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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
douglas_schroeder OP
3,281 posts
 
Well, guys, you're waaay more knowledgeable and technical than I am. I appreciate your insights! I thought I'd just try wiring it both ways and seeing which I prefer.
I've thought the bass was a bit strong with a single pair of LFT-8's biwired at 200wpc, so I thought that maybe I'd "lighten it up" with 165wpc and putting the power more on the mid/tweet.
As you can see, I'm not scientific about this. Hopeful is more the word. I've got an ad in for an additional Outlaw 755 to match my setup if the 750 doesn't perform as hoped. But I'm going to peek at the sensitivity ratings of the different Outlaw amps to see what I can ascertain. Very helpful posts!
eldartford
4,262 posts
 
Douglas_schroeder...Loudness is determined by the GAIN of the amplifier, not by its power rating. (GAIN is volts-out per volts-in). A 20 watt amp may play louder than a 200 watt amp, up to the point where the output reaches 20 watts (very loud).

Note that GAIN is often stated as "Sensitivity"... usually as input voltage for rated power out. For example 1.23 volts. In this case, if the sensitivity is the same for two amps, the one with the higher power rating will play louder, not because it is more powerful, but because its gain is higher.
douglas_schroeder OP
3,281 posts
 
Thanks for the clarification!
I have heard of people even pairing tube amps and solid state on speakers, so I'm guessing this shouldn't be the world of difference between these two amps:

Outlaw Audio 755 (200wpc) input sens. 1.43v
Outlaw Audio 750 (165wpc) input sens. 1.2v

Again, much obliged for info!
eldartford
4,262 posts
 
Douglas_schroeder...I'm sure this is more than you need to know...but:

200 watts means 40 volts into 8 ohms
The gain is 40/1.43 = 27.972 volts/volt
This is 28.93 dB

165 watts means 36.33 volts into 8 ohms
The gain is 36.33/1.2 = 30.275 volts/volt
This is 29.62 dB

In practice I bet that the two amps use the same driver circuit, and actually have the same gain.
douglas_schroeder OP
3,281 posts
 
Eldartford, you have gone above and beyond the call on helping me learn about my amps. I appreciate it! I'll probably post on my audiogon virtual system the results.
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