[atledreier]

Hi!

After much grief and sweat and tears I've finally got my fronts set up properly.
Now i've concentrated on my subwoofer.

I have my fronts crossed over at 80Hz (12dB/oct).

My SVS PB12+/2 is right behind my couch. This is the spot where it gives the best frequency response in my room. I also like the tactile feel when it thumps away. I've set the receiver delay by looking at the frequency response. The flattest response I got with the sub set at 6.7m (The longest my pre will go). My fronts are set to 3.0m (Their 'real' distance).

Now, somehow it sounds pretty good with music, I don't notice any significant delay there, maybe just a little. But with movies it's getting annoying. A good example are the lightning strikes in WotW. The initial crack is awesome, then a split second later the awesome low frequency shaking of my couch and body. Other sudden impacts as well. Every single shot in Shoot'em up is delayed like this. The constant rumbles are fine, timing is not critical with those, and the level of the thumps are fine. But it sound delayed by quite a bit.
So I decided to try to measure this delay.
I used REW and impulse graph to try to see what was happening.

Now, I'm not exactly sure what I am seeing, but it seems to relate to what I'm hearing, so...

I see the initial impulse from one of my mains ( I chose the right one). Then the usual reflections from that where I'm used to see them. Then, after about 35ms there is a large impulse, less defined than the initial, but still a definite impulse. I'm assuming this is the subwoofer. It moves in time when I use the distance control in my pre, and also change when I use the phase control on my subwoofer.
So I thought I'd bring it in as close as I could. I set the distance for my mains to 0.0m, and the subwoofer at 6.7. This is the longest delay difference my pre will allow. I also set phase on my sub to 0 degrees, as this brought the delay down further. Now, Doing this I got my impulse delay down to around 23-25ms, but still a significant delay. I run my subwoofer through a BFD. I seem to recall reading somewhere that this introduced a slight delay, but I think that was in the order of 1-2ms, not 20-30.
Am I seeing what I'm hearing in the impulse plot? Is this two totally unrelated things?
Lookign at Iilka's subwoofer measurements, group delay can be in the region of 30-ish ms. Is this group delay? How does that sound?

Any input? It's really annoying to have thumps delayed like that.