AudioAficionado.org - Biamping 802 Diamonds?

AudioAficionado.org (https://www.audioaficionado.org/index.php)

- B&W Speakers (https://www.audioaficionado.org/forumdisplay.php?f=26)

- - Biamping 802 Diamonds? (https://www.audioaficionado.org/showthread.php?t=33009)

Biamping 802 Diamonds?

Any experience of pitfalls of doing this:

Cary 211FE for mid/high
Classe M600 for lows

Thoughts?

Reason I ask is I find I like the top end of the Cary 211FE... but I like the overall performance and bass of the Classe M600. I have both amps.

I know that there is no active cross over and so that'll mess things up. But I want to know what happens if you have a 600w amp on one end and a 70w amp on the top end... what happens when you control the volume?

Do I need 2 preamps??

DON'T DO IT. You won't need two preamps, but you don't want to be juggling non-linked volume on two preamps to have a correct tonal balance every time you adjust the volume. You would send signal from the preamp to the active crossover then to the power amps and speakers.

The amps should be the same and have the same gain.

The "mid point" of power usage, I read in an active crossover article (sorry about the lack of reference) is actually about 350Hz, so your midrange and tweeter still need a lot of power.

The 9.33 dB difference between those two amps (600 vs 70 watts) is too much.

Well I guess my post isn't exactly what your looking for but I figured I would chime in just in case it was of any value anyway.

I own 803 D2's and am currently powering them with X 4 separate Monoblocs in combination with a Classe CP-800 Pre. I too was concerned about matching when I first went down this road but luckily things have worked out very well for me using this combo.

I'm using Hypex NC400 amps which I've read are matched very close to each other (.5db) as measured by someone on Audiocircle who has played with and measured several of them that came from different batch's.

Based on the measurements posted in the Stereophile review of the 802's and if I remember correctly its the Midrange where the speaker takes a dip into the 3ohm range so I would be concerned about using a lower powered Amp for those duties in combo with the muscle bound CAM 600's. You may find that there just isn't enough oomph in the Midrange by doing so and things may sound unbalanced.

Are you currently Biwiring the 802's with the big Classe's by chance? If not, that may give you a bit more SQ out of them but unfortunately I couldn't say for sure. I know many have reported positive results with Biwiring on them.

So it would be tough to biamp a 77w tube and a 600w ss???

You absolutely need an active crossover to do that, and it would need a lot of adjustability in its output levels. I don't think the Bryston 10B-STD has enough volume range to do that (mine is sitting new unused in its box) but something like the PassLabs XVR1 with its sets of single ended AND balanced inputs and outputs and fully adjustable volume controls is definitely indicated if you do that. It's still NOT a good combination.

You should read this thread

http://www.audioaficionado.org/mcint...00-mc501s.html

This member has your same speakers with a similar question but different amplifiers. You will find the information there very helpful.

Info from the B&W website:

Quote:

Originally Posted by GaryProtein (Post 718144)

From the 802 owners manual:

Quote:

Note: Bi-wiring separates the signal paths to each section of the speaker and can improve both stereo imaging and detail resolution. It also enables the use of different types of cable for each frequency band.

Bi-amplification goes a stage further and involves the use of two independent power amplifier channels for each speaker. This is not the same as a fully “active” drive as the speaker's internal passive crossover is still used. If bi-amplification is employed, ensure that each amplifier channel has the same gain, otherwise the speaker’s tonal balance will be distorted.

Check also the absolute polarity of the amplifiers. Some amplifiers invert the signal, and their use in combination with non-inverting types will result in a distorted frequency response. If you have a mixture of inverting and non-inverting amplifiers, reverse the polarity of the speaker connections from the inverting amplifier.

Bear in mind that, even though midrange and, even more so, tweeter drivers can (and only need to) handle less continuous power than bass drivers, the amplifier feeding them needs to have an adequate voltage swing in order to supply the short-term high-frequency peaks in music without distortion. A high voltage capability implies high power, so it is not particularly desirable to have a lower powered amplifier feeding the midrange and tweeter than is used for bass drivers.

The bi-wiring statement in the first paragraph is bullcrap--a lie. Bi-wiring is solely a way the dealer can sell you more cables.

The last paragraph is true. That is why I said to sell your present amps and buy a pair of bigger amps.

Gotcha.... this makes sense Gary.

No go. :nono:

You could do it with four of the same mono or two stereo amps and an active crossover, but you'll have to perform a little surgery on the passive crossover in your 802's. Snip, snip.

Unless the speaker is really designed to be multi amped as an option, just get a bigger amplifier.

I've experimented with bi-amping both my 802's and 800's and found there was little if any benefit. I bi-amped using two 4B-SST's so it was equal wattage and equal amp specifications. I never tried bi-amping using say my 4B-SST for the highs/mids and my 28's for the lows but I suspect more of the same. These are passive speakers afterall so most if not all benefits of bi-amping are lost without the use of an active crossover.