I'm starting to see a pattern here.

[CurtZHP]

Here's another interesting wrinkle.....

With the treatments out of the room, I decided to run a tone generator through the speakers and listen with the SPL meter. I rocked the the generator back and forth in the 100-140Hz range until I found the point where the meter read the lowest from the normal listening position. Not surprisingly, this point was around 130-133Hz. I then took the meter and began to move around the room to see if it would climb. Nothing.

For some dumb reason I put the meter on the floor. Suddenly it jumped a good 10dB! Moving it around the floor, I discovered that the null disappears when the meter is placed on the floor where my chair would normally be. I even held it up to the ceiling around the room, but the null remained until I put the meter in the center of the floor.

Hmm....

[Nick Sevilla]

Here's another interesting wrinkle.....

With the treatments out of the room, I decided to run a tone generator through the speakers and listen with the SPL meter. I rocked the the generator back and forth in the 100-140Hz range until I found the point where the meter read the lowest from the normal listening position. Not surprisingly, this point was around 130-133Hz. I then took the meter and began to move around the room to see if it would climb. Nothing.

For some dumb reason I put the meter on the floor. Suddenly it jumped a good 10dB! Moving it around the floor, I discovered that the null disappears when the meter is placed on the floor where my chair would normally be. I even held it up to the ceiling around the room, but the null remained until I put the meter in the center of the floor.

Hmm....

Have you made the map I suggested?

[CurtZHP]

Working on it. Still trying to make heads or tails out of the different plots. I shouldn't have done sweeps, I should have done individual tones at every spot. Yes?

If anything, I've found that, apart from the dip at 130Hz, my existing treatments have certainly been effective.

[Nick Sevilla]

Working on it. Still trying to make heads or tails out of the different plots. I shouldn't have done sweeps, I should have done individual tones at every spot. Yes?

If anything, I've found that, apart from the dip at 130Hz, my existing treatments have certainly been effective.

Yes, steady tones for each plot.

Cheers

[CurtZHP]

Redid a few plots at "problem" frequencies. Ran 50Hz, 100Hz, 125Hz, and 250Hz.

50Hz was odd. It was stronger on the left side of the room and gradually sloped off as I moved to the right, until I got to the back right corner, where it came up slightly.

100Hz seemed better. Peaks were right where I sit and against the walls. Nulls were where they could conceivably stay out of trouble.

125 was ugly. It behaved much like 130-133 as tested before. It was as if the whole room was one big null until I put the meter on the floor.

Then I stuck my head under the desk (that the console is sitting on) and was very interested to hear the tone many times louder than in the "sweet spot." I tried this with the 100Hz tone and had the same result.

I'm beginning to think the desk is acting like some sort of resonator similar to the port on a loudspeaker cabinet. As it's directing low frequency energy from the speakers (reflected off the front wall) into the center floor of the room, who knows what sort of acoustic hijinks it's causing??

The speakers are on stands situated between the desk and the wall. The desk consists of two side panels of 1" MDF, a top of the same, and a "modesty" panel about 1/3 of the way in from the back.

[Nick Sevilla]

Redid a few plots at "problem" frequencies. Ran 50Hz, 100Hz, 125Hz, and 250Hz.

50Hz was odd. It was stronger on the left side of the room and gradually sloped off as I moved to the right, until I got to the back right corner, where it came up slightly.

100Hz seemed better. Peaks were right where I sit and against the walls. Nulls were where they could conceivably stay out of trouble.

125 was ugly. It behaved much like 130-133 as tested before. It was as if the whole room was one big null until I put the meter on the floor.

Then I stuck my head under the desk (that the console is sitting on) and was very interested to hear the tone many times louder than in the "sweet spot." I tried this with the 100Hz tone and had the same result.

I'm beginning to think the desk is acting like some sort of resonator similar to the port on a loudspeaker cabinet. As it's directing low frequency energy from the speakers (reflected off the front wall) into the center floor of the room, who knows what sort of acoustic hijinks it's causing??

The speakers are on stands situated between the desk and the wall. The desk consists of two side panels of 1" MDF, a top of the same, and a "modesty" panel about 1/3 of the way in from the back.

I would eliminate the speaker stands, and put the speakers on a shelf above the console. And please, get rid of your Modesty... panel that is... looks do not matter.

Pictures?

[CurtZHP]

From the looks of things, that panel is sort of holding the desk together.

If I put the speakers on a shelf above the console, that puts them too high. (Tweeters well above my ears and the woofers halfway between floor and ceiling.)

I tried putting the speakers on the desk itself and that made things worse.

I'll see if I can scrounge some different furniture to try. Either that or modify the existing desk to eliminate the unnecessary.

[vvv]

Real quick, couldja with a drill and some screws, mebbe just replace the modesty panel (you know, the thing they mount the webcams on ) with a 1x4" (or 2) you pre-drill?

[CurtZHP]

I was thinking of that. A couple big honkin' L-brackets or something.

But then where am I supposed to put the webcam? I guess I'll need a subwoofer.