biamping question


hi,
sorry, i accidently posted this under speakers. I have a pair of vtl mb 125 mono blocks at 125 per channel, i have ascendo c7 speakers which are power hungry at 87 db. i want to biamp, but am at a loss as to which amp to use with the vtls. Should i get another pair of vtl 125? or should i go ssolid state with more power for the bottom end and use the vtls for the mids and highs. Any input would be much appreciated
thanks
syhilly
Sy, you're welcome!

Stewie, I don't doubt that you have an excellent sounding configuration. And I see nothing wrong with Sy obtaining a second set of amps, or a stereo amp, and trying it in a biamp'd configuration, before deciding whether or not to sell the VTL's (provided that the gain-matching issue is addressed).

However, since his main concern is obtaining more power, my main point is that he should NOT choose the power rating of the new amp(s) based on the expectation that bi-amping will provide a significant power increase. Because it will not, as explained in the other thread that I linked to.

He should choose the new amp(s) such that it has sufficient power to satisfy his requirements while operating alone. I note that the C7 manual recommends amps of up to 350 watts.

Also, the fact that his speakers are rated as being only slightly less efficient than yours says little about the amount of power he needs. The dynamic range of the music you and he listen to may be quite different, the room size and listening distance may be different, and the sensitivity ratings of the speakers may be defined differently and/or be inaccurate.

Two basic points should be kept in mind:

1)Passively bi-amping two pairs of 125W monoblocks will not result in the equivalent of a 250W amp (which is only a 3db increase anyway), and will probably result in the equivalent of very little more than a 125W amp.

2)Passively bi-amping 125W monoblocks on top and a 350W amp on the bottom will also result in the equivalent of very little more than a 125W amp, because since the top and bottom amps will have the same input signals (assuming gains are matched) and the same output voltage swings, maximum power delivery will be limited by the clipping point of the lower powered amp. That clipping point may be slightly higher in the biamp'd configuration, due to increases in its internal voltages resulting from reduced current demand (since it would be supplying current essentially just to the mid/hi drivers, and not to the woofers), but in terms of audible volume that increase will be negligible or close to it.

Regards,
-- Al
al,
thanks for your wisdom!!! very impressive.. i know who to come to in the future for REAL info!!!
be well
Sorry Al and Kal

I bought a CJ MF 2500A in 2002 to replace my CJ MF 2100. A year later I bought bi-wireable speakers. First I bi-wired and then I bi-amped horizontally. Both times there was a significant improvement in sound quality. I had the advantage of amps with identical gain,input impedance and sensitivity.

ET
Econotweaks -- Nothing I said was meant to negate the possibility that bi-amping can produce a significant improvement in sound quality, if done right. In fact my post in the other thread that I linked to above specifically pointed out, among other things, that the sound quality of the amps may benefit from the reduction in the current demand on each amp that biamping results in.

The issue here is not sound quality -- it is how to obtain a significant increase in power.

Regards,
-- Al