To All Experts:Please Help:Apartment Sound Reduction

[dversion]

Hello,

Firstly, thanks for all the great advice. This forum saves so much money for it's members by insuriing they buy the correct materials for the specified job.

I hope I have interpreted the rules for posting correctly. I did a search and read the FAQ. Here I go...

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LOCATION:Vancouver, BC

DESCRIPTION:Home studio for composer in rental apartment.

ROOM SIZE: Rectangle 8ft wide X 13ft long X 9ft high

ROOM CONSTRUCTION:Older Plaster walls(1921 construction). No insulation between interior walls. Handwood floor.

VOLUME IN STUDIO:Some vocal work and medium monitoring. I will buy a db meter this week at RadioShack.

PROBLEM:Thin walls with neighbour. I can hear muffled conversation quite easily. I can only imagine what they will hear when I fire up my monitors.

GOAL:Reduce my transmitted volume by 20-25 db in most frequences.

BUDGET:$1500 for Sound Isolation/Soundproofing - or - I am willing to spend up to $7500 for ISO Booth/Whisper Room type that I can take with me.

PROBLEMS:Rental unit. No major construction. I can put some holes in the wall, but I don't think a STC 63 level double staggered stud with double exterior gyprock is a possibility. Also, I don't like the idea of fibreglass being exposed, so that is out.

POSSIBLE SOLUTIONS SO FAR: After speaking with some techs at Acoustical Surfaces, they recommended the EchoEliminator Composite Panels. They are cotton based, which I like. They have a STC of 17. On my own, I thought about applying some SheetBlok Sound Barrier from Auralex. It has a STC of 27. I know it is mainly for sandwich in between drywall layers, but my plan was to attach to existing wall and the apply the Composite Panels. After searching the forum, I know that the secret is mass and airspace, but I am in a bind. Please offer what help you can.

Truly,
DV

[sharward]

Learn more about STC. You can't just add STC numbers -- that's not how it works. To say a product "has an STC of 17" is meaningless because an STC rating applies to an entire assembly, not just one component of it.

I don't blame you for this -- I blame the purveyors of so-called soundproofing products. They make millions of dollars every year from the ignorance of their customers who don't know the ins and outs. I was very close to becoming one of their victims before I discovered this Web site.

Using lightweight closed-cell foam for soundproofing is likely to disappoint everyone involved except the company that sells you the product.

I haven't studied the Acoustical Surfaces site too carefully, but what I see I don't like... It looks like they're presenting data and fancy charts to imply that the products are more beneficial than they actually are. I welcome being corrected on this by someone whose B.S. detector is more accurately calibrated than mine.

Stopping sound -- especially the obnoxious low-end bassy stuff -- takes lots of mass-air-mass. There is no substitute.

--Keith

[dversion]

Keith,

Thanks for the reply. I'm well aware that due to the exponential nature of measuring the STC level, you can't simply add STC numbers, but wouldn't adding some products together, whilst increasing mass, attain some level of increased reduction? (ie. 2 sheets of gyprock on the exterior walls increases STC by significant amounts. SAE Reference )

In any event, anybody have any ideas, other than a stud wall, that would help me reduce some db's?

Thanks,
DV

[knightfly]

In your case, the largest ENHANCED whisperroom you can afford may be your best bet; with older construction, not only is there usually no insulation in interior walls, but things generally aren't sealed all that well; in addition, framing was done without any sound control in mind; so there are typically multiple flanking paths (see REFERENCE section, there are a couple of papers listed there for more info) that will keep you from even getting CLOSE to that much more isolation.

Which is why I talk about the booth; if you get a booth and rest it on 4", 3 PCF rockwool instead of casters, you will break the flanking path (somewhat, not totally) and the double wall construction of the ENHANCED versions will increase isolation into your room; then, as long as you locate the booth several feet AWAY from the party wall, it should give you a fair amount of isolation.

Keep in mind that this will STILL act as a multi-leaf wall, which is why I recommend keeping the booth away from the common party wall - this will NOT eliminate the multi-leaf effect of reduced bass isolation, but should alleviate it somewhat.

I know this isn't as much as you'd hoped for, but the changes you'd need to make in order to get where you want to be isolation-wise are NOT gonna happen in a rental unit, unless you REALLY luck out and your landlord decids to convert his place to musician rehearsal apartments... Steve

[dversion]

Thanks for your help. Looking into the rooms on vocalbooth.com.

DV

[knightfly]

Yeah, I need to examine that site sometime too; haven't compared them to whisperroom yet, or even been to their site... Steve

[JP YVR]

This is such an old post so I hope I'm not hijacking it, but rather, resurrecting it.

It is my first post so please be gentle...

The reason I am asking my question here is that my room size and build material (and age!) are the same...

Some background... I am planning to build a small iso booth (in the neighbourhood of 4x5x8 OD) with sound reduction being the primary goal. I want this to practice saxophone. The booth would not be near a common wall, but the room does adjoin one neighbour (I practice quietly and he doesn't mind at all). My apartment is above a restaurant and we do not hear each other. I do have some building experience and will be doing this myself.

My questions:

1) Would a staggered double-leaf 6" framed wall be more effective than a standard double-leaf 4" framed wall? OR 1b) would a single-leaf with, say, 1 layer of 5/8" and 1 layer of 1/2" sheetrock (acoustically sealed, of course) with Donnacona as the inside layer (or simply, cotton sheets if the Donnacona is superfluous?) be more effective?

2) The area of room I have would allow for up to a 4x6x8 footprint. I'm thinking the 4x5x8 would sound better. Is this the fact?

3) The booth would sit on neoprene castors. Good idea, or are pucks or some type of ML vinyl mat better?

Thanks for any and all replies! I hope I haven't broken any rules with my maiden post ; )

Jeremy

[Soundman2020]

Hi Jeremy. Welcome!

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

Also, it would probably be better to start your own thread with these questions, and just post a link back to this one for reference.

(in the neighbourhood of 4x5x8 OD)

Feet? Or meters? If feet, that's rather small, if meters: Nice!

with sound reduction being the primary goal. I want this to practice saxophone. The booth would not be near a common wall, but the room does adjoin one neighbour (I practice quietly and he doesn't mind at all). My apartment is above a restaurant and we do not hear each other. I do have some building experience and will be doing this myself.

It would be good if you could put real numbers to that, in terms of how many decibels of isolation you need.

1) Would a staggered double-leaf 6" framed wall be more effective than a standard double-leaf 4" framed wall? OR 1b) would a single-leaf with, say, 1 layer of 5/8" and 1 layer of 1/2" sheetrock (acoustically sealed, of course) with Donnacona as the inside layer (or simply, cotton sheets if the Donnacona is superfluous?) be more effective?

In terms of increasing isolation, first comes single-stud with drywall on both sides, then single-stud with drywall on once side and resilient channel plus drywall on the other side, then comes staggered stud with drywall on both sides, and finally comes separate double-stud framing, with drywall on only one side of each frame. That's pretty much the best isolation you an get in a typical home studio / iso booth / vocal booth. All of those are two-leaf, but there's a big difference at each step.

The question of how many layers / what type of drywall you need on each of the two layers is closely related to the question "how much isolation do you need, in terms of decibels?". There is extensive research on how much isolation you get from each type of construction, so if you now that number then it's just a matter of looking at the options that give you your number, and choosing the least expensive one, or the simplest one to build.

2) The area of room I have would allow for up to a 4x6x8 footprint. I'm thinking the 4x5x8 would sound better. Is this the fact?

Both would be bad, actually, since the "8" is exactly twice the "4", so all of the first order modes in one axis would line up perfectly with all of the second order modes on the other axes, and your booth would be very "boomy" and resonant at those frequencies. It is better to choose dimensions that are not a multiple of each other, and not even withing 5% of being multiples of each other, in order to spread the modes out evenly, instead of bunching them all up at similar or identical frequencies.

3) The booth would sit on neoprene castors. Good idea, or are pucks or some type of ML vinyl mat better?

What is the existing floor made of? Most likely you don't need anything under it at all, and certainly not MLV.


- Stuart -

[JP YVR]

Thanks a lot, Stuart! I'll start a new post and hopefully gather some more details for you.

Jeremy