[Johnhill]

Before installing the Helix.3 DSP I had run three sets of rca cables to the trunk, front, rear, and sub to get the signal to the amps.
After installing the DSP when I first set it up, I used two sets, front, and rear.
I am now setting up a three way front, and rear door speakers will be mono rear fill.
For input to the helix, is there any reason to use front, and rear? I was thinking just using the front channels would be all that is needed.
Also, the rear door speakers are 6.5" Morel Tempo Ultra that were up front in the doors playing from 80 to 3200hz in stereo.
With the new setup the rear speakers will be mono.
The front mid base door speakers will be Stereo Integrity TM8, with a recommended crossover point of 55hz. There is a pair of Stereo Integrity SQL-12 in the trunk that they will be crossed over with.
What would be a recommended crossover point for the rear fill speakers?
Thanks for any help.

 

[ItsonlyaHONDA]

I've never done rear fill but from my understanding the frequency should be 300-ish-3khz-ish, delayed a bunch and attenuated until it's not noticeable. Seems like a waste of a channel to me honestly. But ppl like what they like 🤷🏽‍♂️.

There's no need to use 2 sets if RCAs unless you want to keep fader function from your head unit.

Since your running a mono signal for your rear I think there is a trick. I think you flip polarity on one speaker so they are both not playing the same signal. I think 🤔.

 

[Cutaway]

You definitely dont "Kneed" Front + Rear inputs into the DSP unless you want fade control like @ItsonlyaHONDA mentioned. I ran Front + Rear into mine just because they were there and i really havent needed the rear inputs...

But since you have a HELIX with Virtual Channels, one of the fun ways to do Rear Fill is be enabling the Center Channel

and then bringing that into your rear channels with a flipped Polarity. I really like setting up "Differential" this way on a helix. it truly takes away the mono/shared sounds from the left & right rears

 

[Muu]

like that tip above, had differential rear in my merc and it was good in moderation from the front, but in the back sounded like a stereo with the crossed wire somewhere

 

[Johnhill]

Thanks for the reply. i found the option in the Helix software.