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
Robert1976 wrote: " Anybody an idea what @millercarbon meant by a “$3k DBA”. Any links to a product like this?"

Millercarbon may have been referring to a subwoofer system I make which uses four small subs and costs a little over three grand. Briefly the premise is that room interaction issues are the biggest problem in the bass region, so the idea is to spread multiple bass sources asymmetrically around the room, each interacting with the room differently, the sum being considerably smoother than any one alone. This concept can be (and often is) implemented quite well using subwoofers other than mine.

However you made it clear that subwoofer are not desirable, so I would guess that four subwoofers are even less desirable!!

Imo your idea of using two amps and making the amp driving the bass section a bit louder than the other amp can definitely make the bass a bit louder, but it’s arguably "painting with a broad brush". It looks like the crossover is at about 220 Hz, which means that the bottom 3 octaves or so could be boosted. Imo you run the risk of any room-induced response peaks being exaggerated if you boost everything down there, and those peaks will make the low end sound fat and sluggish.

In my opinion it might make more sense to use equalization which will allow you to tailor what you’re doing in the bass region with a fair amount of precision, assuming your speakers already have adequate extension. (If your speakers do not have adequate extension, and you have a big room which implies that a lot of power is needed, imo EQ is not the way to get adequate extension - you’d be better off with speakers which already have it.) If you’d rather not have an equalizer in your signal path north of 220 Hz, perhaps you can find an analog equalizer (which would have no latency) that could be inserted in the signal path of the lower-frequency amp, south of 220 Hz only. And I agree with those who suggest you not overspend for that south-of-220 Hz amp.

Duke

edit: I had overlooked your post where you mention your dealer’s comments and suggestions. What he said makes sense to me. I think you’re in good hands.
One other very important point...finding the best bass is also extremely dependent on the location off the bass driver in the room as well as the phase adjustment of the bass speakers. The room has bass cancellations and that you can't eliminate. However these cancellations are movable especially at the listening area and it must be corrected for optimum sound.

Once again the advantage to a movable pair of subwoofers is the only way to go if you're looking for exceptional sound. Once positioned in the best 'location' for your particular room, then they are individually 'tuned' by way of phase adjustment to help eliminate (minimize) any cancellation occurring at the sweet spot.

There will always be wave cancellation in a room. It needs to be dealt with. Stationary speakers in a set location unfortunately give the least amount of options for correction of these dead zones. You can NOT power or EQ your way out of wave cancellation.

The best sound is not achieved by placing the speakers in the most visually appealing room location. It just doesn't work that way. Physics rules.




“In my opinion it might make more sense to use equalization which will allow you to tailor what you’re doing in the bass region with a fair amount of precision, assuming your speakers already have adequate extension. “

you might consider this:


https://www.decware.com/newsite/ZROCK.html


Heresy below:

1 - I find Pass does not so well with these speakers and low impedance.  A single amp from Ayre or Luxman may do better, not to mention a host of Class D amps.

2 - If you do insist on bi-amping, consider the Vandersteen trick, and put an EQ in series with the bass amp. 

3 - Of course, bass is greatly affected by proper room treatment.  Too many mid/high frequency reflections can tilt the entire response the wrong way.  Room modes can make the bass sound tubby or overbearing. Always a good place to start.

Above all, please yourself.