@lanx0003 wrote:
I completely agree if we are discussing vertical bi-amping, where one amp powers one speaker and the second amp powers the other; in this case, the amps would need to be matched to achieve the best performance.
Of course, with vertical bi-amping you need similar amps so not to have different amps on the left and right channel - with all that could entail.
In my case of horizontal bi-amping, which I believe is the context here, I was fortunate that the low-wattage class A amp I use for the tweeters has good synergy with the speakers. Although the class A amp lacks gain control, both the class A/B and D amps I’ve used for the woofers have gain controls, allowing me to fine-tune the loudness until tonal balance between the high and low ends is achieved. I’m pleased with the sound, though I believe this experience might be dependent on the specific speakers and amplifiers used, making it difficult to generalize.
That’s the opportunity offered with horizontal bi-amping, yes - i.e.: using different amps for each left and right channel driver section - and as you’ve found out it can lead to desirable results. In your configuration, passively, it may also be the most if not the only sensible approach as there’s little to gain just by doubling up on the same amp here.
If you're configuring outboard actively, however, like in my case, you’re bound to use the number of amplifier channels that corresponds with the number of individual driver sections per channel, and this can be done either vertically using similar amps per channel section (necessitated), or horizontally with similar or different amps (optionally). As your recently supplied video shows, this is where the real benefits of bi-amping occurs, on top of the advantage of active config. by coupling each amplifier channel directly to its driver section - sans intervening passive crossover between the amp and driver(s).
Outboard actively my point is this: just because you can use different amps horizontally over each driver section it’s not to say you necessarily should. In fact, I’d argue you shouldn’t for the reasons mentioned in my earlier post, although I’m fully aware very good results can be had with a differentiated amp approach that is (to the ears of the specific listener) a sonically tailormade match to the respective driver section. Whatever floats one’s boat.
Of course what I’m advocating means finding an amp that’s both sonically adept on up as well as sufficiently powerful/handling down low, which shouldn’t be too hard, especially if you have efficient speakers and potentially subs. Then it’s just a matter of multiplying into the number of amps required, and you’ll have the benefit of the same amplifier imprinting top to bottom. To my ears, this is not trivial.
What about the excess power then to the top end since the max. and much higher power requirement is dictated by the lows? Yeah, what about it - does it hurt? Of course not, you’ll just have loads of headroom and an amplifier that’s relieved of the low end to boot, which means it’s cruising along effortlessly with ultra low distortion. If you could power differentiate with basically the same amplifier, by all means go ahead and do it, but be mindful that it may lead to slight sonic variations that may or may not be of significance.