Acoustics - cost effective walls and ceiling treatments

A

andyg_prs

New member
Hi there,

I am converting my garage which is 5.7m x 2.3m, and 2.7m high into a rehearsal studio. I have already decided on the sound proofing strategy. Having done that, the floor will be covered in carpet tiles, the inner walls will be plasterboard and the ceiling bare concrete.

Should I rehearse first and check out the sound or will I definitely need to cover the interior surfaces, and what am I trying to avoid - high frequencies echoing around?

Acoustic foam is madly expensive in the UK. Carpet underlay has been suggested by some. Cheap carpet by others - some say it will work great as it is soft, others say it is ineffective and is a massive fire risk.

Any advice would be gratefully received as I am doing the studio build this weekend!

Thanks,
Andy
 
andyg_prs said:
Acoustic foam is madly expensive in the UK. Carpet underlay has been suggested by some. Cheap carpet by others - some say it will work great as it is soft, others say it is ineffective and is a massive fire risk.
Click to expand...
Foam, carpet, and carpet underlay are all horrible ideas when talking about acoustic treatment. What you need is fibreglass or a reasonable facsimile thereof. You can then make your own panels and place them where needed. Almost always with out fail, you will need to treat as many corners as possible for starters.

The main objective when treating a room is controlling the low end. In 99% of rooms, this is 99% of the problem. Foam (even if it's called "acoustic foam" by the companies trying to sell it) does nothing for bass frequencies. It can even make a room sound worse because it will kill your high's and mids, but leave the bass un-tamed, so now the bass becomes an even bigger problem. The room ends up "deader", which ar first might seem like an improvement, but it now sounds like you're in a box.

When you say you have your sound-proofing sorted out, what are you doing for sound-proofing?
 
Also keep in mind that the more soundproofed a space is, the MORE problems it's going to have with low end buildup.

No doubt though - Foam, carpeting -- Expensive or not, ineffective with controlling the actual problem.
 
Thanks both. The garage is in a very unusal location, it runs underneath my back garden....so essentially the roof and back wall are entombed by concrete and earth.

The garage however runs in a block of other garages, also running under other gardens. The garages are used for storage mainly. However, I want to limit the sound going through the walls in case it then escapes out of the front through my neighbours' flimsy garage doors.

The walls are a breeze block constuction. I plan to put in studwork that is 10 cm deep and fill with Rockwool - RWA45 - 100mm to be exact. I will then close in the rockwool using 15mm thick plasterboard.

The main weakness is the garage door. The entrance space is 2.1 metres squared. I am installing a frame....all four sides. Closing against this will be 2 side hinged doors made of Scandanavian Cedar. These will be framed, ledged and braced and have 21mm tongue and groove panels. The construction means the back of each door will have 4 triangular sections that are 20mm recessed from the triangular braces and frame. I will fill this out with plasterboard. I will then use the stud RWA45 method for the first layer of insulation. I will then use a 18mm ply wood cap. Then another RWA45 layer and finally 15mm plasterboard cap. Each door will weigh over 80 kilos and so special hinge arrangements will be necessary. I will probably use some kind of rubber seal on the 4 sided frame to get the best fit possible.

How does this sound?

Any more info on the type of fibreglass....dimensions, fixing etc that I need for the inside walls / ceiling as I have never heard of this approach?

Thanks,
Andy
 
Thicker as in deeper? How deep? If not plasterboard, what is the rockwool closed in with? The rockwool site recommends sandwiching the rockwool in 12.5mm plasterboard....
 
Not sure what John means by no plasterboard as it certainly makes sense on the walls. However, I would suggest that you soundproof the roof as well. If the roof isn't soundproofed, the vibrations will simply travel along the concrete roof and into the neighbouring garages.

Soundproofing the roof will also allow you to create a completely stand-alone room within a room where the only point of contact between the inner and outer rooms is at the floor. You won't lose any space as you can use 75mm studs instead of 100mm studs and also 75mm thick Rockwool (or the Rocksil equivalent if it comes out cheaper). I would also suggest using a sandwich of 19mm plasterboard next to the studs, a layer of Green Glue and then a layer of 12mm acoustic plasterboard.

As far as the doors are concerned, it sounds like you have a 3 leaf construction at the moment. This isn't good. You would probably be better off forgetting about the Rockwool and just making them as heavy as possible. I would also try to beef up the existing outer door and to have a bit of space between the inner and outer doors.

James.
 
What I'm getting at is to leave the rockwool unimpeded (well, cover it with cloth or something, certainly).

If you cover it, it will help with transmission (it will help *outside* the space) leaving it semi-exposed will help *inside* the space.

A quick thought comes to mind that I haven't personally tried -- Stagger plasterboard / exposed rockwool (every other stud space covered with drywall and the facing side "exposed" - covered with cloth). I would think off the top that would offer a decent amount of control without completely deadening the room...

An air gap behind the rockwool would help also... I've seen rooms made with 2x6's instead of 2x4's where they basically put screws & wire 2" deep to hold the rockwool 2" off the wall, filled the void with rockwool, stapled fabric to the studs and trimmed with wood strips.

Granted - I'm concentrating more on the space than the transmission... If I needed both, I'd probably stud the (assuming concrete) walls with 2x2's and plasterboard then put a 2x4 wall right up against it (staggered studs though) filled with rockwool and covered with fabric. Good for transmission, good for the space, much more time consuming, not much more expensive.
 
If a higher STC rating is desired, plasterboard is absolutely necessary. Staggering drywall strips will give you the same STC rating as no drywall at all. If you want to build an acoustically treated wall, the way to do it is inside the already finished walls. And if you do fabric covering the walls, be sure to get flame-retardant fabric or that whole wall could go up in seconds should a fire ever happen. Certainly is important to be safe!

If fluffy attic insulation is cheaper in your area I would use that for the walls and use mineral wool for the panels instead. Or if you did a treated wall (or multiples thereof) I would go with the thickest insulation possible. Slats can be used to introduce life back into the room as it would easily be extremely dead in the room with just 100% absorption on the walls.

If you didn't go with multiple full walls of treatment, making or buying - and hanging panels would be suggested.
 
I'm hoping the initial dimensions given are wrong >> 2.3 meters wide? By the time you add your planned 10cm insulated walls either side, you are looking at a space only 2.1 meters (less than 7 ft on this side of the ocean) wide - more wall thickness would make it even narrower. Add some bass traps in ceiling-wall corners and its going to be even more coffin-like.
 
mjbphotos said:
I'm hoping the initial dimensions given are wrong >> 2.3 meters wide? By the time you add your planned 10cm insulated walls either side, you are looking at a space only 2.1 meters (less than 7 ft on this side of the ocean) wide - more wall thickness would make it even narrower. Add some bass traps in ceiling-wall corners and its going to be even more coffin-like.
Click to expand...

Welcome to my world. :)
 
Unfortunately the dimensions are correct....but I have to work with the space I have. I have rehearsed with an 8 piece reggae band in a smaller space than that! :)

mjbphotos said:
I'm hoping the initial dimensions given are wrong >> 2.3 meters wide? By the time you add your planned 10cm insulated walls either side, you are looking at a space only 2.1 meters (less than 7 ft on this side of the ocean) wide - more wall thickness would make it even narrower. Add some bass traps in ceiling-wall corners and its going to be even more coffin-like.
Click to expand...
 
What lighting would you guys recomend? Tracks seem to have halogen and other spotlight type bulbs that in my experience constantly need to be replaced. Fluorescent lights are harsh, and standard light bulbs (energy saver versions) are ok but perhaps not very flexible in the way they direct / cast light.....

Any ideas.....ideally a directable lighting solution but using energy saver bulbs.

Thanks,
Andy
 
I've used GU10 LED spotlights in my new studio. I bought the 3 LED 3W ones on Ebay although normal retailers are now starting to sell them.

You can get a vague idea of what they look like from the photo album linked from my studio Facebook page at

http://www.facebook.com/pages/JRP-Music/273921376017508

While I took most of the photos in daylight, you can see the effect of the lighting in a couple of pics near the bottom.

James.
 
Sorry for your garage sizes there! I can see having a 6 ft wide room ok for doing solo work/recording, but a whole band? With very dead sound, everyone is going to need in-ear monitors or headphones to hear well - and everything will need to be miced up. I don't know what drums will sound like in that space, without room for air to move.
My band uses a single car garage for rehearsal, but it's 12' x 20' (with a lot of crap stored inside, too), and we have a tough time hearing everything because we don't mic the instruments.
 
Ikea have these cheap desk lamps that clamp to a flat surface or attach to a wall and they have an arm and hood that are flexible. They tend to face down when mounted on a flat wall though. You could use these with an amber coloured energy saving bulb....
 
You must log in or register to reply here.
Back
Top