John Sayers' Recording Studio Design Forum Archive

Hello there.

I'm looking to buy a new house. In that house I would like to build a soundproof recording studio to record rock bands.

I'd prefer to have:
• a control room
• a main tracking room, and
• a vocal isolation booth

Since I'm starting from scratch and looking at houses that I do not own yet, what should I look for?

For example, how much space should I plan for this? How tall should the ceilings be? I would like to have rooms that are acoustically treated and sound great so I need to account for increased wall depths etc.

Also, are there other things I should be looking for besides just the space considerations? e.g. do existing electric, HVAC, floor/wall/ceiling materials matter much?

Also, my wife is helping me identify properties. Are there things she can search for in real estate listings that would help us quickly find candidates for the new house with studio?

Thanks very much. Any tips would be appreciated.

Hi. Please read the forum rules for posting (click here). You seem to be missing a couple of things!

I'd suggest two books: "Master Handbook of Acoustics" by F. Alton Everest, and "Home Recording Studio: Build it Like the Pros", by Rod Gervais.

- Stuart -

Hi Soundman2020. Thank you for your reply. I'm new here and did not read the rules. I have now and hopefully I'm now in compliance.

I'm not completely new to acoustics but I am brushing up and reading a lot about it lately since this will be the first time I would actually have a studio at home. I've read one of Everest's books already (not sure which one it was a while ago) and I am actually in the middle of the Gervais book right now. Thanks for pointing these books out and confirming I am on track with the correct references.

Currently I'm in California but I want to move to Austin TX and setting up a studio in the new house there.

I'm looking for some quick shortcuts, tips, and rules of thumb to help with the house search.
Does anyone have any?

A large unfinished basement would seem obvious/ideal because of the natural soundproofing. However when searching the MLS I haven't seen too many houses in the Austin area with basements.

Since I can't find basements, I look for houses with large bedrooms on the ground floor that I may be able to retrofit into a studio. Is that what you would to?

I intend to record and mix small ensembles (5-6 people max), rock bands etc. Assuming I'm looking at houses without any treatments yet (no soundproofing, no acoustics), what dimensions make sense? What would be the minimum sizes for the rooms if I plan to leave existing walls in place and do proper soundproofing, bass traps, diffusers etc?

I'm going to generate a list of houses to look at for a trip on August 18-21. What else would you search the MLS for besides large bedrooms? Maybe I should look at detached in-law units or large garages?

Thanks in advance for any help you can provide.

A large unfinished basement would seem obvious/ideal because of the natural soundproofing.

Right. basement is generally the best first option, assuming that the ceiling is high. Many basements have low ceilings (less than 8'), which is a problem, but a basement with an 8' or higher ceiling would be good.

Second choice is a detached two-car garage, unfinished, also assuming a high ceiling.

Third choice is ground-floor room with a concrete slab floor and no basement below (just dirt).

A very, very distant fourth choice is a room on an upper floor.

Also, we generally prefer to not use the word "soundproof", since it is basically meaningless: any sufficiently loud sound will penetrate any conceivable barrier (the loudest sound ever to occur on planet Earth cracked concrete 300 miles away...). "Soundproofing" is sort of like claims of "waterproofing" on your watch: there is no such thing. Your watch my keep rain out, or even keep out water 3 feet below the surface, but at 100 feet, or 2000 feet, or 10,000 feet, it won't! you'll find that most places talk about "sound isolation" and "transmission loss" rather than "soundproofing".

Since I can't find basements, I look for houses with large bedrooms on the ground floor that I may be able to retrofit into a studio. Is that what you would to?

A garage would be better, but a large bedromm is a possibility too.

I intend to record and mix small ensembles (5-6 people max), rock bands etc.

How loud? And how quiet do you need that to be to meet legal regulations? In real-world decibels...

what dimensions make sense?

For the control room, there are sets of dimensions or "room ratios" that will give you a good acoustic base to start with, and those are named after the scientists who discovered them. So you'll see people talking about Sepmeyer ratios, or Louden rations, or Boner ratios, or the Bolt area. Search the forum for those, and you are sure to find more than you ever wanted to know about room ratios!

What would be the minimum sizes for the rooms if I plan to leave existing walls in place and do proper soundproofing, bass traps, diffusers etc?

For the control room, the recommended minimum floor area is 215 square feet. That is set out in several common international specifications for critical listening rooms, such as ITU BS.1116-2, AES TD-1001, EBU Tech-3276, and others. That doesn't mean you cant' have a good room in a small space: you certainly can (John has designed complete studios inside a shipping container!). But for a world-class studio, that's what you need.

For the live room, generally you want at least 5 times the total room volume of the control room, for best acoustic relationship. Once again, that doesn't mean you can't have good sound in a much smaller room (eg, shipping container...), but for optimum acoustics, you should have much more total volume in the LR in general, as compared to the CR.

So if your CR is 200 ft2 with an 8' ceiling, that would be 1,600 ft3, so your LR would need to be 8,000 ft3. That might be a 580 ft2 room with a 14' ceiling, for example.

But do note that those are all for world-class studios with optimum acoustics. It would be unusual to find that in a home studio (although I have designed a couple of home studios along those lines). Far more common is to fir the entire studio into a converted 22' x 22' garage, with a 170 ft2 CR and a 300 ft2 LR, both with 8' ceilings.

...or large garages?

Yep!

Or the best option of all, if you have a decent sized budget, is to find a place with a lot of empty space in the back yard, and build your studio from the ground up. I've done a few like that, and it's the simplest and best overall, since you have total control and don't have to continuously work around existing structures or limitations. It costs more to do that, of course, but if you have a good budget, that's the best option, hand's down.


- Stuart -

Thank you for the very useful response Stuart.

You asked how loud I will be. I think around 115 dB will be common.

I checked the residential sound ordinance in Austin and these are the 2 clauses that apply:
- A person may not use sound equipment that produces sound audible beyond the property line of a residence in a residential area between 10:00 p.m. and 10:00 a.m.
- A person may not use sound equipment audible beyond the property line of a residence in a residential area that produces sound in excess of 75 decibels.

The ordinance uses the term “decibels” to mean dBA, measured using the “slow” setting on a sound level meter.
"Audible" is defined as any sound or noise from any source that can be clearly heard by a person with normal hearing faculties.

My main concern is the night time issue I would like to record drums after 10 PM sometimes.

Should I expect to need extreme sound isolation techniques or a large lot size (long distance to property line) in order to stay within legal limits?

If you have any more tips or back of the envelope equations to help me compute typical scenarios please send them along

Thanks again.

- A person may not use sound equipment that produces sound audible beyond the property line of a residence in a residential area between 10:00 p.m. and 10:00 a.m.
- A person may not use sound equipment audible beyond the property line of a residence in a residential area that produces sound in excess of 75 decibels.

Those are two rather different requirements! The first is the typical "gotcha" clause found in many noise regulations these days, since it doesn't define a level at all! "Audible" can mean whatever they want it to mean. Even though it also says that audible is anything "that can be clearly heard by a person with normal hearing faculties", that's also highly subjective. what does "clearly heard" mean? What does "normal hearing faculties" mean? "Normal" for a 20 year old woman, or "normal" for a 90 year old man? See the problem? So if an inspector pitches up and insists he can hear it at the property line, even though you say you can't hear a thing there, all he has to suggest is that his hearing is "normal" and yours isn't.

In other words, there is no legal way to meet that requirement, since there is no legal standard for judging it.

Which makes the second definition entirely superfluous. 75A dB is loud by anybody's standard, so that clause would never be invoked, since the "audible to normal hearing" would cover all other cases.

In other words, you are basically screwed by those regulations. They mean nothing.

Should I expect to need extreme sound isolation techniques or a large lot size (long distance to property line) in order to stay within legal limits?

"Both" would be good! Since sound levels fall off naturally at 6 dB per distance doubling figure that you need 35 dBA at your property line and work backwards from there to three feet away from the wall. If your studio is 48 feet from the property line, then at half that distance (24 feet) you could have 41 dB, at 12 feet you could have 47 dB, at 6 feet you could have 53 dB, and at 3 feet you could have 59 dB. If you have 115 dB inside, then your studio building would need to give you 56 dB of isolation, which is within reason. However, if you can only find some place that gives you 24 feet to the property line, then you'd need 6 dB more in your building system, which would make it 62 dB. That's quiet a bit harder to achieve. And if the place you find only has 12 feet to the property line, your walls would need to give you another 6 dB, for a total of 68 dB, which is really hard to do. Decibels is an exponential (logarithmic) scale, so the more isolation you need, the exponentially harder it gets...

So, to answer your question: it's a combination. If you have a large property then you can get by with less isolation in your studio walls, floor, ceiling, windows, doors and HVAC system (they all need to be done to the same level). But if you can only find a small property, then you'll need to increase the isolation of your building to compensate.

- Stuart -