Home Cinema - Detached Garage

[Triggaaar]

On the garage door, did this proved to be harder to treat? Should I build a deeper wall there?

Well the other walls are solid, and the garage door is just a thin bit of metal (or wood), so yes it's going to need more help. I'd seal up the door, and then add a separate stud wall, with cheap insulation, and then a couple of layers of plasterboard.

 

[Praetorpwj]

Have you read the sound proofing thread on AVS forums? That's a great starting point.
My build thread below should give you some good ideas.

I wouldn't do the ceiling first.

Ideally you want some stud work that is isolated.

So in an ideal world stud work built not touching any of the outside walls. You can even put new timber joists on top of this to create an isolated box. Another way is to fix the stud work to your walls and then use clips and channel to attach the plasterboard, so the clips and channel create the isolation instead. If you do the ceiling first then you won't be able to attach the isolated studs to the ceiling joists. Double layers of plasterboard, or soundblok is worthwhile. Cheap insulation between studs.

You could go for narrow stud work (50mm? )and use clips and channel to minimise width lost. I went with 100mm stud work but used in wall speakers with backboxes. That way I didn't actually loose any width from tweeter to ear.

How do you actually build inner stud walls that don’t touch the outer walls? Do you just bolt them into the floor? Or do you build 4 independent stud frames and then brace them together?

I assumed that you normally just genie clip stud walls to the existing. Still isolated but technically ‘touching’.

 

[Harkon321]

If you go all out, then yes you build 4 frames, braced together and then build new ceiling joists sat on the stop. So it only touches the concrete slab and joined at the door framing.

You can fix to the floor. Don’t think we did as it’s so heavy anyway. I couldn’t do independent joists due a steel being in the way. We therefore used existing joists and used acoustic brackets with a rubber mount, to fix the new stud work to the existing joists. Some people also put rubber tape or strip under the framing, but I wasn’t too worried about transfer to the slab due to its high mass.

 

[Triggaaar]

If you go all out, then yes you build 4 frames, braced together and then build new ceiling joists sat on the stop. So it only touches the concrete slab and joined at the door framing.

Mine's not even joined at the door framing. I added the inner door frame first, and temporarily fixed it to the outer frame, with a 4mm gap (in face the temporary join is still there). I then added the studs to that, and continued building. With the osb and plasterboard on the studs and ceiling joists, I don't imaging the frame will move. For the air gap between the two frames I added a bit of tecsound around the outside of the 2 frames.

 

[diverdog]

Those block walls won't need any help with sound isolation. Concentrate on the ceiling and wall that will replace the garage door. Double framing with an air gap is the way to go. Multi layer rock on the outside single on the inside.

The bad thing about block is it causes very large bass peaks and nulls. framing on 24" centers with a small air gap and a single layer of sheetrock on clips with fiber glass behind will absorb some bass energy and smooth out the modes a bit.

 

[Paulo Favinha]

My plan is to do a double wall on the garage door.
I started the work this week, but it's slower progress than I anticipated. It's just me and my son, and we're kinda figuring some stuff out as we go along

Here are some photos of the progress

I do have question: what height did you put your LCR and back speakers? I now it's supposed to be ear level, but that kinda depends on the sofa / chair, so I assume there must be a rule of thumb.
I'm aiming to put them at 1.3m height (measure at the middle of the speaker), or is that too high?

 

[Triggaaar]

I started the work this week, but it's slower progress than I anticipated.

Tell me about it. I started in June and told the kids it would be ready around the end of the summer holidays. It's still not ready.

I do have question: what height did you put your LCR and back speakers? I now it's supposed to be ear level, but that kinda depends on the sofa / chair, so I assume there must be a rule of thumb.

LCR between ear level and centre of the screen. If you're going for typical cinema recliners, ear level could be around 40". If you're going for cinema chairs, it's a bit higher.

So plan your screen size and height now, so you can work it all out.

Rear speakers are different. If you're having atmos, and 1 row, then rear can be close to ear height, but needs to be high enough to clear the back of your seats. I'd say as low as possible, that clears the back of the seats. That may mean building with ability to raise or lower them, once the seats are in and you can test. That's what I had to do.

I'm aiming to put them at 1.3m height (measure at the middle of the speaker), or is that too high?

It depends how high the screen is. If the screen is high, that may be ok, but if not, that might be a bit high. And you measure to the acoustic centre of the speaker, which is usually closer to the tweeter than the woofer. I couldn't fit mine low enough (room constraints), so I've installed my speakers upside down.

 

[Paulo Favinha]

Hi all. Just a couple of more photos of the progress that I made.
I have the plasterboard in, so it's just a matter of available time to finish the room.
I already placed the order for the M&K speakers and the receiver, so hopefully I'll get it all done before the end of February, around my birthday
As for subs, I'll go with 2 x SVS SB-3000 at the front and a REL 1508 Predator at the back.

I know that people love to see pictures, so here you go

 

[SeanRo]

Great thread, following with interest. In the pics above it looks like you have screwed the clips into the side block wall but through the rockwool - how rigid are the slabs?

 

[Triggaaar]

Great thread, following with interest. In the pics above it looks like you have screwed the clips into the side block wall but through the rockwool - how rigid are the slabs?

I thought the clips were screwed on first, and the Rockwool cut around them?

 

[SeanRo]

I thought the clips were screwed on first, and the Rockwool cut around them?

Ah, that makes so much more sense - thanks, I should have enlarged the pic first

 

[Paulo Favinha]

Great thread, following with interest. In the pics above it looks like you have screwed the clips into the side block wall but through the rockwool - how rigid are the slabs?

Hi SeanRo. Sorry for taking so long to reply, but trying to do as much work as possible on the cinema room.
Like Triggaaar said, the clips go on first and then you cut the rockwool around them.
I’ll post a couple of more pictures about the progress later.

 

[Paulo Favinha]

Hi everyone. Here's some more photos of the progress so far.
The last weekend I finished installing the plasterboard, so this week is just tapping and sanding. Hopefully I'll get to the paint phase this weekend, as I have the carpet being installed next week, so fingers crossed!

 

[Paulo Favinha]

Hi everyone!

It's almost done, really looking good, if I can say so myself

I have the speakers and the AV Receiver in the boxes in my living room, just waiting for the rack, projector screen and projector!

The chairs just arrived, and they are soooo comfy.

Anyway, here are the more recent photos