Wall-mounting a speaker is normally a bad idea unless it's designed to be wall mounted. Also you want the tweeter to always be aimed toward the ears for accurate response.
Originally Posted by kikonenko
1. You might have a bad seating placement(couch against the wall)
2. You might have bad speaker placement in 5.1 surrounds are side(not rears)
3. You might be too close to the speakers.(1 meter from the speaker to your ear is a bad thing)
4. You might be crazy.(Sometimes we can manufacture issues in our head and need to grab a favorite beverage and just enjoy the movie.)
I think 4 is definitely true for all of us here. Moving the speakers up can help with 2 and 3, but it won't fix issues with number 1. Make sure you aim the tweeter at your ears wherever you put the speakers.
I've found in some situations adding additional surrounds really helps.(This should be a last resort though)
Don't get too carried away with resonance science these are surrounds.
Fronts:Madisound RB Kits Rears and Sides: Kef 2001.2, Subwoofer: TC Tiger-1000
Receiver:Onkyo NR-708 Amp: Behringer EP4000 Players: Panasonic BDP-60, Onkyo DX-C390 Projector: Epson 8350 Screen: FAVI PD-HD-92
That's like trying to get decent sound in a public lavatory.-TLS Guy
Heck, if you've got the cash, go the NSA supercomputer route and use Fluorinert- Adam
A shovel of dirt can stop a flood. -Westom