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?