B&W 800D2 - Bi-amping vs Bi-wiring


Hello folks,

I am looking for feedback on bi-amping these amazing speakers. I currently own a CA-2200 amp and it seems 200w per channel may not be adequate to realize full potential of 800D2. So i was thinking of bi-amping two classe ca-2200 for L/R speakers, thus feeding 400w each to Left and Right speakers. Or am i better off buying a pair of CA-M600 for each speaker? I would like to stick with Classe amps only... love the way they sound.

Next question is about bi-wiring. There seems to be bit of confusion (atleast in my head) on the best way to bi-wire speakers. The true shotgun cable is terminated with two split(+ and -)on amp end and 4 splits (2 + and 2 -)on speaker end. I have seen illustrations where bi-wiring is done with 2 identical runs of cables between dual binding posts on amp and speaker ends feeding seperate signal to LF and HF speaker inputs. I have read about the advantages of two single runs but my cable manufacturer doesn't seems to agree with this configuration. He is still recommending shotgun configuration.

I hope to gain some insight before i make an investment in a amp or new cables. I currently own a bi-wire cable in shotgun configuration.
Convert?fit=crop&h=128&policy=eyjlehbpcnkioje1mdg0mti1otisimnhbgwiolsicmvhzcisimnvbnzlcnqixx0%3d&rotate=exif&signature=648215457e5e144e97d10d690b48fd1077c110a61b1c0fef01f21973c5584619&w=128lalitk
Anytime you can go to Mono blocks I would recommend it, over bridging or bi amping with stereo amps. Also, do your self a big favor and dump the MIT's for something that dosent rob the impact and life out of your beautiful sound, IMO you will never hear the true potential of your system until you do. Also, Two runs of cables to each speaker is Bi-wiring in my book. I used to use cables with boxes on them and my Dynaudio speakers never really jumped until I switched away from them. Nordost, Kimber 12tc, Morrow Audio MA7's any of these would be a great audition. Cant hurt to try right. Youll be amazed!
Passively bi-amping with another CA-2200 will get you less than 3dB more output. Using the CA-M600 will get you almost 5dB and, probably, more head room.

I won't stir the hornets by commenting on bi-wiring but I use shotgun cables on my 800D2s, fwiw.
Hello Kr4,

Thank you for your reply. May I know which amp you're using with 802D's?
My dealer is also recommending CA-M600's.
800d2 not 802d.

I use several at the moment.
Mac MC-303
Parasound A31
NAD M22 x 2
Benchmark AHB2
Etc.
"Or am i better off buying a pair of CA-M600 for each speaker?"

I wouldn't do it that way. If you want to biamp, I think its better to use 2 stereo amps and do a vertical biamp.

Worry about the cables later. Its more important to active components first.
Thank you!
07-31-15: Kr4
Passively bi-amping with another CA-2200 will get you less than 3dB more output. Using the CA-M600 will get you almost 5dB and, probably, more head room.

I won't stir the hornets by commenting on bi-wiring but I use shotgun cables on my 800D2s, fwiw.
Good advice. I plan on upgrading from an integrated amp to separates later this year which will give me MUCH more power and control. I could have invested in mono's, but prefer to keep my system balanced. Like Kr4, I use shotgun cables (Jorma Statement). FWIW, my goal is to keep my box count down & focus on quality over quantity, though power amp numbers do matter with a moderately tough load.
"07-31-15: Mattmiller
Anytime you can go to Mono blocks I would recommend it, over bridging or bi amping with stereo amps."

Whats the logic behind that? If you could by a stereo amp that sounds better and has more power than 2 mono amps, why wouldn't that be the better choice?
Or am i better off buying a pair of CA-M600 for each speaker?
Do you mean four CA-M600's? I'm thinking no, as that would not be necessary. I do agree that you would benefit from having more power. Adding another CA-2200 will achieve this, and as Zd542 said, the vertical configuration will be best, however, a pair of CA-M600's, one per speaker makes better sense.

Kept in mind that the most demanding and power hungry part of that speaker is the woofers. The midrange and tweeter use far less power compared to the woofers. In the bi-amp scenario, you still just have 200w available to the woofers, although the vertical configuration gives you a little advantage having a entire stereo amp's power supply on a single speaker. Using the CA-M600's, you now have 600w available to power and control those woofers.

As far as bi-wiring, I agree with Kr4, and will not disturb that hornet's nest.
I totally agree with Mattmiller. With my B&W 800d2,I tried with (1) MC275V, no big deal. Then added another "WOW..." what a different.
Because B&W demands higher power to be better, I added a pair of MC601 and never look back.
My experience with bi-amping was painful and bi-wiring was enjoyable with my B&W 800D2.
08-01-15: Zd542
If you could by a stereo amp that sounds better and has more power than 2
mono amps, why wouldn't that be the better choice?
I
agree with your view Zd. Carte blanche, I personally prefer the sound of the
Vitus SS-102 stereo amp which sounds a bit warmer and more organic
than the SM-102 mono's. That's in a perfect world, though as with most
audiophiles here I have some room and budget constraints which mean I
don't have the room to accommodate the big SS-102, nor the funds to also
buy the matching preamp (SL-102). I briefly considered the option of bi-
amping the new Vitus SS-025 stereo amp with my current SIA-025
integrated before I remembered the S5's are single wired, so I scrubbed
that option. I could have maybe gone for the SM-011 mono's, but don't
need that much power. Also in that case I would not have been able to
afford the SL-102. I still wanted more power and control & wanted to take
my system to the next level, so in my situation I decided the best solution
was to trade up my integrated amp for an SS-025 stereo amp which shares
the same chassis and price as my SIA-025, but has a LOT more power and
control & is designed in the same way as the SM-011 mono's. That move
leaves sufficient funds to add an SL-102 pre (incl: the requisite cables
and isolation). So it's a question of finding the best compromise within your
budget.
I don't have 802D, but 804S. I biwire. Does it make a difference? Probably not.

I drive the speakers with one MC275 and love the sound. I am finishing a couple of class D Hypex monoblocks to drive the woofers. I plan to get rid of the passive crossover between woofers and midrange and apply an active crossover there, keeping the tweeter-to-midrange passive crossover driven by the 275. My understanding is that active multi-amping (as in active crossovers) is the real deal. FWIW my subwoofers run below 80Hz while the MC275 takes it from there and up.
My experience across various B&W 800 series speakers is that both bi-amping and bi-wiring are worthwhile and discernable.
The improvements from bi-amping are obvious in improved both sound-staging precision and detail, while bi-wiring improvement in detail is only marginal.
Bi-amping is more hassle because need another pair of interconnects and pre-amp with dual outputs unless the amplifier has function to switch from stereo to bi-amp e.g. Cambridge Azur 851W.
One advantage of bi-amping class A or AB amplifiers over stereo/mono-blocks is the treble/mid-range remain longer in Class A.
I currently bi-amp my speakers (800D2 recently upgraded from 803D2) with 2 x CA2300 with no obvious power limitation.
I don't have comparison experience between 2xCA2300 to 2xCAM600 - ideally you need to demo.
"The improvements from bi-amping are obvious in improved both sound-staging precision and detail, while bi-wiring improvement in detail is only marginal"

As per Classe manual, the benefit is a subjectively improved level of clarity and details from the speaker, as a result of being able to feed the two separate sections of its crossover and driver complement with identical, yet separate signals.

What is the point of having two sets of binding posts if you don't use them for bi-wiring?
"What is the point of having two sets of binding posts if you don't use them for bi-wiring?
Lalitk (Threads | Answers | This Thread)"

Most people will use the extra set of binding posts to biwire. You can also use them to get signal to a sub that has speaker cable inputs for signal.
While adding a second CA-2200 in a passive vertical biamp configuration MIGHT prove to be sonically beneficial on some musical passages, as Kr4 and Tls49 indicated it will not provide much in the way of a useful increase in power capability.

That is particularly true given the impedance characteristics of the 800D2, assuming they are similar to those of the 800D as it existed in 2011, shown in Figure 1 here. At frequencies between approximately 50 and 100 Hz, where lots of power is often required (for example, by drum beats), the speaker's combination of low impedance magnitudes and highly capacitive (negative) impedance phase angles will be especially challenging for an amplifier. Biamping two CA-2200's will provide a near zero increase in power capability at those frequencies, compared to what you have now.

Regards,
-- Al
"08-02-15: Almarg
While adding a second CA-2200 in a passive vertical biamp configuration MIGHT prove to be sonically beneficial on some musical passages, as Kr4 and Tls49 indicated it will not provide much in the way of a useful increase in power capability."

I don't understand why that would be. You go from 1 amp powering 2 speakers full range, to 2 of the same amps powering 1 speaker each. The amp is required to do half the work it did before. In my system it seems to make a big difference, but my components are different than the OP's.
While passive bi-amping does not provide a theoretical increase in dynamic range, subjectively it does.
If the amplifiers driving the woofers are stressed (close to clipping), the amplifiers driving the tweeter and mid will not be, resulting in significant less tendency for the sound to harden and imaging to congeal.
Hence you can maintain higher volumes without wanting to turn it down.
Hi ZD,

In addition to what I said in the second paragraph of my post above, take a look at Chart 2 in these measurements of the CA-2200. It can be seen that the CA-2200 clips very sharply at power levels that are just above its ratings of 200W/8 ohms and 400W/4 ohms.

And although the specs shown in its manual don't include an indication of maximum output voltages, the datasheet for the somewhat higher powered CA-2300 shows maximum output voltage capabilities, and therefore clipping points, which even fall slightly short of being consistent with its rated maximum rated power capabilities. The very sharp clipping point and essentially negligible margin relative to rated power that are shown for the CA-2200 in Chart 2 suggest that it is not much if at all better in that respect.

What all this adds up to is that on musical notes where high power levels are called for SIMULTANEOUSLY at mid/hi frequencies and at bass frequencies, passive vertical biamping with two CA-2200s will provide a power increase approaching 3 db, compared to using just one of them. Which is significant although not all that great. However on notes such as high volume drum beats, where most of the power is required at bass frequencies, and where as I mentioned the particular speaker is especially hard to drive, any increase in power capability will occur pretty much just as a result of one amplifier channel being driven rather than two. And the limited voltage headroom of the amp suggests that that increase will be insignificant.

With other amps and other speakers it might be a somewhat different story, but even then passive biamping should not be counted on to produce an increase of more than 3 db, which as I said is significant but certainly not huge.

Keep in mind also that the "big difference" you referred to in your system may be mainly the result of sonic benefits that passive vertical biamping can provide which are unrelated to any increase in power capability. For example, things like elimination of inter-channel crosstalk or other undesirable effects that are reduced by the fact that in a vertical biamp configuration both channels of the amp process the same signal.

Best regards,
-- Al
Thank you all for the feedback. It seems that instead of bi-amping, I should look at investing in a high current monoblocks. The additional expense of running balance and power cables can best be put use towards a quality amp.

I am looking at auditioning AVM MA8.2 and Accustic Arts Mono II in next few weeks.
Al,

I should have mentioned in my last post that I wasn't talking so much about more volume, as I was about overall sound quality. And along with that the impression of the amp being more at ease, with driving the speakers. For me, that sounds like more power, even though I wasn't playing the system at a louder volume. As always, thanks for the excellent explanation.

"08-02-15: Lalitk
Thank you all for the feedback. It seems that instead of bi-amping, I should look at investing in a high current monoblocks. The additional expense of running balance and power cables can best be put use towards a quality amp. "

That sounds like a good idea; especially the part about putting the money towards a better amp instead of cables. The only thing I would add, is that it seems that you are focusing on the design more than the end result. There's nothing that says a mono block has to outperform a stereo amp. It all depends on a variety of factors. Buy the amp that works and sounds the best with your speakers. That's what's really important.
Thanks, ZD. Yes, as we've both said in a number of past threads, vertical biamping can often be sonically beneficial. Including making the amps seem more at ease, as you and Mark indicated above. But as we and some of the others who have posted agree, it won't increase power capability greatly, and in this case it doesn't appear to be the best course of action for the OP.

Best regards,
-- Al
I currently own both 802 Diamonds and 800 Diamonds. The 802's came 1st and were initially powered by a single Bryston 4B-SST. I had a 2nd that wasn't being used so I "bi-amped" them and if it made any difference it was slight. I bi-amped by using one 4B-SST for the woofers and the other for the mids/highs.

When I got my 800's I did the same thing but in reverse order I think. I started with the 2 amps and went to one because I needed the rack space. Again if there was a difference it was slight. Certainly not worth the cost to do. I was lucky I had the 2nd amp on hand anyways but would not spend the money on a 2nd amp to get little to no performance increase.

Later on I replaced the 4B-SST with a pair of 28B-SST2's. Now there was a difference. Much more open at all listening levels. So this was going from 340 watts to 1250 watts.

Based on my experience I say go with more power but make sure you at least double your current wattage to get minimum of 3dB more.
Hello folks,

Thank you all for the feedback. I have narrow it down to Modwright KWA150 SE. Exchanged few emails with Dan at MW, quite an upstanding guy. I plan to run a pair of 150SE in Mono (bridged) mode, 450W x 1 in 8 ohms.

Stay tuned for an update by end of next week.
Good move with the KWA-150SE which is warm & tube-like, has plenty of power & is beautifully built. Dan is a great guy to deal with & very honest. You'll have plenty of grunt with 2 150's!
Bodhi,

You were spot on. Got my KWA's last week. Dan optimized these amps for bridged mode and what I heard right out of the box was pretty impressive. The sound field is spacious, musical, tonally accurate and extremely dynamic!!!!

Very delighted with my purchase.