Please Help: Subwoofer crossover/bypass settings

I would like some help for optimal surround sound settings. I just bought a new subwoofer for my home theatre system as my old one had some weird vibrating problem. So here's the facts:

- I use my home theatre for mostly gaming, but also a lot of rock, classic rock, dance/techno music, as well as movies (just mentioning this because maybe settings would be different based on what you use it for)

- my receiver has an option to adjust the crossover frequency. I don't really know technically what this is for and with the above in mind, I need to know what setting I should use. Right now it is set at 150 Hz and it will let me choose the following settings: 60Hz, 80, 100, 120, and 150

-my new sub is a klipsch 8" and there's a dial for lowpass on the back ranging from 40Hz to 150Hz. I don't know what lowpass is but by ear it seems whatever the dial is set at it will only output frequencies BELOW that number. When I put it at 40 for a particular song I didn't really hear anything because I guess the bass guitar was playin a higher note than 40Hz

My feeling is that the receiver crossover determines what frequencies get sent to the sub and the lowpass is what the sub will accept and output. But tbh I know nothing on the matter and I'm probably far off the truth.

With what I plan on using the system for in mind, what settings would be best for me to use that would give me a happy medium yet not sound muddy or mess up my sub?

Thanx very much in advance

Also, is it safe to have my playstation 3 on top of my sub since I don't have much room (I'm not worried about it falling off from the vibration but rather because it has a hard drive and I think magnetic fields can damage/erase hard drives)

Ok I checked the sub and it DOES have complete bypass available.

I have 7 speakers, 5 of which are http://montreal.kijiji.ca/c-cars-veh...dIdZ275764220# I don't know if this matters but the impedance is 4ohms.

My FL and FR are http://www.futureshop.ca/en-CA/produ.../10020386.aspx

Hope the links work...its tricky cuz I'm on my phone writing this.

Its a bit of a cut-and-paste bang up system right now but Im working on saving enough to be able to replace my tiny speakers with some better ones. Probably will get te matching Bose center speaker next.

So would you say 120 or 150 crossover and complete bypass on the sub would be best after seeing what the speakers look like? And because they are in fact really small.

Also there's a switch on the sub for "phase" it can be either 0 degrees or 180 degrees. It's set at 0 right now...should I leave it that way?

Thanx for the help guys, it honestly means a lot to me

I tried setting the FL and FR (Bose ones) to large and I found it took away from the subwoofer which is a good thing because with them set to small the sub was overpowering. It felt like when they were set to large I achieved a fuller sound with a good balance with the sub. Also the sub on bypass seems to sound the best. I can only barely discern a difference when I tinker with the crossover so I just left it at 100Hz. Maybe my ears are just bad or maybe my test-song wasn't the best choice for a test song but it was pretty minute. Thanks for your help Richard

Then again when I set the front speaker to large I can specifically hear high end bass tones come from the Bose and the lower bass from the sub. This is kind of weird for music because if a particular song has a baseline with high end bass and low end bass in the riff im hearing the sub just kick in for half of the riff and the Bose handles the other half. This causes a discrepancy in the volume of high end bass and low end bass since the Bose doesn't have the low end oomph that the sub does. Plus it's just weird hearing it switch back amd forth. With the speakers set to small it seems the frequency range of the sub is widened. I don't mean the sub's actual range specs but rather the range it outputs due to the speaker size setting.

In the end I think I'm actually gonna go with small front speakers especially for music and maybe switch to large for a movie or game because it sounds better on large for those but bad for music.

It's tricky stuff! Maybe it won't sound so finicky when I get a full set of good speakers.