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Will this amp trick work for increasing bass performance?

I'm considering matching Focal Utopia Scala Evo with two amps for bi-amping, to separate bass and mid/high. 

I'm considering the Pass Labs XP-32 pre-amp, which has individual volume controls for each channel/amp. By slightly increasing bass amp volume over mid/high amp volume, I get to feel more punch from the 11" woofers. The crossover in the Focals cuts off at 220Hz, so only bass and sub bass are affected.

Which two power amps would you consider? Power amp budget is about $30K. Was told Focals like power, so >250W for bass amp seems the minimum. Pre amp will likely be Pass Labs XP-32.
Maybe Pass Labs X250.8 + X150.8 or X250.8 + XA60.8?

Your thoughts please? Any other ideas to get more bass performance from the 11" woofers in the Focals? Subwoofer is not an option. I know McIntosh has a pre-amp with equalizer, which would solve the problem too. But I always thought EQs are a no-no.
robert1976
mkdm11's avatar
mkdm11
13 posts
 
I am not bi-amping.
I am going from the amps to my speakers via a high-wire configuration, dual wiring on the speaker side.
If you are concerned about having enough power, remember xa60.8's are class A to 60w then convert. Class A is much more efficent. My strategy in Class A and Tube Pre was to drive the purest most musical combination I could design. Maybe consider bi-amping as a second option if you feel your speakers are not being driven. In my case, I don't  believe it will be necessary. 
Again Kent at Pass was an excellent resource. I believe I spoke to him three times before making my purchase. The EVO's are sensitive, any of the Pass amps you are considering should drive them.
yzfr1mike's avatar
yzfr1mike
13 posts
 
I also have a large room, and my solution was to triamp with an SS amplifier for the 2 subs (LP @ 48hz 24db/oct) Magneplanar MG 20 bass panels on another SS amp (LP @ 220 Hz 6db/oct, no HP filter), and a third amp (Tube) serving the Midrange/tweeters (HP @ 290 Hz 6db/oct, no LP filter). The crossovers are Pass Labs XVR1s. This stereo is way out there for a system, but it really sings! I have made incremental changes, one at a time! to arrive at its present incarnation.
You really need to experiment with the speaker locations to get the best compromise between imaging and bass response. I am pretty sure you will need to have a stereo pair of subs to get the bass right for audio and audio imaging. Two subs will allow more flexibility in the room setup, and some of them are pretty small, which will help the "cosmetics" of the room. (WAF). I have read good things about JL Audio and SVS for subs. JL Audio has a couple of in wall subs that can be completely unobtrusive.
Good luck, this sounds like a really cool project!
twoleftears's avatar
twoleftears
5,313 posts
 

Just to be clear, there are two versions of bi-amping, vertical and horizontal.

Horizontal, you use one amp on the bass inputs of both speakers, and one on the upper frequencies. In this arrangement, if certain requirements are met, you can use a more powerful amp on the lower.

Vertical bi-amping uses two identical amps, using the L and R channels of one amp to power the upper and lower inputs of one speaker.

I presume that this is what mkdm11 is doing.

mrdecibel
2,927 posts
 
Vertical biamping ( can only be successfully done with identical amplification, as mentioned above ), has always been better, in sq, to my ears.
looscannon
60 posts
 
This is a nice problem to have. Get the XA60.8 on top and a pair of JC1+ amps on the bottom. If they are anything like the old JC1 they will have a damping factor in the thousands and plenty of power Fabulous bass. Better than any Pass amp I have heard and Pass amps are no slouch. The XA60.8 will be like heaven on top. When you get it done please invite me over. 
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