I wondering if anyone out there might have the B&W 804s,HTM3S, and DS7s and what there crossover setting were.
Currently I am dialed in at 60hz for the towers and 80hz for the surrounds and center.
Any opinion is appreciated.

Thanks

I've had the 990 for a few years and got a pair of B&W 804S and an HTM3S center a couple moths later. I tried different crossover settings at that time, and found that having it set at 40HZ for the 804S and 60Hz for the HTM3S was best, so everything lower than that would be sent to the Sub (along with LFE). If I changed the 804S crossover to 60 or 80Hz, they didn't sound as "full", so 40Hz was best. The I'm using DS6 bi-polar surrounds (which is part of the old 600-series) and have their crossover set to 80Hz.

So with those settings, everything below 40Hz for the fronts, 60Hz for the center, and 80Hz for the surround is sent to the sub.

I have none of the things that you have, but since you left me an opening I'll take it

What I did when I got my new bookshelves was use the SMS-1 to look at my system low frequency response and move the crossover point around until it was the best I could get it. Then I used the equalizer in the SMS-1 to flatten the response further. Crossover is at 60Hz in my case.

Set up this way the sub blends so well with the mains that I sometimes forget it's on. I can still shake stuff off the walls but bass isn't the only thing I hear.

Thanks right now I hve my mains at 60hz ,center and surround at 80hz.
40hz,hmmm have to give it a go.
I do wish the 990 was capable of leaving the speaker size to small on the mains while setting the sub to LFE. I hope the new 978 gives that option.

If you set the speakers to small and the sub to LFE only, what would you do with the speaker signal that falls below the crossover point ?

It really comes down to whether you think the B&Ws can better produce the signal down low than the sub. More than likely they will be more accurate down to their lower register than the sub will be trying to cover the higher frequencies up to that point. If the 804s are rated to 40 hz they will be happy with the 40 hz crossover and probably sound pretty good.

Doesn't crossing the signal over at the 3DB point (presumably that is the 3db point for the 804's) create a 3db dip at that point (even with the sub)? I thought the concept was set the crossover point somewhat higher so that there isn't a dip. Obviously if that is higher then the sub can produce that's an issue. But its hard to conceive of a sub being inaccurate at 60Hz. Of course everyone's room and ears are different.

If your speaker response is already down 3 dB and you set the electronic crossover to that same frequency then yes you'll be down 6 dB. So I'll typically set my speaker crossover one step higher than the spec'd 3dB point on the speaker so that the system only sees the electronic 3dB dip and NOT the speaker 3dB dip.

My main speakers are purported to be good down to 30hz, but I cross them over at 60hz. It really sounds smoother than 40hz.

Crossing them over at a higher frequency also saves headroom for your main amp since the sub does the hardest work.