703

Has anyone built a 2x4 frame with 703 on the inside and covered with fabric putting eye-hooks on the top so you can move it around, or remove it as needed? Thanks, Rob

I moved this to the construction forum. You should get more responses here. :) Thomas

Rob, for starters do a search under "gobo", I know there are a few around here - Steve

Thanks Steve I'll check it out.

Hello, I have built several. What do you need to know? I make them out of standard 1"x8" , 1"x6", 1"x4" Yellow pine. The one thing I have learned over the years, DO NOT JUST NAIL OR ScREW THE FRAME TOGETHER> Yellow pine will split, you may not see it, but it will split. Spend the extra 3 bucks and buy a pack of "L" bracets. I make them so that the 703 will fit on side (2'x4') and be a snug fit. so make the box 1" narrower than you need. stuff the 703 in and cover with fabric. If you want to make a hanging cloud for the ceiling, build the box, I made one 8'x8'. but this time run another 1" x 4" flat along the bottom, or the side that will be facing down, on the sides and one up the middle. That way you can just lay the 703 on those 1" x 4" and not need to fasten the 703 at all. I have not found a good way to fasten 703. If you put wire through it, it will eventually come out, and most likely in the middle of a session. If you need more or diagrams let me know. Jai www.themixstudio.com

Jai, Thanks for the information... and the tip on screwing the frames together. Is there anything special about the fabric, should it be heavy? I think that should get me going! I also have some Roxul left, so I think I'll build some with 703 on one side and Roxul on the other with wood slats on the Roxul side to create a live side and a dead side... how thick is the 703? Thanks!! Rob

Rob, The 703 usually comes in thicknesses of 1"-4". Often times in 1/2" increments (at least the first 2 inches- 1", 1 1/2", 2"). Don't know about the larger stuff??

Thanks Aaron. That's good then, I can use 2" 703 on one side and the 4" roxul on the other... Thanks again, Rob

Is you 4" Roxul the AFB stuff? All they had here where I'm at in 4" was the 4 pcf stuff. And of course finding 4" 703...S.O.L. Not to mention cost... If you're making baffles or hangers, I think 1" and 2" is the most common construction method I've read about here on the forum. It sounded like Jai was building them out of 1" 703, judging on his framing size. Most of the prefab'd panels I've seen are either 1" or 2" as well.

I was able to get the 4" AFB Roxul, I have 3 bags left after I finished the studio... you can see pics here: www.pbase.com/riadanza/studio I a little unsure on how to deterime how much, and where to put this stuff so I'm still at that stage. I finally think my slot resonator is down so that's done, maybe, who knows :) Rob

Ah, yes, I remember seeing the pix of this studio several months back. How's it coming along? Is the last set of pix (bedroom setup) the old (current) room? Try the mirror trick to get an idea where to place the absorbtion. There's some good info here and on RO that have popped up recently on placement of panels. Aaron

Yeah the bedroom studio is the current situation... I've achieved really decent results with that cheap little spare room. My expectations are high for the studio. I've made some mistakes along the way but without this forum it would have been a waste of time and money. Next is acoustic caulking all the corners of the sheetrock, install the sliding glass doors and solid core wood doors. My good friend does hardwood floors for a living so he's going to install the floors. We are putting a thick rubber base down called quiet walk, then a Pergo type floor over that. The floor wont touch any of the walls so it will float in each room. The electrician is coming back to install the conduit outlets in each room, then it's just the finishing touches and the electronics. My estimate for this was May 1st when I started in December. But it looks like June 1st is go-live :) I have about 4 bands that keep asking me when I'm going to be finished so I have some motivation. One question - what tool would I use to know what frequencies to eliminate from the room via a slot resonator? Thanks, Rob

Rob, I looked for your current setup and just got more confused. Got a link to plans or pix? Thanks... Steve

knightfly wrote:

Rob, I looked for your current setup and just got more confused. Got a link to plans or pix? Thanks... Steve

Haha... ok. http://mk29.image.pbase.com/u39/riadanz ... rsion3.jpg This image is also on www.pbase.com/riadanza/studio Let me know what questions you have. Rob

Duh, not sure how I missed that link in your earlier post - the top one of your latest post is forbidden but the other works. Do you have a detail drawing of your wall construction where the slot frame goes, showing where your wallboard layers are? I'm curious about isolation, not seeing any actual barrier. Also curious about dimensions on the slot, so I can get a better handle on possible combinations of slat/slot/depth dimensions. As to the slot itself, I would think you should go for a center average frequency that's split between your 3rd and 4th harmonic of average width, that would also treat one of the vertical modes. Slots can't get down low enough for the primary modal frequencies very well, besides your rear trap should be able to handle that part. Speaking of which, do you have a detail of what you're going to do for that rear trap? Looking really good so far, let us know on those details - Maybe John has more suggestions on the slots, he's done a bunch... Steve

The footings for the slot are there, however, it hasn't been built yet. I'll use MDF board every two feet to create a box between the angled footing and the rear wall. I'll put Roxul AFB in between the MDF then cover the whole resonator with fabric. I have 1" thick pine up to 6" wide for the slats that I can then rip down to different widths as needed. I don't have a detail drawing of this but I plan to stick as close to John's design as possible. I'll try to use the spreadsheet to calculate the slat width and spaces. The rear low absorbers will be 2x4 framed with Roxul AFB and fabric. The rest of the walls are 703 where indicated. The live room will mostly diffuse, there will be a drum kit in there as well, with some absorption. That's what I'm thinking so far.

OK, so you're planning on separating the space behind the slats into 2 foot separate absorbers? Also, what are the dimensions of your rear absorber - depth, width, height, angles, etc - if there's room, some hangers would really enhance the effect... Steve

knightfly wrote:

OK, so you're planning on separating the space behind the slats into 2 foot separate absorbers? Also, what are the dimensions of your rear absorber - depth, width, height, angles, etc - if there's room, some hangers would really enhance the effect... Steve

I was planning on separating the space into 2 foot absorbers, is that a problem? I was thinking of creating the rear absorbers to hang - 2x6 wood frame with Roxul covered in fabric. I was planning on leaving about 6" from the rear wall so that the absorber does not touch the wall. Thanks, Rob

No problem at all, in fact preferable - if you seal the slot into 2 foot sections, then you'll get more effect from the differing depth from section to section, which will help smooth out the response more - each section can be tuned differently that way. If you were to put the slats on vertically, you could even vary the slot width per 2' section, possibly treating several modal peaks - As to your rear absorber depth, I was wondering if you had enough room to place hangers in a "herringbone" pattern, with extra damping layers - Newell does a thing with a multi-stage rear wall that almost completely disappears acoustically, but it takes between 2 and 3 feet to pull off. IF you don't have that much space (or enthusiasm) your way will work as good as anything in that amount of space... Steve

Thanks Steve, I'll evaluate how much room I have. Don't think I have 3 feet to spare so I might have to go with plan A, but it's really good to know. I'll take more photos of the construction as it comes along. Thanks again, Rob

knightfly wrote:

If you were to put the slats on vertically, you could even vary the slot width per 2' section, possibly treating several modal peaks -

Have you seen anyone put the slots on a track so they can be moved? If I was to vertically hang the slats with the upper and lower ends mounted on a track I could adjust the slats to fine tune the room.

Not a bad idea, but I'm not sure how it could be accomplished - the slats need to be tight against the backing cloth and locked down so they don't vibrate against their mounts - they also need to be sealed so that the only path into the cavity is through the cloth between the slats - if you can figure out how to accomplish that and keep things adjustable, let me know... Steve

does anyone know a good place to purchase the 703? home depot?

No Home Depot I've ever been in - all they carry is foam insulation (closed cell, worse than nothing for sound) and the pink fluffy stuff. You can check the materials forum on this site, may find DC sources - other than that, the way everyone does it is to call each and every insulation contractor in the local yellow pages til you find one that (a) carries or uses rigid fiberglas, doesn't matter what brand (Owens Corning, Knauf, Johns Manville CertainTeed mainly) and, (b) will sell to you. Don't get discouraged if the first 10-12 won't talk to you, sooner or later one will. If you find one that way, please post your info in the materials section so others can benefit - that's a lot of what this site is about... Steve

Yeah. I am on it! And i'll post my findings here! Thanks, mat