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Need more power, Bi-amping does it work or does it just sound wrong

I am wanting to pull some amps and speakers from storage and put a system together for another room. I have a PS Audio HCA-2 amp 150 watts, PCA-2 preamp with HCPS preamp power supply and LSA Statement towers 2.5 way with ribbon tweeter 87 db 6 ohm. I use to run the LSA’s with a 200 watt high current doubling watts amp with good results. The HCA-2 claims 150 watts but I’m not sure how true that is.

 It’s sounds nice but I would like more authority and drive. So I was going to find/buy another HCA-2 but my current HCA-2 has been modified by Audio Reference Mods, over $1000 in mods 10 or so years ago, does that matter?
I’m guessing one amp would drive the mid and tweeter and other amp the bass drivers. Wouldn’t one amp drawing more watts and through everything off? With one amp modded and the other being standard would that matter?  Would I be better off selling the amp and buying a more powerful amp, only problem it may be more trouble than I want to deal with and cost more than I want to spend. 


paulcreed
knotscott's avatar
knotscott
953 posts
 
A stock version should work fine with your modified HCA-2 in a horizontal bi-amp configuration if both have same output power, and input impedance. I’d put the modified amp on the mids/tweeters, assuming it has better clarity. If the gain doesn’t match, you’ll need a way to balance the two amps.

Vertical vs horizontal bi-amping

I’m running two identical Dyna/VTA 70s in passive vertical bi-amp mode....it gave a nice improvement to soundstage size and depth, mildly improved clarity, and better dynamics. The fact that your amps will be slightly different might lend themselves better to a horizontal bi-amp configuration. In a vertical setup, I suspect one channel would sound different than the other since they’re not quite identical.

I’ll also mention that bi-amping doesn’t add more power per se....you have the same watts per channel, but have more channels. The tweeter amp will have an easy time, with plenty of headroom. The woofer amp will have the same rigorous challenges of driving woofers as a normal stereo amp situation, but without the small drain from the mids/tweeters. It can definitely help dynamics, but the volume levels won’t be notably different.

russ69's avatar
russ69
3,521 posts
 
I’d just get a big brute of an amp. One good stereo amp will do the trick. Getting another amp of the same kind doesn't get you very far. 
paulcreed OP
564 posts
 
If I did buy a brute amp instead of a matching amp to run the low end and choose horizontal biamping how would you put a passive volume control on the amp, I’ve never seen that done? I did modify the crossover with better caps, inductors and resistors and the crossover is outboard for easy access. Could I just add different resistors in the crossover to the low end till I get the out put right or is that a crazy statement? 
mglik
911 posts
 
In order to properly bi-amp two identical amps are needed.
For several technical reasons mainly to match the sound signature.
oldhvymec
5,101 posts
 
I guess I been doing it all wrong, all along..  Identical? Vertical I could see, horizontal I don't think so..

The whole reason to bi amp is to get rid of the tube bloat using tubes as bass amps and use high wattage cooler running SS amps for BASS.

Valves on the other hand, there is no better place for them.. Mids and highs..

Two completely different kinds of amp.. Live and learn ay?

Regards
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