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How to get air in and out of the studio without noise Effects Pedals, Units & Accessories
Old 1 week ago
  #1
Gear Maniac
 

Thread Starter
How to get air in and out of the studio without noise

So I have been researching the concept of HVAC and trying to figure out which system is best for a basement studio. Ductless mini split systems are pretty much the norm around these parts but they don't get fresh air in and out of your recording space which is a problem. After speaking to several HVAC guys about the best way to ventilate my studio this idea was proposed and wanted to run it by the forum to see if I could get some advice from you folks about it.

So, the proposed ductwork will run above the false ceiling as in diagram "1" (it is the one on the left), or within soffits in the corners of the room as in diagram "2" (it is the one on the right). There will be one duct on each side of the room, one for supply and the other for return.

I am obviously a bit worried about sound traveling through these ducts from the fans or from outside. According to image 2 (which I got from a soundproofing company) the PVC ductwork used is transparent to sound so the fiberglass around it in the soffit absorbs it thereby reducing transmission to other end. Is this correct? What other techniques or solutions are used to correctly ventilate a studio without sound leaking through? I have read that you can also use absorptive foam within the ductwork so long as the material used is apt for the application (obviously fiberglass will be a no no)

I am still a beginner with HVAC so please correct me and I look forward to chatting about this

thanks!
Attached Thumbnails
How to get air in and out of the studio without noise-1.jpg   How to get air in and out of the studio without noise-2.jpg  
Old 1 week ago
  #2
Gear Addict
 

From your diagrams it’s hard to get an idea of the engineering you’ll put in to create the ducting. If you were to simply run flex duct from point A to point B you could have some issues.

But that being said, running the ducting through the ceiling/soffits/walls is how almost all studios are built. You just need to do some reasearch on how to mitigate any noise issues. There are lots of good ideas out there. Search google for terms like “dead vent” and “duct silencer.” You’ll get some ideas.


If the partition above the duct (the floor I’m guessing) is reasonably sturdy, your real only concern for noise entry might be where your duct connects to your fan, or penetrates to the outside to exhaust. If the floor is thin and transmits voices and footsteps easily, you may need to engineer something a bit more isolated.

Here’s another thing to remember, and something I keep reminding myself of as I’m building my own studio right now (I have a build thread you can probably find): unless you have deep, deep pockets, it’s never going to be perfect, and that’s okay. Music is my full time job, no other sources of income. I’ve been able to make a career out of it working in extremely imperfect spaces. In my last studio the main tracking room had huge bay windows that looked out over a street. Any time a big truck or motorcycle drove by it would bleed through. The next door building had 3 AC units in the alley between us, and in the summer they all 3 ran so loud. In the control room you could hear birds chirping outside. I worked in that space 3 years and made a lot of records there. I did production, vocal tracking and overdubs on a Grammy nominated record, scored a feature film that killed the festival circuit and got picked up by Netflix, and recorded songs that were licensed for big TV shows and national commercials.

The tracking room never sounded perfect. The isolation was awful and the control room was a disaster (thin floating wood floors, essentially I sat on a reverb tank). I did great work in there. So any time I start obsessing about if my ducting will be too loud in my new spot (after I’ve already taken huge measures to ensure it’s as quiet as possible), or other similar isolation or acoustic issues, I just have to remind myself it will be many times better than my last space, and my last space never held me back from making music and records I was proud of.
Old 1 week ago
  #3
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Quote:
Originally Posted by logjamparty View Post


If the partition above the duct (the floor I’m guessing) is reasonably sturdy, your real only concern for noise entry might be where your duct connects to your fan, or penetrates to the outside to exhaust.
Thanks for your post. Yes this is the only concern I have. I am worried about noise coming in from outside through the ducts or the sound of the fan coming through the ducts into the room.

Good to hear your experiences and that you still made good music despite imperfect workplaces. That is inspiring. I would like to make mine as best I can though so still looking forward to hearing some more great advice

thanks again!
Old 1 week ago
  #4
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Starlight's Avatar
Search the forum for the word baffle to find a PDFs, drawings, photos and descriptions of how others have made baffle boxes, silencers, for our ventilation systems.
Old 1 week ago
  #5
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Quote:
Originally Posted by eljefe View Post
Thanks for your post. Yes this is the only concern I have. I am worried about noise coming in from outside through the ducts or the sound of the fan coming through the ducts into the room.

Good to hear your experiences and that you still made good music despite imperfect workplaces. That is inspiring. I would like to make mine as best I can though so still looking forward to hearing some more great advice

thanks again!
If you want more advice you have to give more info. Your post doesn’t really say anything. You want exactly what we all want. It’s just that every single build has different hurdles to overcome.

How is the ceiling above the false ceiling? How is it constructed? Is the false ceiling truly decoupled? Do you need to decouple it? Is the original ceiling itself insulated both thermally and acoustically? What’s above that? How much space is between the the two assemblies? What’s the construction of the false ceiling? Is the false ceiling even in place or is that something you plan to build? If it’s already built did you take measures to make sure it was isolated from the floor above it? You could have perfectly isolated ducts but if the ceiling, floor, and walls of the basement aren’t isolated from the rest of the building, money spent on isolating HVAC is silly. The sound coming through your ducts is secondary to the sound coming through your structure.

How much air do you need? What’s the cfm of your fan? Do you want balanced ventilation? Positive pressure? Negative pressure? Have you considered the air you’re introducing to your studio, ie, if you live in a somewhat humid climate, or a climate with severe summers or winters, you’ll want to look at an ERV/HRV to temper your air before you dump it in to the studio. Where you place your supply is important in relation to your mini split, mine dumps directly above my split to condition the new air immediately.

Based on how much air you need you’ll need to size your ducts, silencers, supply and return, to have a low enough velocity to be silent coming in and going out. Obviously the area you have between the partitions will determine part of this.

There are a hundred things to consider and no one can really give you advice because you haven’t really given enough information. It’s like walking in to a car dealership and saying: “I want the best car you have.”
That could mean something totally different for a soccer mom, a construction worker, and an off road enthusiast.

Figure out your exact needs in terms of isolation, air flow, ventilation type, then figure out the budget you have to accomplish them, then determine the construction parameters you have to work inside. At that point people could give you some advice.
Old 1 week ago
  #6
Gear Maniac
 

Thread Starter
Quote:
Originally Posted by logjamparty View Post
If you want more advice you have to give more info. Your post doesn’t really say anything. You want exactly what we all want. It’s just that every single build has different hurdles to overcome.

How is the ceiling above the false ceiling? How is it constructed? Is the false ceiling truly decoupled? Do you need to decouple it? Is the original ceiling itself insulated both thermally and acoustically? What’s above that? How much space is between the the two assemblies? What’s the construction of the false ceiling? Is the false ceiling even in place or is that something you plan to build? If it’s already built did you take measures to make sure it was isolated from the floor above it? You could have perfectly isolated ducts but if the ceiling, floor, and walls of the basement aren’t isolated from the rest of the building, money spent on isolating HVAC is silly. The sound coming through your ducts is secondary to the sound coming through your structure.

How much air do you need? What’s the cfm of your fan? Do you want balanced ventilation? Positive pressure? Negative pressure? Have you considered the air you’re introducing to your studio, ie, if you live in a somewhat humid climate, or a climate with severe summers or winters, you’ll want to look at an ERV/HRV to temper your air before you dump it in to the studio. Where you place your supply is important in relation to your mini split, mine dumps directly above my split to condition the new air immediately.

Based on how much air you need you’ll need to size your ducts, silencers, supply and return, to have a low enough velocity to be silent coming in and going out. Obviously the area you have between the partitions will determine part of this.

There are a hundred things to consider and no one can really give you advice because you haven’t really given enough information. It’s like walking in to a car dealership and saying: “I want the best car you have.”
That could mean something totally different for a soccer mom, a construction worker, and an off road enthusiast.

Figure out your exact needs in terms of isolation, air flow, ventilation type, then figure out the budget you have to accomplish them, then determine the construction parameters you have to work inside. At that point people could give you some advice.
I was only asking for general advice on how to get a duct from A to B without sound passing through it into your studio.
Old 1 week ago
  #7
Gear Maniac
 

Thread Starter
Quote:
Originally Posted by Starlight View Post
Search the forum for the word baffle to find a PDFs, drawings, photos and descriptions of how others have made baffle boxes, silencers, for our ventilation systems.
thank you, found some good stuff there!
Old 6 days ago
  #8
Gear Addict
 

Quote:
Originally Posted by eljefe View Post
I was only asking for general advice on how to get a duct from A to B without sound passing through it into your studio.
In a sound proof duct.
Old 6 days ago
  #9
Gear Maniac
 

Thread Starter
Quote:
Originally Posted by logjamparty View Post
In a sound proof duct.
yes ok perfect and thank you! So can we please discuss options for soundproofing the duct now? So the options I have found are

1) the silencer box where the duct is snaked through a box surrounded by fiberglass
2) there is a PVC duct that goes through a soffit as in the diagram in the OP

Are there any other options and are both of the above used simultaneously or are they two different methods?
Old 5 days ago
  #10
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johndykstra's Avatar
 

Logjamparty gave you the info you need.

That is to say, it's not so simple. Too many factors at play to just give you a direct answer.
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