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

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

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

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