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Old 12-09-2013, 10:13 PM - Thread Starter
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Rotel 1075  -  five channel @ 120

Yamaha 3800 Receiver  - seven channel @ 140

 

5 speaker system

Mains are B&W 603S2  rated at 150

Center  B&W LCR 600 S3 rated at 150

Rears B&W 602S3 rated at 120

 

All speakers are bi amp capable

 

Would you guys bi amp? I have read it makes it sound much better?

 

Example: would you give the Main front right 2 full channels from the Rotel. And the same for the Main front left?  Then give the center the last remaining channel from the rotel and not bi amp?

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Old 12-09-2013, 10:33 PM
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passive biamping is a waste of time. whatever it was you read can lead you down audio voodoo paths, best to steer clear.
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I don't need snobs to tell me how to think, thank you!
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Old 12-10-2013, 12:41 AM
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Rather than asking the opinions of random strangers on an interweb forum - try it for yourself and go with whatever you want.
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Old 12-10-2013, 04:42 AM
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This is a question that has always confused me. My speakers are not bi-ampable, so its not an issue for me. But if it was, I want to understand why biamping is not in favor.

Jason, you say passive bi-amping is useless. Why? I have read other posts where other AVS'ers say only using an external crossover would achieve benefits in bi-amping. I thought if you remove the bridges on bi-ampable speakers, you are separating the crossovers? If I am correct, then what's the difference if you biamp at the speakers built in crossover network or at an external crossover network? So I guess I need to know what the difference between passive an active biamping; built-in and external crossovers. Can you be more specific Jason and help me out?

BTW, to the OP...I was always taught that bi-amping is beneficial only if you are using two separate amps (actual components with their own power supply) going into the same speaker. To biamp using extra channels from a AVR is useless, because all the channels share a common power supply. So your not really doubling the power into a speaker. This makes sense to me. I am hoping to now learn more about the passive vs. active argument that I read so much about. Looking forward to a clear explanation. Thanks.

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Old 12-10-2013, 07:38 AM
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Originally Posted by Paraneer View Post

This is a question that has always confused me. My speakers are not bi-ampable, so its not an issue for me. But if it was, I want to understand why biamping is not in favor.

Jason, you say passive bi-amping is useless. Why? I have read other posts where other AVS'ers say only using an external crossover would achieve benefits in bi-amping. I thought if you remove the bridges on bi-ampable speakers, you are separating the crossovers? If I am correct, then what's the difference if you biamp at the speakers built in crossover network or at an external crossover network? So I guess I need to know what the difference between passive an active biamping; built-in and external crossovers. Can you be more specific Jason and help me out?

BTW, to the OP...I was always taught that bi-amping is beneficial only if you are using two separate amps (actual components with their own power supply) going into the same speaker. To biamp using extra channels from a AVR is useless, because all the channels share a common power supply. So your not really doubling the power into a speaker. This makes sense to me. I am hoping to now learn more about the passive vs. active argument that I read so much about. Looking forward to a clear explanation. Thanks.

It is a very technical and fairly complicated subject. Rather than write a book, I suggest you go to the audio theory and setup forum and read some of the threads there. Passive biamplification is almost always meaningless and, when it can make a difference, it is the wrong solution the problem. Active biamplification is another issue entirely. Go check it out.
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Old 12-10-2013, 08:22 AM
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Vandersteen Audio, which makes some of the best speakers in the world. says that their in-house research on their speakers shows an improvement from bi-wiring.

I respect Richard Vandersteen, and would not dismiss this lightly.

I personally think that 95% of all speakers do not benefit from bi-wiring, as long as #10 or #12 wire is used to connect the speakers.

I would only suggest bi-wiring where the speaker has relatively low sensitivity and thus needs a LOT of bass-drive current from the amplifier.

Bi-amping is only beneficial where the main amplifier in use does not have enough power/current capability (which IS often the case with AVRs).
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Old 12-10-2013, 08:49 AM
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Quote:
Originally Posted by commsysman View Post

Vandersteen Audio, which makes some of the best speakers in the world. says that their in-house research on their speakers shows an improvement from bi-wiring.

I respect Richard Vandersteen, and would not dismiss this lightly.

I personally think that 95% of all speakers do not benefit from bi-wiring, as long as #10 or #12 wire is used to connect the speakers.

I would only suggest bi-wiring where the speaker has relatively low sensitivity and thus needs a LOT of bass-drive current from the amplifier.

Bi-amping is only beneficial where the main amplifier in use does not have enough power/current capability (which IS often the case with AVRs).

Go check the threads in the theory section that FMW mentioned.

There is virtuly no audible benefit nor is there any increase in power available to your speakers passivley biamping off an avr.

Passively biamping might offer a limited benefit (albeit the wrong tool for the job) when using two power amps in you might get 1 to 2 more db before clipping. 1 to 2 db is barely audible and if you are this close to the clipping point at your desired SPL levels the the right solution or tool would be a bigger amp.

Your vandetsteens are not immune to the laws of physics and will behave the same way as any other passive biamped speakers.

If people really want to biamp and have true benefits then active biamping is the way to go, but is technically challenging and difficult to implement in the home. You would need speakers with no passive crossover and include an active crossover in order to manipulate the amplified frequencies.

The main reason why passive biamping is marketed to ignorant audiophiles is that there are outfits like vandersteen who perpetuate audio voodoo and there are (deleted by Moderator) . these magic believers and voodoo marketers force the industry to dismiss practical scientific audible differences in favor of gimmicks. Passive biamping is a gimmik with no real audible benefits. If you need more power get a bigger amp.

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Old 12-10-2013, 09:31 AM
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Old 12-10-2013, 09:37 AM
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Here is an excellent post from arnyk about PASSIVE bi-amping:

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Originally Posted by arnyk View Post

Quote:
Originally Posted by UndersAVS View Post

Speakers and AV Receivers with their bi-amping capabilities.

For your reading entertainment, a sort of a mini white paper about passive biamping:


When you passively biamp, the same signal is coming out of the amplifier for the high frequency section of the speaker and amplifier for the low frequency section of the speaker, which is the same signal that would be coming out of a single amplifier driving the same speaker connected normally. In all three cases, the amplifiers produce the same signal. In all three cases the high and low frequency sides of the speaker receive the same signal and produce the same sound. In all three cases if you try to increase the signal past the point where the amplifier clips, there is distortion at the same point. Therefore, no significant additional undistorted output can possibly come from the speaker due to passive biamping.

Modern SS amps are very linear as long as they are not clipping. Clipping is stimulated by trying to make an amplifier produce more voltage or current than it has the resources to deliver.

In the early days of SS amps (second generation) it was not uncommon for power amplifiers to unexpectedly lack sufficient current to deliver a linear signal to certain speakers. The original Crown DC300 interfaced to a pair of AR3s might ave been an early poster boy for this problem. Third generation and successive generation power amplifiers generally address or solve these problems. (BTW first generation SS amps simply fried on the spot!)

The unexpected clipping problem has a number of dimensions:

(1) Clipping may happen unexpectedly, that is at lower power levels than the power ratings of the amplifier would lead us to believe it to be a concern. But, it is not a problem at low and medium power levels.
(2) Clipping can be clean or messy, and messy clipping can be far more audible than clean clipping. The ear is accepting of short term and infrequent clean clipping.
(3) Power amplifiers have a number of different current limits:
(3a) Their power supplies can momentarily run out of current to supply. This is mostly about power transformers and filter capacitors.
(3b) Their output transistors have natural limits on how much current they can pass with reasonable linearity.
(3c) There can be issues with output device safe operating area, where avoidance of destruction of the output devices under esoteric conditions may involve highly non linear protection circuits that can activate at power levels on the order of half or a third of the usual power ratings of the amplifier.

So, when a power amplifier is operating linearly, that is not clipping, passive biamplification has nothing to offer.

When an amplifier is clipping due to it being asked to exceed its ability to provide voltage, again passive biamplification has nothing to offer.

When an amplifier is clipping due to it being asked to exceed its ability to provide current, passive biamplification may have something to offer.

There are some important prerequisites that need to be met for passive biamplification to provide a sound quality advantage:

(1) The amplifier needs to be clipping due to its inability to provide sufficient current.
(2) The amplifier needs to be clipping due to its inability to provide sufficient current due to a limitation of the individual power amplfiier circuit. If the current limitation is due exhaustion of the capacity of a shared power supply, using multiple output stages to route power from that exhausted power supply cannot provide a significant advantage. You can't squeeze blood out of a stone!
(3) The signal needs to have a spectral content that results in a significant spreading of power across the frequency range of both the low frequency and high frequency sections of the loudspeaker system being passively biamplified.

None of these requirements are exactly a slam dunk.

Clipping due to a lack of voltage capability is far more common and is pretty much guaranteed as long as the speaker does not provide an unusually tough reactive or low resistance load. Many AVRs do not have current limiting or SOA limiting circuits in their output stages because modern output devices can be very robust in this way.

People like to criticize AVRs for having weak power supplies, and passive biamping provides very weak if any relief from this situation if it rears its ugly head.

Since we're talking about crossover points in the 2 KHz range, it is very common for most of the energy of the music to be concentrated in the low frequency range, and again passive biamping provides very weak if any relief from this situation if it rears its ugly head. Passive biamping can only have significant advantages if their is near-uniform spreadiing of power above and below the crossover frequency.

Quote:
Another manufacturer farce foisted upon the unsavy consumer.

Equipment manufacturer dishonesty is apparent when examining the overwhelming bench test information provided by numerous second party publications. These tests make it obvious that most AV Receivers produce significantly less wattage than advertised when tasked with driving more than two channels.

I may surprise you by not being overly concerned about AVR power supplies. The hidden agenda is the crest factor or peak-to-average ratio of music and the impedance curves of real world speakers. The second party tests that you are referring to are IME always based on sine wave testing with resistive loads. This is generally very unrealistic, particularly on the test signal end of the story. I've been intensively gathering information about the crest factor of music, and the worst I've seen so far is about 10 dB. This means that music puts only about 1/10 as much load on an AVRs power supply as the conventional sine wave test signals.

AVR power supplies have also be criticized by their lack of oomph below 60 Hz due to undersized power supply filter capacitors. The near-universal use of separate powered subwoofers crossed over at 80 Hz or so makes that situation largely moot.

Another issue is the simple fact that not a lot of people actually use the full power output of their AVRs. If you actually go in and measure the voltage across the speakers it is often so low that a few inexperienced techs think that there is nothing at all! ;-)

AVR power supplies may not be pretty, but they generally work well enough.

Now if we could only say that about rooms and speakers!



Here is a great article (in two parts) from Rod Elliott that explains ACTIVE bi-amping in detail:

Benefits of Bi-Amplification - Not quite magic, but close (Part I)

Benefits of Bi-Amplification - Crossovers, tri-amping, etc. (Part II)
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Old 12-10-2013, 09:42 AM
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Originally Posted by commsysman View Post

Vandersteen Audio, which makes some of the best speakers in the world. says that their in-house research on their speakers shows an improvement from bi-wiring.

What sort of improvement does he claim? All bi wiring does is move the connection between the filters in a crossover from the speaker terminals to the amplifier terminals. It goes against the laws of physics that it would affect anything positively that increasing wire gauge wouldn't also handle. The only possible diffrerence would result from wire that is of inadequate gauge for the distance involved.
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I respect Richard Vandersteen, and would not dismiss this lightly.

So do I as a speaker designer. If he is doing "in-house research" that proves an audible difference from bi-wiring I would dismiss it instantly. I suspect there is something missing from your statements.
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I personally think that 95% of all speakers do not benefit from bi-wiring, as long as #10 or #12 wire is used to connect the speakers.

Change that to 100% and I'm on board.
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I would only suggest bi-wiring where the speaker has relatively low sensitivity and thus needs a LOT of bass-drive current from the amplifier.

Wouldn't it be simpler and more effective just to use the right wire gauge in the first place?
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Bi-amping is only beneficial where the main amplifier in use does not have enough power/current capability (which IS often the case with AVRs).

So the number of wires you connect to an amplifier terminal affects its current handling capability?
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Old 12-10-2013, 09:51 AM
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Suggesting that Vandersteen Audio, or Richard Vandersteen, is practicing "voodoo' suggests an inadequate knowledge of certain facts.

One...The company and the man have designed and produced a huge number of highly-praised speakers over the past 30+ years. which have repeatedly been singled out by the top experts in the field out as some of the very best you can buy at any price.

Two...Richard Vandersteen is highly respected in the audio press and engineering communities for his innovative and effective designs and meaningful research.

I think you would have a hard time finding a single member of the Audio Engineering Society who would consider his research or opinions to be "voodoo" or anything other than substantive.

You can READ his opinions on bi-wiring and bi-amping on the Vandersteen website, so there is no need for any confusion about them.

If you have some research or design experience which qualifies you to criticize an acknowledged expert in the field, feel free to tell us all about it.










Quote:
Originally Posted by 67jason View Post

Go check the threads in the theory section that FMW mentioned.

There is virtuly no audible benefit nor is there any increase in power available to your speakers passivley biamping off an avr.

Passively biamping might offer a limited benefit (albeit the wrong tool for the job) when using two power amps in you might get 1 to 2 more db before clipping. 1 to 2 db is barely audible and if you are this close to the clipping point at your desired SPL levels the the right solution or tool would be a bigger amp.

Your vandetsteens are not immune to the laws of physics and will behave the same way as any other passive biamped speakers.

If people really want to biamp and have true benefits then active biamping is the way to go, but is technically challenging and difficult to implement in the home. You would need speakers with no passive crossover and include an active crossover in order to manipulate the amplified frequencies.

The main reason why passive biamping is marketed to ignorant audiophiles is that there are outfits like vandersteen who perpetuate audio voodoo and there are (deleted by Moderator) . these magic believers and voodoo marketers force the industry to dismiss practical scientific audible differences in favor of gimmicks. Passive biamping is a gimmik with no real audible benefits. If you need more power get a bigger amp.
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Old 12-10-2013, 11:26 AM
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You can READ his opinions on bi-wiring and bi-amping on the Vandersteen website, so there is no need for any confusion about them.


Perhaps you could provide a link. I couldn't find anything about biwiring.
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Old 12-10-2013, 03:27 PM
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Quote:
Originally Posted by FMW View Post

Quote:
Originally Posted by commsysman View Post


You can READ his opinions on bi-wiring and bi-amping on the Vandersteen website, so there is no need for any confusion about them.


Perhaps you could provide a link. I couldn't find anything about biwiring.

Allow me fellas... wink.gifsmile.gif
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Old 12-10-2013, 04:07 PM
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The top result in that ^ search links back to an "orphan" FAQ page that no longer links to the Vandersteen site.

Probably with good reason too... it IS pseudo-scientific "audio voodoo", summed up nicely with these two classics:
Quote:
All the cables in a bi-wire set must be the same. There is often great temptation to use a wire known for good bass response on the woofer inputs and a different wire known for good treble response on the midrange/tweeter inputs. This will cause the different sonic characteristics of the two wires in the middle frequencies to interfere with the proper blending of the woofer and midrange driver through the crossover point.
Quote:
The cables should all be the same length. This is not due to the time that the signal takes to travel through a cable, but rather that two different lengths of the same cable will sound different. If the cables connecting one speaker are a different length than the cables connecting the other speaker, the resulting difference in sound between the two speakers will compromise the imaging and coherence of the system.

OK, one more for giggles:
Quote:
Since short runs of speaker cable sound better than long runs, consider placing your electronics between the speakers rather than off to one side. If for convenience or aesthetic considerations, the electronics must be located a considerable distance from the speakers, it is usually preferable to place the amplifier between the speakers and use long interconnect cables and short speaker wire.

Commsysman, surely you don't subscribe to this stuff? There is no direct evidence that Mr R. Vandersteen does.
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Old 12-10-2013, 06:18 PM
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Sorry, I don't use Google. The article is pure nonsense. Typical high end voodoo, as you say. But it works on some people.
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