John Sayers' Recording Studio Design Forum Archive

Here are the dimensions of my small room.

http://johnlsayers.com/phpBB2/viewtopic ... highlight=

I have built the slot resonators in accordance to a suggestion from John. You can see them below on the left and right side.

I was planning on using 3/4" mdf for the slats and trying to tune a broadband.

Does this seem like a good idea, bad idea, after looking at the picture and where it is located?

Any other advice is greatly appreciated.

Ryan

PS the picture makes it appear that they are not lined up, but they are the same spacing etc on both sides. ie symetric.

If he recommended a slat absorber then you shoudl slat it.

Bryan Giles

I'm sure Steve will tell you that using that MDF will be fine.

I can't wait 'till you get the slats on cuz right now your room makes we want to wear a straight jacket and start drooling.

Ron

Yeah things are a little cramped in there. I was planning on using a dark paint on the slats to help a little.

I just hope those boxes cut into the walls aren't for your speakers. I don't see how speakers facing in to the corner like that could sound good. Not that I know some double secret mathmatical mode code or anything. My gut just tells me that that can't sound right.

Steve

Low on time (duh) but

MDF is OK for slats, either paint or laminate with something that looks nice. Thickness of laminate must be included in calculations.

varying slot/slat width won't matter, because wavelengths are long relative to trap (unless you're trapping 1 kHz...) Only way around this is putting dividers inside the trap to make several "mini" Helmholz's...

Ryan, just what angles ARE those between the two speakers? Looks wrong, somehow... Steve

if you use an MDF sheet you can cut out the slots with a power saw or router. It can look very cool

cheers
john

knightfly wrote

Thickness of laminate must be included in calculations

REALLY? Most laminates that I've dealt are about .04" thick. And even then, it varies from different manufactures. Preveneered MDF are VERY thin veneers. Usually on the order of 1/40". Chemetals and solid core laminates can be up to 1/16". Which calculations are you referring to Steve? Room LWH? Or are you talking about the thickness of the slats, in regards to the slot depth?
It would seem to me, for room calcs, that even with walls that are mudded, you would have to calculate a couple of layers of mud, and then any texturing also. I just can't fathom these differences would make an audible difference in regards to modes. Or am I completely out in left field? Because if it should be included in room dim's, holy moly, I bet a lot of people have missed their mark.
fitZ

Hey Fitz, long hair no time... -

I made that "over the shoulder as he ran from the room" comment just in case someone thought they could glue 1/4" birch/oak/pakka wood plywood to the front of a sheet of 1" MDF, then rip it into slats and make an absorber, while using 1" as the slat DEPTH in the Helmholz calculator instead of the TRUE 1-1/4" depth caused by the 1" MDF and the 1/4" ply glued to it.

You're right, NORMAL laminates would make no noticeable diff - however, after moderating here since March I've discovered that when everyone in the room isn't either a cabinetmaker, a designer, or even an experienced carpenter, you don't often GET "normal", more typical is the parable about the three blind men describing an Elephant - sooo, I've tried never to take for granted that ANYONE knows what I'm talking about. (Half the time that includes ME, so it's probably a safe Modus Operandi... )

As to that small dimension making a diff in room modes, if you can hear that I want to kill you and steal your ears... (nothing personal, of course :=)

However, under the right circumstances you probably COULD hear some difference in a room comparing with and without an extra mud layer on sheet rock, because it would change the panel resonance of the sheet rock somewhat. That would change the "panel trap" effect caused by drywall on studs, especially if that leaf of the wall were only one layer, which is an approach I've been giving some serious thought to...

Clarification of that last paragraph - I've been doing some serious "mass-spring-mass" calculations lately, and have discovered that if I use outer walls of ICF construction, consisting of 2.8" foam forms filled with 8" concrete, then move inside that barrier by 6" and put up a sheet rock inner leaf, that it only makes about 1-2 dB difference in TL whether you put up one layer of rock or three. Most of the TL is caused by the mass of the concrete, the air space, and the FIRST layer of wallboard.

Following this logic, Everest and others have commented on the "free" bass trapping that can be caused by gypsum on studs (almost sounds like a title for a porn movie, huh?) - Sooo, my thoughts lately have been running to 8" concrete, 6" gap (2.5 PCF rockwool inside) and 1/2" single layer sheetrock inner leaf damped with glued-on spun fiberglas (R-13) - Damping also changes resonant frequency slightly, so alternating between 3 different treatments inside stud cavities (no insulation against panel, wide strip, narrow strip) could even out quite a bit of mid-bass before ever having to build a real bass trap...

Following this train of thought, I then calculated STC and TL of walls using gypsum on BOTH leaves, and again there is very little difference in TL between, say, 3 layers one side, 2-1/2 layers other side, vs. FIVE layers on ONE side and ONE layer on the other. Might work pretty cool for a drum room, for one... (The single layer on the drum side)

BUT BUT BUT BUT BUT BUT BUT BUT BUT ... PuhLEEEEZE, don't ask for drawings or final "contusions" yet, because THERE AIN'T ANY... What you're witnessing here are (so far) just glorified Brain Farts, possibly based on (at least partly) wishful thinking. I'm also working on plans (paid download probably) for a DIY vocal booth, and may incorporate this concept into 1 or 2 walls of that. Wonder if anyone here has ever DIY'd a DOOR with RC on the inner leaf...

OK, back on my meds now, show's over folks Steve

Hotdang Steve....you are DA MAN!!! You absolutly crucify my brain

That info is terrrrrrrific! Thankyou. And as far as my ears are concerned ha, Steve I can't hear the tv at 3/4 volume anymore, so ALL these questions are just to satisfy my unquenchable curiosity. Besides, it gives me something I can link to, cause as far as I'm concerned Steve, you ARE "da man."

As to the laminate thing, that is exactly what I thought you meant. Nothing wrong with a little clarification though. IN CASE.
Kno wha 'm sayn? Hehehehe!

Well, that undoubtably is a ton of info to ponder.

And as for not visiting for a while, I LURK everyday Just don't have anything to offer very often....although....I do have an offer for you. I know you are VERY busy with work, family, home, SANTANA concerts and your duties here, so if I could take some drawing load off ya, I'd be more than happy. I can now change formats easy, for posting here or what ever you would like. Just let me know. Well thanks a lot for taking your time to fill in some more gaps in my "education" Steve . Hopefully I can return the favor.

fitZ

Wonder if anyone here has ever DIY'd a DOOR with RC on the inner leaf...

Unbelievable. I started drawing a plan for a DIY booth myself just the other night and that same thing crossed my mind. But the further I got into it, the more questions it raised. Thats why I visited here to read some more of your stuff.
How bout this Steve. I got a couple of ideas bout floating a floor on upside down cone or pyramid shaped rubber isolators. I even emailed a guy on ebay who does custom rubber work..Haven't got an answer back yet though. Sort of like an engine mount, with a 1/2" bolt, cast in the rubber at the fat end, with 2 nuts and washers for height adjustment, and the point or flattened point resting on concrete blocks or concrete primary floor. Maybe have some pieces of 1/4" steel angle bolted to joists with a 1/2" hole in the other flange for the bolt in the isolators. Maybe a female matching hole in the concrete or somethin. Hmmmm
like you said, probably brain farts.

"Today's brain farts are tomorrow's solid waste" - how's that for catchy? I really oughta start an ad agency - Naaahh...

Re: Brainfarts, Case in point -

http://www.kineticsnoise.com/architectural/pdf/Flm.pdf

http://www.kineticsnoise.com/architectural/lsm.html

And for ceilings -

http://www.kineticsnoise.com/architectu ... ation.html

BTW, some of their simpler hangers run about $25-30 each, but they are pretty stout and you could space them about 48" with 20 ga. steel studs - simple way to slope a ceiling, just mount the hangers at different depths up into joist cavities, and hang channel for the ceiling layers...

Well, thats it for me. I'm done. Couldn't affort that stuff even if I COULD afford it. And if thats the only true way, well, I'm on to woodworking or something. This hobby has gotten out of touch with reality. Ha, brain farts? More like mental breakdown. Thanks for putting this reality into perspective Steve.
fitZ

Hey, Fitz - don't give up so easily - if that was the only way, how do you think so many of our members would already be enjoying their studios? Trust me, there are much less expensive ways of accomplishing nearly as good, not to mention the numerous NAME bands that have rented a house somewhere, brought in gear, found rooms that ALREADY had a good sound, and made records that are SELLING as we speak - James Taylor comes to mind, as well as Dream Theater, QueensRyche, Van Halen, etc -

Crap, if I'd known you were gonna get all defeatist on me, I wouldn't have shown you the OTHER end of the spectrum - Don't be tellin' me you haven't read a copy or two of MIX magazine - do you have an SSL console waiting to be installed? What you DO have is a pretty respectable collection of good-sounding analog gear that needs a home. YOUR home.

When you're to the point that having a decent studio is your next project, you KNOW where to come for ideas/advice, and that it is NOT gonna cost you both arms and legs... (maybe just ONE leg, and just a teensy-weensy bit of the tip O' yer nose...)

One step at a time, Mr. Rick, just like me - one step at a time... Steve

Hello Steve. Ya know, sometimes, I get the feeling that I'm spittin in the wind. The wrong direction.

Your right though. One step at a time, but I have to be careful. I'm going down a curved staircase with one leg. I've already spent the other.
Ha! Ok, thanks for the "lift". Today, I am going to attempt, given there are no "honey do's", to assemble my console
in my temporary room. At least to the point I can plug my stuff in. I've had a new Tascam 42b for a year now, and haver never even plugged it in. My vintage stuff will have to do though. Newer technology is out of my reach anymore. Just like the studio construction technology. Soooooo, I'll just do what I can. And be done with it. After all, for me, this whole studio thing started as a hobby, and I've yet to record anything worth a darn. Anyway, on to the assembly. Thanks again Steve. BTW, I hope your feeling better.
fitZ