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Topic: Passive bi-amping: What is the benefit? (Read 23369 times) previous topic - next topic
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Passive bi-amping: What is the benefit?

Reply #25 –
Quote from: ajinfla on
the claimed advantage is that the nature of that distortion will first be identifiable to human hearing in the treble content and since there is no tweeter to
Full range clipping spectra vs clipping spectra with a 3rd-4th order filter @ 2k, being discernible, isn't grasping at straws. Claiming absolutes pushes only ignorance.



In passive biamping there is no filtering of the input to the amplifier for either speaker.  Both amps are driven with full-range signals.

Passive bi-amping: What is the benefit?

Reply #26 –
Quote from: mzil on
It's easy to show that passive bi-amping is electrically different compared to using a conventional  single amp, however nobody in the history of hifi has ever shown any evidence to support the notion that the difference is audible to humans, using music (or for that matter, a specially designed test signal), without intentionally driving one or more of the amps beyond its linear operating range, via ABX or any other similar, carefully conducted testing methodology, meeting our forum's TOS #8 criteria.

I'm not aware of any specific bi-amp ABX test and you are free to believe 3rd-4th order low passed @ 2-3k clipping spectra, is indiscernible to human ears from full ranged clipping spectra. You are also free to believe that AVRs only clip with wide range dynamic music when "intentionally driven".
Loudspeaker manufacturer

Passive bi-amping: What is the benefit?

Reply #27 –
Quote from: ajinfla on
you are free to believe 3rd-4th order low passed @ 2-3k clipping spectra, is indiscernible to human ears from full ranged clipping spectra. You are also free to believe that AVRs only clip with wide range dynamic music when "intentionally driven".

"Clipping spectra"? Seems to me you missed where I said: "without driving one or more of the amps beyond its linear operating range" [intentionally or unintentionally, doesn't matter]

Passive bi-amp setups are 100% audibly indistinguishable from conventional singular amp systems when the amps aren't overdriven and clipped for any part of the musical passage.

Passive bi-amping: What is the benefit?

Reply #28 –
Quote from: mzil on
Quote from: ajinfla on
you are free to believe 3rd-4th order low passed @ 2-3k clipping spectra, is indiscernible to human ears from full ranged clipping spectra. You are also free to believe that AVRs only clip with wide range dynamic music when "intentionally driven".

"Clipping spectra"? Seems to me you missed where I said: "without driving one or more of the amps beyond its linear operating range" [intentionally or unintentionally, doesn't matter]

Passive bi-amp setups are 100% audibly indistinguishable from conventional singular amp systems when the amps aren't overdriven and clipped for any part of the musical passage.



Not only that, but offloading the tweeter amplifier from the load provided by the woofer does increase its power output measurably, but only by a dB or so.

Passive bi-amping: What is the benefit?

Reply #29 –
Quote from: ajinfla on
No, "more power" is not the possible benefit. Lower HF distortion is.
There should be no difference at all until the amplifier is driven into non-linear behavior. That depends on quite a few variables, especially if the difference is to rise to "audible" thresholds. But that is absolutely possible.

It is possible that some clipping would still go undetected. Its also possible that folks can imagine hearing things that aren't there. Many, many variables involved.
Highly doubtful you'll hear any (real) difference other than at higher levels....if any at all. But it is possible, not impossible.


Quote from: mzil on
Seems to me you missed where I said: "without driving one or more of the amps beyond its linear operating range" [intentionally or unintentionally, doesn't matter]
Passive bi-amp setups are 100% audibly indistinguishable from conventional singular amp systems when the amps aren't overdriven and clipped for any part of the musical passage.

Right. That's exactly what I said. Seems to me you missed that. Glad you've come around and now adding caveats like I did.

Quote from: mzil on
"Clipping spectra"?

Yep. That's the difference. Seems you're getting it now. Bravo.
Loudspeaker manufacturer

Passive bi-amping: What is the benefit?

Reply #30 –
"Coming around"? "Getting it now"?  My position is completely unchanged from what I originally wrote in post #23. Perhaps my exact use of the idiom, "grasping at straws" isn't clear. I meant "Their contrived scenario is most likely trivially important, at best, in most real world situations, listening to music and not steady state test signals carefully dialed up to the exact transitional point, the onset of of clipping in the woofer's amp yet not the tweeter's amp, where the bi-amp setup might seem to benefit briefly ".

Passive bi-amping: What is the benefit?

Reply #31 –
Quote from: mzil on
"Coming around"? "Getting it now"?

Yep, seeming so:

Quote from: mzil on
Passive bi-amping is audibly worthless to a consumer and costs twice as much. It won't make your system play even a scant 1 dB more loudly, whereas buying a single amp that has twice the power of the first one being consider really does increase output by 3 dB. That's discernible in some instances and arguably worth it, but passive bi-amping never is.


Quote from: ajinfla on
No, "more power" is not the possible benefit. Lower HF distortion is.
In short, if you already have the AVR (as the OP specifically states)
, bi-ampable speakers and an extra 2pcs of zip wire ($2 ?), you can give it a whirl yourself.


Quote from: mzil on
I meant "Their contrived scenario is most likely trivially important, at best, in most real world situations, listening to music and not steady state test signals carefully dialed up to the exact transitional point, the onset of of clipping in the woofer's amp yet not the tweeter's amp, where the bi-amp setup might seem to benefit briefly ".

Clearly you didn't understand the concept and now that the distinction (low passed HF distortion) has been pointed out to you, you have wisely chose to add caveats as to how its entirely possible for audible differences to manifest (vs "never").
No big deal, see this all the time on audio forums.

cheers,

AJ
Loudspeaker manufacturer

Passive bi-amping: What is the benefit?

Reply #32 –
Passive bi-amplifying is 100% completely inaudible to every single human on earth, without exception, when listening to undistorted music, or for that matter specially designed test signals claimed to make "the difference" easier to detect.

Both music and music distorted by overdriving an amplifier will sound different through a speaker with no tweeter.

Passive bi-amping: What is the benefit?

Reply #33 –
Quote from: ajinfla on
Clearly you didn't understand the concept and now that the distinction (low passed HF distortion) has been pointed out to you...

Incorrect.

Passive bi-amping: What is the benefit?

Reply #34 –
Quote from: ajinfla on
Obviously the current loading/draw is quite different from the single Ch.
This can lead to the LF Ch clipping before the HF Ch does


Source of data: AmirM.

Observed difference - 0.8 dB

Game, set match.

Passive bi-amping: What is the benefit?

Reply #35 –
I only skimmed that thread earlier but as I understand it whoever wrote on top of the image in magenta was mistaken.

A. The 13.6 V and 12.4v seen in the upper left corner aren't the peak values but rather the divisions, the gray grid on the screen, of this dual trace oscope which can overlay two differing ones at once. [Which means the image itself makes no sense since you can't compare one curve to the other. The scales are different!

B. The difference was later, at least at the point where I stopped skimming, determined claimed to be a little bit more. Maybe 1.6 or was it 1.8 dB? I can't recall. Still not much and hard to pick out by the time you've reconnected the jumper straps on each speaker and switched to the alternate mono amp. Acoustical memory is fleeting.

C. Consider the source of the image. I can't stomach this king of the black hats of the audio industry and don't trust anything about him. Perhaps the dancing man Photoshopped the whole thing? He's a known liar, like claiming I said Bob Stuart's digital filter audibility findings weren't statistically significant. That's a lie; I said when viewed in aggregate form they showed good statistical significance. [references available upon request]
 

Passive bi-amping: What is the benefit?

Reply #36 –
Quote from: mzil on
B. The difference was later, at least at the point where I stopped skimming, determined claimed to be a little bit more. Maybe 1.6 or was it 1.8 dB? I can't recall. Still not much and hard to pick out by the time you've reconnected the jumper straps on each speaker and switched to the alternate mono amp. Acoustical memory is fleeting.

Its been a while, but I seem to remember some other asymmetries in the test, but that was a while ago, and we are how many dances down the line? ;-)

Agreed that an additional 1.6 or 1.8 dB are still nothing worth finding the extra cables to obtain.

In typical use, even 3 dB (twice the power) can easily fall through the usual subjective cracks unless it is your typical audiophile sighted evaluation, in which case the levels may not have been matched that well! ;-)