How does my mixing room treatment look?

Hello all, I'm hoping to turn an extra room in my basement into a dedicated mixing room and am looking for some advice on treating it. As of right now, I don't have any sort of audio equipment in there, and I don't think I will have a chance to test the acoustics right off the bat with REW. I know that there is a decent bit of flutter echo and slapback without treatment, so I will need to target the first reflection points (as always). Here are the approximate specs and rundown of the room as-is: Length: 15'-15'8.5" Width: 14' Height: 7' Floor material: hardwood Wall material: drywall Ceiling material: drop-in tiles I have attached a drawing of the room, best as I can. As you can see, it is not the best space for listening, partially because it is near-square and because of the odd structural obstacles, but I'm hoping I can make it usable. I'm planning on facing down the length of the room with 5" monitors directed towards the flat wall (not shelved), and place a small couch and maybe a couple bookcases in the back of the room. However, if there are better options for which direction to face, I'm open to suggestions. The basic placement of the furniture and treatment is attached. The absorption panels are 4'x2' Auralex 2" Studiofoam wedges, and the corner bass traps are made of Roxul Safe 'n' Sound covered in muslin, approximately 30.5" wide and 15.25" deep. I have not decided how I plan on treating the corner where the door is just yet. How does this design look so far? Is it worth following through on and produce a decent, workable space, or will it just be a waste of money? I'm pretty much open to all suggestions, as this is my first build. Thanks everyone, JGAN

Hi JGAN. Welcome! :)

I don't have any sort of audio equipment in there, and I don't think I will have a chance to test the acoustics right off the bat with REW.

All you need is a computer with audio interface, a speaker, and an omni mic on a stand. And it is very much recommended to do a "baseline" test of the room before you do any treatment, so you can see what the acoustic problems are, and devise a good plan. You should then do additional REW tests after installing each piece of treatment, to check that it is doing what it is supposed to do, then proceed to the next step.

I know that there is a decent bit of flutter echo and slapback without treatment, so I will need to target the first reflection points (as always).

The first reflection points are not related to either flutter or slapback. Those are different things. First reflection points are the places on the side walls and ceiling where reflections from the speakers will reach your ears with a timing difference of less than about 20ms with respect to the direct sound, and at a level greater than -10dB with respect to the direct sounds. Flutter echo and slapback are different acoustic problems.

Length: 15'-15'8.5" Width: 14' Height: 7'

How come there are two different lengths? But that's not a very good ratio at all. It fails one of the three critical tests, since the width is exactly twice the height. You will have a major issue at 80.7 Hz (and all harmonics), since that's where the 0,0,1 axial mode lines up with the 0,2,0 axial, and another big issue at 108 Hz, since that's the frequency where 3.0ñ0 axial mode lines up perfectly with the 2,0,1 tangential mode and also the 2,2,0 tangential. There will also be overlapping modes at 88 Hz, 115 Hz, 135 Hz, 141 Hz, and many others. I would seriously consider fixing that.

Floor material: hardwood

I thought you said this is a basement? So how come the floor is hardwood? Since you only have 7' of height, I would take out that hardwood and just leave the bare concrete as the floor. IT will gain you the thickness of the hardwood for your room height. That's not much (maybe an inch?) but it's better than nothing!

I'm planning on facing down the length of the room with 5" monitors directed towards the flat wall (not shelved), and place a small couch and maybe a couple bookcases in the back of the room. However, if there are better options for which direction to face, I'm open to suggestions.

Photos of the room would help to understand it better! Also, it would help a lot if you could do do your room in SketchUp, and post the model here, so we can get a better idea of what you are dealing with, and what you plan to do. 2D line drawings are OK, but sound is 3D so it is much better to actually model the room in 3D. - Stuart -