10" three way system. I could not afford them at the time. The Bostons came closer than any other speaker I heard so I got those. Sealed system.Anyway, IIRC the Boston A-150s were 0.7 % THD at 1,000 Hz. Of course that is not the bass region but then any THD spec on a speaker is pretty rare. I do seem to remember that Quad ESL63s are rated very low in distortion and I mean less than alot of amps. I also wonder how the hell they measured it.
Edits: 07/14/16
Amplifier distortion can be measured but to hear it a set of speakers are needed, now you have a system, and the distortion of the system is strictly dependent on speaker distortion which usually are a several orders of magnitude higher than the amplifier.
Also, if you check out the specs of any high end speaker by checking manufacturers website you will notice that most specs exclude the lowest octave simply because those numbers are embarrassing.
Now back to Class A and the low distortion.
Vahe
I don't buy your argument vahe. I'm not sure I see the logic in it. One thing I do know is that millions and millions of audiophiles can hear that Class A sounds better. How do you come to the conclusion that because the speaker has more distortion that feeding it a signal with an increased or decreased distortion level cannot be perceived or isn't important? You are assuming that the level of distortion in the speaker is some kind of limiting factor. Tweaker
Edits: 07/05/16
"strictly dependent on speaker distortion which usually are a several orders of magnitude higher than the amplifier."
Maybe but the type of distortion and the distortion caused by the interaction of the amp and speaker are probably more detrimental to what you are hearing.
Surely you have had the experience of swapping out an amp on a pair of speakers and then it sounds almost like a completely different system? If you have then you are ignoring evidence that invalidates your comment above.
Or has every amp you have tried on a given set of speakers all sounded the same??
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