bi amp with a upa-2

Again, complete misleading regurgitation of internet blather.

In passive biamping the input impedance of the highs section increases as the frequency decreases, so the highs section draws less power from the amp as the frequency decreases. The amp that is driving the highs is now doing a lot less work than when that amp was also driving the lows section of the loudspeaker, where most of the power is used. The input impedance of the lows section increases as the frequency increases, so the lows section draws less power from the amp as the frequency increases. But as the highs use much less power than the lows, the performance difference in the lows section is less.

So no, amplifier power is not wasted on the crossover and the amplifiers are not "seeing" the entire frequency range.

Not all passive crossovers contain just simple filters. Some have significant frequency response and other "tweaking" such as notch filters and baffle step compensation. Therefore going active can in many cases actually degrade the performance of the loudspeaker. Unless you are able to match the intent of the crossover circuitry design, an active setup is what is really pointless.

I was just looking at the upa-2 to bi-amp my center (paradigm cc690) and came across this. I did a poor-man's bi-amp test with my yammie A3000. I rigged something together and utilized the A3000 "Pattern" functionality so I could test a bi-amped Studio 20 with a regularly wired Studio 20 very quickly switching between the 2.

I noticed that the regular wired one was louder (maybe more noise?) and the bi-amp one was cleaner in that I heard subtle differences. For example the silent scenes were more quiet.

So, based on my experience there is a difference. However, that was in a very quiet setting unlike the majority of time I am home and kids are running around.

Now, what I did not do is try a bi-wired setup. For all I know the jumpers are the root cause.

Which leads to my dilema - one can bi-amp the mains with the A3000 but not the center. If I bi-amped the center with a Emo and left the A3000 to power the fronts (Studios) then will that pose a problem by using different amps for the fronts?

Correct. Which is why I'm here. I can bi-amp the mains with the Yamaha and move the center to a UPA-2. So question is - will having different amps power the mains and center pose an issue?

I think rather than blasting each other, offering a little education helps allot.

The first question you must ask is WHY are you trying to do it?

It very simple terms: Most speakers have an internal "passive" cross-over that separates the signal, sending the high frequencies to the tweeter and the lower freqs to the mid/bass speaker.

Bi-amping a speaker with a "passive' internal cross-over will accomplish nothing, EVEN if it has two binding posts.

There are SOME speakers with two binding posts that have an internal cross over, but with some frequency dials or switches on the back. This allows for some limited adjustments to the hi / low frequency and most likely WILL require Bi-amping.

Most people are already familiar with bi-amping but do not realize it. If you run a powered sub-woofer, the sub-woofer is receiving the frequency from the pre-amp or source, but the sub-woofer has it's own internal amp and also dials on the back to control the frequency cross-over.

To truly bi-amp a speaker you need to run an ACTIVE cross-over. Some popular active crossovers are Behringer and MiniDSP. The wiring is fairly simple.

Source (Pre-amp) -> cross-over -> 2 amps (one for the high-freq / one for the low freq) -> to the speakers.

There are a few speakers out there that are made for active bi-amping (example: Emerald Physics with active crossover).

The question is why would you want to do this?

The cross-over in speakers are design by engineers to not only bring out the best in the speakers, but to also meet the most likely listening rooms. The end result leaves the speaker owner with limited ability to adjust the harmonics and sound - they do this by speaker placement (how far from the wall, angle, toe, distance etc). Pretty much the speaker owner can only adjust the speaker by placing the speaker.

Active Crossovers allow the listener to make further adjustments, by changing the cross-over frequencies and cut-offs that are driven to the tweeter, mid, and bass.

The two most common Active Cross-overs are 2 Channels per speaker and 3 Channels per speaker. 2 Channels per speaker will require bi-amping with two wires per speaker and 3 Channels per speaker require tri-amping with three wires per speaker.

Most home systems are NOT designed for bi-amping with active cross-overs because of the cost and also the time/complexity of setting up the cross-over frequencies. Additionally many passive cross-overs are very well designed in that it would be very hard to gain any additional noticeable improvement using an active cross-over.

I built my own speakers which are a combination of passive and active cross-overs. The tweeter and mid-range run on a custom made passive cross-over with one UPA-2 amp and my woofers run on a separate UPA-2 amp. I run a Behringer C3400 active cross-over to control the frequency cut-off between the two UPA-2 amps.

For more information I suggest reading: sound.westhost.com/biamp-vs-passive.htm

Also if you are interested in my speaker build experience you can read about it here:
www.hawthorneaudio.com/forums/viewtopic.php?f=2&t=4222&sid=14b7584f144c272e53ab77690afb300c

BTW: Bi-wiring is a waste of time and will offer no improvement in sound or power.