Connecting A/V receiver to an M&S Intercom/speaker system

It's odd that one would put RCA ends on speaker cable. RCA's would suggest they are feeding a line-level input on some device somewhere.

3 scenarios:

1) You mean banana plugs and not RCA's.
2) He did use RCA's and the cables go right to the speaker(s) (and the guy doesn't know what he's doing)
3) They are RCA's but they are not speaker cables (ie, the are line level going to the input of the distributed audio system)

You said he replaced the unit - so let's assume it is number 3. The RCA's lead to a L/R line-level input on the new audio system. Does this system have an outboard volume control somewhere?

Is this your receiver? If so, this is drawing of the rear.



I see two ways to get analog out of the receiver to your other system. Your receiver does not appear to have a "Zone 2", which would be the common means for doing this. Your manual shows diagrams using both outputs to a recording device.



This note was found below one of the sections about recording.



If this were my setup, the first thing I'd do would be to hook up an MP3 player or something to your RCA's (3.5mm male headphone to 2xRCA female). See if/how it works. From there you can see if there's a way to get the audio source you want to the system using your receiver. The note above is important though. None of your digital sources will send audio out via analog. Some sources maye have digital and analog, and you can probably make that work by assigning them to different input selections in the receiver. One input for regular playback, another input for playback over your "zone 2".

Looks about right. Mono input fed by a stereo to mono RCA Y-cable I presume.

Start with any source that you can connect to those RCA's. CD player, DVD, mp3 with adapter. Let it rip and see if it works.

Or just plug it in to the receiver's CD/R output and try it out with various sources, the radio being the easiest to try.

Well that's a start. Assuming your wiring is all intact, you've got the hard part out of the way. I bet you have a lot of options for replacing that unit altogether. Can you see how many speaker wires (pairs or wire (+/-)) are going out of the unit? I guess an easier question might be simply, how many speakers are there? Mono audio doesn't have to sound bad, you just won't have the stereo separation. And for background music that is less important anyway. Are any of your speakers arranged in a stereo-type configuration? I mean, if you replaced the unit with one that had stereo inputs and stereo outputs to the speakers, do you have pairs of speakers to take advantage of that?

If the speakers are all the same, you could pull out the bad one and get any info on it you can. Make/model - or dimensions at the very least. Then we can explore replacement options.

This thread from a few months ago might be worth reading. It is peppered with some weird stuff, but there may be some good take-away info for you about ceiling speakers and how to power them. I believe it had some links to some budget audio distribution systems and some ceiling speakers.