Looking for Advice on Drum Isolation

[Mattof79]

Hi all,

I have a question i regards to how to treat my drum room to make it sound better inside, and quieter outside.

Here is the deal:
I live in a rental house and therefore am unable to build anything permanent.
The room has solid double brick walls on all sides and a door and window.
I have put a seal around the door and built a window plug from acoustic foam and MDF. The kit is on a home built platform that isolates the vibrations through the floor. (1.8m x1.8m)

The noise outside is not too bad, but just enough to be on my mind and disrupting my practice, and in other rooms of the house it is a bit louder.

Basically i'm wondering if building some sort of enclosure or at least baffles around the kit will help reduce the noise outside. Ie. would it have to be a complete room to cut back some of the sound, or would baffles say, 1.5 metres high around the kit do something.

I have recently purchased a load of flat acoustic foam and was thinking of building walls/ an enclosure out of pine and MDF.

Can anyone put me on the right track here? I've read loads of forums and websites and they have been great, but don't exactly help with my situation. Or i'm just not getting it???? Either way, any advice would be appreciated.

And the other thing is that i need it to sound ok too

Thanks
Matt

 

[jhbrandt]

Matt,

The foam that you bought is for room treatment and not sound-proofing or isolation.

You are probably getting most of the leakage through the window and door.

Do some testing.

If these are the culprits, fabricate a heavy window panel that will fit into the existing window and seal it. Also replace the current door with a heavy solid-core door and new weather stripping. If the door does not have a bottom threshold, you should replace the entire assembly with a solid-core exterior type door and frame.

The next thing to check would be the ceiling.

Cheers,
John

 

[Mattof79]

Hi John,

Thanks for your advice.
As i said. I have applied a new seal around the door and constructed a plug to fill in the window. And now the sound levels outside are passable. (ie. no complaints yet)

Assuming i bought the correct foam...... does it have no sound isolating qualities at all?
for example, If i was to build an enclosure around the kit would that not help "at all" with the isolation? even if only a little bit.

My other reason for getting the foam was to treat the room. It is basically a concrete rectangular box. A house built in the 50's with solid brick walls with a stucco coating.
The floor is carpet over floorboards.
I don't want the kit taking up the whole room and thats why i am looking at the enclosure idea. maybe 2m x 2m.

I thought about making a frame with mdf board to attach the foam to.
I'm not sure weather to put the foam on the outside/ inside or both.

Any suggestions,
Thanks
Matt

Thanks matt

 

[jhbrandt]

Assuming i bought the correct foam...... does it have no sound isolating qualities at all?
for example, If i was to build an enclosure around the kit would that not help "at all" with the isolation? even if only a little bit.

Not really.
Try this: have someone hold a piece of the foam in front of their face between you two.. have them talk to you. Can you hear them? Through the foam or from the room... I think you will find that you are hearing them right through the foam.

Foam works well as a mid to high frequency absorber when it is placed on a boundary surface. I could be a good option if you are creating an RFZ for your mix position. But don't cover all the walls with it. This is not effective use of this kind of material. You would have better luck with rock wool for corner traps and ceiling clouds.

I thought about making a frame with mdf board to attach the foam to. I'm not sure weather to put the foam on the outside/ inside or both.

A sealed enclosure made of 15 - 18mm MDF would have sound-proofing value. - with or without foam. The transmission loss is improved with the use of absorptive material. I would put it only on the inside.

Are you on a wood floor? - Not much you can do there without great expense.. but if you want to build an enclosure properly, you should frame it out on your existing platform. 50mm X 100mm studs with 12mm gypsum board inside and out & filled with fluffy stuff. Frame a ceiling in the same way. Get a good solid core exterior door and frame installed in your booth & bang away. You should get close to STC 36-40 with that with the exception of flanking noise from the platform/floor.

Use gypsum board.. MDF's increased mass is not comparable to it's cost. - And finished gypsum looks better.

Cheers,
John

 

[Mattof79]

Thanks for the great info john,

So a couple more questions if you have the time:

What would be the ideal height for an enclosure like this? Obviously tall enough to stand in but the room has a pretty high roof (3m).

Would the acoustic foam that i have be suitable to fill the void if i made walls of gypsum board as per your description? It's just that i already have it

What would be the ideal width of the gap between inside and outside walls(50mm or 100 mm)? The smaller the better as it will take up less platform space. The platform is only 1.8 x 1.8

And finally, without knowing the house etc.... would you forsee the weight of such a booth as being too heavy for the floor. I obviously don't want to go through the floor

Thanks
Matt

 

[jhbrandt]

100mm would be best.. 50mm may give you 3db less transmission loss.

As far as weight is concerned. I HAVE NOOOOO IDEA! hahaha.

You'd better do some weight calculations to make sure. It could happen... going through the floor - I mean.

But the only way to acheive sound isolation is with Mass - air - mass. And mass is by nature... heavy.

Cheers,
John

 

[Mattof79]

hi john,

thanks mate... so i have ruled out the building of a booth due to cost, facilities and other reasons.

if i was to go along these lines:

A sealed enclosure made of 15 - 18mm MDF would have sound-proofing value. - with or without foam. The transmission loss is improved with the use of absorptive material. I would put it only on the inside.

Would MDF be the best thing to use? Would a sheet of ply attached a sheet of Gypsum board do the same thing (to bring the weight down)?

Thanks anyway.
You have already been most helpful.

Matt

 

[jhbrandt]

Matt,

MDF panels will attenuate the sound but the LF, like the kick and snare thump, will come through fairly well.

It's better than nothing.

Good luck, my friend
John