good rca y-adapter

thanks. the sub i need to use in this application does not have high level inputs. two rca sub cables problematic but not impossible. probably should just bite bullet and buy and install another sub cable.

thanks for the input, helpful.

i am thinking i have a design flaw. i wanted to combine the left and right preamp outputs for the sub downstream of the splitters, in order to only have to run one cable to the sub. But am wondering what that will do to sound quality of stereo signals from splitters upstream run into the inputs for the amplifier section of integrated. not smart enough to figure this out but intuition tells me this is a bad idea. please advise.

that is really helpful, thanks.