Passive summing circuit

[cornajatwa]

You’re the man. Thanks wolf

[Wolf]

The summation network has to go in the low-level connection section, not at speaker level, and not in the xover.
If the Dongle only has an optical output, then you also require a DAC to change the signal from digital to analog. Then the combining/summing circuit is placed at the analog output of the DAC, and then goes into a single channel amplifier, and then connect the amp output to the single speaker.
Wolf

[cornajatwa]

We’re talking about a circuit downstream of a DAC, right? Are my terms off? The only airplay dongle I can find only has an optical output.
sorry guys, I’m new to this.
If there is, great! If there isn’t, is there a way to incorporate it into the passive crossover? Thanks!

[Wolf]

Uh, that IS the passive way to do this.
Wolf

[cornajatwa]

thanks wogg. is there a passive way to do this as well?

[wogg]

Nice! Thank you! I was hoping to use a Bluetooth or, preferably, an AirPlay dingle 😬 is this still possible?

Sure! Put that circuit between the dingle and the amp.

[cornajatwa]

Nice! Thank you! I was hoping to use a Bluetooth or, preferably, an AirPlay dingle 😬 is this still possible?

[wogg]

Yes, before an amp this is an easy task. What's your signal source going to be?

For generic line level signals, you'd use a pair of resistors in series with the L and R outputs of about 1k ohm. Put a 10k ohm resistor after those to ground, the other side of which will be your mono output. The resistor values are pretty arbitrary and can have a wide range and still work fine.

Google "stereo to mono summing circuit", lots of schematic examples in there. Some omit the parallel resistor to ground, which would work fine too once connected to the amp input.

Here's one with some different values, but you should get the gist:

[cornajatwa]

Bump
is this possible guys?

[cornajatwa]

Hey guys, thanks for the feedback. I need to do a better job of communicating the idea.

I had a 3 channel (left center right) bagby continuum setup in the living room and decided to switch to stereo by getting rid of the center channel speaker.

Now I have a very nice speaker without a purpose. I’d like to turn it into a portable radio.

One problem with that is sending a stereo signal to it. I don’t want to miss out on any part of the signal so I’d like to “sum to mono”.

If I can pull that off somehow I’ll be able to slap a full range plate amp (been sitting in the garage for years) on it and be good to go.

I have an amp and a speaker and the only thing keeping them from going to work is the stereo to mono signal problem.

[DeZZar]

My hope is to get it done between the amp and crossover. It’s a a center channel bagby continuum mtm

Not sure what you're trying to achieve. If you don't have a center channel output from your amplifier - then you don't have a center channel signal. Simply summing together your stereo output to send it to a center channel is....well....kind of pointless - you're just ruining your stereo image. You can't just create a center channel from a stereo mix - center channels, just like surround channels have their own dedicated audio tracks.

[billfitzmaurice]

My advise is to just use the center channel output of the AVR, and if you don't have an AVR you don't need a center channel.

[cornajatwa]

Is it possible to do this without having to buy a bridgable amp?

[cornajatwa]

Trying to sum the signal from stereo to mono before it reaches the speaker

[cornajatwa]

My hope is to get it done between the amp and crossover. It’s a a center channel bagby continuum mtm