I have everything set to to small except for def tech towers.... I'm wondering if I should set them to small but then I think the sound kind of thin... I have everything set to 80hz but am wondering if my center should be set higher than that or maybe lower such as 60hz.. Audyssey sets center at 150hz... So Im not sure where to go from here? I have my towers with subs facing in and it's kind of boomy not to bad but at times it is any ideas as to if I should face them out...and again thxs for all this advice.
It is very hard to say with your Definitive Technology BP7002 tower speakers.
They rate them down to 15 Hz, but they do not specify a tolerance for the frequency response of 15-30kHz. So it could be +/-10dB or anything else, which makes the rating pretty much meaningless. I would try them both run full range ("large") and then try crossing them over ("small"), perhaps at 60 or 80 Hz. I would try all three, and if the 60 Hz setting sounded best, I would also try 40 Hz. This is assuming that your receiver can set the crossover frequency differently for the different speakers in your system, because 40 Hz would be way too low for the other speakers you have. Although I recommend that you try the various possibilities mentioned above and listening for yourself, if you do not want to bother with trying out the various possibilities, just set them to small and select 80 Hz. That will work okay.
Your subwoofer, on the other hand,
is rated with a tolerance of +/-2dB, so you can count on actually getting 25Hz with them (Outlaw seems respectable in their performance being pretty much what they say it is). My guess is that you want the deepest bass going to it, but if the main speakers could actually do the range they state at +/-3db, you would not want to do it that way, and would probably want to get rid of the subwoofer and just use the front speakers. But, again, the main speakers are not rated +/-3dB, so you can regard their claim as meaningless nonsense that has nothing to do with their actual performance.
The
center at 150 Hz seems high. I would try 80 Hz and see how well that worked.
Basically, what the general rule is, is that the crossover setting in the receiver should be above the -3dB point of the bass end of the frequency response of the speaker. If one cannot set this differently for speakers in different positions (e.g., front right and left vs. surround, etc.), then one should set it above the -3dB point of all of them (or in other words, one sets it for the least capable speaker). In my case, I use identical speakers for all positions (other than subwoofers, obviously), and mine have a rated frequency response of 50-40kHz +/-3dB, and I set my crossover to 80 Hz. My automatic setup selects "large" (or full range) on its own, which is obviously not right, and so I manually set my speakers to small and select an 80 Hz crossover.
The second general rule is that you want the crossover to not be too high; the reason being, that otherwise you will start to hear sounds coming from the direction of the subwoofer that should be coming from the direction of one of your other speakers. The THX standard is to use 80 Hz, but you are probably okay with anything from 100 Hz on down, though I recommend using 80 Hz if you can. This second general rule cannot be followed when one has tiny main speakers that can only go down to 120Hz, which is a reason to not buy such speakers.