Install Problems!

[willwork4beer]

Hey all I recently installed a system over the this past weekend. I previously just had 4 speakers in the rear 2 sets at 2 ohm each and two 2 ohm in front, all speakers were connected to a MB Quart 4.70 Everything worked beautifully. I went to install my subs yesterday and the subs played fine but the 4 channel amp is only playing two sets of speakers at one time. I can't seem to get them all playing at the same time. I've checked all my amp settings and it's exactly the settings from when it did work fine. I swapped amps about 20 mins ago and its the same thing only two sets will work. I have RCAs going to chan 1/2 of the 4 chan amp and RCAS going to the sub amp. I never had to plug RCAS to chans 3/4 on the 4 chan before, I just swapped the ones from chans 3/4 to the sub amp. Really confused and checked every connection possible at this point. Do I HAVE to provide RCAS to chans 3/4 with this amp or am I still off? Thanks

[RMac18]

I assume you have the MB Quart FX4.70, if so it should look like this on the side correct? Make sure the input mode is set to 2 channel. 2 channel should use 1 pair of rca's for all 4 channels of the amp. If its on 4 channel then you would need the second set of rca's for all 4 channels to work.

[willwork4beer]

Yes that is the amp, I threw in a hifonics 600.4 to see if it may have been the speaker inputs on the amp but its the same probem. I had the MB Quart on 2 chan with one set of RCAS and only two channels were working not all 4. Same thing is happenening with the Hifonics I know their basically the same amps but with the Hifonics on mode 4 it shows 2 sets of RCAS being used when in mode 2-3 only one set is used Sorry if I'm confusing anyone with my wording