Small Mix Room Layout - Please help.

Hi, I am new to this amazing forum but my mate Eric at the Echo Bar told me how helpful you chaps are so i thought i would come to you for advice. I am turning my spare room into a mix room. Please see the design layout attached. I have a budget of about $1000 to put in bass traps, diffusers, cloud etc. I can do that kind of woodwork myself. I own a set of Dynaudio BM5A MK II with a cheap M-Audio SBX10 sub. Can you offer advice about where i set my monitors and where to place the acoustic treatments? Any help would be hugely appreciated. Cheers, Jett

Hi Jett. Welcome! Please read the forum rules for posting (click here). You seem to be missing a couple of things! :) Anyway, your room has a reasonable ratio, and assuming that you do NOT need any isolation (you didn't mention it, so I assume you don't), and you only need layout and treatment:... There's a more or less "standard" way of laying out a studio, which goes something like this: Speakers fire down the longest axis of the room (meaning the 4.15m axis in your case), and you need the corners for bass trapping, plus the front part of the side walls for first reflection point treatment, so your room should be set up facing straight ahead, in the orientation you show in your drawing. So the door will be on your right, behind you, and the front wall will be the one with the "2700mm" label next to it. Your room is not big enough to get the speakers far enough away from the front wall, so they will have to go right up against it. Unfortunately, the BM5A MKII's are rear-ported, meaning that they should NOT go hard up against the wall! So you are kind of stuck in limbo here: you'll have to compromise a bit, knowing that you can't get really good results out of those speakers in that room. Best-case is probably to leave maybe 10-20cm or so gap between the rear panel of the speaker and the wall. Set the bass roll-off control to -2dB and see how that works out: you probably really need -4dB, but your speakers don't have that option, so -2 will have to do. The speakers must go on stands, NOT on the desk or on top of the console. The stand must be massive (very heavy). Some people make them by stacking concrete blocks, others buy hollow steel stands and fill them with dry sand. Others build their own from heavy, thick, solid wood. The choice is yours, but the key is that they must be very massive. And even then, the speakers should be decoupled from the stands with a thick pad of Sorbathane rubber in between. The stands must be just the right height such that the acoustic axis of the speakers ends up 1.2 m above the floor. Note that it says "acoustic axis", not the top or bottom of the speaker cabinet, nor the center of the woofer or tweeter. The manufacturer should be able to tell you where the acoustic axis is on your speaker. The EBU recommends that the speakers should be between 2 and 4 m away from you, and about 1.8 m to 3.6 m apart. But your room isn't big enough for that, so we'll go with "plan B". In your case, that means setting up the speakers roughly 87cm from the side walls, so you'll have roughly 151cm between them. I'm always talking about "acoustic centers" here, not sides of the cabinet! So the vertical center line of the front panel will be 87 cm from the wall, and the vertical center lines of the two front panels will be about 151 cm apart. So set your speakers up as above, then angle them inwards ("toed in") by 30°. Now set up your chair so that your EARS end up about 158 cm from the front wall, and at 1.2m above the floor. Bingo! You have your speaker geometry roughly correct. Now turn on the system, and see if you can improve things by moving the speakers a bit further apart or close together, or a bit further from the front wall, or a bit closer to it. Or by moving your chair a bit further forwards. But just move things around by a couple of cm at a time, and ALWAYS keep the setup perfectly symmetrical. Now for the basic treatment: Speaker damping: Set up half of a panel of OC-703 (10cm thick) on the front wall, vertically behind each speaker. Bass trapping: Put large "Suberpchunk" bass traps in all vertical corners of the room. Make them about 60cm across the front diagonal face, and floor to ceiling. First reflections: Put a half-width panel of OC-703 on each side wall, centered on the first reflection point, and spaced away from the wall if you can. Also put a full panel on the ceiling as a cloud. Rear absorber: Cover the entire rear wall with two panels of OC-703, side by side. Leave a gap of at least 10cm between the panel and the wall. If you have enough money, then add another two panels directly in front of that, for a total of 20 cm thick. That should give you roughly two thirds of the absorption that you'd need for that room, so that would be a good point to stop and test the room with REW, to see what still needs doing. You should also test the room with REW before you do ANYTHING to it, so you have a base-line to check against, for all future readings. That's the basic concept. Something like this: - Stuart -

Hi Stuart, I can't thank you enough. That is hugely helpful. Thank you for being so generous with your time. I will post photos of the real thing once i have it constructed. Since i am going to be in this room for some time would you be able to recommend near-fields similar to the dynaudios that may be better suited to the space? best, jett

Personally, I'm a fan of Adam speakers, and maybe a nice pair of A8X´s might fit the bill for you, for that room. Although, I'm sure that other people will also have their own preferred speaker brands! :) A good second choice (if you are not planning to soffit mount) might be one of the Genelec "egg" shaped systems, which tend to minimize SBIR and other unhappy interactions with room boundaries. If Eric Best is around on the forum, he might have a good suggestion for you. And if Barefoot is around, then I'm pretty sure he would recommend a nice pair of Barefoot monitors for you! :) Looking forward to the photos! But BEFORE you start treating that room, do yourself a big favor: Download REW from Home Theater Shack and use it to run an analysis of the empty room, with nothing in it except your speakers and the test mic. That will be your base-line, so you can compare the results you get after each stage of treatment, and see how you are doing. Make sure you carefully note down the exact position of the mic in the room for that first test (it should be at the mix position, where your head will be), since you will need to get the mic back to that EXACT SAME position for all subsequent tests, or you won't be able to compare. - Stuart -

Thanks again Stuart, sorry to keep pestering you with questions but i really want to get this as right as i can: Does the cloud need to be attached to the ceiling or can it hang about 30cm below the ceiling? The reason for my question is that i have halogen down lights fixed in the ceiling and i want to be able to position the cloud so that the lights wont set it on fire. Should the cloud be parallel with the ceiling or should i angle it in a particular way? best, jett

You can do the cloud either way. A common method is to build a simple wooden frame with the insulation held inside it in some way, and hang that form the ceiling from chains or wires, angled at about 12° or so (lower at the front of the room, over the speakers, and higher towards the rear of the room, over your head). If your room has modal issue, then you could put a hard back on the cloud, such as plywood or OSB, to help break up the modes a bit. If you are concerned about the halogen lights, then you could move those to the cloud itself: just add a small wood or drywall inset in the middle of the cloud somewhere, and mount the the lights through that. The wiring will be hidden above the cloud, as will the original mounting holes where the lights were before, and if you ever leave, then it would be easy to take out the cloud and return the lights to their original location. Just a thought. - Stuart -