[mjock3]

I have my stereo set up in the living room, the dimensions are 19’ 2” x 15’ 2” x 7’ 5.5”. I have recently done a update to my system and I am thinking of doing some acoustic treatment. I currently have 2- 2’4’4” panels on walls behind speakers. I have some bass boom going on, variable to the cut that is playing. I just put some new power cords in the system, while they did a lot of good, one thing went bad. The shimmer that on a good recording the cymbals had.

I took the panels off the wall and set them on a chair across the corner, the shimmer returned with a bit more. The boomy bass left, this was a short listening experience but it convinced me that I know little of nothing in acoustics.  Do you have any suggestions?

Mark

[poseidonsvoice]

For starters, upload a drawing or picture of your room so we can see what we can work with. And you have Salk HT3's yes?

Thanks,
Anand.

[mjock3]

Yes I have Salk HT3's.

[bpape]

Where is your seat in relation to the room length?

Bryan

[mjock3]

Head position is about 14 feet from wall behind the speakers. Speakers are about 2 and 1/4 feet off the wall. Reason being that is where they sounded best.

[Ethan Winer]

I currently have 2- 2’4’4” panels on walls behind speakers. I have some bass boom going on, variable to the cut that is playing.

Yes, "boom" frequencies in a room are excited or not depending on the key of the music. The main problems I see are you have only two panels in a large room, and they're not in the right places. To attack bass problems the panels should straddle the front corners at an angle like the panel on the left in this photo:



But you really need more than only two panels to tame bass in a room that large.

--Ethan

[bpape]

I would agree that more would be required overall.  Your seated head position could be farther from the wall behind you to avoid buildup and some of the modal issues.

Bryan

[mjock3]

How many do I need for a room this size? I have to consider it is a multi purpose room, not to mention the first thing someone sees coming in the front door.

Thanks,
Mark

[bpape]

Within reason, as many as you can tolerate. That's not a concrete answer but you seem to be sensitive to any sort of absorption so I would go slowly and make sure every piece you put in goes down as low as possible into the bass.

Bryan

[mjock3]

So focus on bass. That means thicker panels or corner panels right. If I wanted to tame the highs or mids where would I need to put those panels? I have temporarily put the panels in the corners and it is amazing what that did to the highs and upper mids. (much more of both) Why is this? The panels were behind the speakers.

How much should I move listening chair forward? I moved it some and again a real change in the way things are presented.

Thanks,
Mark

[bpape]

For best bass response, try between 33 and 38% of the room length from ears to wall behind you.

Overall, taming the bass is more a matter of addressing excessive decay times which can mask harmonics, imaging cues, micro-dynamics, etc.  If you want to minimize mid/high frequency absorption, try using some 4-5 mil plastic on the faces of the absorption before you wrap them in fabric.  That will still be pretty broadband but minimizes the upper mid and high attenuation which you seem to be sensitive to.

Bryan