Stereo pre-out into mono subwoofer amp

[dccj]

Hi,
I want to conect a subwoofer that has its own amp but is only mono input.
My audio unit has two pre-outs (left and right of course). Can I just make up a Y lead that joins the pre-outs into one lead going into the subwoofer amp.
I can adjust the pre-outputs from the audio unit, therefore controlling the volume of the subwoofer. I'm concerned that the two signals coming out, and being combined into one, may cause a problem with each other and possibly damage my audio unit. I could just use either the right or left output but don't just want to hear the base from only one channel.
Any advise would be appreciated.
Regards,
Dave

 

[Spiffyfast]

so your stereo amp doesn't have a subwoofer pre out built in?

 

[dccj]

Hi,
I don't know. I only have the diagram and not the manual and the diagram shows the outputs feeding an amplifier (stereo of course). If my subwoofer had two inputs, I would have no trouble connecting it.
Thanks,
Dave

 

[jaxvon]

Your concerns were correct, it would damage the audio unit to try summing L&R signals into mono with a cable.

Is this for a car installation or a home audio setup? What equipment are you running?

 

[Spiffyfast]

Your concerns were correct, it would damage the audio unit to try summing L&R signals into mono with a cable.

Is this for a car installation or a home audio setup? What equipment are you running?

Didnt even think about it being for a car, good call you get a chicklet

 

[dccj]

It's an old hitachi stereo, I'm having a play with gear I've collected over the years. Thanks for the advise, I'll just feed the sub amp from one output.
Have a good evening and again thanks. Dave.