I bought a new receiver and sub the other day. I thought the sub only required one cable into the left input but on the installation instructions it says to get a cable with a y-split and plug an end into both the right and left input. Is this correct or is the sub cable into the left or lfe post ok?
Thanks for the information.

You are probably ok; my sub also has L + R inputs, but says that if you don't have L + R sub outputs on your reciever that the one cable (without splitter) is fine.

But, you can get a decent splitter pretty cheaply, so you could go that route, too.

The sub input will be the sum of the left and right inputs to a Mono amplifier. The only adavantage to a y-cable is if you need to boost your gain more than allowed on the sub and/or receiver settings. Sometimes people have trouble with getting the sub to turn on and boosting the input level can help with that. A ycable will not improve your sound quality so its only needed if you have a gain problem.

Thanks for all the information. Talk to you all later.

Bass is mostly omnidirectional. A sub does not always have to be in the front of the setup. You can hide it bihind you couch if you want to. Just another option.