I recently purchased a Infinity SW-12 for a really good price but I'm having some trouble with it. It has 2 RCA plugs on the back according to my Yamaha HTR-6180 and the SUB manual it says you only need to plug one in for LFE. So I found a old RCA cable that was long enough to reach plugged it in the Preamp spot for it on the back of the reciever. The sub works but it is nearly inaudible with the volume on the sub turned up all the way. I messed around with the reciever for a bit and it should be working fine.. any suggestions? I was thinking maybe I need to get a male RCA splitter and plug it into both RCA jacks on the back of the sub..

I think you're on to your solution. The Y connector you described should fix your problem

I recently purchased a Infinity SW-12 for a really good price but I'm having some trouble with it. It has 2 RCA plugs on the back according to my Yamaha HTR-6180 and the SUB manual it says you only need to plug one in for LFE. So I found a old RCA cable that was long enough to reach plugged it in the Preamp spot for it on the back of the reciever. The sub works but it is nearly inaudible with the volume on the sub turned up all the way. I messed around with the reciever for a bit and it should be working fine.. any suggestions? I was thinking maybe I need to get a male RCA splitter and plug it into both RCA jacks on the back of the sub..First, turn down the gain on the sub. Now, check the speaker set up on the receiver. Is sub set to Yes or On? Are other speaker channls set to small. Try another cable. Are you sure you are connected to the SW pre OUT? Some connect to an input by mistake.

I bought the Y connection no different and I did everything ransac suggested it's still pretty dim sounding... any other suggestions?

Need to check out your source signal path settings. What are you using as a source for the sound being sent, or not sent, to the sub?

I've been using the xbox 360 in DD 5.1, PS3 (blu-ray) in 7.1 lossless and the iPod dock. This is my first time using a sub so I could just be a stupid noob. I had a old pioneer deck with some technic speakers before this... this is all new to me

So I think I finally got it set up correctly now just like my Beta 50's it really doesn't get going until you hit a certain volume level.. What other settings should I set it to as far as the Crossover, Phase (180 or 0) LFE or Normal. It has the RABOS what nots on it i'll fool with that soon enough