Vocal Booth Dimensions?

[anemicrock]

Hi guys I'm wondering if anyone can help me out. I have looked everywhere before this post with with no prevail on what dimensions are good for a vocal booth to achieve the best possible acoustics.

Before I have a bunch of people telling me vocal booths are not that great and I don't really need one let me tell you that I do. I'm recording in my apartment living room/kitchen. It's one of those open floor type plans. Obviously you can see why I need the booth as I can't track vocals whilst my girlfriend,brother or his girlfriend are cooking or using the washing machine. I also can ask my paying client to hold off for hlf and hour or so while there cooking etc.

I was going to build my booth following a design on
johnlsayers page. I can't post the link yet as this is my first post. Sorry.
but have read on this board somewhere that it would sound to boxy
or just generally have bad acoustics.

So to get to my question what size is good to build my booth for the best possible acoustics. I have about 10 feet high ceilings and plenty of room on the floor for depth and length.

I know how to do everything else in regards to isolation material etc but I'm still debating whether or not to have a window.

Thanks.

 

[tmix]

My thoughts

Since you know of the Sayer's site,what you need first to glean from them is the room ratio formulas. Secondary is the acoustic and sound proofing.

I have never had a bad vocal booth sound because I followed the dimensional ratios so there were never frequency peaks or build up. I also made them totally absorbent.
Windows are good for line of site directing, but always cause some sound reflection inside the booth. The smaller the booth, the worse it affects it.

I say that to make the point, if you really don't absolutely need a window, don't put one in.
Not only do they create a hot spot acoustically inside the booth, they are always a weak link for soundproofing. They are difficult to install correct and unless you use thick glass it allows way too much sound through that area. I have found most times just having a talk back mic running into the vocalist's earphones has been adequate.

The smallest vocal booth I ever had that sounded good was approximately 5 by 6 foot floor plan , by 7 foot tall. Try to build with nonparallel walls and certainly fully trap the ceiling as much as possible.

Since you probably are not going to try for a double walled mass - air - mass setup I would build one with a single leaf of mass to the outside of the wall / ceiling studs (maybe 2 or more layers of 5/8th sheetrock) and a heavy solid core door, and then put all your absorbent materiel in the stud cavities, covering the inside with some acoustically transparent cloth.
Since you are not in your own place this would make for a unit that could feasibly be assembled and later disassembled to be moved. Obviously it would be heavy.

Obviously my opinion also.

 

[anemicrock]

Hi. Thank you for the reply. I was going to use this setup for my walls and use the same principle for the ceiling. The Floor I will do the same but with MDF instead of Gypsum Board. I would float the floor but I only have about 10f for height in my room.

I'm also going to use this booth for putting guitar cabs in. I realise it would much better to float the floor for this but I previously made a box out of MDF that wasn't floated and although it wasn't completely soundproof, it brought the noise leakage down a lot. Enough so when I had my monitors on for playback I could not hear the cab in the box.

Basically my plan was to have the ceiling 7 1/2 feet tall, 5 feet in length and 4 feet by depth. Do you think this should be okay? I would make it longer but it would block access off to my backyard which we use a frequently. Also a nice place for band members to chill.

Please let me know what you think. Oh and I have read about not making parallel walls but forgot what that meant. Any chance of a recap?

Thanks.

 

[tmix]

As far as the size, the 4 foot will work, it is on the small side of having someone feel claustrophobic though. You are not going to want to spend prolonged time in there.

Floating the floor can work if done right, but if done wrong would make your isolation worse.
Plus I would mention, you could build a small amp platform with a piece of mineral wool or compressed fiberglass with a cap of plywood on top that would work well for keeping some sound transmission through the floor.

The wall cross section is going to be a waste of time and materials the way you have it planned. It is good that you want serious mass in the wall but separating it on 2 sides of the same stud would not be near as effective as putting it all one side. To make your choice work you would want to have two separate wall faces with no common wood to keep structure born vibrations from happening, and to be quite honest, you booth is too small to afford that luxury. You would then need 2 doors... and the list goes on.
Plus if you have mass to the inside you would Still need the absorbing material inside of that to absorb the sound in the booth which would make your booth even smaller.
Putting the absorbing materials inside the wall does little for taming what is going on in the booth.

 

[anemicrock]

Okay I get what your saying. Thanks for the advise. What if I extend the 4 foot in depth to 6 feet and the length from 5 to 9 feet. Mind you these will be the dimensions inside the booth. So add 3 1/2 inches for the 2/4 studs. So my booth will be 6 feet 3 1/2 inches in depth and 9 feet 3 1/2 inches in length?

Does that sound better? Also, when you said I would want to have two separate wall faces with no common wood to keep structure born vibrations from happening, How do I do that? Can you show me a quick sketch or something?

Thank you once again for your advise.

Kevin

 

[anemicrock]

Do you mean something like this? I have never seen a vocal booth this thick before. I was going with the second design originally like my first post but if you think it won't work then please let me know.

Thanks

 

[tmix]

My vocal booth is built like that, as is my drum booth and mix room and tracking room.
It ends up being around a foot face to face.

I guess what I am trying to say is under the best circumstance, if you were dealing with really loud sources such as blistering amps and drums and had the space, time, and money to devote to building something like that... great! Go for it.
The average drummer in my studio plays around 105 or so decibels, so if you were PERFECT in building a setup like the double wall scenario the wall structure would theoretically decrease the volume of the drums on the opposite side of the wall structure by around 60 to 65 decibels in many frequencies, but not all. Bass tends to travel more through walls unless they are massive.

If all you are trying to do is block the sound level of people talking from interfering with the recording, you don't need near that much isolation. Obviously more is better, but most time we have to compromise our desires with the cold hard facts of budget time and space.

It does no good at all to have a wall structure capable of blocking 100 decibels, if you only hang a curtain in the doorway. If you put a heavy door capable of about 40 decibels of isolation than building a wall structure of much more than that is useless.
If you don't seal the room perfectly airtight including the door structure you lose sound there as well.
If you have 2 leafs of mass (such as the double wall set up) you must complete the leaf with a second set of doors, otherwise you have a weak link at the opening.

No matter how much isolation the structure affords you from external sources(or the external world from what's going on in the booth), you must also deal with absorbing the sound INSIDE the booth, otherwise the recorded sound is horrible. This is where you get your "Boxy" sound from. Lots of folks make sound absorber panels to hang on the walls for this purpose.

This why I offered the suggestion ( and compromise) of creating a booth with all the mass to one side and using the stud /wall and ceiling cavities on the inside of the booth to fill with sound absorptive materials and the simply cover the insulation with fabric.

Just think of this; if it would work for you to put someone inside a spare bedroom on the other side of a wall from you to record. then a single sided wall of 2 layers of sheetrock would suffice.

Yes I realize it is a bit of an oversimplification... but you get my drift.

A 5 by 6 vocal booth is fine for vocals and amps (even acoustic guitar) so going bigger ( like 9 feet ) may or may not get you any extra benefit, but if you are thinking of recording a drum kit, 6 by 9 would be better.

I know I am not explaining it well.
I hope someone else jumps in.

 

[anemicrock]

I understand what your saying a lot better now. Thanks for clearing things up a bit. I would just throw the singer in my bedroom behind my desk which would be ideal but

1. It's the only place for my girlfriend who lives with me to chill. I think she would leave me if I told her I'm gonna throw some guy in there while she's watching tv to sing.
2. I would have to soundproof my entire bedroom If I we're to use it for guitars and drums which would cost more than building a booth.

I just threw another thread up but no one has responded yet regarding making it big enough for drums. I would much rather do that so I don't have to record my drums else where. So my questions I have now are.

1. Would drums sound shit in a room 6 by 9 if it was properly acoustically treated? Obviously not as good as a big room but will it sound recordable?
2. Can I get away with making the wall as shown in the seconds picture. The smaller wall without the air gap? I would want to try this option because of cost, space and it might get a bit complicated for me trying to connect the L shaped corners of all the walls together.

Thanks in advance and again, thanks for your help.

 

[anemicrock]

Please guys I really need to know if the second pic "STC 45" will contain the drums enough?

Please help.

Thanks

 

[diyguy]

No one ever factors in if this is a second level or a basement slab floor. It is totaly pointless to build mass STC 55 walls using staggered stud or double wall as vibrations though the floor will simply leak form the floor joists just like a giant bass drum.

1. The floor the rooms sit on will vibrate
2. The sheer mass will crash or damage joisting, bow the floor.

Just wanted you to know this before you drop 10k and get crap results and damage your home if it will not support the weight.

Also you are going to have to use plenum driven ventilation or your perfect acoustic rooms will have tons of HVAC noise.

consider using this and modding it to run between the walls. standard materials from home depot and very effective and killing cross talk and allowing enough airflow.

http://www.dawbox.com/acoustic products Ventilation.htm