Odd mixing room

tvm · Post by **tvm** » Thu Mar 24, 2005 3:34 am

I've got a problem I can't find the answer to. I've got a modest setup in my basement, and I want to see where I still have problem freq's. The deal is, I really only have 3 walls. The fourth is open to the rest of my basement. From where I sit it sounds good, and translates okay, but always seems light between 100-300 anywhere but my room. Under 100 is fine. All the calculators I've used say I have a DIP around 250-350, and of less than 3 db. Nothing I've ran gives me a boost anywhere above 1 db, and I come out flat above 400. I've got 2 inch pyramids on the 3 walls, mostly on the front, and bass traps in the corners where side and front meet and between ceiling and front.

Anybody have some ideas on how I would calculate that room? For all practical purposes, my room is H 92.5 in, W 132 in, L 177 in. Or you could change the w to 33 feet

knightfly · Post by **knightfly** » Thu Mar 24, 2005 8:21 am

You might check out this thread, and for your "non-existent" wall, just use the full distance between the wall that DOES exist and the solid boundary (in the next room, whatever) that faces that wall -

http://www.johnlsayers.com/phpBB2/viewtopic.php?p=18059

Generally, if you're mixing light in the 100-300 range then you probably have an excess of that at your listening position; this can be caused by SBIR or speaker/head height relative to total room height, etc, check out the link and let me know if it does/doesn't help... Steve

tvm · Post by **tvm** » Thu Mar 24, 2005 5:56 pm

I'd run that already, I didn't know which number to use for width. I do have a null from height at the height my head is, at 73 and 220 Hz. I had my room analyzed by Auralex and they recommended t-fusers in the ceiling. I didn't because of price, I had to do bass traps and walls on the main room plus a booth. Any way I can test that? I'd hate to have to drop the extra cash and not fix it.

Let me know if you need more info, I really appreciate the help.

knightfly · Post by **knightfly** » Fri Mar 25, 2005 2:03 am

It would be good if you could edit your profile to include a location; this just makes it easier to recommend things that may actually be available to you.

A basic sketch of how your room is laid out, with positions of desk/speakers/your head, and which wall is missing -

I'm a bit surprised that anyone at Auralex recommended a diffusion product for that low a ceiling; I would go with 2-3" of rockwool spaced 2-3" away from the ceiling if possible, and centered halfway between speakers and your head (no backing; you want the extra air gap behind the absorbent)

So, a sketch if you can, maybe a pic or two as well - please size them so they are 750 pixels wide or less, otherwise everyone has to scroll sideways to read the text... Steve

tvm · Post by **tvm** » Fri Mar 25, 2005 4:06 am

I'll try to get a layout and some pics up tonight, I have to figure out where to host them. Thanks again for the prompt help!

tvm · Post by **tvm** » Fri Mar 25, 2005 6:17 pm

Hope these work. The couch isn't normally there. The scale on the layout is 1/4 inch = 1 foot. I'm not sure if the pic is right, it looks to long (top to bottom). It's 22 feet from drywall to drywall, top to bottom. I don't have the Max-Wall. The 177 in is to the front wall of the rooms behind the mix position. I don't have bass traps in the (upper right) corner, but I do have more Pyramids behind me, one directly and one at the back of the hall on the right.

Let me know if you need more info.

knightfly · Post by **knightfly** » Sun Mar 27, 2005 5:19 am

If your head (and speakers??) are in nulls vertically at those freq's, then you're ALSO in a PEAK of the 4th harmonic of your vertical axial mode, which just happens to calculate at 295 hZ - BTW, are your speaker ALSO at the same height? (Center of woofer)

Also, your layout isn't even close to symmetrical so you will likely have other balance problems - if you can't relocate so you have same distances to walls from either side, then you might put ALL those Lenyrds in the corner, put the rest of your foam across that corner and along the walls for 3-4 feet (spaced away from the wall by at least 3-4"), and see what that sounds like. Save some foam for a cloud over the mix position.

First though, I'd play with changing the height of your chair and speakers, and maybe stand off that diamond-shaped foam a few inches from the wall... Steve