Vocal Booth

Problem My studio is located in the same building as a night club that’s approximately 35-40 yards away from me on the first floor (I’m on the mezzanine) The building is a historical landmark so it’s old (first Bank Of America or first in the state… something like that) and I’m picking up a lot of the clubs low frequency when I record vocals in my studio. Not only that, but I am picking ambient noise from the street below (Light rail, people fighting after the club gets out… you know, the norm) so I also wanted to deal with that. Solution BUILD A VOCAL BOOTH!!!! (at least I hope it’s my solution!) I thought that I would build a booth and decouple it from the floor to deal with the low end coming from the club and to isolate the vocals from all the other ambient noise. Question I was looking to buy booth and just be done with it so I checked the booths being sold by vocalbooth.com which seem awesome, but waaayy to expensive. So I’m going to build my own. The only part im caught up on is the door situation. 1. What kind of doors are companies like vocalbooth.com using? Are they manufacturing their own or are they sourcing it from someone else? 2. Can I use a glass double pane storm door?

Hi Astin, and welcome! :) Is this just for vocal singing, or also to be used as an isolation booth for things like guitar cabs, solo instruments, etc? One big issue is going to be the door for sure, but another even bigger issue si going to be the thing that you passed over lightly as though it would be easy to do: "and decouple it from the floor to deal with the low end coming from the club and to isolate the vocals from all the other ambient noise.". What you are proposing is to float your booth, and in your situation that might well be the best thing to do. But the issue is: it ain't easy to do that right! Neither is it cheap. Here's thread that is somewhat pertinent, even though it is more about floating floors for entire studios, but the same basic principles apply, so you might want to spend some time reading over it. viewtopic.php?f=2&t=8173 Fortunately, your case isn't as bad as that thread makes it sound, but still, floating an iso booth is not as simple as it sounds. The basic concept is to support it on some type of "spring" (which might be a physical metal spring, or might be some type of special rubber), such that vibration on either side of the spring (your booth side, or the floor side) is not transmitted to the other side. The mass of the booth and the resilience of the spring basically make a "tuned" system that resonates at one specific frequency, and you "tune" the system such that that frequency is way lower than the lowest one you need to isolate. So just throwing down some bits of rubber and building your booth on top is not the answer. The probability of that working out by pure chance, is zero. That's the basics, but there's more to it than that, so you should probably look into the method that you need in order to float the booth properly.

1. What kind of doors are companies like vocalbooth.com using? Are they manufacturing their own or are they sourcing it from someone else?

I'm not sure what they do, but if cost is an issue for you then building your door is waaaay cheaper than buying it, and not that hard to do, if you are handy with basic tools. The basic concepts behind a good isolation door are mass and seals. In other words, the door has to be very heavy, and it has to be sealed all the way around the perimeter (top, bottom and both sides) with at least two independent seals. No seal = no isolation. Insufficient mass = insufficient isolation. That leads to the obvious question: How much isolation do you need? In terms of real-world decibels. That number is the basis for your design. Once you have figured out that you need X dB of isolation, then you can look at the possible materials and techniques that will give you that much isolation, and choose the option that best fits your budget. But if you don't have a number, then it is all just guesswork: you have no idea what materials you should be buying, or what techniques you should be using to put them together. So that should be your first order of business: find out how many decibels of isolation you need. And while you are doing that, also find out where the problematic frequencies are, and how bad each one is. For example, you mention street noise but didn't say if the problem is low frequency rumble, engine noise, horns honking, tire hiss, or maybe even impact noise from vehicles going over potholes, or some such. You did say "light rail", which could be several of the above. So it's important to identify what frequency bands are giving you trouble, and how loud each of those is.

2. Can I use a glass double pane storm door?

Perhaps, but probably not, but that depends on your "number". The big issues with door design is to maintain the surface density of the entire leaf, to ensure that you have at least two independent seals, and to ensure that the hinges, closer and magnetic latch are all working correctly, and are heavy duty enough. There's one item you didn't mention, and is often overlooked in vocal booth design: ventilation. You need to breathe in there! :) It will be sealed airtight (it must be, in order to isolate) so you do need to consider a pair of small silencer boxes and a couple of fans, to keep you alive. That's rather important, I think! :) - Stuart -

In soundproofing, the best sounding booths are in a diamond shape.

With all due respect, you are talking garbage. The shape of the booth itself has absolutely NO effect on how well it is soundproofed. Zero. Zilch. Nada. "Soundproofing" does not depend on shape: it depends on rigidity, mass, decoupling, and damping. Period. There is nothing in the equations for soundproofing even remotely related to shape. While shape certainly can affect the acoustic response inside the booth, it simply has nothing at all to do with the isolation.

Build a sound booth with tips from an acoustics specialist

That's why Astin Martin is here: to get advice from the acoustic specialists on the forum. Why are you here? - Stuart -