Unconventional Bi-amping B&W 802D - WOW

[ED K]

Been listening to my CDs for hours now since I did my experiment of running the tweeter/mid drivers using the Mcintosh 402 and the bass drivers using the Bryston 7B-SSTs on the B&W 802Ds. I have been VERY pleasently surprized and VERY happy with the results. The issue I had after "upgrading" the digital cable from my Mcintosh MVD861 CD/DVD player to the Mcintosh MX135 pre/pro with a GREEN HORNET digital IC (for the purpose of increasing detail), was that the detail was greatly improved but the music became more bright/harsh. So, I tried bi-amping using the Bryston amps to drive the bass and the mcintosh 402 to drive the high/mids. The music has become (to my ears) more natural. The highs and mids are very detailed but without the brightness and the bass just continued to be fantastic!. I'm sure there are folks who will not agree with this set up for one reason or another but as with all things audio, you need to try it to see if you like it regardless of your beliefs.

[Kal Rubinson]

How did you adjust the relative gain on the amps?

Kal

[ED K]

Kal
When I tried this I had a concern that the gain of each amp would cause an issue but, this has not been the case. I played many CDs that I was familar with so that i could do a good comparison before and after the change. The volumes I play music at I would consider "normal to high normal". There may be an issue at very high volumes but not at the volumes I listen to. The only change I could hear was with the high to mid range. With just the Brystons and the 802Ds there was a bright sound but with a fantastic bass response. With the Mcintosh added to the mix, the brightness just went away but it still produced the detail I was looking for and I still could enjoy the bass response that the Brystons do so well. I'm not sure why it has worked out as well as it has (maybe my accustics, my ICs, speaker cables or the amps I chose for this experiment), I really don't know.

[DM3000 Owner]

Ed,

Great! Sounds like you reached a happy mix. You are very lucky that you do not need to adjust gain. A B&W engineer told me that they normally say just use the same power on the top as the bottom. But then again with two different amps and two different input sensitivities, you are lucky it worked so well. Congrats.

I tri-amplified a pair of K Horns with a professional Yamaha D2040 dividing network. It was really nice because I could set each driver individually. You can also mute each driver and adjust (like if the midrange was not quite right, mute the other driver, adjust, then turn them back on). Great control and made tuning a breeze.

[Kal Rubinson]

Kal
When I tried this I had a concern that the gain of each amp would cause an issue but, this has not been the case. I played many CDs that I was familar with so that i could do a good comparison before and after the change. The volumes I play music at I would consider "normal to high normal". There may be an issue at very high volumes but not at the volumes I listen to. The only change I could hear was with the high to mid range. With just the Brystons and the 802Ds there was a bright sound but with a fantastic bass response. With the Mcintosh added to the mix, the brightness just went away but it still produced the detail I was looking for and I still could enjoy the bass response that the Brystons do so well. I'm not sure why it has worked out as well as it has (maybe my accustics, my ICs, speaker cables or the amps I chose for this experiment), I really don't know.

Without measurement to assure exactly equal levels, you cannot know if you haven't merely introduced a tone control adjustment.

IMHO, that's the major foundation of passive bi-amping stories.

Kal

[ED K]

Was just passing on something that worked for me. I am aware that there are many technical issues when bi-amping. Thanks for your feedback.

[Kal Rubinson]

I am sorry if you took my comment/query as criticism. Your positive observations would be more generally useful to others, who may not have the exactly identical components as you do, with more info.

Kal

[ED K]

No problem Kal. I appreciated your feedback. Since I retired a few years ago I have been "playing around and experimenting" almost non stop. This is a great hobby and pass time with a significant amount to learn. That's what makes it so much fun!

[Jesse111]

How did you adjust the relative gain on the amps?

Kal

Hey Kal, or anybody else that may know,

You seem to be the technical inclined type. I will be recieving a pair of 800D's in a few weeks. I have a pair of McIntosh 501s. If I wanted to biamp, should I stay with another pair of 501s or could I go to the 250 watt per channel stereo amp model MC 252? Or perhaps the MC 402 which is also a stereo amp but with 400 watts per channel both from McIntosh? It just seems that a 500 watt mono block for the mid and tweeter is a bit overkill. Would it throw the sound out of balance by using two different size amps even if they are from the same manufacturer?

Thanks

[Kal Rubinson]

Hey Kal, or anybody else that may know,
You seem to be the technical inclined type. I will be recieving a pair of 800D's in a few weeks. I have a pair of McIntosh 501s. If I wanted to biamp, should I stay with another pair of 501s or could I go to the 250 watt per channel stereo amp model MC 252? Or perhaps the MC 402 which is also a stereo amp but with 400 watts per channel both from McIntosh? It just seems that a 500 watt mono block for the mid and tweeter is a bit overkill. Would it throw the sound out of balance by using two different size amps even if they are from the same manufacturer?
Thanks

The size has less to do with this than the relative gain of each amp. Unless they are of identical gain (or can be so adjusted), you will be driving the HF more or less than the LF and that will tilt the frequency response.

As for power, the difference between 250 and 400 is only 2dB and between 250 and 500, it is only 3dB. So, how much power do you thing the mid/highs will take? Frankly, I am not a big fan of passive bi-amping and prefer just using an adequate single amp per channel.

Kal

[Jesse111]

Well, I will choose to agree with you because agreeing with you will save me about 9 thousand bucks. If for some reason I'm not satisfied with my 501's, might you have a suggestion on an upgrade path I could consider? Or do you feel the 501s will do the job?

Thanks Kal.

[Kal Rubinson]

Well, I will choose to agree with you because agreeing with you will save me about 9 thousand bucks. If for some reason I'm not satisfied with my 501's, might you have a suggestion on an upgrade path I could consider? Or do you feel the 501s will do the job?
Thanks Kal.

I cannot advise you here since I've never heard the 501s (or any other McIntosh amp) on anything except McIntosh speakers at shows and, certainly, never with B&W speakers. My comments were based simply on their power ratings which I do not doubt.

If you are not satisfied with the combination, then you must try to characterize the reasons for your dissatisfaction so that you can find appropriate alternatives. There are too many different amps out there for me to say, simply, 'these are better.'

Kal (using Classe and BelCanto amps now)

[Jesse111]

I cannot advise you here since I've never heard the 501s (or any other McIntosh amp) on anything except McIntosh speakers at shows and, certainly, never with B&W speakers. My comments were based simply on their power ratings which I do not doubt.

If you are not satisfied with the combination, then you must try to characterize the reasons for your dissatisfaction so that you can find appropriate alternatives. There are too many different amps out there for me to say, simply, 'these are better.'

Kal (using Classe and BelCanto amps now)

Agreed.
I will of course listen to my Mac combo for many many weeks. I may be fully satisfied as I presume I will. Thanks.

[Kal Rubinson]

Agreed.
I will of course listen to my Mac combo for many many weeks. I may be fully satisfied as I presume I will. Thanks.

One can only hope! :T

Kal

[PavelL]

Frankly, I am not a big fan of passive bi-amping and prefer just using an adequate single amp per channel.

Kal

Kal, may I ask why? It must be easier for an amp to deal with ONLY one driver at a time and with only part of the whole crossover... With hard-to-drive speakers with complicated crossovers an amp's performance will improve? will it not? But what do I know...

[Kal Rubinson]

Kal, may I ask why? It must be easier for an amp to deal with ONLY one driver at a time and with only part of the whole crossover... With hard-to-drive speakers with complicated crossovers an amp's performance will improve? will it not? But what do I know...

The amps are not dealing with one driver at a time as they would with active multi-amping but with the same networks that sit between them and the drivers. Besides, let's not anthropomorphize the amps. They provide voltage and current into a complex load and, as long as they are stable into that load and have adequate output capability, they do their job. Finally, the power gain achieved by using two identical amps on the low and the high side of the network is small (and not double) since the power demands of the high side is usually so much less than the low side that the power increase on it is superfluous. If the amp driving the low side performs better if relieved of the need to drive the high side, it was marginally inadequate to begin with. If the single amp can drive the whole speaker, adding another is not useful. IMHO!

Active multi-amping is another kettle of fish with distinctive advantages but with substantial overhead in cost and complexity.

Kal

[PavelL]

The amps are not dealing with one driver at a time as they would with active multi-amping but with the same networks that sit between them and the drivers. Besides, let's not anthropomorphize the amps. They provide voltage and current into a complex load and, as long as they are stable into that load and have adequate output capability, they do their job. Finally, the power gain achieved by using two identical amps on the low and the high side of the network is small (and not double) since the power demands of the high side is usually so much less than the low side that the power increase on it is superfluous. If the amp driving the low side performs better if relieved of the need to drive the high side, it was marginally inadequate to begin with. If the single amp can drive the whole speaker, adding another is not useful. IMHO!

Active multi-amping is another kettle of fish with distinctive advantages but with substantial overhead in cost and complexity.

Kal

Thank you, Kal! Your reply and your IMHO give me something to think about... :W I purposefully did not ask about ACTIVE biamplification. /I still do not understand what corrects drivers' freq. response in place of a crossover in most active biamp schemes/ Please correct me if I'm wrong but your reply can be interpreted as "provided speakers' sensitivity is high enough - any amp will drive them just fine... No matter how complex a load an amp has to deal with.. And there won't be any improvements whatsoever in terms of overall sound quality if passive biamplification is implemented" Now how does one measure an amp's performance given a particular COMPLEX load of a three-way speaker? I do not recollect any amp reviews with such measurements...

P.S. what did I just say in English? Should have said sorry upfront - no mother tongue you know...

[Kal Rubinson]

/I still do not understand what corrects drivers' freq. response in place of a crossover in most active biamp schemes/

There is an active electronic crossover before the power amps that does than in place of the now-removed original crossover from the speaker box.

Please correct me if I'm wrong but your reply can be interpreted as "provided speakers' sensitivity is high enough - any amp will drive them just fine...

Any competent amp.

No matter how complex a load an amp has to deal with.. And there won't be any improvements whatsoever in terms of overall sound quality if passive biamplification is implemented"

I only spoke about power, not other aspects of performance which, I believe, are not variables between single amp or biamp situations.

Now how does one measure an amp's performance given a particular COMPLEX load of a three-way speaker? I do not recollect any amp reviews with such measurements...

Well, you can measure performance with the speaker connected. However, that is only a particular result, so most such tests are done with a "simulated" standard load.

Kal

[PavelL]

Thank you, sir!!!

[D-bucket]

I had raised this question a while back but didn't get a response.

When passively bi-amping a pair of b&w 803D's (or any of the other 800 series) with 2 identical stereo power amps, are there major advantages or differences between these two connections?

Connection 1 - (one 2-channel amp dedicated to each speaker)

• amp #1 - one channel connected to HF posts of left speaker & second channel connected to the LF posts of left speaker
  
• amp #2 - one channel connected to HF posts of right speaker & second channel connected to the LF posts of right speaker

Connection 2 - (one 2-channel amp dedicated to each frequency filter)

• amp #1 - one channel connected to HF posts of left speaker & second channel connected to the HF posts of right speaker
  
• amp #2 - one channel connected to LF posts of left speaker & second channel connected to the LF posts of right speaker

One day during some future upgrade cycle I may to get around to checking this out for myself but in the meantime does anyone have any thoughts or experiences with either of the above setup connections?

[Kal Rubinson]

If the amps are identical, I would go with Connection 1 for reasons of channel separation and so that the other amp is not stressed when one LF channel has a huge power demand. Also, with simultaneous LF demands in both channels, it would be shared by the power supplies in the two amps.

If one amp is more potent than the other, I woud go with Connection 2 and use it for both LF sections.

All theoretical, of course.

Kal

[PavelL]

And with connection 1 you could place your amps closer to speakers thus making speaker wire runs MINIMAL. Some audiophiles I talked to believe that speaker cables do affect sound and that the shorter sp cables the better /not the case with interconnects of reasonable length/ And just like Kal said LR channel separation will be determined by your preamp and will not be affected by your power amp...

[D-bucket]

Thanks a lot for the responses Kal & PavelL, and especially for giving an understandable rationale for one connection method vs the other one. This is helping me get a clearer handle on some approaches to upgrade and/or enhancement possibilities.

[PavelL]

Thanks a lot for the responses Kal & PavelL, and especially for giving an understandable rationale for one connection method vs the other one. This is helping me get a clearer handle on some approaches to upgrade and/or enhancement possibilities.

but the big question in the end is wether it will SOUND any better if you passively biamplify your speakers... Does it have real practical benefits? I've heard quite opposite opinions from folks who played with pass. biamping. :W

[fauzigarib]

Another biamping question:

Kal,

Thanks for the informative responses.

A couple more questions for you:

First of all: How does one measure gains of the amps, other than the specs. Is there a way for us normal folks?

The other question: Let's take a speaker like the B&W 802D. Someone has spent about US$12,000 to aquire a pair of speakers that have been known for the amount of R&D they spend on their crossovers and matching / tuning them to not only the drivers in the speakers, but also to achieve that B&W sound.

Am I correct in my thinking that if you actively biamp, then you are, in effect bypassing the internal crossover? And if so, would you ever be able to do an as good a job as the B&W engineers on a pair of speakers like that at making it sound good?

I'm just someone who messed around with passive byamplification, and I just didn't think it did my speaker justice. It looked cool as hell having two different amps running, and cool to talk about with friends.. but it was just no good.

Look forward to your response!

-Fauzi

[Kal Rubinson]

but the big question in the end is wether it will SOUND any better if you passively biamplify your speakers... Does it have real practical benefits? I've heard quite opposite opinions from folks who played with pass. biamping. :W

Trust your own ears. If you think you hear a difference/improvement, mebbe that's good enough.

Kal

[Kal Rubinson]

First of all: How does one measure gains of the amps, other than the specs. Is there a way for us normal folks?

Signal generator (or test tone on a disc) and a audio-frequency voltmeter.

The other question: Let's take a speaker like the B&W 802D. Someone has spent about US$12,000 to aquire a pair of speakers that have been known for the amount of R&D they spend on their crossovers and matching / tuning them to not only the drivers in the speakers, but also to achieve that B&W sound.

Am I correct in my thinking that if you actively biamp, then you are, in effect bypassing the internal crossover? And if so, would you ever be able to do an as good a job as the B&W engineers on a pair of speakers like that at making it sound good?

Excellent point and the exact reason why, despite the theoretical advantages of active bi-amping, it is not for the faint of heart and/or the the technically inexperienced. It can be done but it ain't simple or easy.

Kal

[D-bucket]

... if you actively biamp, then you are, in effect bypassing the internal crossover? And if so, would you ever be able to do an as good a job as the B&W engineers on a pair of speakers like that at making it sound good?...

... Excellent point and the exact reason why, despite the theoretical advantages of active bi-amping, it is not for the faint of heart and/or the the technically inexperienced. It can be done but it ain't simple or easy...

Bingo! You have hit the nail squarely on the head for me. In the past, I could never quite put my finger on exactly why I couldn't bring myself to seriously consider active biamping possibilities irregardless of the sonic benefits. Whenever the topic would come up and I thought about looking into it further, I would immediately experience that heightened sense of anxiety you get when you are in a danger zone. Guess I fit into your "faint of heart" category, :lol:

[Edit] Good catch & you are right the word "active" could easily be missed

[RobP]

Actually B&W speakers that have two sets of terminals are designed so they can be bi-amped without bypassing the internal crossovers, so unless you actually remove the crossover, bi-amping your 803's or 802's etc. will not harm them by this act alone.

Edit: Duh...... I failed to see the phrase "active bi-amping" in the above post. Let the oke: at me begin! :lol:

[PavelL]

The music has become (to my ears) more natural. The highs and mids are very detailed but without the brightness and the bass just continued to be fantastic!

By the way I recollect 800 series manual that says no lesser amps on tweeters... Reason why some B&W setups sound "bright" anyone?!?!?

[gerardhn]

Now the big question:
what is better on the 802 D
1. 2 * M400 classe monoblock standard
2. 2 * CA2200 (btw how do I get an XLR Y split cable) biamp..
??

[D-bucket]

Haha, some choice, either of those Classe amps are great choices and has a V.I.P invitation to the party! arty: But that pair of CA-M400's would get my vote. However I would be almost as happy with a pair of CA-200's also.

Just place that same search string "xlr y split cable" in a google search for more info & choices.