Texas Attic / Bonus Room

hello everyone. i've posted some stuff in the construction area and sharward is helping me with some of my construction needs. there is a little background and some pictures on this too... http://www.johnlsayers.com/phpBB2/viewtopic.php?t=9178&highlight= i also ordered rods book and should get it thursday and will read it immediately! looking forward to that. i've spent a good bit of time reading all the great designs for absorbers and resonators and traps and looking at my room and my budget and what i've already built (movable 703 and rockwool panels) i want to know what you guys think of what i want to do acoustics wise with this space. i'd rather keep the shape of the room if its not going to be completely useless to a good sound. i'd like to have room to practice drums and have a desk at the other end for electronics projects. mostly i want to get opinions on where i've put the soffits in this sketchup and if have so much room behind me will be bad. also i want to do hanging clouds in the triangular area behind the wall to my left and under the soffit (as john's design). i have three 8'x2'x4" rockwool panels to lay on the floor on the right side, and some 703 absorbers for first reflections. :arrow: is this a good plan? are the soffits going to work as i've drawn them or should i place them elsewhere? :arrow: i'm guessing i'll frame the soffits before i drywall the room and use thick MDF for the face. This is an attic above a garage and sits on a truss flooring system. should i try to fill a stand with sand to keep the speakers isolated (dynaudio bm6a's) or just use my mopads in a sturdy frame? thanks for reading. let me know if i need to give more info? here is a sketchup: http://www.bwacksforum.com/images/attic2.zip

it looks like a good plan - just double check your room mode calculations to ensure the speakers aren't sitting squarely in a null, otherwise nice work!

i wasn't sure if the 45 degree sides would make the calculations not fully exact. i'll run the numbers and get back.

it looks like width wise they are pretty close, but is that tweeters? and with the soffit where i have it how do i figure modes for the length? they are in the "front wall (baffle)" i would think, so i can't really have them out in the room in a green spot on the chart. but the are inbetween a null and a peak if you put the graph all the way to the hidden actual front wall behind the soffit. does this make sense? am i making it more confusing than i should? i think i will have to raise them an inch or two. i would just really think the weird ceiling would throw the calculator off a bit. but i'm no expert...

there's a link on this site to a spreadsheet which allows you to calculate room modes on length, width, and height. you can use that to decide where they sit vertically and relative to your seating position. i don't think the ceiling angle will be too detrimental since its symmetrical - just plan on treating the angled ceiling with absorbers on the first reflection points - same as ceiling and side walls.

gulfo, bear in mind that the kneewalls on each long side are different heights... ...so it isn't exactly symmetrical... :roll: I don't know if that's relevant or not. You guys here on the Design forum would know better than I do! :) --Keith :mrgreen:

ok, i want to put hangers on the inside of the triangular section to the left of my mix position. what if i framed same on the right just at the end of the room where i will sit, for a little more symmetry. would that be too much bass trap? is too much bass trap possible? like this... (photoshop obviously)

this would be nicer than not being symmetrical - adding the additional trapping would be a benefit - and if its balanced its also nicer. so unless you need that space for equipment, i'd say add the additional wall and trapping.

ok, starting to frame some of this project soon and wanted to make a soffit decision. i would like to finish this room out without the angled walls for the soffited speakers. I'd like to build the soffits as an added piece after i'm done (able to be removed if i leave). here is a sketchup of a possible soffit. i would make it to completely fill the corner and use something like MDF for all the faces. the speaker stand on the inside would be sand filled and only connect at the base. speakers would be on MoPads and poke out to be flush (but not touching) the front baffle. could this work or does the soffit need to be actually part of the room wall structure.

you might check some of the soffit designs on this site which include using a concrete box, blocks to support the speaker, etc. sand can get damp so you want to use something waterproof to avoid having it get damaged. otherwise, no reason tou can't build your soffit containers as cabinets which can be put together and placed as needed.

gullfo wrote:

otherwise, no reason tou can't build your soffit containers as cabinets which can be put together and placed as needed.

Thanks gullfo, that was i guess my basic question. I've seen a lot of soffit threads but i'll search a bit more for some plans. that sketch is exactly what i was thinking.