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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
twoleftears's avatar
twoleftears
5,318 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
3,064 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. 
gdaddy1
135 posts
 
FYI... Paul McGowen just posted another video explanation of the importance of the subwoofer and the importance of the connection to the 'high level input' of a quality sub. 
https://www.youtube.com/watch?v=7PIoSbboDf0
audiorusty
273 posts
 
Robert,

I believe you are on the right track. You probably don't need a sub unless you are listening to EDM or at concert level volume. Focal recommends an amp up to 500 watts, so depending on how much bass you are looking for I would get an amp as close to 500 watts as I could afford. You have a large room which makes it easier to over drive an amp powering the low end if you going for high volume.

Adding eq can help tailor the sound even more if desired. If you are looking for that chest thump you could further accent the 40 to 80 hz region with out boosting the 160 to 220 hz area which can start to give you that hollow, in a tunnel type sound, depending how surgical your eq is.

I believe that Pass amps and pre amps are truly balanced so if you convert the balanced output to RCA I believe you will loose 6db of out put
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