Rebuilding of Dr. Mike Records

Hi guys, I’m going to refurbish my control room and live room and I want to do it right this time :( So this time, I would like to ask the right people for their good input! :) First of all, to meet the codex, here are some details about me: I've read quite a lot in this forum, went thru a couple of books on this topic, so I hope, I did get a good impression, what's good and what's not... let's see... Location: Europe/Austria/Carinthia, where I constructed my house three years ago Music to be recorded/mixed: from local folk to jazz to classics, once in a while rock/pop Noise level: I live in the countryside, so insulation is not an issue Money to spend: about 3,000 EURO Please find a sketchup from the current rooms, pretty perfect in scale, only the joists are pretty random, since I don’t know the exact position because of gypsum hiding them :) Room Basics: Two rooms with about 11 m2 (CR) and 21 m2 (live) usable floor size and a height of 2,34 meters. All floors are finished with hard ceramic tiles. There are some specialities: yes, the brick wall is not straightly in an 90 degree angle and I can’t change its position, because it’s part of the floor foundation (not ceiling!). Still, I’m planning to cut it down to half height to get rid of the small window and the door, and then I want to build it half up again with a new, bigger and centered window with 8mm thickness, using the same-sized bricks. From the old (too dry acoustics) days, there are some panels of acoustic foam (BASOTECT) available and to be used wherever they fit: 6 pcs of 45cm x 45cm x 10cm pyramid gray 16 pcs of 45cm x 45cm x 7cm pyramid gray 14 pcs of 100cm x 50cm x 10cm flat white The other walls are specially built huge concrete blocks with concrete joists with gypsum on top. Every joist has a 2cm pad of wood, so it’s easy to apply gypsum or wooden panels. Note, that the joists have holes in the vertical, so it’s easy to get cabeling thru (so --> about 20cm deep and mostly 55cm wide cavities, but not air tight!) I thought of ripping off the gypsum to get room volume for free…. Just covering the cavities with fabric will obviously damp too much, so I thought of mainly use slats for reflection of higher frequencies. Knowing that no air seal will render the Helmholtz-concept fairly useless, I wondered if it would still be an acceptable way to go?!? Please have a look at the current plan of how the new studio could look like. Control Room: The big window and the entrance door is fixed and will have to stay as is. There is a hole in the east (left) wall (shown in pink), which is used for cabeling of the computer, which is silently positioned in the attached “hardware room”. I have KRK VXT6 nearfields, which are not edegly but smoothly shaped, so I assume, soffiting will be complicated. So I’d put them on the table or on stands behind the table. An extra double wall with wooden framing, double gypsum and insulation, but with a 5cm air gap to the brick wall, should be set up. The thick glass on the CR side could be obtained for nearly no money (15 EUR!)… it’s laminated glass with 2x10mm, so it’s 20mm thick and sized 100x100cm. Well, obviously there is a downside: there are four holes with a 2cm diameter punched along one edge, but I would just try to seal them and build the framing a little more overlapping, so the window would be only 90x100cm then. Bass Super-traps in the corners and a slanted wall left and right. Note, that on the west (right) wall, the slanted wall can only be built up to a height of 95 cm, since above that, the window is mounted :( Also below the CR window, I’d mount some broadband absorber. I could reuse my acoustic foam panels on the ceiling to have an acoustic cloud over the mixing position. Live Room: The big window, the entrance door and the terrace door is fixed and will have to stay as is. Again, I’d place corner traps and absorber pikes to break flutter echoes. Further, I’d glue the acoustic foam panels to the ceiling. Possible Problems: 1. I haven’t placed tuned low/mid absorbers anywhere (real Helmholtz or eg. Swinging plates). 2. In the CR, the big window will break symmetry. 3. My mixing position is more of 50% then 38% from the front wall. 4. Building slat absorbers is easy, but the cavities are not air tight. 5. The dirt-cheap 20mm window has holes punched on one edge. 6. The double wall between CR and live room are not parallel. […] Please help me and point out, how critical the above topics really are?!? What would you change, also in the layout of the absorber or mixing positions? thanks! Mike

here is a pic of the walls in the days, when everything was built, no glasswool and gypsum inside.... you see the left corner of live room with brick wall&window to CR. dont worry about the water hoses and drainage, they are not in use and it's just if maybe in some years someone wants to have a kitchen there... so it's save to pack it into glasswool as a super-corner bass trap

The main problem is really the height of the room but you can't solve that. That non-parallel wall can be easily solved from the inside of the CR, you can just place the framing in it and in the other room leave it angled since this is a tracking room. I think you are abusing a bit on the angled walls in the tracking room on the second drawing.

Hi, yes, the height of the rooms is fixed :) but this is the reason, why I want to put the acoustic foam on the ceiling, to reduce early reflections and flutter echoes. regarding the non-parallel walls, this is exactly the plan of my drawing: just leave the bricks and build a second wall, which is straight to the CR. The only thing I have to do to the brick wall is to cut it down and rebuild it without the door and a bigger, centered window. what do you mean by "abusing"? can you guys give me more input on the other "problems" I might face? (see the list) one thing that came up to my mind: maybe I'm planning too mcuh absorbers in my drawings? even if it's slats, it will reduce the lower mids as well, not only the bass frequencies....

hi guys, isnt there anybody out there? *ggg* at least some answers to my nicely compiled list of questions? I want to go on with my project but I badly need your input! thanks!!! Mike

Try something like this Mike. cheers john

Hi John! that's great! you are answering some of my answer due to your drawing, I'll try to sum up: you moved my mixing position straight to the wall, so I sit at 38%. So for you, this seems better/more important than having the speakers away from the wall, then... there are just some open and critical questions: how would you use my open non-airtight cavities of the wall? or shouldnt I? I mean, it's nicely planked with gypsum right now, tearing everything off, would be a hidious task :( your slanted slat walls are also not symmetrical to each other. anyway, do you think, it's really worth the effort for the right window to embed it into the slanted wall? I could just put some slanted wall below the Window. why should I put two windows in, I dont care about sound spill to/from outside. what are the walls you where painting? yes, big slats on the sides, but what is the front and rear? broadband with cloth on the front? or just joists with (double) gypsum, so very reflective? you wouldnt care about the four holes punched in that wonderfully cheap 20mm glass? how would you design the live room? I'm still in trouble about the concrete cavities I have, and about the mega-absorption I could achieve by open everything up... thanks for your valuable input! THANKS A LOT! Mike

hi everybody! there are some great news from my side: I managed to get an even bigger glass window, so two glasses 170x90cm each, one laminated to 12mm, the other 8mm. This gives me a wider view into the bigger live room... or is this crazy, and the window is too big, better stick to 100x100cm? I adjusted the plans according to Johns inputs (moved closer to the 38% spot and nearer to the glass, adjusted the slat absorbers to a steeper angle. In the live room, I optimized the window-side absorbers and the left wall. Still, there are some big open questions before I can start, and I hope, you guys have any input on this: 1) Building slat absorbers is easy, but the cavities are not air tight. Dont care? how to calculate? 2) when I create the rockwool-filled slat absorbers to full room height, won't there be too much absorption also in the mids? (yea, bass is fine, and highs are reflected by slats...) any input is welcome! thx, Mike

hi again, this time I spent extra time into the live room... I tried to reduce the absorption, and still generate more diffusion by slanted walls. The orange absorbers are slat absorbers tuned to a very low frequency, so all above 500Hz should be reflected back into the room. Also note the extra slanted wall behind the right door going to the garden. The white thingies are three wardrobes, it's slanted and offers storage for stuff like shoes, clothes and tech stuff. ahem, what you say, is it a bad idea because if the air volume starts to resonate the wardrobes? On the right there is another couch, used as the performers lounge and for guests to sleep on. there is now a third room in the drawing, it's used as the "Amp and hardware room". It will be connected to the control room then, for monitor and keyboard. This room is below a staircase, so it's just small and has a heavily slanted roof. regards, Mike

Hi guys, It aint no game anymore :) I started demolishing!!! Further, I got the two glasses with 170x90 each, one 12mm, the other 8mm... isnt there any input from you guys before it's too late? Esp. regarding the live room, the wardrobes and the calculation of absorption due to the non-airtight cavities in the wall? thx, Mike

hi! here is an update... the big window is cut thru and the durn (the stable thing over the window :) is mounted... I still would need your input regarding the live room! John, anybody, could you give me some inputs how I should build it? esp. regarding slats, corner-traps, wardrobes-as-helmholtz and so on.... THANKS!

hi guys, here is an update to my current status: the second wall is built, the framing for the CR-window side slanted ceiling and walls is done. In the upper corner, I have placed a Helmholtz-resonator, not yet drilled the holes, since measurements are missing, yet. Spot lights are built in and we are currently soldering the multicore to the live room. In the window, the window frames are built in, but no glass yet :)