Axiom Home Page Forums General Discussion Hearing Things Stupid Room Tricks

I have to agree.
I can't say much about John's journey here, but reading this inner monologue like posting is quite fascinating.
It's like reading everything that goes through a tweaker's head that usually doesn't come out of the mouth.

Gotta agree with Mark and Chess. This is a great thread for someone else searching for logic in the endless variables when it comes to system response, speaker character and room treatment. Good read and thorough explanations.

Thumbs up!

Thanks, hope it helps someone, or at least serves as a warning to others. I've pretty much hit the limit of what I know how to do, unfortunately -- last thing was moving that stupid rockwool panel against the window from left to right trying to get some kind of balance to the imaging... otherwise it sounds a bit too dead on one side and live on the other. Or I could be imagining things... I figure I'm about ready to start investing in crystals and $300 power cords

The right solution would probably be putting fiberglass on the fireplace behind me instead of the window in front of me, but that would look too ugly even for me. Think it's time to focus on making the place look better -- I guess getting some Varathane on the speaker stands would be a good start.

... and yes, since that photo was taken I *did* move the electronics a few inches to the left so they would line up with the coffee table and the rockwool panel against the window.

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Maybe a mirror behind the LH speaker?

Question for you. When you added the roxul centered behind the speakers, it centered the phantom image better for you I understand, an overall improvement in image specificity. Did it have any effect on the depth of the soundstage? Ie did it make the soundstage extend back less in your opinion?

Hmm, good question. I'll experiment a bit and post back.

It didn't center the phantom image as much as center the "cloud of spaciousness" if you'll forgive the lame expression.

Bit of background. The listening area is now on one side of the living room, under one side of a 45 degree cathedral ceiling (so sound going straight up would bounce off to the left). I have walls & windows to the right and a big open space to the left, so I decided to leave the wall-mounted absorbers / bass traps (originally added for a different room orientation) in place, in the hope of balancing "absorbent on the right" with "open on the left".

I had to add a panel leaning against the RH window to treat the FRP, and the combination made the room seem fairly well balanced left-to-right.

The panel against the window on the front wall was originally placed at the left side of the window to treat what seemed like a bit of slap echo off the fireplace (actually a big-ass masonry heater) about 5 feet to my back-left when seated. The panel seemed to help with the echo (could be placebo effect 'cause I don't have time for any credible testing at the moment) but over the next few days I noticed that the room seemed a bit "unbalanced" again.
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I tried moving the panel over to the right of the window and that was too much, so after a brief binary search I ended up with the current position. It's probably obvious that I don't know the proper terminology for whatever I was adjusting, but I'm talking about whatever your brain uses to recognize by sound that there's a wall off to your right, for example. I guess it's basically the sum of reflected sounds from all around -- too much with the wrong delays and it mucks up imaging, too little and the room sounds dead, just right and everything sounds spacious & natural.

Whatever the name is, I unbalanced it a bit by adding that panel (in the hope of addressing slap echo that seemed to be hurting imaging a bit) and moving the panel to the right a bit at least centered the impact without losing too much of the benefit. The next obvious test would be with/without the panel in its current position to see if it is still helping, but I used up all my playtime for the weekend already.

EDIT - the fact that I could unbalance the sound by adding a panel on the front wall suggests that there's more energy reflecting off the front wall than I had expected. I don't really have a back wall in the usual sense -- the living room, dining room and kitchen are all part of one big area -- so I didn't expect much energy from the drivers to reach the front wall since there was not much for it to bounce off (other than the kitchen cupboards and the back wall of the loft, both 40 or 50 feet away).

Wonder if anyone makes quadratic residue diffuser window blinds ?

Interesting idea. I think I have a big mirror somewhere in the basement, will give it a try. I had been thinking that there probably wasn't much difference in reflectivity between drywall and glass at higher frequencies, but that was nothing more than an unverified "simplifying assumption".

This pic shows the room layout a bit better. This is taken from the extreme left of the masonry heater, using the chimney to stabilize the camera.



You can see all the sound-absorbing stuff on the right wall -- 4" Safe'nSound in the wall-mounted panels, 2" rigid ComfortBoard leaning against the window. I believe the panel on the front wall was just fine tuning the balance, not establishing it, but that said I don't remember if I actually tested with the panel centered between the speakers.

Bah. There's an old saying along the lines of "experience is what protects us from doing stupid things... and doing stupid things is how we gain experience".

I put a coat of varathane on the stands last night but it didn't warm up the colour the way I was expecting. Apparently (based on research done *after* applying the finish) oil-based poly finishes dry with an amber hue but water-based finishes dry clear... and all the other pine in the room has an oil-based finish.

Did I mention "Bah !!" ?