New Soundproofed walls from scrach (deisgn and ideas)

[avare]

Originally Posted by demetrisag

I was wondering is it a very unrealistic idea to create a door from solid steel 3cm? 2m high and 1 meter wide.

The idea is to build two of them for a door to door scenario, with an air gap between them as much as my walls around 39cm.

The goal is to reach my walls dense which they are as you know filled cement blocks 15cm and 10cm

Yes it is unrealistic. Such a door would weigh ~500 kg. Can you afford the crane to move it and the hinges to support it? Beyond that, I am unaware of any single sets of door seals that can provide such levels of isolation.

Andre

[demetrisag]

Originally Posted by avare

Yes it is unrealistic. Such a door would weigh ~500 kg. Can you afford the crane to move it and the hinges to support it? Beyond that, I am unaware of any single sets of door seals that can provide such levels of isolation.

Andre

I thought so, can you help me with any idea for a door/doors in that case? anything that would provide me 45db at the low frequencies

[avare]

Originally Posted by demetrisag

I thought so, can you help me with any idea for a door/doors in that case? anything that would provide me 45db at the low frequencies

You are not going to find single doors that isolate that much. Use sound locks with double doors.

I would not worry about matching the wall isolation performance. Determine how much isolation you need and work from there.

Andre

[demetrisag]

Andre my target is 45db at low frequencies, and from what I understand I need two doors. Now according to my air gap which is around 39cm what do you think is a good material to use for my doors to reach my target? or any other recomendation for that matter.

I could use solid wood or make hollow metal doors?

[avare]

Originally Posted by demetrisag

Andre my target is 45db at low frequencies, and from what I understand I need two doors. Now according to my air gap which is around 39cm what do you think is a good material to use for my doors to reach my target? or any other recomendation for that matter.

I could use solid wood or make hollow metal doors?

I wrote whatt you need, not what you want. To achieve 45 dB at low frequencies you need with that gap you need doors that weigh 1 800 kg each!

You have no doors directly from the live room to the outside. Build doors like in Rod's book. If you do not have Rod's book, get it. More improtantly is finding suitable material for making the door seals.

Andre

[demetrisag]

pics from building

First two walls with corner









Plastering of outer side





More Walls







And another one







And final Exterior Wall









Wood fro this one was only put there to be able to fill the gap on top of it from the inside

[avare]

Thank you for the update with the great pictures.

Andre

[Sebg]

Theoretically, two separate doors, independently supported, separated by an airspace of 39cm would get close to 45dB transmission loss at low frequency, if each door weighed 40kg/m^2 and there was insulation in the cavity (e.g. 50mm medium-density insulation batts glued to the inside face of each door). of course, the doors would need effective door seals etc etc.

[demetrisag]

Andre i thank you, you and everybody else for all the guidance you've given me all the way!

Sebq,
Thats exactly the kind of advice i was waiting to hear! But to make sure i understand it, if for example i have 1 meter width and 2 meters high for the door then does that means my door should be 80kg? And as for the medium density insulation would a 50kg/50mm rockwool considered medium density?
Thanks!

[Sebg]

Yes and yes.

For example, 1 layer of 30mm medium density fibreboard (MDF) + another layer of 25mm would be about 40kg/m^2. Or a typical solid core door about 40mm would be about 22kg/m^2 so would need to add say 1mm sheet steel (8kg/m^2) plus 20mm plywood (10kg/m^2). Remember that sound-rated doors typically have deep rebated jambs (at least 25mm) so that this will affect the clear opening width of the doorway.

Medium density insulation (at least in my mind...) is between about 30-60kg/m^2.

For reference, Fig 11(b) of BBC RD 1995-06 shows a plasterboard wall of about this mass-per-unit-area and cavity size achieving 47dB transmission loss at 63Hz 1/3-octave band. (Note that the BBC Figure quotes wall mass/area as including framing and cavity infill). A layer of 100mm thick infill on each door would be better but starts to get a bit impractical.

Also note that if you do use sheet steel, a carpentry joiner once told me a trick of cutting the steel sheet into small pieces of say 200x300mm before gluing them on the door. This is particularly relevant to external doors where there is likely to be a bit more swelling and shrinking of the wood due to temperature and humidity changes. If the steel sheet is left as a single sheet of 1m x 2m then the door will warp as the steel will not expand when the wood expands.

[demetrisag]

The building stack for a little while because of problems the friend of mine who helps me with it had. So I am resuming later that week or next.

Now I'm looking to buy rockwool for between the walls. My choice for that would be a 40kg.

But since I will buy rockwool for the walls I thought I will also buy that extra rockwool which I will build my bass traps from it as well to get a better combined price. My bass traps design would the 24 inch 'superchunks' from here.

Acoustics Forum • View topic - Studiotips SuperChunk

Now what I was wondering is: for bass traps would a 75kg rockwool be a better performer than the 40kg one? I was considering the 75kg one.

Thanks

[avare]

Originally Posted by demetrisag

The building stack for a little while because of problems the friend of mine who helps me with it had. So I am resuming later that week or next.

Now I'm looking to buy rockwool for between the walls. My choice for that would be a 40kg.

But since I will buy rockwool for the walls I thought I will also buy that extra rockwool which I will build my bass traps from it as well to get a better combined price. My bass traps design would the 24 inch 'superchunks' from here.

Acoustics Forum • View topic - Studiotips SuperChunk

Now what I was wondering is: for bass traps would a 75kg rockwool be a better performer than the 40kg one? I was considering the 75kg one.

The lighter the better for both.

Andre

[demetrisag]

Andre thanks for the reply.
Could please guide me to link where it says why lighter is better for my case or expain it to me to get a better understanding of it?

Thanks a lot!

[demetrisag]

Absolutely satisfied with my soundproofing now that I installed the doors and tested it!!

Inside I have a big radio playing at 105db and outside, just outside the doors I can only hear very lighly only the bass, the db meter cannot capture any difference and my neighbours would be much happier!

Moving now with the acoustics of it! Now if that is a difficult chapter..

p.s sorry for not posting any more pics, but I actually also proceeded and made the inner wall too. 10cm deep. as my plans above

[avare]

Originally Posted by demetrisag

Absolutely satisfied with my soundproofing now that I installed the doors and tested it!!

Inside I have a big radio playing at 105db and outside, just outside the doors I can only hear very lighly only the bass, the db meter cannot capture any difference and my neighbours would be much happier!

Congratulations!

Andre

[demetrisag]

thanks andre! really wouldnt have done it without your help and others!