Sound delay when playing through home theater system

I recently purchased a new Yamaha DTX 530K, and so far I am really enjoying it. I bought it to practice for my all too infrequent jam sessions with my brother and his friends. I play an acoustic kit when we jam, and although the physical size / layout differs I find the utility (neighbor and family friendly) features of the E kit outstanding. Little problem transitiojning between the two.

I mostly play to a set list from my iPod through the DTX brain and out through headphones. Recently tried to play through my home theater system, using the Brain's L / R Line Out to AUX in (RCA style) port. I get a significant delay in the drum sounds compared to the iPod, probably close to a 32nd note delay.

I am playing the iPod in through the DTX brain and then using the line out to carry both signals to the home theater system. (ONKYO 5:1).

Thoughts??

Thanks for any help

Even though I received no replies or suggestions, I wanted to offer a solution in case anyone was interested. The problem was simple to correct. The audio setting needs to be on a straight audio, with enhancements such as cinema, surround etc. turned off. Works fine now, thanks to David at FMC in Freehold, NJ.