Audio Systems: Connecting older speakers with built-in sub to new receiver, audio distribution amplifier, rca jack

Question
Hi Parke,

I have an old (but good) Sansui stereo system. The receiver is dying and will probably go any day now. I want to buy a new receiver but would like to keep the existing speakers. The speakers have built-in subs, with 2 sets of +/- speaker wire connections. If I buy a new, say, 6.1 receiver (the 6.1 is for future expansion), one set of wires will obviously run from the front speakers output on the receiver to the speakers. But how would I enable the built-in subs on each speaker? All receivers these days only have 1 line output that looks like a RCA jack.

Thanks,
Henry

Answer
Henry,
  At first blush I was just going to recommend that you buy a convection-cooled 2-Channel amplifier (like the Stewart Audio World 600 or Onkyo M-282) but after some thought I am a little hesitant.

  I seem to recall that those old Sansui's weren't exactly like a "speaker/sub" combination like we think of them in modern consumer audio terms.  In fact, I think they were something much better, a real biamped 3-way full-range cabinet.  
  I truthfully do not recall whether there was some pre-crossover in the Sansui reciever or whether there was a passive cross in the speaker boxes.  This may have some impact on the performance of these speakers if you adapt them as "LFE and mains" for a surround-sound use.  I just do not have enough information to make the call.  Some of the old Sansui stuff was quite good (I still have some myself) and might adapt quite nicely anyway.

  If you want to charge ahead anyway, then I would continue to recommend you make the following purchases (in addition to the Surround Sound processor of your choosing):

1) audio "Distribution Amplifier" such as this-
http://www.extron.com/product/product.asp?id=mda3arca&subtype=109
To split the single "LFE" output out into two equal signals, one for each speaker amp.
-this is a bit excessive, especially if you are handy with a soldering gun, have low expectations, or find an amplifier with a 'pre-out' that you can daisy-chain into the other amp input.

2) Two channels of amplification (either one stereo amp or two monoblocks) of your choosing.  (Onkyo, Rotel, AudioSource, etc.)  Although not top-of-the-heap, the AudioSource 5.3 might be a good choice because it has a 'pre-out" you can use to daisy chain and skip Step 1 above.



  If you are willing and able to give me more information about your speakers (model, date of purchase, serial #, anything) I would very much like to do more research on this topic.   If you feel comfortable you can send a follow-up message and click the "private" box and include a personal email address.