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Biamping; Amps w. Different power ratings?

If a person uses two amps of differing power levels, will there be a noticeable difference in volume? I've got an Outlaw Audio 755 which is 200wpc. I'm thinking of adding an Outlaw 750, which is 165wpc also. I would use the lower power amp for the bass, and the higher for the treble.
I will have a speaker system comprising four Eminent Technology LFT-8's (biwired and biamped configuration for each of them) and will use 8 channels of amplification. The four bass drivers would be from the lower power Outlaw amp (165) and the highs from the 200wpc amp.

Or, would I be better served to make one speaker completely driven by the 165wpc, and the other by the 200wpc?

I will be sending signal to all 8 amp inputs through the same preamp - a Rogue Audio Magnum 66 (which has a selectable second main out; the signal from each pair of outs will be split and delivered to the 8 amp inputs.

So, would the difference in power cause volume discrepancies between either the bass and treble, or between entire speakers (depending on how I hooked them up).

Comments, suggestions welcome!
douglas_schroeder
gregm
3,395 posts
 
I'd use the higher powered amp for the bass units of course.
The relative amplitude is not a matter of Watt rating but of input sensitivity of each amp. If it's the same there's no problem.

If I understood yr questions correctly. CHeers
jeffreybehr's avatar
jeffreybehr
805 posts
 
...and 'the same input sensitivity' doesn't mean the same number of volts for rated output, it means the same input voltage for the SAME output. If it's specified, that's usually stated for 1 Watt of output.

Since your amps have slightly different maximum outputs, I would not use them in mono; if you do, one channel will have slightly more dynamic range than the other.

The -8 uses a low crossover, and its MR/treble panels need LOTS of power, so do indeed use the 200W. channels on the planar drivers.

You'll be using the 4 speakers in a surround system?
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eldartford
4,262 posts
 
Until recently I would have agreed with Gregm about using the higher power amp for the low frequency. However, in my system, where, for each channel, a stereo amp drives high and low frequency drivers, the power required for the low frequency is much less than the high. In my case this is because the low frequency drivers are more sensitive than the Magneplanars (high frequency drivers), but, in general I don't think we can assume that, in any system, low frequency takes more power.

I would suggest that you take some simple voltage measurements while music is playing and see which amp (high or Low) is working harder. Truth to tell, the difference between 165 and 200 watts is almost too small to worry about.
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