Run two channels to a single-voice speaker?

semiotomatic said:

Hi all!

I have a single-voice speaker installed in a steam shower. Obviously it'd be better not to only hear the L or R channel while I'm slowly melting in a steamy mist.

What's the best way for me combine two channels off the amp into the speaker? Would I build a circuit with some resistors off each channel to make sure I'm not overpowering the speaker? Is there a pre-built solution to this?

Click to expand...

If you have to ask, you should not attempt this. - at least not on the amplifier output side.

On the preamp side piece of cake. Use Y-adopters to sum the L&R into a summed mono output and us only one channel of the amp.

Yes it could be done with some resistors but somebody with a good technical background would have to analyze the amp circuits to make sure no damage will be incurred. And this would also cause a substantial volume drop.

Also doing this with passive resistors would compromise the separation on other stereo speakers off the same amp.

As stated above the best option would be a small auxiliary amp with L&R combined on the input side with a simple Y adaptor. Parts Express.com has some low cost amps.

semiotomatic said:

Hi all!

I have a single-voice speaker installed in a steam shower. Obviously it'd be better not to only hear the L or R channel while I'm slowly melting in a steamy mist.

What's the best way for me combine two channels off the amp into the speaker? Would I build a circuit with some resistors off each channel to make sure I'm not overpowering the speaker? Is there a pre-built solution to this?

Click to expand...

connecting two power amp outputs to a single speaker is not significantly different from simply plugging one amp output into another amp output. The 4 or 8 ohms of the speaker will see very little of the total power, since the speaker cables connected at the speaker terminals will total, most likely, less than half an ohm. The two amps will try to drive each other. If you're lucky, the amps' protection circuits will kick in and you'll get silence. If you're not lucky, something will fail. Like a power transistor. Possibly with smoke involved.

At the preamp level, you could try a simple Y cord from the left and right outputs into a single amplifier output. Might work okay. Might not (resulting in unwanted noisiness - - ie a bunch of audible crap notrelaly related to the sound you're trying to reproduce, in my limited experience) in which case you'll want a mixer, even if it simply consists of resistors in the line level signal path.

IMHO, you should have installed a "pair" for waterproof speakers for stereo to enjoy the steamy mist without retrofitting and/or extra expense. You know, hindsight is ...

The way to do what you want is to employ a mixer. You can mix two channels into one prior to the amplifier and get a monaural signal to a single speaker.