Studio floor isolation (help needed)

[AudioMedios]

Hello. I'm new to this site but everyone at the protools forum recommended me this place to lear more about acoustics and resolving my studio problems.

I'm plannig to redesign my studio and one, if not the biggest, problem is the floor isolation. My studio is in an apartment in the fifth floor of a five floors building, so I have no problems with ceiling because I don't have neighbours walking over me. My headache is my neighbour in the fourth floor complaining each time I record drums, I guess due to the low freq transmission over the floor. I tryed some solutions and they improved in some degree the sound leakage problem but I'm not yet able to completely eliminate it. This is what I did: I put all over the floor surface what I call "a sandwich" it is one layer of carpet, then one layer of a material called superlon that is similar to neoprene 1 inch thick, then 1/2 inch thick plywood, then the superlon again and then a carpet wall to wall. Over this sandwich I build a drum riser 5 inches high with plywood over neoprene stands to prevent low freq transmission. I treated the walls with just foam. The drums are the only problem and specially the kick drum. I don't want to build a concrete floating floor becuse I think it is too drastic and If I had to move that could be a real problem to remove it.

Any suggestions will be greatly appreciate it.ç

Thanks

[knightfly]

Hi, and welcome - couple of questions right off -

when you say this "superlon" is similar to neoprene, do you mean the solid stuff or neoprene foam? Any Durometer specifications for it?

What you described is technically a triple leaf construction, unless your original floor is wood joist; in which case, it's a quad-leaf - generally, the more leaves in a barrier the worse the low frequency isolation becomes.

Are the cavities between framing in your riser filled with any insulation, or just empty? Empty lets the plywood act as a giant drum head, which amplifies the noise.

Can you describe the construction of your building? things like wall thickness, concrete or wood or steel studs, same with floor...

The more info you can provide, the better we can do with suggestions. Also, are you willing to take out what's there and start from scratch in order to solve the problem?

Also, you may be getting most of the problem through the floor, but you could also be seeing flanking noise through your walls into the other apartment and re-radiated through their wall/ceiling surfaces - we can get a better idea of this once you describe construction more thoroughly... Steve

[AudioMedios]

Thanks a lot Steve. I'm going to take measurements of the walls and describe better the materials and all that's involved in my current studio acoustic setup.

I was wondering if it is possible to send to you small photos or graphics of my place in order to explain better want I have, so you can have an accurate image of the things involved. If so let me know.

Wait for the next reply with a better description of what I have.

Thanks
Ed.

[cfuehrer]

YEAH!!! Great to see you took our advice from the DUC and posted.

[AudioMedios]

Ok Steve. This is the complete description of my apartment and the space for the studio.
I’m the owner of the place and I can consider to remove the actual sound treatment in order to start a new and better one from scratch.

Being said that let’s go to the facts:

1. Floor: it is made of 5” thick concrete with hard floor tiles made of little marble stones on its surface. This structure is supported by concrete joists 7” x 8” thick, with a space of 14” of separation between each one. In the live room we have 6 joists that run parallel to the wall that divides the control room from the live room. In the control room we have 5 joist in the same shape.

2. Walls: The walls are made of big concrete blocks (16”x8”) with 6” thick for structure walls and 4” thick for division walls. The only division wall is the one that separates the control room from the live room, in this wall a studio window should be installed for visual contact.

As I said the apartment is in the fifth and last floor and occupies the left wing of the building. The space for the control and studio rooms have only contact with neighbours by the floor and of course the structure walls that we share.

I think the soundproofing should be stronger in the live room to avoid problems with neighbours when recording loud instruments like drums and maybe bass so the low freq absorption should be a priority. I’ve never had complains with other kind of sound sources (vocals, brass, guitar amps). Anyway I understand that a good noise control over the whole studio is needed in order to work at night.

The area of the studio is like this (sorry I have the measurements in metric):

Live room: 3.89m x 2.94m
Control room: 3.48m x 2.94m

I think the first thing to resolve is the floor treatment, then the walls, later the ceilings, etc.

I’ll try to send pictures and plans I did trying to explain better the space to work.

Thanks a lot and I’ll be looking for your reply.

Ed.
www.audiomedios.com

[AudioMedios]

I guess you are very busy to answer now, no problem I can wait but meanwhile I'm reading a lot on acoustics. I printed all that it's available at SAE site and I'm starting to see the things more clearly about my studio.
I hope not to be wrong but I think one positive thing is the matter that the studio is completely surrounded by concrete that makes a good isolation barrier for noise coming outside the studio.
Right now the studio is located in the two rooms at the right of the apartment, that is the control room is in the live room of the graphic above and the studio is where the office is indicated. I want to change the room for the studio because it is too small, is more like a vocal booth although i've been able to record drums in there several times but being the room so small, the drums don't have enough space to "breath", besides the other rooms can have the ceiling higher making possible to make a more acoustic friendly space for sound recording in there.

Talking about floors I have the plans about it and I've been reading the sticky posts to see how others have dealed with similar problems. I think the floating floor (made of plywood, not concrete) is the solution for the noise leaking in to the neigbour's appartment, but I'd like to have the help of an expert before making anything because I don't want to expend money if I'm not sure it is going to work.

I'll wait for your answers
Thanks.
Ed.

[knightfly]

A few questions -

What is the maximum distance those concrete joists span?

Does the wall between CR and live room have hard contact with the wall between you and neighbors?

What is your ceiling height (if you posted, I missed it)

You can build just the floor first, but won't see a lot of improvement til you've also isolated your concrete walls from the sound source - so, if you start with the floor please don't be discouraged if the results aren't what you hoped - concrete, while it's great for mass, isn't much of an insulator without the help of an air/insulation gap and another leaf of mass. Keeping the concrete from direct contact with the sound is the best thing you can do.

Sorry for the delay, life's been pretty concentrated lately... Steve

[AudioMedios]

What is the maximum distance those concrete joists span?

The distance between joists is 14 inches and they are 3 metres or 10'long, both rooms CR and LR are 4x3m. Actually the LR is a little bigger

Does the wall between CR and live room have hard contact with the wall between you and neighbors?
I supose the wall between me and my neighbours is the floor and the answer is yes, that wall is a division wall made of concrete blocks that have and 1" air space inside them. This wall is builded over the same floor I mean it is supported by the floor itself.

What is your ceiling height (if you posted, I missed it)
The ceiling height is actually 2.20m but I can raise it up to 3m 'cos the roof is high and the ceiling is just thin pine wood in a light structure of 2"x2" joists.

You can build just the floor first, but won't see a lot of improvement til you've also isolated your concrete walls from the sound source - so, if you start with the floor please don't be discouraged if the results aren't what you hoped - concrete, while it's great for mass, isn't much of an insulator without the help of an air/insulation gap and another leaf of mass. Keeping the concrete from direct contact with the sound is the best thing you can do.

I understand I have to build a floating floor. I supose a timber floating floor could do the job with a double layer of 2"plywood over the joists and neoprene. But what about the walls?... I was thinking in bass traps and slot resonator wall treatment. I looked at the diagrams at the SAE site that shows how to build them.

[John Sayers]

Ed - I agree with Steve - you are going to get flanking through those sollid concrete walls and until you build a room within a room construction you'll never shut in the sound.


I'd wait for the architect to check you internal wall construction because it would appear from your description that you could probably move them, or better still eliminate them by replacing them with supporting beams.

This would then allow you to build new walls as a room within room construction as well as get more appropriate room shapes.

cheers
john

[AudioMedios]

OK John I understand the necesity of a room in a room.

I have one question: if you look at the plans what walls would you move(or create) in order to make more space for the CR and the LR?

I ask because the architect is not an studio designer, he just builds normal buildings and houses so I have to explain to him want kind of changes I'm intended to do and this way he can help me with a feasible design.

I really thank you for your help, I finally feel I'm talking with experts and learning. Here in my country (Colombia) is very dificult to find people that knows about studio building, it's, indeed, hard to find an acoustically good sounding studio, there is a lot of misconceptions about soundproofing and acoustics as a cience here in my home town.

So thanks again.