This is a really great question. Considering your receiver has a low-level sub pre-out, I would use that rather than wire the sub up like it was passive. This gives you several benefits, but most importantly:

1. Allows the receiver to perform bass management in the digital domain prior to amplification.

2. Allows the amplifiers to work more efficiently by not having to amplify full range audio.

Given the speakers, I can't see any real compelling reason to hook it up any other way.

Go back to wiring the receiver directly to the speakers, then hook up the sub to the low level pre-out. Set the receiver crossover around 80Hz, then set the sub around the same mark. Set all your speakers to small and your sub to yes in the bass management setup, and you should be all set.

Mind Over Matt'er - Technology musings, opinion, and more straight from TechLore's head geek.

Glad I could help. Don't forget that speaker volume calibration is also very important to getting a good surround experience. Check out this article for more on how to do it: http://www.techlore.com/article/10037/How-To-Calibrate-Your-Surround-Sytem-Us...

Mind Over Matt'er - Technology musings, opinion, and more straight from TechLore's head geek.

I haven't always had the best luck with automatic calibration systems. Some work better than others, but there's nothing like doing it yourself. I'd opt for manual if you have the gear, but you will need a SPL meter to do it correctly.

On those meters, I have a full article on how to use one. I DO prefer and recommend analog over digital. If Radio Shack no longer sells analog meters, you can still get them at Amazon. Here's the NADY Analog SPL Meter. Never used it, but it looks like it will work nicely.

You can see the article on how to use it here: How To Calibrate Your Surround Sytem Using an SPL Meter

Mind Over Matt'er - Technology musings, opinion, and more straight from TechLore's head geek.