A/B Speaker Config Selector?

[Stoopalini]

Here is an odd request, hope you guys can help me:

In my room, I have a projector screen installed on the rear wall with the projector mounted inside the component cabinet. We use the projector for family movie night/game night, which is maybe once a week. We just flip the couch around for seating. I know it seems odd, but due to the vault in the center of the room, it's the only place to hang the screen.

For the audio, I manually swap the front and rear RCA cables on the back of my receiver when using the projector and turn off the center speaker. Then I just swap back when going back to the TV.

I'm looking for a speaker selector which will allow me to do this swap just by pressing a button, It needs to swap positions between the FR/RL and FL/RR.

I found speakers selectors which use speaker wire, but I'd rather interrupt the signal between the receiver and amplifiers (6 channels of outboard amplification).

Any suggestions on a device which can do this, passively? (ie: I don't want one with a volume control)

Thanks,
Thomas.

[Chris D]

Wow, Thomas, that's a good one that I haven't run into before! I'm sorry to say I can't come up with a solution in my head, but you've got me really curious as to how to solve that one!

[Kal Rubinson]

Switches are easy. Zektor makes/made some of the best.

How are you going to reset all the speaker/channel adjustments for each of the two situations? Might be easier to have two AVRs.

[Stoopalini]

Ya, I try to ask only good questions LOL

As for the levels, I wasn't going to bother. I'm planning to leave the calibration set for the TV, as we mainly use the projector for family games (PS3) and movies for the kids.

I don't plan to spend a bunch of money on a solution, and for what we use it for, the wife is happy to leave the sound coming from the rear; but it bothers me

I haven't found a reasonable priced solution yet, but started thinking about what it would take to build one.

Here is what I've got thus far, just not sure if the transformer (110v input, 12v output) to the mechanical relays will cause noise induction. I sent this diagram to a buddy who is more savvy than I at this stuff (he builds custom guitar effects pedals/boards) and waiting on his reply.

Looks like the color of the hot wire to the relay coils is faded into the background, but the switch would just send power to the coils causing the leads to swap in the relays.



Maybe there is a cheap IC I can buy which will do this within [minimal to zero] noise introduction ....

Thomas.

[Chris D]

Yes, switchers like Zektor are available, I'm just not sure that either (1) the right switcher is available to do what you want to do, and/or (2) if the wiring would work out with the switchers.

The typical scenario when adding a switcher is that you want to switch two or more different components to one set of input/outputs. (or more than one set, and then you get a matrix) But in your case, you're wanting to switch one set of speakers to your receiver in two different configurations. So, typically, what you'd have is maybe switching between two different speakers, so that for example, you'd have one output from your left front speaker output of the receiver to a switcher. Then in state #1, you'd be outputting from the switcher over speaker wire to Speaker A, and in state #2, you'd use a different speaker wire to a distinct Speaker B. But in your case, your speaker B also does double-duty as right-rear Speaker A during state #1.

So would you run two different speaker wires to each speaker from the switcher? Or would you go the other route, as it appears like from your diagram, and split each output from the receiver into twin wires and run to the switcher, to be switched to a single output wire to each speaker? (or your diagram actually seems like you're "jumping" each connection at the switcher to an alternate input) I just don't know if you'll run into problems with those two wires. I suppose you're not actually splitting the impedance, if one of the speaker wires isn't actively connected to a speaker load.

[Stoopalini]

The diagram actually has the signal interruption between the receiver and the amplifiers, so still only using one speaker wire from the amps to each speaker.

And you are correct, in the fact the impedance doesn't change, due to the 2nd signal path being disconnected by the relays.

I think a switcher may actually work, as long as the unused input paths are disconnected from the output completely. I could just use RCA splitters to connect the appropriate inputs together.

I'll have to do some digging and see if I can find one for a decent price. Otherwise, I may just build this thing.

Thomas.

[Kevin D]

Here:

http://www.usa.philips.com/c/cables-connectors/high-definition-manual-sws2325w_17/prd/

$20 on Amazon:

http://www.amazon.com/Philips-SWS2325W-17-Definition-Selector/dp/B001EK74WW

Confirmed to be a pure mechanical switch, so you can use the component video section for L/C/R, and the analog audio section for SR, SL.

http://www.avsforum.com/t/956770/atlona-video-switch-for-5-1-audio/30

So get 5 RCA y-cables, and Y out from the receiver. Hook up the switcher's output to your amp. Use input 2,3 or 3,4 and just crossover what ever RCA's you need to make it right.

Kevin D.

[Stoopalini]

Thanks Kevin, that Philips unit with 4 RCA 'Y' cables should do the trick, and the price point is perfect. I'll give it a go and hope for no noise introduction.

Thanks again guys,
Thomas.