Remove the ceiling? Don't know what else to do!!

Posted: Sun Aug 26, 2007 10:25 am

Hi all,

I hate reading long posts but if you can wade your way through this because I'm desperate for help

My situation is this, having converted a double uk garage with a room within a room setup three years later I still feel like I'm fighting my room. I have old aboslute 2's on my net machine in an untreated room and get perfectly acceptable mixes from that so I'm pretty sure it's not my ears.

Right stay with me, when I first constructed the studio I did the whole sitting on neoprene thing, 60kg/m2 rockwool 4inches thick in the walls, the whole 9 yards. Unfortunately I had to make a few concessions on the way which I think may have screwed it up completely. I wanted one skin of plasterboard (sheetrock?) on the inside and two on the outside and to cut a long story short it worked out the reverse of that.
Another concession was I ended up needing taller roof beams to support the span, I think it was 6x4 inch or 8 x 6 can't remember now but the upshot was I lost another couple of inches headroom.
I've ended up with a room that's 4.28m x 4.64m x2.02 (horrible dimensions I know). Despite numerous bass traps and proper foam treatment I always find myself with mixes which don't translate onto other systems at all. I have Genelec 1031's with the 15inch sub (I think it's the 7070)
I'm tearing my hair out here and short of moving don't know what else I can do!
One thing I did come up with was stripping the room and taking down the first two layers of plasterboard on the ceiling, keeping the rockwool in place and covering with cloth, now this won't do wonders for my isolation (right in the middle of lots of houses and I can work at 100db @3am if I have to!) but would the extra headroom and absorption be worth the effort?
As it is I'm sure I'm getting pretty heavy comb filtering with the ceiling being so low and I only have a foam backed carpet on the floor, so vertically I have hardly any treatment, this way I would increase that by loads and get wooden flooring (the classic setup)
Well thanks for sticking with it and let me know what you think, I REALLY need your help here!
I have pictures but can't see an attachment button?

Thanks again

Scoobz

Posted: Sun Aug 26, 2007 11:16 am

I do not know anything about specialized room acoustics. I said that to say this...what is that "plywood" thing in the corner? That is not a bass trap is it? The plywood alone will reflect whatever hits it, even putting some type of foam over it will not produce the effect you are reaching for. Density in a bass trap is the goal in my acoustically uneducated mind.

Like this one

I have been wrong before, recently:), so just a grain of salt with this,

Brien

Posted: Sun Aug 26, 2007 11:26 am

Yeah pic one is what's behind pic 2 so reflections are sorted I have foam on a moveable panel which usually sits in front of the bass trap, I just moevd it so you could see what was behind there. So it's a broadband damped bass trap, the bass excites the front panel which is damped by the rockwool inside. It's broadband because it's variable depth, hope that clears everything up

Posted: Sun Aug 26, 2007 7:52 pm

Sorry Scoobz,

but i do not see your bass trap working the way you envision - if yuo had space between the panel face and the fiberglass - then it would- but with the panels damped by the fiberglass behind you will reflect most everything above the panels center frequency - and it won't work very well below that either.

You would get much more out of it by removing the plywood facing and let the fierglass do it's job.........

As far as the rest of it goes.........

If the foam was mounted off the wall - they way that rigid fiberglass usually is - with a 2 to 4 inch gap - it would be much more effetive for you -

Personally - I would get some rigid fiberglass - and use that in my reflection zones (with the air gap) - you can still always use your foam as a face finish for that -

I would also add a 2" thick cloud below my ceiling - (I would NOT remove the ceiling itself and throw away all of my isolation) and would try to get a 2" air gap between the ceiling and the cloud.......

Live with the 4" loss in ceiling height - it will be worth it for the improvement........

BTW - just a comment on this - you said:

Quote:

I wanted one skin of plasterboard (sheetrock?) on the inside and two on the outside and to cut a long story short it worked out the reverse of that.

well it doesn't make a single bit of difference in your room - the wall attenuates exactly the same in both directions - what remains in the room is the samein either case - so don't let it bother you........

Rod

Posted: Mon Aug 27, 2007 11:31 am

Rod,

Thanks for the reply. Yes, there is an air gap of an inch inside each trap. I guess things have changed since I made these, it was THE way to do it at the time. So I would be better off making a 2' x 6' frame to hold some 4" rockwool and angling it across the corner then? And what about the dead space behind it? Fill that too?
I see the methodology in having an airgap between wall and treatment, so am I looking at making an openbacked frame for the foam and mounting 2" off the wall (I paid alot of money for the foam, seems silly to throw it away). I was thinking of doing the same on the ceiling between the lights, mounting the foam on a frame and suspending it 2" like you said.
Right, just to clear up my perception a bit, I would have thought a single skinned wall would have a certain resonant frequency which would absorb bass in the room, doubling the thickness would drop that frequency by quite a lot, no? Or have I got this completely wrong? (<Wouldn't be the first time! Wink

)
Look 4ward to hearing from you
Lee

Posted: Mon Aug 27, 2007 7:34 pm

Lee,

the wall s a whole is going to have a TL value of "A" - and it is exactly the same in both directions - so whatever stays in the room just stays in the room..........

filling behing the 4" rockwool sraddling the corner is a big boost - a bit expensive - but good gains in performance.

Personally I do not recommend panel traps except as an absolute last resort - they really don't perform all that well in comparison with standard rigid fg........ the same goes with the 2" eggrcrate foams you have on the wall.........

I know what you mean about investment - which is why i did not say to throw the foam away - I said to add FG to the back of it for extra performance........

Rod

Posted: Tue Aug 28, 2007 2:38 pm

dupe post

Posted: Tue Aug 28, 2007 2:40 pm

Thankyou Rod

Regarding the panel traps, the same has been pointed out to me by ethan whiner. You may be able to see a 2m x 1m screen I had made from 4" rockwool in the original pictures, putting those across the front corners has already helped a lot, so I'll be making more of those. It highlights how little the panel traps were doing. Here is my current plan....

I would be interested to hear your thoughts and if you think it would be a big improvement

Thanks for putting my mind as ease about the 2 skin inside/outside thing.

I've also got some Rockwool off cuts lying around so will put those behind the straddled screens

Thanks for your input

Lee

Posted: Sun Sep 09, 2007 1:37 pm

well even tho this topic died a death I thought I'd let you know what I did, I think it sounds alot better, loads more focus and even response

Posted: Sun Sep 09, 2007 3:01 pm

Wow nice work, how does the cloud on the ceiling work for you? I wonder would it be less efficent if it was not angled? Is stuffed full of rock wool?
thanks for posting the final pic!

Posted: Sun Sep 09, 2007 3:32 pm

scoobz,

A bit off the subject... just curious, what is the console you're using?

Bill

Posted: Sun Sep 09, 2007 3:35 pm

That looks like the Mackie D8B?

Posted: Mon Sep 10, 2007 7:05 am

Hi,

The cloud is amazing in terms of definition, you can almost reach out and touch the sounds now. Overall my analogy to non music people is this, it was like trying to paint a tiny masterpiece wearing glasses with vasolene on the lenses, now I have a big canvas in perfect clarity. It allows me to HEAR all the rubbish I couldn't before and sculpt the mix so it's clear, defined and punchy.

And yes it's a d8b. Served me well over the years. Got an avalon front end into the motu, from there on out there's no a/d d/a conversions at all.

Posted: Mon Sep 10, 2007 7:39 am

So the cloud is stuffed full with rock wool?

Posted: Mon Sep 10, 2007 5:12 pm

It has a single layer of 4" running along the bottom of it, the airgap behind extends the effectiveness of the attenuation to a lower frequency <just read that back, it's a bit wordy aint it? It makes it work better lower down. Very Happy

I was suprised at how heavy it was, it's only a 1"x1" frame but it needed heavy duty hooks in the joists to keep it up there!

Hope that helps

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