Have I built myself into a hole? (newbie first post)

The speaker sits in a 1" thick MDF box. The speaker itself is surrounded in fiberglass within the box. The MDF box is surrounded by packed "pink" insulation.

Unless you try barefoots approach like I did -- no MDF box, but a speaker stand that does not touch the soffit frame at all. Dave

Hello again, I've been hammering away at the house putting exterior siding on. . . HVAC and electrical subcontractors are on the way. My trial version of smartdraw has expired, but I purchased a student version of Archicad 8. . . lead time in getting up to speed will be a while. I've made the descision to build the downstairs control room! The tenant who has been renting the existing side of the house is moving out.. .. and I've managed to pay off the entire mortgage so there is no more need to rent out half the house! I do not have a way of doing ray tracing except by hand. . . I was wondering if anyone could help verify that the design will work as drawn. . . and I'll be building it soon. -'Chung

Hey Chung - "by hand" is kinda what I do also - I use an old DOS based pgm called Generic Cadd - I've not found an affordable proggie that will Ray trace, plus I hate learning a new program for one little feature, got more things to do with the time. What I do in my Cad program is to draw a line from speaker to one end of a wall section (like the rear door planes in your case) - then, I set the ortho angle to be equal to the plane in question (in your case, that same door plane) - then I snap to the intersection of the new line (speaker to plane) and draw a short ray perpendicular to the plane being checked (the door) - with the ortho angle still set same as the plane, I draw a line from the end of the short, perpendicular line last drawn, over to the original "ray", snapping to that ray. Now I copy that short perpendicular, using the end of it that snaps to the original ray as a reference, and "slide" the new copy to the other end of the newest short line I'm copying - this gives me a line that is twice as long as the first one, which makes a point that, with the intersection point at the plane (your door), you can now draw the identical angle coming AWAY from your door as the angle going TO your door. I then repeat this process for the OTHER end of the plane in question, so now I have a range of where all reflections from that plane will reflect. This is more difficult to explain than it is to do, it's just basic geometry in actual practice. I wouldn't want to "ray trace" an entire setup with this method though - I did a nearly square bedroom that way, trying to find out what needed absorbing if the mix position was in a corner - took a while... If you have as hard a time understanding my description as I did describing it, let me know and I'll try to do a drawing example and label the steps. May take a while though, I'm so far behind in home stuff I'm starting to look like I'm ahead... Steve

Hi guys, Got myself into quite a snag. . . my floor floating pucks are back-ordered. . . Mason industries EAFM 16114 durometer 40. 1/2" by 1" round pucks. These i believe are made of rubber. Am I able to approximate with 1/2" neoprene at durometer 40? Is there an alternative material I can use? Neoprene strips? Need a source quickly. . . San Francisco area preferred, but if anybody's got something good in stock, I'll take it. I've gotta get the floor on before the sheet rock guys put the rock in so this little stunt is holding everything up. Any advise would help. thanks, 'Chung

EPDM is reported to be longer lived than neoprene by about double - approximately 10 years for neoprene vs. maybe 25 or more for EPDM - Auralex U-boats are (according to Jeff Szymanski, their head engineer) made of EPDM just because of that lifespan difference. However, if Im not mistaken they are 60 Duro instead of 40, so loading would need recalculation. Most neoprene I've seen available is 60 duro. I didn't notice what you're using for joists and whether vertical or laid flat - you'd need to be careful of spans and point loading depending on those parameters as well as subfloor construction/support capability - Have you checked with kineticsnoise.com to see if they can supply what you need? They have reps in Portland, hard to believe they wouldn't also have them in the Bay area... Steve

Thanks for the tip to check Kinetics. I've also searched far and wide for EPDM and only found it in 60-65 duro in 1/2". I think I'm going to use the Kinetics fiberglass composite pucks. -'Chung

That Duro and thickness is fine for what u are doing. Bryan Giles

Hello folks, Thought I'd update you guys on progress. I've been a busy little fellow. Got my electrical %90 in and have my insulation and SAFB piled into the garage. Also found a good source for it in the Bay Area. I posted in the materials section of the website. More pictures to come of progress. The camera I borrowed did not have a very wide angle lens so I couldn't get a feel for the interior of the space. THanks for all the support! -'Chung

Looking good. This place has some useful stuff: Like - limp mass vinyl, silica beads, neoprene etc. Great website/service too: http://www.mcmaster.com/ Best, Dave

Hey guys, Thought I'd update you guys on progress. . . I finally got my rough framing, plumbing, and electrical inspections passed :o I've installed insulation. . . for walls, 1 layer R13 yellow stuff and 1 layer 2" mineral wool (Thermafiber SAFB). . . . for roofs and floors, 1 layer R19 yellow stuff and 2 layers 2" mineral wool. For some odd reason, 2" was MUCH cheaper than comparable volume of 4". As usual, lemme know if I'm messing something up. I wanted to use 2x4's for my floated floor frame w/ 1/2" rubber, but supplier was out of stock so I had to change plans and adapt 1" rubber. . . so I went to metal studs to keep my profile the same depth.

Anyone notice a slight increase in steel and plywood prices over the last several months? Something to the effect of 80%?

Yeah, no joke - contractor friend of mine says rebar is 4x what it was last year, cdx ply is just over double... That should be an interesting floor, never saw anyone use steel studs on a floor of this type before. Be sure and fill the cavities with insulation to kill the ringing... Steve

will do, Steve. I hope the normal fluffy stuff will suffice. I've got a bunch of extra. I'm putting 1 layer of 1/2" MDF on the 16 gauge tracks and another layer of 3/4" toungue and groove ply on top of that and installing 3/4"x4" purpleheart solid flooring on top of that. I hope it'll have enough stiffness and mass to hold me. Should I glue the layers? -'Chung

Hello guys, Wanted to ask a question about sound isolation. . . Due to budgetary constraints, I'm wondering if it is necessary for me to float the floor on the downstairs rear living room portion of the space. It is labelled "AUXILARY LIVE ROOM" in the color, furnished plan on page 2 of this post. This is an auxillary space as it is not directly intended for tracking. It sits on a solid concrete slab floor and I am considering not floating a framed floor on it. My question is, will my sound isolation suffer for it tremendously? Does that slab have enough mass to inhibit sound transmission? It is 24" deep on perimeter and 6" thick at the center sections. Also due to budgetary constraints, I will not be able to use the RSIC-1's too float the sheetrock in this room either. The rock will be on regular resilient channel. That is all, right now, it's a question of do I float that floor and apply hardwood? Or do I get my kitchen moved and gain a bedroom in the house? I guess I can always float it later if needs be. Look forward to the replies. -'Chung

Flanking transmission will be your main concern Looking good guy. :) Bryan Giles

a 6" concrete floor should be adequate isolation IMO. cheers john

Hello, Made some more progress. . . installed insulation between joists as per Steve's recommendation. Finished my iso room subfloor and "jump-tested" it like every 5 year old should on his new bouncy floor. Results were good. . . can sleep in the room directly beneath with full-force bouncing upstairs. Finished framing out the main room floor and vacuumed it. Tomorrow, I do MDF and 3/4" plywood. Thanks for the input, guys on the auxilary live room. I will not float the floors and will sell off my steel and you guys just bought me a kitchen :) bravo! -'Chung

Looking good. And thanks John for clearing that up for me :) BTW I am almost done securing the land for the new studio project. :) the lot size is 70 x 120. Bryan giles

Hey Bryan, Is that feet or meters? Boy, wish I could have started from scratch on this one. . . knowing there are so many compromises in sound proofing and in design. If I had gone from the ground up as a studio, things would have been different :) And my next one WILL be different. . . if I ever finish :? -'Chung

I'd say that's feet and I'd also say that sounds cool Bryan :) cheers john

hello folks, More progress. . .. slowly but surely. I've been wanting to get more drawings up to get some aid in acoustic treatments, but I've been learning the student version of Archicad because the "not-so-free" version of Smartdraw doesn't have layers. . . very dissappointing. At any rate, a good 3D model will help get better feeback anyways, but for now, some progress pics. Finished the floated floor upstairs in both rooms. I was thinking about putting PA speakers in the live room for rehearsal and such, but stumbled upon some large studio moniters (Westlake Audio BBSM-10's) and a Bryston amp to drive them. So I decided to ditch the PA and instead install large moniters which lets me use the main room as reverb chamber if needs be and a secondary listening/reference spot since I have a small control room. Because of this, I had to beef up some floated support beams. . . so I got creative w/ some braces so I'll have a solid yet floated area to mount my soffits in the live room since the speakers are now 150 lbs. instead of 30 lbs. each as per my original plans. And finally, I started installing the RSICS and hat track for sheetrock.

pic of finished floated floor

I have enjoyed your thread very much and look forward to reding till the completion. Thanks Andre

Yes, It's always fun to read up on these works in progress - from start to finish. Looking forward to more updates! I always learn a lot myself just seeing what other people are doing. Good job! -Krag

Hello, Had a quick question. I was wondering if there is a budget-type spectrum analyzer and calibrated mic that can be used w/ a laptop or computer that I can use to test my rooms before acoustical treatment? Mabe a program that would allow me to save and post curves for forum scrutiny? I figure w/ lack of experience, I might try emperical data to verify problem areas before attempting to fix them. -'Chung