Down Stairs Studio - starting construction

I saved the scarps from the hickory flooring for the house and some pine from the ceilings and made a slot resonator out of the ceiling in the drum room.

2nd dayBuilding soffit closetsThe speakers can slide in on these trays

Got the front of the studio done. Well almost. Ceiling done. Wood pile going down - (what messy pictures.)

Nice looking place Bill. Hey, are you up around where Madmax is...?

I believe he's east of Greensboro - about 2 hours east of here.

Some more pictures. I can finally see the floor! Doors go in tomorrow and the glass for the rooms has been ordered. Soldering up the patch bays now. And the front.

Bill, that is a NICE looking job...dude you after my job or WHAT!!!? Man, looks great, it really does....sounds pretty good?

Yeah Brien is absolutely right! :D Looking really good. Very precise work on a side wall slat cuttings! Are you planning to measure room response? -Janne

Thanks for the comments. As soon as the doors are in the speakers are going in and the measurements will begin. Door guys are today. I noticed my car door seals are also going to hit today too. My measurement mic came in early this week too.

I am still getting some AC sound - (only in the main room) when the system's second stage kicks in and I was wondering if anyone as used this product? http://www.fabricair.com/ or http://www.ductsox.com/ I had some circular grills on my vents (2 8" holes) but they had some high frequency things going on so I took them off. You can see one of the openings in the ceiling in the last picture. The other is about 5 feet next to it.

I am still getting some AC sound - (only in the main room) when the system's second stage kicks in

I just looked back over the thread but I couldn't see the details of your silencer box. Maybe I missed that. What type of silencer did you install? Did you make sure that the inner cross section is much larger than the cross section of the ducts (preferably at least twice the area)? Also, did you line the silencer with proper duct liner, or did you use something else? If you have any photos of the silencer, that might help to understand the problem. Also: are the ducts properly decoupled from the air handler? and are they properly decoupled where they pass through the walls? If not, there might be some flanking going on there. - Stuart -

Soundman2020 wrote:

What type of silencer did you install? Did you make sure that the inner cross section is much larger than the cross section of the ducts (preferably at least twice the area)? Also, did you line the silencer with proper duct liner, or did you use something else?

The small rooms have an access space behind them so I could build bigger boxes ( 2' x 2' x 4') and they are working fine - I don't even know the heat is on in those rooms. In the main room these 2 boxes had to go into the over head rafters and they were smaller. 2' wide and 8" tall and 4' long. They have 8" flex supplies and an 8" opening with 2 diverters. Because of the 3/4" MDF and duct board the actual inner dimensions leave about 3" x about 16". That would make the cross sections about the same as the duct at the diverters. 25.4 sq. in. to 48/2=24 sq. in. at the diverters. At this point I can't do much about the build except cut back the last diverter, increase the opening to an 8" x 18" slot or possible add these duct socks. I put my Radio Shack SPL meter 1 foot from the outlet with the heater on high and it could only read 54db. Standing on the floor I couldn't even get a reading.

Soundman2020 wrote:

Also: are the ducts properly decoupled from the air handler? and are they properly decoupled where they pass through the walls? If not, there might be some flanking going on there.

No problem there - I did them the same as the small rooms which are great. Actually this is not bad, and I wouldn't even be bothered if I didn't have the other rooms to compare it to.

I was looking at this site: http://www.engineeringtoolbox.com/nc-no ... d_725.html and I was wondering how to measure for NC-15 or NC-20 based on the things I have in the studio. I realize holding a SPL meter in front of the vent is not very informative.

Hmmmmmm... it seems like you did everything as best you could, given the space restrictions. Maybe enlarging that final slot might help a bit, but the ideal thing is to create the larger cross-section further back, and try to keep the last part of the run straight, with nothing to create turbulence. Not sure about those two links, though. Maybe Rod will see your post, and hopefully have some suggestions! - Stuart -

Removing part of the last diverter is actually the easiest thing to do here and I will try it on one of the supplies. thanks

soundman your the bomb. Taking out the last diverter instantly dropped the sound by 3/4. Probably won't need anything else now.

Cool! Glad it worked! :) :thu: - Stuart -

Final got some measurements done.Left and Right Seems I have two dips there to figure out.

A couple of questions, Bill. First, did you do the bass roll-off for your speakers? You seem to be getting a bass rise there, that looks suspiciously like there's no compensation. And the other one: What level did you take those measurements at? The graphs show everything BELOW 0 dB, which would be a rather silent way to test a room! :) Maybe it's just the way you set up your system, but I'd expect to see a median level of around 85 dB for valid testing. As for the bumps and dips: What are the final dimensions of your room, and what other treatment do you have in there? (Besides the obvious slot walls, of course!). - Stuart -

I went thru the Blue Sky Manual and re-calibrated my speakers and the sub. Also did the 10 second sweep instead of the 1 sec. With the 10 sec seep things look better don't know why that is. (The one second sweep was also better. but not as smooth. The ceilings are 9'10" with 8" of fiberglass then cloth, The room width is w 13'3" x L 16'3" before 3.5"stud wall with 3/4" slats. The ceiling in the front over the desk is tilted down to 7'3" and that soffit has a sheet of 2" 703 and then fiberglass batts. also the wall in the drum room that had no space has been on my mind and I played drums in there for the first time today while my wife was lying down in the room above and she never heard them. (I am not a rock drummer.)

Well it's not the room. Here is a plot of my Dynaudio BM5a MKII's and it shows a nice response at a 1 sec sweep.