Yes but the stuff you are linking to is *irrelevant*. These circuits are talking about driving line level inputs. Those line level inputs have ~tens of kohm input impedance -- that is not at all what you are trying to do. You are trying to blend a signal that is driving a very low impedance (nominally 4 ohm or 8 ohm) speaker. If you want to blend low output impedance signals to drive something like a speaker you need to buffer that low impedance, which gets you into an op amp or similar buffer on each channel and and/or drive a summing amplifier directly, then a power driver circuit. Basically you are building an active audio panel. All that complexity and need to power it and have yet another thing to fail.

The simple solution is use two speakers. Not hard at all.


On Thursday, February 26, 2015 at 9:40:28 PM UTC-8, Paul B wrote:
On Friday, 27 February 2015 15:05:45 UTC+10, Bruce Hoult wrote:


Now you're getting fancy :-)

Thanks Bruce

The fancy is what I want to avoid, as the initial idea was to simplify things - i.e. one speaker instead of four .

Cheers

Paul