Getting the absolute best sound out of your system

[Gohanto]

I've been on these boards for a while, debating the differences between speakers, cables, uncompressed vs. uncompressed audio, ect...

The fact is, all this amounts to about 50% of how the audio is finally heard by your ears. Your room is the other 50% and the vast majority that go out and grab a 5.1 system never bother to consider or treat this 50% with nearly the same care they put into getting bigger speaker wires, upgrading to Dolby TrueHD, getting the latest and greatest speakers, ect... (not that these don't help improve sound)

Audyssey is a great tool, but isn't an all-one-solution as many people believe. It can make a bad room listenable, but it can make a properly treated room sound amazing. Even the designers of Audyssey agree that the best results always come from treating the room acoustically before using Audyssey calibration.

A few things to consider...
1. First order reflections - these are the sound reflections where the sound hits one wall, and then your ears directly after. This is the first sound your ear hears after the direct sound from the speaker, however because this is nearly always heard within the first 20ms of hearing the direct sound, your brain interprets this reflected sound as combined with the direct sound. Sadly the wall doesn't reflection all frequencies equally, so this cancels and peaks select frequencies making your great speakers sound like cheaper ones.
A larger problem in many cases though, is that the reflection from the right speaker bounces off the left wall, and your brain is then thinking the signal from the right speaker is coming from the left and the signal from the left channel is partially coming from the right. For stereo imagining, this is detrimental. Placing absorptive panels at these point is quick, easy, and greatly improves imaging between speakers. No amount of EQ can fix this.

2. Ringing can also be a problem. This occurs when you have two parallel walls and sound bounces back and forth between them quickly. This can be quickly identified by clapping your hands between two parallel walls and you'll notice the sounds sustains much longer than it should.

3. Diffusion - With too much absorption, a room can sound too dead (usually between 40-60% over the rooms gets to be too much depending on the room and your preferences). But well placed diffusion can open up the sweet spot in the listening area and ensure that everyone has the same sonic experience. Placed in the back of the room, these panels can help bounce sound from the surround speakers more evenly around the seating area and create a more immersive expereince.

4. Bass is another issue especially in small rooms like most home theaters. In a rectangular room you have easily calculated frequencies where bass amplifies, cancels itself out, or rings. And for each problem frequency, you'll have identical problems at those frequencies harmonics (2x,3x,4x,ect...). One of the smart things about Audyssey EQ is that it specifically doesn't address room mode problems because the designers knows that no boost in EQ will help a frequency that is being canceled at the listening position. Other problems can be slightly masked to varying degrees, or you can treat the problem frequencies and let the EQ handle the fine tuning like it's supposed to.

There is a lot more information out there for anyone interested...

http://www.gikacoustics.com/education.html
http://www.acoustics101.com/

GIK, Auralex, RealTraps, and RPG are just a few well known companies that manufacture acoustic products for home use (but be careful of useless eggcarton or "foam by mail" acoustic scams). Auralex and GIK even look at people's room's layouts, dimensions, and photos to determine what treatments would work best for their rooms and budgets. And they offer this information free of charge.

If you want to hear your audio gear at it's best, learn about and invest in room treatment and you'll never doubt you decision.