[MME1122]

Yeah I know, another one...

I read through most of the threads on setting up a differential rear fill, and maybe I'm dense but the wiring side of it is still not super clear to me.

I'm not looking to debate whether it's good or bad etc, I'm just looking to experiment and get some help on the wiring.

I'm using an APF8.9bit and my stock rears. I've got digital input going into the amp, and it's a DSP/amp in one so I can't change anything in the middle.
I can't mix the signals in the DSP like the helix can, but I can invert polarity on just 1 or both of the rear channels.

So does this diagram look like it will create the differential signal? Based off the stickied threads.
Would this be a mono signal playing in both speakers, minus the center information?
Or would I actually be getting left signal minus center to the left speaker, and right signal minus center to the right speaker?

Should I be connecting to the (-) on ch8 or (+)? ch7(+)>speakers>ch8(+) is what I gathered from my reading but it doesn't seam right...don't I need a ground somewhere?

In this configuration the amp itself is NOT bridged.

From there I can bandpass, delay/TA, EQ, etc.

I'm also looking at this diagram, but the difference here is I have separate channels for front and rear - here it's just 2 channels.

Thanks!

 

[156546]

(R-L) = -(L-R) and "-" is a simple polarity inversion.

 

[MME1122]

(R-L) = -(L-R) and "-" is a simple polarity inversion.

Got it, that makes sense.

So are you saying I shouldn't invert the polarity on the 1 channel? Or that I shouldn't invert the one speaker?

 

[Kell12]

Any more info on this? I also need an answer.

 

[MME1122]

So I got this wired up per my first diagram and I'm getting sound from the left rear but not right rear. Played a left/right/center track and hear left and center from the left speaker but nothing else. No right signal, and it seems like nothing is coming from the right speaker.

Seems like the right rear channel isn't working at all, I get nothing from it even with the left channel muted. Might need to troubleshoot the wiring.

 

[156546]

So I got this wired up per my first diagram and I'm getting sound from the left rear but not right rear. Played a left/right/center track and hear left and center from the left speaker but nothing else. No right signal, and it seems like nothing is coming from the right speaker.

Seems like the right rear channel isn't working at all, I get nothing from it even with the left channel muted. Might need to troubleshoot the wiring.

If your amplifier can be bridged, then the polarity of the input and the output are already inverted in one channel.

 

[MME1122]

If your amplifier can be bridged, then the polarity of the input and the output are already inverted in one channel.

Is that true even if the amp isn't set to be bridged?

I tried both inverted and not and there was no difference.

 

[MME1122]

So I decided to revisit this and play around a bit more. I kept the setup exactly as my diagram above, but instead I connected to the negative terminal on channel 8 instead of the positive terminal.
And the result was a summed mono channel, kind of as expected. The amp seems fine even though it's not configured as a "bridged" channel.
I realized I forgot to flip the polarity on one of the channels, I only had a few minutes to play with it today.
So that will be next, I'm thinking it will work since it's already summed, I just need one inverted. And then it should a mono differential signal.

 

[MythosDreamLab]

If there a reason why you don't want to hook up your rear speakers in the normal way?

 

[MME1122]

Doing it this way is supposed to add to the front stage without interfering with the imaging.

 

[NW JLUR]

Try looking here.