Rehearsal room advice

[Reinoud]

Hi there,

Let me introduce myself. I'm a drummer in a five piece cover-band located in Belgium. Our guitarist is currently building a new house and was so kind to incorporate a basement in the house so we could have a rehearsal room.
The basement is basically a big concrete box with walls and ceiling of about 20cm thick. One part of the basement will be a home office, the other part will be our playing ground. We have about 4,4mx7m floor space and a ceiling height of about 2,2m. The dividing wall between the office and rehearsal area will be a wall of "Silka" blocks, which are calcium silicate blocks. In front of this wall we'll put some double drywall to block the sound some more. We could lay our hands on a professional acoustic door. This door is currently still mounted in a TV-studio but will be available in a couple of months when they start construction work on a new studio. I don't have more details about the door yet, but I've been told it will be very good...

I've made a sketch of the room:
https://3dwarehouse.sketchup.com/model/ ... arsal-room

We plan to cover one of the "long" walls with osb to hide the electrics and have an easy surface to mount all kinds of stuff. We want to avoid drilling in the concrete as much as possible to prevent waterproofing issues. In the back of the room we'll build a storage space of about 80cm deep to keep cases, bags, stands and all kinds of gear. The room will have a hardwood floor.

Our setup consist of three guitars, using tube amplifiers. One bass amp and a five piece drumkit with hihat, 2 crashes and a ride. We mic up the guitar amps and try to keep the volume low and put everything through the PA together with the three vocal mics. We don't have equipment to measure how loud we are, but generally speaking we are "medium loud".

We still have some loose ends to cover:
-ceiling
-acoustic treatment
-ventilation

Our guitarist is worried about sound reflections from the concrete ceiling and suggested the use of "Accorub" insulation and finish off with "Heraklith" panels. We have Heraklith in our current rehearsal room and it works very good. Would this be a good combination, our are their better ways to deal with this? Keeping in mind we have limited ceiling height and limited budget. If we can lower the sound from the jam room to the house we also don't have to worry about the neighbors. The basement is not build against their house, there is a few meters in between the two.

As for the room acoustics we were thinking of the DIY bass traps we've seen on the forum here. How many of these should we place? Is it necessary to put them in the corners as well or can we get away with only putting them on the walls? We're not looking to build a high end recording room, but we want to look at the "quick and easy fixes" to make it more comfortable to jam.
What other things should we think about to improve the acoustics without blowing the budget? Additional absorbers? Diffusors?

We are also worried about the ventilation system. The basement is hooked up on a central ventilation system and we want to prevent the sound ending up in the rest of the house while playing. Ventilation noise in the basement is not an issue as we don't plan to record. What would be the best way to do this?

All help and advice is more then welcome. If you need more info, please ask. I'll try to put some pics up in the next few weeks, but at the moment it's just a building site.

Greetings, Reinoud

[Sarahk]

Hi Reinoud,

I also am a big drummer!! I'm excited to see how this project turns out. I would buy soundproof material for your basement if you're worried about the noise traveling. Also, if you want to improve the room's acoustic sound I would place several speakers in your basement and have it clutter-free so there's no furniture to obstruct the noise.

[Soundman2020]

Hi there "Reinoud" and Welcome! I'm not sure how I missed your post when you first made it, but at least I found it now.

The basement is basically a big concrete box with walls and ceiling of about 20cm thick.

That's excellent! You should be able to get good isolation with that basis.

The dividing wall between the office and rehearsal area will be a wall of "Silka" blocks, which are calcium silicate blocks. In front of this wall we'll put some double drywall to block the sound some more.

The Silka block wall is correct, but just adding a stud wall in front of that is not the right solution. Rather, you need to build a stud wall all around the entire room, not just on one wall. If you only do one wall, you will be wasting your time and money.

The concept you should be doing is called "room in a room". IT means what it says: you build a second room inside the existing room. The inner-room is slight smaller, and does not touch the existing room at all. The inner room consists of framing for the four walls and the ceiling, and it has drywall on one side of it (NOT both sides!).

We could lay our hands on a professional acoustic door.

That's great, but you will need two doors: one in the outer-leaf Sika-block wall, and the second door in the inner-leaf stud-framed wall.

We don't have equipment to measure how loud we are,

You should get it! A decent sound level meter is not expensive: compared to what you will spend on actually building the room, it's just a tiny fraction of the entire cost. A good one is maybe US$ 100 or so. At the beginning of this thread ( http://www.johnlsayers.com/phpBB2/viewt ... =3&t=21122 ) I mention some pointers on how to choose a good one. You really do need one, to determine how much isolation you need, so you can build your room correctly. Without that, you are just guessing, and "guessing" is never a good way to build anything...

Our guitarist is worried about sound reflections from the concrete ceiling and suggested the use of "Accorub" insulation and finish off with "Heraklith" panels.

Teh concrete you see above you is NOT your final ceiling: your "inner room" will have it's own ceiling, and uf you build that using the "inside out" construction technique, then you won't need much additional treatment on it.

We have Heraklith in our current rehearsal room and it works very good. Would this be a good combination, our are their better ways to deal with this?

There are better ways! Much better ways! Every room is different, and every room needs it's own individual treatment.

As for the room acoustics we were thinking of the DIY bass traps we've seen on the forum here. How many of these should we place? Is it necessary to put them in the corners as well or can we get away with only putting them on the walls?

To make it sound good, your room will need "tuning". In other words, you will analyze it using acoustic software, such as the one I mention in that link I gave you above, then based on that you will determine what is needed, and where to put it in the room.

One gain, "guessing" is a bad idea...

We are also worried about the ventilation system. The basement is hooked up on a central ventilation system and we want to prevent the sound ending up in the rest of the house while playing. Ventilation noise in the basement is not an issue as we don't plan to record. What would be the best way to do this?

This is a VERY valid concern! Yes you absolutely do need good ventilation, and yes there is a major problem with sound getting into the rest of the house through the ventilation system. You will need to build "silencer boxes" to put on the ducts at the points where they go through walls. Here are some examples of silencer boxes that forum members have built:

http://www.johnlsayers.com/phpBB2/viewt ... 0&start=45
http://www.johnlsayers.com/phpBB2/viewt ... 9&start=74
http://www.johnlsayers.com/phpBB2/viewt ... 42&start=5
http://www.johnlsayers.com/phpBB2/viewt ... 61&start=0
http://www.johnlsayers.com/phpBB2/viewt ... 5&start=98
http://www.johnlsayers.com/phpBB2/viewt ... &start=157
http://www.johnlsayers.com/phpBB2/viewt ... =2&t=13821
http://www.johnlsayers.com/phpBB2/viewt ... 8&start=44
http://www.johnlsayers.com/phpBB2/viewt ... 2&start=16

However, once again, you can't guess! You need to do the math to ensure that your boxes are the right size, and the right thickness, for your room.

I'll try to put some pics up in the next few weeks, but at the moment it's just a building site.

Excellent! If it is just a building site at present, and the room has not yet been built, is there any chance you can lower the floor? Dig down deeper, before you pour the concrete, so that you will have a higher ceiling? For a drum room, you need the ceiling as high as you can get it! For example, if you could dig down 80 cm just for this room, that would be fantastic, as it would give you 3m of ceiling height for the outer leaf.

Finally, if you want to read a sad story of how NOT to build a drum room, then please take a few minutes to work through this one:

http://www.johnlsayers.com/phpBB2/viewt ... =2&t=17363

It ends up fine in the end, but the drummer in this case went through some pretty bad moments at the beginning, when he listened to the wrong people at the beginning, and made many mistakes. It would REALLY be worth your while to read that entire thread, so you can learn what things to avoid, and not make the same mistakes he did!


- Stuart -

[Reinoud]

Somehow I missed the replies to my post I apologize.

Here's an update. Most of the room in finished, for now...

We've build the Silka wall and installed the door last Saturday. The wall is blocking a lot, but the door is the weak spot, as expected. There is a rubber seal missing on the bottom, we'll have to find a replacement for it. But even with the seal there will still be a lot of sound coming thru. Unfortunately I don't have any pics of the door, but it's a basically two solid core doors with cork in between, complete with a layered hardwood door frame. It's a bloody heavy door, somewhere in the 150kg range. The new doors of the tv studio we got it from are more then twice as thick then our door. It was the best we could lay our hands on. We're still looking to add some extra soundproofing for the door, all suggestions are welcome.

The height of the ceiling is now 232cm, not a lot, but we had to deal with building regulations, keep an eye on the budget and we were basically lucky to even have a basement. When they started digging they hit a big rock, Belgian blue stone. It couldn't be removed and luckily we got permission to rise the entire building 20cm.

One side is covered with osb to hide all the wiring and give us all kinds of mounting options for stuff like guitars and lighting. The floor is hardwood, glued to the concrete.

We never considered a box in box, we're completely aware this is a far superior system, but technically and financially it was not an option at all. It's just a rehearsal room, and there is no problem with sound in the rest of the house while jamming, we just have to keep the level of sound "acceptable".

Last Saturday we've jammed for the first time, and didn't really know what to expect. It was not what we hoped for The amount of reflections is high. We tried to keep the volume as low as possible but everything was bouncing all over the place. There was also quite some sound transfer to the living room above. Even tough it's almost 50 cm of concrete with PUR insulation in between.

We'll be ordering some large curtains to cover up the storage area, and now we are looking for a solution for the ceiling. We're considering Heraklith Tektalan A2 panels, basically Heraklith combined with rockwool. It seems like a good option to reduce the transfer upstairs because of the limited ceiling height. We also had good experience with Heraklith in our previous jam room.

We're also looking to get some diy bass traps and maybe corner traps. We haven't had the chance to do a decent sound analyse of the room, since it's not possible yet do jam like we're used to.

I'll try to update the 3d sketch to give you an idea of the current status of the room.

All help is welcome. Thank you.

Greetings, Reinoud

[Reinoud]

By the way, I've updated the 3d sketch of the room. Here you can see what the room looks like right now. The curtains aren't there yet. The hidden wall is made out of 20cm thick concrete. We have proper ventilation, suck and blow. So far we don't have much noise leaking from the ventilation.

https://3dwarehouse.sketchup.com/model/ ... arsal-room