Room Treatments added, with negative effects..

Gbmcleod,

Indeed you are correct in saying that tube traps cannot be placed along the wall & then be forgotten. They must be tuned. I didn't go into that in my post as the main objective there was to introduce him to the product more than teach him how to use it.

Yes, that classic article from J. Peter Moncrieff is a killer article. I have read that article many times. Once again you are right - many people just don't use the traps correctly. Turning them 2" at a time is indeed too much! BTW, that tube trap article is available on ASC's website too: www.acousticsciences.com & click on "articles". Both the 1985 & 1989 papers are there. This is seminal work done w/ tube traps & worth reading every page of.
FWIW.

Absorption sucks...

It is quite obvious that you are used to listening to your room, as well as your system.

Assume a "nearfield" (7-9feet) listening positions adjust your speakers exactly on axis, leave all treaments exactly as they are, and be prepared to hear your system, instead of room reflections and false ambience.

You will also have to use reasonable volume 75-80db or more to attain the precedence affect.

The near field thing will never make proper room acoustics redundant. Headphones will do that. So unless you are prepared to attach your speakers to your head, no amount of near field mumbo jumbo will negate the need to have the best acoustics possible for the room. Getting a good room to start with is probably just as important, but, like most everyone, we don't necessarily have a choice of rooms. To Sumitav: have you any idea how fast sound travels and the fact that it bounces all over the room, whether you are fifteen feet away from the speakers or six? How long do you think you get to hear the first arrival wave?

To Pbb,

Yes, I know how fast sound travels and have studied acoustics enough to know why nearfield is a valid method of reducing the effects of reflected sound.

It is quite obvious you don't understand the "precedence effect" and how it works.

It is also obvious that you don't understand the differences between direct and reflected sound and how the ear/brain interprets them.

Just so you completely understand my position, I suggest using reasonable room treament to reduce reflection to a minimum and listening nearfield to reduce exposure to what is left.

And the speed of sound really has nothing to do with nearfield listening or reflected sound since the moment sound hits something its amplitude is adjusted down, by absorption and dispersion.

When a sound hits an object part of it is reflected in a dispersive pattern, obviously in a different time/phase domain and some of the energy is absorbed (turned to heat energy)

The sound from the speaker that travels directly to us does not suffer from this, and is what your brain takes as real and if the amplitude is adequate, it takes precedence when the brain interprets the sound.

The resulting mismash of sonic haze from reflection/dispersion is no match if one is listening nearfield.

Maybe if I make this simple you'll understand.

Take a flashlight and set it atop your speaker. Turn off all the lights in the room and notice that in your listening postition the light shine on your face and some of the light disperses to the side walls, in fact it gives "low" light to all the room.

The beam in your face is direct. The one at the wall is reflected/dispersed. The fact that the light is traveling at the same speed does nothing to reconstruct the reflected light and make it a threat to the direct light.

Sound has the same properties, just at lower frequencies.

In a room, your goal is to reduce the reflected and maintain the direct.

So maybe you use Bose 901s and this doesn't mean anything, cause your listening to mostly reflected sound anyhow.

I don't know what experience you have in setting up rooms, but if you think you need to use headphones for the best sound, it would seem not to many.