Two amps into one set of speakers

Discussion in 'Archived Threads 2001-2004' started by Larry Carlson, May 22, 2002.

  1. Larry Carlson

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    Hope someone can help me on this one. I have one set of front speakers (Mirage OM-5) and two A/V systems. My main system, which is too complicated for my family to use and a Pioneer reciever, which my family uses for normal TV/DVD viewing. What I currently do is have the speaker cables for the Pioneer banana-plugged into the speakers for their use and I then switch cables and plug the speaker wires from my Adcom 555II into the speakers whenever I want to listen to my system. This works, but is a pain. I would like to find a switcher that I can use to feed either speaker output into the speakers. Does anyone know of such a beast? It would have to be capable of handling 300 watts without degrading the sound quality. The only one I have been able to find is made by Niles Audio, but it doesn't look like it's a top quality unit. Or is there a better way to accomplish the same end? I also thought of plugging one set of banana plugs into the other set of bananas so both units are connected at the same time, since neither amp would ever be on at the same time, but I was worried that it might somehow feed back into the amp that was not in use and damage it, I have no idea if that would be a problem, but am not knowledgeable enough to try it - I would hate to fry an amp or speakers experimenting. I'd sure appreicate some advice. Thanks.
     
  2. Drew Eckhardt

    Drew Eckhardt Stunt Coordinator

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    Can you use a soldering iron?

    If the answer's yes, I'd wire up a pair RCA jacked y-cables connecting a pair of female connectors to a male with ~10K Ohm resistors connecting the cable to the center conductors on the single male end.

    Assuming the receiver has pre-outs, hook one leg of the Y directly to the receiver. If not, figure out what sort of attenuation you need to convert from speaker to line level and make a adapter or buy one from Rat Shack or your favorite car audio store.
     
  3. ThomasL

    ThomasL Supporting Actor

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    Larry, can you use a speaker selector switch but just in reverse? Hook up the speakers to the L/R from amp/receiver and then hook the receivers up to the A and B selectors on the switch. Just make sure that both are never on and chosen at the same time. Having never tried this, I don't know if it will work but it seems, in theory, it should work.

    good luck,


    --tom
     
  4. RobertSchaez

    RobertSchaez Stunt Coordinator

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    I'm interested in that idea too. Seems like a A/B speaker switcher in reverse would work, but I've never tried it.
     
  5. Larry Carlson

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    All the speaker selector switches I looked at either can't handle much above 75 watts or so, or have impedence matching circuitry that I'm concerned may alter the sound quality.

    Keep those ideas rolling in. I appreciate it.
     
  6. Mike Veroukis

    Mike Veroukis Second Unit

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    Just an idea but something worth considering...

    If you get 3 sets of stereo binding posts and four two-way switches from radio shack you could build your own switch.

    Wire two of the stereo binding posts to the amps and the third one to the speakers. The switches will connect the two stereo amp posts and the stereo speaker posts. Still with me? The reason you need 4 switches is because you have 4 individual wires/binding posts that need to be switched (+ve/-ve for both right and left). You could tape the switches together somehow so that they all switch together (this is important!). This way, the switches will connect one of the amps to the speakers, and when they are "switched" the other amp will be connected to the speakers. Make sense?

    Well, that's my crude idea. I'd have to go to Radio Shack to find the right parts but shouldn't be a problem. Won't be pretty though.

    Anyways, there MUST be something out there that should do this for you. All those audio shops I've been to use something of the sort to switch between components and speakers on the fly. Just ask for what they use.

    - Mike
     
  7. Drew Eckhardt

    Drew Eckhardt Stunt Coordinator

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    With a speaker switch, you could accidentally connect one amp to the other. Power amps can have a .01 Ohm output impedance, although they usually don't like driving anything under a couple Ohms which would not make for a good combination.
     
  8. Jeff Hipps

    Jeff Hipps Stunt Coordinator

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    We used to see this in autosound fairly often. The easy solution was a double pole, double throw switch. In one postion the speakers see the Pioneer. In the other they'd see the Adcom. If you do this, get a "break before make" switch.

    Jeff
     
  9. Alex F.

    Alex F. Second Unit

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    The Niles unit (DSP-1, if I recall correctly) is a very ruggedly built and nicely finished unit. I have one, but changed my system requirements and never used it, so I cannot comment on its sound. But I can speak for its construction quality.
     
  10. Larry Carlson

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    Thanks for the help, guys. I picked up the Niles Audio DSP-1 and will probably get everything rewired this weekend and I'll let you know how it goes. Thanks again.

    Larry
     

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