Originally Posted by sb1
Back in the old days my cheap and huge speakers had much bigger drivers than the current offerings of the popular 5" - 7". Perhaps my memory is a little off, but I seem to remember having the movie theater punch with those speakers, and with no sub. In other words, I'd say it takes a main speaker with a larger driver (and sufficient power or efficiency) than most of the popular stuff today.
Most people don't run their subs over 100hz, and in my opinion this "midbass" slam that is so sought after these days is in higher frequencies than that and are going to have to be covered by left and right (or l/c/r) mains.
Room acoustics have to allow for you to turn up the volume enough to hear these frequencies, as well. Elevated LFE and high frequencies will drown out the midbass frequencies responsible for the hit you in the chest feeling.
Did an interesting test on my system the other day. I have Dali Mentor 8's with dual 8" woofers and a 6.5 midbass in them - and I have a SubMersive HP. My buddy and I decided to test the mid-bass out by moving the x-over up and down using Spiderman 3 as the demo (the scene where the dude turns into sandman).
We found that a 40hz x-over yielded no less than 5dB higher than the 80hz setting (with AVR at -5 we hit 111dB vs 106dB at 80hz)!!! That's a really impressive difference and really shocked us.
I don't have any way to see what exact frequencies this scene is working over, but, clearly my mains eat it uplike it!
The reason we decided to try the experiment was that a -12 on my AVR I just wasn't getting much of that "slam" mentioned above. What I realized was that I had bumped up my SubMersive gain to try to get the slam, when really I just needed to dial the sub back and increase my AVR volume to -5 or even -3, and drop my x-o down. Now, I'm really enjoying great slam!!!
Should mention that I also have decent room treatments so that the increased volume isn't loading up the room and giving ear fatigue, etc.
As usual, YMMV, but this has worked really well for me.