Any acoustic engineers out there? Need some advice about soundproofing.

[galain]

I teach Japanese taiko drumming for a living. I usually teach in groups of 7-9 drummers. I'm thinking of buying or building a house with an attached dojo space (about 50-60sq meters). In my part of Germany there are lots of old houses with barns that I could convert, but from what I've heard, there can be lots of hidden costs in renovating a 200+ year old building. A new house would have pretty much most of the costs visible and up front.

My options are a room within a room situation with an older house/barn or stable, or a separate newly built space. Going underground with a cellar room is too expensive.

Has anyone got any experience with sound dampening? Right now it's more important to stop sound getting out of the room and reaching any neighbours, than it is to keep it down inside the room. We all wear earplug during practice anyway.

If anyone out there has any experience, I wouldn't mind running some of the building options I've seen past you.

Thanks in advance.

[B_B_C]

Sound damping (absorption) is not the same as sound proofing though it is in many respect an easier and cheaper way to reduce sound transmission beyond the immediate area

many things can be used to increase sound absorption; slotted dry lining to walls, slotted / louvred ceilings with rock/ glass wool insulation behind the linings. draught seals to doors and windows, dense hedging around the noise chamber (in the way shrubbing is used to reduce road noise. Even heavy curtains & carpets will reduce the sound level though may affect your experience of the sound. Have the room at ground level as sound will travel further from above as there will be less absorbing obstructions.

As for keeping noise within the room ie sound proofing) them Mass is the key i.e. heavy thick masonery walls with sealed openings

[galain]

Thanks for the reply.

Yeah - mass would be no issue with some of the older houses, but I'd want to renovate the whole house as well as just a training/teaching space. I spoke with a guy last week who renovated (is still renovating) his 300 year old house. Beautiful job so far but the amount of extra money he's had to lay out just due to unforseen stuff that old houses hide....there's just no way of knowing.

I've seen insulation offerings involving an inner and outer wooden wall (about 10 inches apart) with a filling of small pebbles. It's used mainly as temperature insulation due to it's thermal mass, but the builder was saying it was also an excellent acoustic insulator.

I've also seen the same sandwich type arrangement, but the space between the 2 wooden walls was filled with another zigzag wooden wall in the middle (a 3rd wall in the middle, but not straight), and the spaces between each angle filled with a hemp type of material.

I was shown some cellulose insulation yesterday which did a good job of dampening a high frequency noise, but taiko is a lot of low deep frequencies which the guy couldn't tell me about.

I wish I had a way to directly compare some of these spaces. Do any of the ones I mentioned sound like anything you've had experience with?

[B_B_C]

Once you start thinking of designing and building  for different frequencies then you enter a zone of science and unpredictability - the sound science is there but there are so many variables in practice that prediction at a domestic level are virtually impossible. There is a casual link between sound and thermal insulation where by either can give some benifit to the other but few methods answer both. You could consider just adding some extra absorption to the drumming room and supplement / add change when up and running rather than layout time money and effort with difficult to predict results

Old buildings always throw up problems as technology, method and material is always changing.
However be careful with thermal insulation- it has to be balanced with ventilation / condensation needs particularly in a moist / damp climate. Applying insulation standards from a cold arid climate to a damp / moist climate nearly always causes problems

It may be worthwhile consulting an architect or building surveyor - allow for a megaton of "iffs, buts and maybes) and listen to what they are not saying

[galain]

Thanks mate. Yes- the breathability of the room is also worrying me. With a group of people all playing away, humidity will be an issue.

I'm going to ask as many professionals as I can. The few I've spoken to thus far have either tried to sell their product, or seen it as a challenge, but like you say, if the challenge defeats them, I'm left with an expensive and unuseable space.

I appreciate your replying - muchos danke!

[B_B_C]

Thanks mate. Yes- the breathability of the room is also worrying me. With a group of people all playing away, humidity will be an issue.
I'm going to ask as many professionals as I can. The few I've spoken to thus far have either tried to sell their product, or seen it as a challenge, but like you say, if the challenge defeats them, I'm left with an expensive and unuseable space.I appreciate your replying - muchos danke!

The word professional is banded about the place with very wide meanings but in this instance I suggest you consult and pay for professional whose product is their advise (hence the iffs buts and maybes) if the task goes beyond you risk zone (should be well beyond the comfort zone:  )
Breathability is one of those buzz words that have left construction academic papers and colonised sales depts.
In the case of your sound room a simple extract fan might be much more effiecient, practical and cheaper though less eco-exotic. Many of the current condensation problems are a downside of technological improvements eg plastics (inc. plastic paints)and double glazing etc.

[Tapeworm]

I'm experienced in wall and ceiling installations.  I haven't soundproofed before but am somewhat familiar with relevant products like resilient framing mounts and soundcheck drywall.  

I can't speak to the precise decibel reduction achievable for Hz ranges but a manufacturer should be able to provide that data to you.  I'm good for installation procedures for basic or more architectural designs, estimating materials quantities, required tools, etc.

Shoot me a pm or post up a design proposal, galain.