Bi-Amping question

PIBM

I bought a nice kit this christmas (RTI10, CS5, FXI3) and it was important to me that I could bi-amp my front speaker and that was a good part of the decision So, I got those, played with my very old 8 channel 100W amplifier (I have a discrete 7.1 DVD output being a linux box ) and I set that up, only to find out that the noise was just too high and that when one channel had no sound/music I was immediatly noticing the noice. This was not coming from the computer output since I was able to 'separate' it from the output levels, and there was no wires (power or whatever) making interferences

So I went back to the shop (Future Shop - Higher quality best buy) and I asked questions about amps they had. Turned out that allegedly only the Harman Kardon 645 or 745 could bi-amp and so I decided to buy the AVR 645 (http://www.futureshop.ca/catalog/proddetail.asp?logon=&langid=FR&sku_id=0665000FS10071470&catid=10551)

When I first configured it I tried without bi-amping. This sound great (no more noises, yeah for optical connections!), but I can't achieve a very good volume compared to what I had before (mostly miss my loudness button I guess )

I've searched everywhere on how to set up the AVR 645 for bi-amping, and I can't find anything. I went back to the future shop but the guy who sold me that amp is no longer working there (he was only there for christmas, lol we got to hate those companies) and they won't support me.

So, anyone has any information for me ? Can I change the firmware in the 645 ? Is there good devices I could use (optical, ideally) which would take a 2 channel input and rewrite it as a 4 channels output with split frequencies so I can get a total power higher than currently ?

Also, since the 'best' crossover is around 350hz, and the RTI 10 loudspeakers crossover is at around 125hz, how much can I really gain ? Would it be better to send the full signal from both the front and back channel of my amp, and let the speakers crossover split the signal ?

Thank you a lot
PIBM

PolkWannabie

I started to respond to your post a few times and backed away because of the number of questions ...

For the moment I'll keep the reply simple ...

Most speakers including the RTi10's can be biamped ...

For a standard pre/pro -> amp -> speaker setup this would involve splitting the output signal of the preamp, amplifying both of the split signals and sending the result to the top and bottom terminals of the speaker respectively.

While I am not terribly familiar with the H/K receivers it may be possible with them to use the surround back channels of the receiver to independently amplify the left and right front channel thereby allowing biamplification of front speakers.

Hopefully that answers at least one of your questions ...

edbert

I wanted to be able to do the same with my Monitor 40's. I ended up with a Pioneer receiver. For my setup I connected the rear back surround channels into one input on the speaker and the front channels to the other. I made sure to connect them individually so that the fronts were connected to the same inputs on the speakers. The levels are supposed to be the same for the front and surround back channels. I actually have a setting for the rear channels to say they are setup as bi-amping the front speakers. I think the primary reason is so that when you are setting all the levels and doing test tones, it doesn't see the front and rear back channels as two separate channels for two sets of speakers, but as one channel. I would think that if you don't have this setting it could become a royal pain to try and properly setup your speakers. I hope that helps.