Advice Please: Live Room Layout

Started by Jeemy on 14 October 2004. 16 replies.

Originally posted at johnlsayers.com, topic 2481.

Hi, Here is link to my current live room, showing positioning of all sound treatment. All foam tiles are from Studiospares, they are the rippled type (2 small, one large curve) so they absorb and redistribute in equal amount. They can be seen here: http://www.customaudiodesigns.co.uk/absorbers/siab.htm And the room and positioning here: http://www.verdenstudios.co.uk/main-room-acoustics.jpg My questions are this: 1) What further should I do to the room to improve it for general recording. I have been planning to build Ethan Winer's bass traps, maybe 3 of each type, and mount them to the ceiling on removable battens so I can "liven" or "deaden" the room. I also have 100 sheets of .75" 2lb density acoustic foam which I have been planning on "wallpapering" some of my rehearsal spaces with. I am considering covering the wall behind the drumkit with these? And I have some of the markertek blade tiles coming. And a few more of the checkerboard tiles left. 2) Where should I position the kit for recording it individually? 3) Where should I position the guitar amps for recording them individually? 4) Where should I position the entire band (drum, bass, up to 2 guitars) for when recording live? Any help or thoughts appreciated. Cheers, Jamie
Ethan Hawke makes bass traps? :shock: Just picking on you. We know who you mean. In general, your low freq absorption is good, but the room might be too dead. Can't tell for certain without hearing it myself or knowing how live or dead you want it for your own recording style. My recommendation would be to make it adjustable somehow... John Sayers has plans for wall panels that swing open and closed like cabinet doors, and are absorbent on one side, but reflective on the other. I'm almost done with a set for my room, and although I haven't been as careful about their construction they work very well. Within a minute or 2 my room totally changes it's sound.
Its not dead at all, a lot of bands are still complaining that it is to verby. Thats for rehearsal not recording mind you. Hence the removable bass/mid/high traps made by that guy out of Gattaca - sheesh :oops: I figure thats my live/dead adjustment right there. Any thoughts on positioning?
/bump/
Jeemy's room resized
Image not preserved: jeemy's room.JPG
Thanks Kendale; sooo, Jamie, I don't want to chase this all over the web, so where ya wanna do it? Steve
lets do it here cos the graphic has been re-sized here. i have tons of rockwool, we've used it in all the walls to soundproof, so i will try what you suggest, I have plenty of purple velvet cloth to cover it with.... i am also gonna buy some RWA45 semi-rigid fibreglass for the basstraps. Just in case anybody is struggling to find it, I'm getting it here: Sheffield Insulations Righead Industrial Estate Melford Road Bellshill Lanarkshire NL4 3NA Give me some time to digest this and I will post up my suggested alterations, Jamie
Thanks Jamie; could you post your insulation source on the Building Products forum so it's easier for others to find? Thanks... Steve
okay, first question. i am just about to finish constructing another rehearsal room. i've been using the rockwool inside wooden frames, sheeted with acoustic plasterboard for walls. just wondering, would airspace be as effective? i'e. could i save the rockwool to use in treating the live room? sdvice appreciated, thanks, jamie
You need insulation in walls, so they don't resonate; it also improves sound isolation of the wall by anywhere from 4 to 10 dB, depending on the wall construction and type of insulation - I'm not sure what you mean by "acoustic plasterboard" - is this something special, and if so do you have a link or picture? Steve
acoustic plasterboard is just denser plasterboard, sold as such by most builders merchants, would doubt it is anything you haven't heard of by a different name...
Okay, Firstly here is Steve's post from the other forum.
First, your thin foam will mostly get you in trouble instead of helping; you'd be better off using what you have but gluing several layers together to get at least 2" thickness; 4" is even better. Before you buy any more, consider finding a source of rockwool insulation and some cloth, and building frames for this; it's more of a DIY approach, but is cheaper and works better. It takes about twice the thickness of foam to equal a piece of rockwool or rigid fiberglass insulation in acoustic absorption. Then, for a live room (not mixing) you want absorption patches on One of two opposing walls ONLY; you can alternate a kind of checkerboard pattern so you'll tame flutter echo (caused by parallel walls) but NOT make the room too dead by having ALL of ALL the walls covered with absorbent. For ceilings, unless the ceiling is several feet taller than normal you should put absorbent on the ceiling wherever you will have instruments, mics, speakers, or ears; all absorbent used on ceiling and floor should be on the ceiling, since carpet is only good for upper mid and high frequency absorption (unbalanced) and other absorbents don't take kindly to being walked on. Placement; a lot of people just move things around til they sound good; a better way is to first find the places that WON'T be good - if your room is a true rectangle, this can be fairly easy. The following link is to a spreadsheet (requires Excel on your computer) that will graphically show you where the first four harmonics of each room dimension will cause peaks and nulls in room response; if you put a sound source, mic, ear, etc, in one of these nulls there is almost no amount of power that will let you hear the frequency of that null; so it's necessary to MOVE whatever it is OUT of that null instead. Using this calculator you can "map out" your room to find the BAD spots; just avoid nulls like the plague, and try to stay away from the highest PEAKS as well. This applies to HEIGHT as well as the other two dimensions - http://www.harman.com/wp/index.jsp?articleId=131 There's a lot more to be said on this, but I'm temporarily out of time; hopefully this will get you started. And PLEASE resize that graphic so we can see it all at once... Steve
************* Here's what I reckon I'll do. The wall on the opposite side of the basstrap is covered in .75" absorbent foam. This is quite high-density so effectively is a half-dead wall, aside from the door. The facing short wall has the basstraps (they don't extend all the way to the floor as mentioned above) and the foam which occupies the centre of the room about 2.5ft from the ground and ceiling. So taking these walls first as a facing pair, really one should be live, and one completely dead?? I record the drums against the wall with the door, facing down the room. While I understand I can move them to a 'sweet spot' when tracking individually, a lot of what I do is recording bands live, and therefore I am limited for where I can put them. So assuming that a dead wall behind the drums is preferable, if I leave the bass traps where they are, but move the rippled foam to mount on top of the existing foam behind the kit, this gives a better degree of deadness to the dead wall, and livens up the live wall. The long walls have the checkerboard. Is it essential these patterns are exactly opposite? and if so, and if my foam is not thick enough, how can I use rockwool/rwa45 to create areas of dead/live. Shall I build frames the size of a sheet of rockwool, approx 3 x 5 feet, and fill them with rockwool, cover in fabric and then mount the foam on top of these, and then mount them in opposite checkerboard on the long walls? Finally I will then build Ethan Winer's basstraps/mid/high traps and mount them in a fairly random pattern across the ceiling, leaving it half-live, half dead. Sound like a good plan? Anybody know how to mount foam to fabric/other foam easily? J
/bump/
/bump again/ I have looked into this much more now. I did a calculation of my room modes and although fascinating, it seems that a 4-foot wide drumkit will cross so many nulls, no matter if I try to move it off-centre, that the damping approach has to be the best thing. First thing I am going to do is build rockwool four-inch frames the height of the room and approx 1200mm wide. This will be laid out alternately on the long walls so that one damped side faces one reflective side, alternating. I am then going to tile the reflective areas with the foam, leaving it at 1" thick. Hopefully this will scatter the sound which does get reflected and even out the response more. The foam bass-traps will remain where they are and I will add Ethan's basstrap design to the ceiling in places. Does this sound like a better plan Steve?
Overall I'd have to agree with this last; one other thing I'd consider is making some of those rockwool panels portable - you could then move them around to fix various modal problems while micing the drum kit. Dymaxian's not the only advocate of variable acoustics here - and you're right, finding good "modal" spots for each part of a drum kit would be even more frustrating than micing a kit USUALLY is. Buidling 3-4 panels 1200mm square with one live and one dead side would be a very useful thing - if they're light enough, you can make their feet out of lengths of 4x1 (90mm x 19mm) lumber, with only one screw in center; that way, when they're not in use they can be stored flat by just rotating the feet parallel with the frame. Sorry for the delay in answering, this isn't my normal "beat", and sometimes when time's tight I miss it for several days... Steve
Okay, Friday (everything is built) 7 traps go in, they are 4inch 60kg/sqm rockwool frames held solid with Christmas Tree netting / pond netting (I mention this as it may be a tip for others), then covered in velvet. They will go on the long walls, not facing each other, and the foam checkerboards will face them. So I now have the 2 short walls to deal with (one covered in 20mm acoustic foam, the other covered in the diffusing 20mm foam. I think for now I will leave those, and will mount the angled diffusors on the far wall later (mentioned in John's homepage link). Next question: ceiling! I've had a good browse and need to do something, I had 13ft to play with and rushed into an 8ft ceiling without researching (commercial pressures, sheesh) so I need to know what to put on the ceiling. I have no idea - I've had a damn good browse about this forum and recording.org and found nothing, strangely. The ceiling is wooden framed, 2-inches of rockwool, 1 layer of acoustic plasterboard (gypsum board you call it?) 5 foot airspace above. As mentioned before this is a temporary facility so all solutions need to be movable. I am just worried that the rockwool will sag if I put it up in frames, even with the netting. I will post pics on Friday of both this and the control room, Cheers, Jamie