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Bi-Wiring/Bi-Amping With Onkyo 605...Viable? - Page 2

post #31 of 214
Quote:
Originally Posted by IntelliVolume View Post

Okay, fellas, so to summarize the thread (before it goes off the proverbial track of increasingly technical jargin)...

No discernable performance (i.e. perceived power) increases can be verified by doing this "passive bi-amping" which, one more time, I was referring to was:

Taking the "back surround" channels of my AVR and using them in conjunction with the main front channels of the receiver in order to feed the two terminals on my bi-ampable Polk RTi12s...

...correct? I wouldn't perceive the mains as being "louder, punchier" or otherwise "better powered" in any way, would I?
You may smile.gif. Here is the simple explanation of what is going on (in forum arguments). Folks put forward proof that if add a 100 watt amp to an existing 100 watt amp through passive bi-amp, you will not get 200 watts. This is true. It is also true that if I had one amp that was not taxed at its maximum power (100 watts in this case), doubling its power would do me no good. We don't buy a 200 watt amp unless we had maxed out our 100 watt one. So this argument creates an exaggerated potential benefit of bi-amping and then says, "look, it can't happen." Answer is so what? The amplifier heavily distorts once you reach its limits. Just adding 10 or 20% more power may result in significant reduction in distortion.

One of the main benefit of bi-amping comes from isolation of the two parts of the system: woofer and tweeter. If you look at music spectrum you see that low frequencies are far louder than highs. So the part that forces the amp to max out is the low frequencies. When amp distorts due to its inability to have clean power at that listening level, it creates distortion that is at higher frequencies which normally are reproduced by the tweeter. If you have two amps and have each one of the independently drive the woofer and tweeter, that extra distortion no longer makes it to the tweeter. So you get cleaner sound. And it will be "better powered."

Now the power gain may just be 10% so we go from 100 watts to 100+10 watts (100 for woofer and 10 for the tweeter). That is OK. We don't need to go to 200 watts to have a benefit. There is a flippant comment made that this benefit won't be there ("current limiting is not common"). But no data is provided to back that and in the other long complicated thread, I showed how that argument can be false.

So the issue here is not the theory. The theory is helpful. What you need to determine is if your amp is operating near its limit. If it is not, then you should stay with your current setup. The way to determine that is to play music with very high dynamics. I like drums. Then turn up the volume and keep going up even to uncomfortable levels. Do you notice a change in the quality of the sound? If so, repeat this a few times with your eyes closed and see if you arrive at roughly the same volume level. If you do, then you have likely hit the limits of your amp and it is worthwhile to add the second amp and try the same experiment. If there is no improvement, then you can stay with this or go back to single amp.
post #32 of 214
Thread Starter 
Thanks everyone for your ongoing assistance, and thank you to those who provided the links to the calculators and such...

At this point, I don't know if the "passive bi-amping" process we've been discussing is a waste of time and speaker cable (as Jason originally stated it definitely is) or if some measure of "improvement" will come out of my RTi12s by using my 605's back surround channels to combine with the main channels; the thing is, if the concensus is that this will NOT yield any better results, I don't want to waste my time crawling to the back of my complicated installation (our system resides in a massive wall unit with the two RTi12s on either side of the entertainment center and our display in the middle with the Blu-ray player and AVR in a cabinet on the right as part of the wall unit) and adding the extra wires to run to the 12s' extra connectors, etc...

So, in a nutshell, I'd like to know if in general, based on what others have heard or experienced for themselves, it's better NOT to do this passive bi-amping when just tapping off the back surround channels of an AVR like the Onkyo 605 and rather more efficient to just leave the two back surrounds unused while letting the receiver power the remaining five channels of the system...
post #33 of 214
Yes, I would say engaging in passive biamplification is pretty much a waste of time, effort and resources. You can argue theory all you like. If you passively biamplify, it won't make your system sound better. that's the bottom line.
post #34 of 214
I don't think that there is enough gain / improvement that you will be able to notice the difference. Most on the forum agree that passive bi-amping has only very limited benefits and that they are too minor to make an audible difference - I too agree with this opinion. Amir has been very vocal in his support of passive bi-amping:

Quote:
Originally Posted by amirm View Post

One of the main benefit of bi-amping comes from isolation of the two parts of the system: woofer and tweeter. If you look at music spectrum you see that low frequencies are far louder than highs. So the part that forces the amp to max out is the low frequencies. When amp distorts due to its inability to have clean power at that listening level, it creates distortion that is at higher frequencies which normally are reproduced by the tweeter. If you have two amps and have each one of the independently drive the woofer and tweeter, that extra distortion no longer makes it to the tweeter. So you get cleaner sound. And it will be "better powered."

Now the power gain may just be 10% so we go from 100 watts to 100+10 watts (100 for woofer and 10 for the tweeter). That is OK. We don't need to go to 200 watts to have a benefit. There is a flippant comment made that this benefit won't be there ("current limiting is not common"). But no data is provided to back that and in the other long complicated thread, I showed how that argument can be false.

But even in his comments he concedes that there will only be a 10% improvement (the percentage of power originally used by the high frequency side of the crossover in standard configuration) in the power delivery to the more power hungry low frequency drivers - not enough to worry about. And his argument that when driven to its limits, isolation of distortion to the low frequency drivers will make a worthwhile difference is also flawed - the signal to the tweeter may be cleaner but you are still going to hear distortion from the low frequency drivers - those speakers can sound bad with excessive distortion as well - especially 2-way speakers where the mid driver reproduces part of the human voice (80Hz to 2kHz+)
post #35 of 214
Thread Starter 
Quote:
Originally Posted by FMW View Post

Yes, I would say engaging in passive biamplification is pretty much a waste of time, effort and resources. You can argue theory all you like. If you passively biamplify, it won't make your system sound better. that's the bottom line.

Thank you FMW...

Have you tried this yourself?
post #36 of 214
Thread Starter 
Quote:
Originally Posted by mtn-tech View Post

I don't think that there is enough gain / improvement that you will be able to notice the difference. Most on the forum agree that passive bi-amping has only very limited benefits and that they are too minor to make an audible difference - I too agree with this opinion. Amir has been very vocal in his support of passive bi-amping:
But even in his comments he concedes that there will only be a 10% improvement (the percentage of power originally used by the high frequency side of the crossover in standard configuration) in the power delivery to the more power hungry low frequency drivers - not enough to worry about. And his argument that when driven to its limits, isolation of distortion to the low frequency drivers will make a worthwhile difference is also flawed - the signal to the tweeter may be cleaner but you are still going to hear distortion from the low frequency drivers - those speakers can sound bad with excessive distortion as well - especially 2-way speakers where the mid driver reproduces part of the human voice (80Hz to 2kHz+)

Thank you MTN...

So it's pretty much just better to leave the back surround terminals "dormant" if I'm running 5.1 and leave the RTi12s hooked up "normally" as I have them now (that is, one set of speaker cables to one speaker running to the main front channels of the 605 and the same on the other RTi12)?
post #37 of 214
Quote:
Originally Posted by mtn-tech View Post

I don't think that there is enough gain / improvement that you will be able to notice the difference.
Is this based on personal experience, measurements, listening tests or knowledge of amplifier and crossover design?
Quote:
Most on the forum agree that passive bi-amping has only very limited benefits and that they are too minor to make an audible difference - I too agree with this opinion.
Most forum members have no knowledge of how an amplifier works internally. It is like being in a forum of people racing cars for fun and expecting them to be expert engine designers. So what everyone thinks is not reality. In the parallel thread, I showed as a matter of electronic design, the damnations of this technique are without merit. If there is an argument that has not been made, please post it there so I can address it.
Quote:
Amir has been very vocal in his support of passive bi-amping:
Not really. I have been vocal in correcting wrong explanation of how the system works. I am a great fan of active bi-amplification. I think many will say they like active bi-amplification but then say things about passive that applies just the same to active!
Quote:
But even in his comments he concedes that there will only be a 10% improvement (the percentage of power originally used by the high frequency side of the crossover in standard configuration) in the power delivery to the more power hungry low frequency drivers - not enough to worry about.
This is an example that applies just as well to active designs. The high frequency energy of music is much lower than bass. So whether you use active or passive bi-amping, the power gain may only be the 10%. It sounds like a small number until you consider typical measurements of an amplifier with respect to harmonic distortion (and noise):

508Marfig4.jpg
If you are the knee of that curve to the right, 10% additional demand will manifest in a ton of distortion. It will also cause the amp to run hotter and possibly shut down. And potentially damage the tweeter in your speaker. Add a second amp and pull it back before the curve goes vertical and you are doing a ton of good.
Quote:
And his argument that when driven to its limits, isolation of distortion to the low frequency drivers will make a worthwhile difference is also flawed - the signal to the tweeter may be cleaner but you are still going to hear distortion from the low frequency drivers - those speakers can sound bad with excessive distortion as well - especially 2-way speakers where the mid driver reproduces part of the human voice (80Hz to 2kHz+)
You are ignoring psychoacoustics. Low frequencies have ton more power and their harmonics pretty close to them (e.g. 100 and 200 hz). Therefore the signal will likely mask a ton of distortions. Not so when the harmonics extend to tweeter frequencies where the music power is much lower and hence may not mask it anymore. This is why we tolerate a lot more distortion in low frequencies.

Now if you do have distortion when bi-amped, then going to single amp will make things far worse due to above measurement. What you need to do is stay bi-amped and get a more powerful amplifier.
post #38 of 214
Amir link me to a proper dbt test between a passive biamped and non biamped setup using the same gear. If you can't, please stop with the handwaving and grandstanding. You make the claims that passive biamping can be beneficial, show us a test that proves reliably these so called benifits are audible.

Of course you would rather everyone biamp, actively or passive doesn't matter, so you can sell more amps.
post #39 of 214
Thread Starter 
Thanks, Jason.

I've always valued your opinion from the onset of this thread regarding the value -- or lack thereof, apparently -- of this passive bi-amping and my instinct has always leaned towards taking what you originally stated under complete advisement. Conversely, I didn't want this thread to degrade into a technological warfare stage which it undoubtedly has -- though in its infancy stage -- as I have seen this in other forums in which someone like me had asked a seemingly harmless question about surge protectors and the whole thread spiraled out of control and into dozens upon dozens of pages of "electrical engineer" types duking it out about transistor ratings and why the electrical currents run the way they do and ultimately crumbling into threatening rhetoric about who held the bigger engineering degree et al...

All I wanted to know was whether it was necessary for "premium" power conditioning to be part of a HT...rolleyes.gif
post #40 of 214
Quote:
Originally Posted by IntelliVolume View Post

Thanks, Jason.

I've always valued your opinion from the onset of this thread regarding the value -- or lack thereof, apparently -- of this passive bi-amping and my instinct has always leaned towards taking what you originally stated under complete advisement. Conversely, I didn't want this thread to degrade into a technological warfare stage which it undoubtedly has -- though in its infancy stage -- as I have seen this in other forums in which someone like me had asked a seemingly harmless question about surge protectors and the whole thread spiraled out of control and into dozens upon dozens of pages of "electrical engineer" types duking it out about transistor ratings and why the electrical currents run the way they do and ultimately crumbling into threatening rhetoric about who held the bigger engineering degree et al...
Hey! I can tell when I am not wanted biggrin.gif. I apologize for posting in your thread. I will leave now.

Jason, when I have time I will respond in the other thread.
Quote:
All I wanted to know was whether it was necessary for "premium" power conditioning to be part of a HT...rolleyes.gif
Le't hope you didn't get one Because if you did, you will be crucified by the very people you are trusting here smile.gif. Take care.
post #41 of 214
Amirm, nicely done bowing out instead of facing the challenge.
post #42 of 214
Quote:
Originally Posted by IntelliVolume View Post

I didn't want this thread to degrade into a technological warfare stage
Quote:
Originally Posted by amirm View Post

I apologize for posting in your thread. I will leave now.

Jason, when I have time I will respond in the other thread.
Quote:
Originally Posted by 67jason View Post

Amirm, nicely done bowing out instead of facing the challenge.

Hrmmmmm! ????
post #43 of 214
My question was posted in this thread he is planning on responding at some point in the future by taking it to some "other" thread....seems like bowing out to me.....ymmv.
post #44 of 214
I would call it respecting the wishes of the OP.

Also, since this section of the forums is titled, "Audio theory, Setup and Chat", I would expect the onus to be on you to show that the theory doesn't translate to sonic benefits.
post #45 of 214
Nice spin, but that's not the way it works. I don't have anything to prove audible or not.

Amirm on the other hand has a vested interest in proving claims. He spouted off potential benifits, I asked him to prove those are reliably audible benefits in a proper test. He backed out of the thread.....so whatever.

Theories are great, but only have merit in the context we are discussing if the said theory can be tested to yield audible benifits.

Passive biwiring from an avr (you know what the topic of this thread is right?) has not been proven to provide an audible benefit to the best of my knowledge, hence I don't have to prove anything. Someone who says there are audible benefits to such should be able to back the claim up with some evidence.
post #46 of 214
Quote:
Originally Posted by 67jason View Post

Nice spin, but that's not the way it works. I don't have anything to prove audible or not.

You've got to be joking!

Quote:
Originally Posted by 67jason View Post

Amirm on the other hand has a vested interest in proving claims.

This is conjecture. Nothing more, nothing less.

Quote:
Originally Posted by 67jason View Post

He spouted off potential benifits,

He provided theory!

Also,
Quote:
Originally Posted by amirm View Post

So the issue here is not the theory. The theory is helpful. What you need to determine is if your amp is operating near its limit. If it is not, then you should stay with your current setup. The way to determine that is to play music with very high dynamics.

Maybe you missed this part?

Or maybe I am mistaken, perhaps the above quote could be construed in a manner that assumes he is doing his best to get you into his store to purchase a high end product that "wouldn't provide audible benefits under any circumstances"!

Quote:
Originally Posted by 67jason View Post

I asked him to prove those are reliably audible benefits in a proper test.

He provided the theory Jason. If you feel that the theory doesn't translate to audible benefits, then again, the onus is on you to prove such.
"Sprouting off" that theory as providing no audible benefits is no better then what you claim amir is doing!
Quite frankly, if you cannot provide links to testing that has been done to prove otherwise, or your own testing, then what gives you the right to request that amir provides further evidence over and above the theory, in the manner that you do?

Quote:
Originally Posted by 67jason View Post

Theories are great, but only have merit in the context we are discussing if the said theory can be tested to yield audible benifits.

Theories are part of the context. Audible benefits are the other. Neither of which you have contributed.

Quote:
Originally Posted by 67jason View Post

Passive biwiring from an avr (you know what the topic of this thread is right?) has not been proven to provide an audible benefit to the best of my knowledge, hence I don't have to prove anything.

I personally like to test all theories for myself (where possible), regardless of what is considered to be correct.



Further more, if the theory doesn't translate into audible benefits, then I still don't see how anyone finds the right to claim amir is providing a disservice to this forum, especially in the manner that people in this forum do.
I would suggest that you guys petition the admins to have the word theory removed from the title of this forum, since the theory obviously isn't worth a pinch a salt.
Edited by Audionut11 - 11/24/13 at 11:53pm
post #47 of 214
Quote:
Originally Posted by IntelliVolume View Post

Thank you FMW...

Have you tried this yourself?

Yes and I've tried biwiring as well. Even though I understand the issues, I tested them during our bias controlled tests.
post #48 of 214
Quote:
Originally Posted by Audionut11 View Post

Quote:
Originally Posted by 67jason View Post

Nice spin, but that's not the way it works. I don't have anything to prove audible or not.

You've got to be joking!

Quote:
Originally Posted by 67jason View Post

Amirm on the other hand has a vested interest in proving claims.

This is conjecture. Nothing more, nothing less.

Quote:
Originally Posted by 67jason View Post

He spouted off potential benifits,

He provided theory!

Also,
Quote:
Originally Posted by amirm View Post

So the issue here is not the theory. The theory is helpful. What you need to determine is if your amp is operating near its limit. If it is not, then you should stay with your current setup. The way to determine that is to play music with very high dynamics.

Maybe you missed this part?

Or maybe I am mistaken, perhaps the above quote could be construed in a manner that assumes he is doing his best to get you into his store to purchase a high end product that "wouldn't provide audible benefits under any circumstances"!

Quote:
Originally Posted by 67jason View Post

I asked him to prove those are reliably audible benefits in a proper test.

He provided the theory Jason. If you feel that the theory doesn't translate to audible benefits, then again, the onus is on you to prove such.
"Sprouting off" that theory as providing no audible benefits is no better then what you claim amir is doing!
Quite frankly, if you cannot provide links to testing that has been done to prove otherwise, or your own testing, then what gives you the right to request that amir provides further evidence over and above the theory, in the manner that you do?

Quote:
Originally Posted by 67jason View Post

Theories are great, but only have merit in the context we are discussing if the said theory can be tested to yield audible benifits.

Theories are part of the context. Audible benefits are the other. Neither of which you have contributed.

Quote:
Originally Posted by 67jason View Post

Passive biwiring from an avr (you know what the topic of this thread is right?) has not been proven to provide an audible benefit to the best of my knowledge, hence I don't have to prove anything.

I personally like to test all theories for myself (where possible), regardless of what is considered to be correct.



Further more, if the theory doesn't translate into audible benefits, then I still don't see how anyone finds the right to claim amir is providing a disservice to this forum, especially in the manner that people in this forum do.
I would suggest that you guys petition the admins to have the word theory removed from the title of this forum, since the theory obviously isn't worth a pinch a salt.

Feel better about yourself?

Sees Amirm has a nutswinger on this forum.
post #49 of 214
Quote:
Originally Posted by Audionut11 View Post
 
 
He provided the theory Jason. If you feel that the theory doesn't translate to audible benefits, then again, the onus is on you to prove such.
"Sprouting off" that theory as providing no audible benefits is no better then what you claim amir is doing!
Quite frankly, if you cannot provide links to testing that has been done to prove otherwise, or your own testing, then what gives you the right to request that amir provides further evidence over and above the theory, in the manner that you do?
 
 

 

No. The burden of proof always lies with the person making the claim. If someone believes there is an audible benefit from passive biamping, and makes this claim, then it is up to that person to provide the proof which supports the claim.

 

Clue: in the case of the claim that passive biamping brings audible benefits, it is not advised to hold one's breath while awaiting proof ;)

post #50 of 214
Quote:
Originally Posted by 67jason View Post

Amirm, nicely done bowing out instead of facing the challenge.

 

To be fair, it is an impossible challenge... since passive biamping brings zero audible benefits, it is going to be pretty darn difficult to find some ABX tests that show otherwise isn’t it?  :)

post #51 of 214
Quote:
Originally Posted by amirm View Post

But even in his comments he concedes that there will only be a 10% improvement (the percentage of power

Please note that 10% more power corresponds to only about 1 dB greater loudness. That is barely audible under ideal circumstances and may be completely impossible to notice if the music is very dynamic and rapidly-changing.
Quote:
originally used by the high frequency side of the crossover in standard configuration) in the power delivery to the more power hungry low frequency drivers - not enough to worry about.
Quote:
Originally Posted by amir 
This is an example that applies just as well to active designs. The high frequency energy of music is much lower than bass.

This is not a global fact. It depends on the speakers and speakers with unusually wide-range tweeters can reverse this situation.
Quote:
So whether you use active or passive bi-amping, the power gain may only be the 10%. It sounds like a small number until you consider typical measurements of an amplifier with respect to harmonic distortion (and noise):

508Marfig4.jpg
If you are the knee of that curve to the right, 10% additional demand will manifest in a ton of distortion. It will also cause the amp to run hotter and possibly shut down. And potentially damage the tweeter in your speaker. Add a second amp and pull it back before the curve goes vertical and you are doing a ton of good.

The knee of the power/distortion curve is the point where the power amplifier starts clipping. Non-clipping operation is a reasonable expectation in a high quality audio system. Virtually every detailed technical explanation that I have added to this thread has excluded situations where there is clipping. Amir's apparently convenient memory which seems to allow him to forget crtical technical considerations seems to be active here.

One of the big problems that many audiophiles seem to be struggling with that only a small percentage of power amplifiers used in home audio have effective clipping indicators. Pro audio suppliers generally include them, and have shown that they can be implemented with a small number of very inexpensive parts.
post #52 of 214
FWIW< the way I read that Marantz power to THD+N chart, the knee of the curve for an eight ohm load is just over 100 watts. THD+N is less than .002 percent (so distortion products are over 90 decibels below the fundamental, http://www.sengpielaudio.com/calculator-thd.htm.) My eye tells me that roughly at 110 watts or so distortion has risen to .01 percent (THD+N 80 dB below the signal). the original article states, "the SM-11S1 easily exceeded [its specified power output] on the test bench, not clipping (defined as 1% THD+N) until 140Wpc into 8 ohms." At 1% distortion, THD+N is 40 dB below the signal. (FWIW, the dreaded "square wave" from clipping

so yes distortion increases a lot once you get past the knee But does it matter? This handy little article collects a fair amount of research into audibility of harmonic distortion. http://www.audioholics.com/room-acoustics/human-hearing-distortion-audibility-part-3.

Thresholds of audibility (that is, the point where the distortion became just noticeable) in the various cited studies seem to run between 0.7% to 5%. looks like audibility of distortion depends a whole lot on the specific sound being reproduced, and at least to some extent on one's experience. You can learn to hear lower levels of distortion, IOW. But not, apparently, down to 0.1% (let alone .001 percent).

So that extra 10 percent of power above the knee takes THD from "very very very inaudible" to merely something like "very inaudible." If the massively increased theoretical distortion number has no audible impact, does it mean much? especially since the higher distortion will occur on momentary (well under a second, unless the sound is compressed to death) peaks, and even a 3 dB peak to average ratio means that after that, let's be generous and say tenth of a second, power requirements are cut in half. I can't recall if I've seen science on audibility of distortion for very short term peaks when the rest of the signal is audibly clean.
post #53 of 214
Quote:
If you are the knee of that curve to the right, 10% additional demand will manifest in a ton of distortion. It will also cause the amp to run hotter and possibly shut down. And potentially damage the tweeter in your speaker. Add a second amp and pull it back before the curve goes vertical and you are doing a ton of good.
This is a plausible hypothesis, but we should recognize what a weak claim it is. If the benefit of passive biamping is limited to a situation where a single amp would be pushed just into the knee of the power-vs-distortion curve, that probably excludes >99% of all systems out there. And it's still only a hypothesis. We'd need some sort of experimental confirmation, either a listening test or measurements that showed significantly lower distortion with the second amp. Neither of those proofs would be easy to do. (Which is why the question remains open, which is why we can argue about it forever.)

But I think two things are clear:

1. Passive biamping will not benefit you unless you are experiencing audible distortion or other obvious problems, such as shutdowns.

2. Switching to a more powerful amp will provide substantially more power than switching to passive biamping.
post #54 of 214
Quote:
Originally Posted by JHAz View Post

FWIW< the way I read that Marantz power to THD+N chart, the knee of the curve for an eight ohm load is just over 100 watts. THD+N is less than .002 percent (so distortion products are over 90 decibels below the fundamental, http://www.sengpielaudio.com/calculator-thd.htm.) My eye tells me that roughly at 110 watts or so distortion has risen to .01 percent (THD+N 80 dB below the signal). the original article states, "the SM-11S1 easily exceeded [its specified power output] on the test bench, not clipping (defined as 1% THD+N) until 140Wpc into 8 ohms." At 1% distortion, THD+N is 40 dB below the signal. (FWIW, the dreaded "square wave" from clipping

All true.
Quote:
so yes distortion increases a lot once you get past the knee But does it matter? This handy little article collects a fair amount of research into audibility of harmonic distortion.
http://www.audioholics.com/room-acoustics/human-hearing-distortion-audibility-part-3.

Note that the period at the end of the sentence breaks the link.

http://www.audioholics.com/room-acoustics/human-hearing-distortion-audibility-part-3

Works.
Quote:
Thresholds of audibility (that is, the point where the distortion became just noticeable) in the various cited studies seem to run between 0.7% to 5%. looks like audibility of distortion depends a whole lot on the specific sound being reproduced, and at least to some extent on one's experience. You can learn to hear lower levels of distortion, IOW. But not, apparently, down to 0.1% (let alone .001 percent).

As you say the threshold of distortion depends and let me add depends greatly on the specific sound being reproduced. 0.1% nonlinear distortion can be heard fairly easily using a test signal composed of 16 Khz and 20 Khz or 17 KHz and 21 KHz mixed together in equal parts. When you distort it, you get an IM product at 4 KHz which "just happens" to coincide with the peak sensitivity of the human ear. ;-) The two stimulus tones are high enough to be pretty hard to hear but will pass though a 44/16 reproduction system. My threshold when I developed this test was well below 0.1% maybe 0.03%. This contrasts with adding second order distortion to an organ pedal note where 10% or more can slip by the ear.
Quote:
So that extra 10 percent of power above the knee takes THD from "very very very inaudible" to merely something like "very inaudible."

And what would one expect, 10% more power is only about 1 dB louder? Audible under ideal conditions, but change the test conditions to some lively music, and then its seriously flirting with inaudible.
Quote:
If the massively increased theoretical distortion number has no audible impact, does it mean much? especially since the higher distortion will occur on momentary (well under a second, unless the sound is compressed to death) peaks, and even a 3 dB peak to average ratio means that after that, let's be generous and say tenth of a second, power requirements are cut in half. I can't recall if I've seen science on audibility of distortion for very short term peaks when the rest of the signal is audibly clean.

Which is one reason why you can challenge some people's assertions in these matters with DBTs and they have nothing to show.

On the bench the knee of those curves is indeed the point where clipping begins. If you have a really good scope you may notice the slight flat-topping, but an old fashioned THD analyzer will show the clipping in its residual and if you use a FFT the grass starts springing right up at the expected frequencies.

The very simple clipping indicator that QSC uses in their amps starts lighting up the clipping LED around 0.01-0.02% if you are testing with sine waves.



The clip detector/indicator is composed of B1, LD2 and adjusted with TR2. There might be $1 worth of parts at single-piece prices.
post #55 of 214
Quote:
Originally Posted by 67jason View Post

Nice spin, but that's not the way it works. I don't have anything to prove audible or not.

Amirm on the other hand has a vested interest in proving claims. He spouted off potential benifits, I asked him to prove those are reliably audible benefits in a proper test. He backed out of the thread.....so whatever.

Theories are great, but only have merit in the context we are discussing if the said theory can be tested to yield audible benifits.

Passive biwiring from an avr (you know what the topic of this thread is right?) has not been proven to provide an audible benefit to the best of my knowledge, hence I don't have to prove anything. Someone who says there are audible benefits to such should be able to back the claim up with some evidence.

It should be clear from both of the ongoing passive biamping discussions that the purported primary benefit of passive biamping has nothing really to do with providing an audible benefit.

Basically, it MIGHT save your tweeter in certain circumstances. MIGHT. I guess it would be audibly beneficial to have a working tweeter in your speaker. biggrin.gif

Of course, passive biamping is also, by defintion, biwiring. So, you'd get those audible benefits. wink.gif <<<< this is a wink
post #56 of 214
Quote:
Originally Posted by sivadselim View Post


It should be clear from both of the ongoing passive biamping discussions that the purported primary benefit of passive biamping has nothing really to do with providing an audible benefit.

Basically, it MIGHT save your tweeter in certain circumstances. MIGHT. I guess it would be audibly beneficial to have a working tweeter in your speaker. biggrin.gif

Passive biamping save your tweeter?

Do tell unless you are going to dredge up the "a too small power amp will burn out your tweeter" myth.

I pronounce that stacked audiophile myths! ;-)
post #57 of 214
Quote:
Originally Posted by arnyk View Post

Passive biamping save your tweeter?

That's my (simple-minded?) understanding of it, arnyk.


Quote:
Originally Posted by arnyk View Post

I pronounce that stacked audiophile myths! ;-)

Pass the syrup!
post #58 of 214
Quote:
Originally Posted by sivadselim View Post

Quote:
Originally Posted by arnyk View Post

Passive biamping save your tweeter?

That's my (simple-minded?) understanding of it, arnyk.

Details?

Quote:
Quote:
Originally Posted by arnyk View Post

I pronounce that stacked audiophile myths! ;-)

Pass the syrup!

Stacked audiophile myths are so sour and indigestible that no amount of sweetening can help/
post #59 of 214
Thread Starter 
Quote:
Originally Posted by amirm View Post

Hey! I can tell when I am not wanted biggrin.gif. I apologize for posting in your thread. I will leave now.

Jason, when I have time I will respond in the other thread.
Le't hope you didn't get one Because if you did, you will be crucified by the very people you are trusting here smile.gif. Take care.

No, amir, I didn't mean that, at all -- it's just that Jason and I have had PM discussions in the past about certain topics and we normally get to more "basic" breakdowns of some of these discussions/topics. I didn't mean to make you feel like you "weren't wanted" or that you should leave the thread...the topic here and its associated rhetoric have gotten out of line already and over my head so perhaps I posted the question in the wrong section of the forum ("Audio THEORY" etc.)...

No need to "apologize" for posting in my thread, sir; all opinions are welcome and what I was asking for. It's just that now I think we've gotten off the rails a bit...wink.gif
post #60 of 214
Thread Starter 
Quote:
Originally Posted by mcnarus View Post

But I think two things are clear:

1. Passive biamping will not benefit you unless you are experiencing audible distortion or other obvious problems, such as shutdowns.

2. Switching to a more powerful amp will provide substantially more power than switching to passive biamping.

Thank you, McNarus...
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