2. amps-preamps
  3. 193485-41563

Mixing XLR and RCA outputs when biamping?

I’m about to introduce two new (to me) amps into my 2-channel system, and wondered about how to hook them up.

 

The amps are refurbished Adcom GFA555s1, and I plan to bi-wire them vertically.  My preamp (NAD C658) has both XLR and RCA outputs,  and it appears they output simultaneously.    However, the amps are RCA input only (no XLR input).          It would seem I have a couple of options:

 

1. use the RCA output of the preamp, and split each signal to feed both channels of each amp.    
 

2. Use both XLR and RCA outputs, with the two left channels going to the left speaker amp.

 

Would the voltage/sound level be the same for situation 2?    I was thinking running the left XLR into the low freq on the left speaker, and the right XLR not the low freq of the right speaker.

 

this is probably a dumb idea and I should split the RCA signal.

 

 

 

 

chessie
avanti1960
1,523 posts
 

@chessie

alignment filter is the crossover network between woofer, midrange and tweeter. you would need 3 amps to run fully active and a good working knowledge of appropriate crossover frequencies, slopes and level matching the drivers as well as if there was an impedance flattener, notch filter, baffle step compensation and roll off filter. not for the uninitiated.

run the amps as you have planned using a splitter off one set of outputs. you should enjoy the difference assuming the adcoms are up to snuff.

chessie OP
25 posts
 

@avanti1960

 

Thanks, yes... sounds like more than I am looking to do at this time.

The amps have been serviced/refurbished by an adcom specialist using new Hoppe boards.

erik_squires
16,441 posts
 

My suggestion was hybrid, keep the mid to tweeter cross and use a minDSP  for mid to woofer

chessie OP
25 posts
 

Interesting, trying to understand how this would work.  

Is this what you mean?
--------------------------------------

1. Don't do anything to the existing (built-in) crossover.

2. send a regular signal to the "high" speaker input.
         (Source->Preamp->Amp->HSI)

3. use the miniDSP to process the signal that goes to the "low" speaker input.
        (Source->Preamp->miniDSP->Amp->LSI)

 

Thanks,

Ted

boxcarman
431 posts
 

I started out with Adcom separates in the 90's. MHO is that  Adcom was and is, starter equipment. You can and should go for something better.

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