How to mix center chanell with R&L?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
My 5.1 set up lets me have a phantom center channel but there is a problem. (I've reasons for preffering not to use a real center.) If you opt for this, the phantom channel's level cannot be set independently. It is just split to the R&L in a fixed fashion. Sometimes this is OK but often it needs to be a bit higher or lower and there is no way to make an adjustment.

I've been trying to find a way to take the L,R, & C pre-out signals, split the C-channel and mix it into the L&R. If fact I've sort of accomplished this but there a big (I say BIG!) glitch -- cross talk. I didn't expect a solution based just on resistors to work well and I've confirmed that it doesn't. The cross talk path is onbviously across the C-channel. After splitting the C output from the pre-out I tried passing each leg through a unity-gain opamp before combining it with the L&R channels to see if that would isolate the L&R. It's better but not acceptable. When input is applied to only the L or R channel enough signal is still leaks into the opposite channel to be heard -- the ratio is about 1:5.

I've looked around a diy mixer projects to see if there is any inspiration there but no luck. This particular configuration doesn't seem to be one that comes up. My next experiment will rout the R & L channels though an opamp before combining C+L and C+R to see if that works better. Meanwhile, any ideas would be welcome.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.