I'm planning to put a listening space in my upcoming ecoline van conversion. I haven't bought the van yet so I don't have specific measurements, I just want to develop a general plan of attack.
The space will just be for listening, no mixing or tracking. I want to be able to listen to near field speakers at high volumes late at night without disturbing those in my near surroundings.
My plan is as follows:
Use spray foam insulation or adhesive MLV to dampen the sheet metal walls. Leave space for an air gap with pink fluffy. Attach 2lb/sqft MLV to the ribs of the van using rubber to decouple.
Will this achieve any result worth my time and money? If not, what is a more practical way to approach this given the weight requirements and abnormal shape/limited space?
interesting. by loud, how loud? would there be low frequencies involved? loud volumes in a small space (or any space really) can damage hearing. and i think if you're listening to loud music with low frequencies, it will be virtually impossible to reduce it to levels that won't disturb your neighbors. you'd be better off starting with a large refrigeration truck then building all necessary decoupled interior. this way you could apply the levels of mass needed and the truck would be able to support it. the van would not likely support the 2+ tons of mass needed.
I don't have a decibel meter so I can't say exactly, but nothing crazy. Typical casual listening levels, probably even somewhat lower as I listen very near field.
Yes, I listen to rock music so there would be low frequencies. However I figure that it won't be any more harmful than listening to music in the car
gullfo wrote:interesting. by loud, how loud? would there be low frequencies involved? loud volumes in a small space (or any space really) can damage hearing. and i think if you're listening to loud music with low frequencies, it will be virtually impossible to reduce it to levels that won't disturb your neighbors. you'd be better off starting with a large refrigeration truck then building all necessary decoupled interior. this way you could apply the levels of mass needed and the truck would be able to support it. the van would not likely support the 2+ tons of mass needed.
I don't have a decibel meter so I can't say exactly, but nothing crazy. Typical casual listening levels, probably even somewhat lower as I listen very near field.
Yes, I listen to rock music so there would be low frequencies. However I figure that it won't be any more harmful than listening to music in the car
I don't have iOS, but this highly rated android app is reading an average of 84 dB, peaking at about 90 dB from about 3 or 4 feet away from the speakers.
I'd like to bring this down to the point where if I'm parked on the street, people in house won't be able to hear at all.
Is this reasonable with my plan? Is there a better method?
STC is limited measurement since it really only applies down to 125hz.
most kick drums will be 60-80hz. a decent listening "loud" level is 85db - similar to what a calibrated movie theater would use. peaks will be up to 105db, so if you could achieve a LF isolation of 40db - the exterior peak levels would be 60db or so - a normal speaking conversation - with very low frequency. more vibration than hearing (hearing sensitivity drops off below 100hz rather quickly) and since it's a spring isolated vehicle, the transfer will be airborne and little via road/structure.
so, perhaps starting with spraying the interior back space with marine boat damping compound, then 2x6 metal framing on the walls, ceiling, floor, plus dividing wall between driver space and back doors (create framing for one door width on either end), then packed with rockwool, 1x layer of 1/2" ply + 2x 5/8" type x drywall. on the floor just use 3x 3/4" ply. corner trapping + ceiling soffit (lights, air - even people listening to loud rock music need oxygen), comfy chair, and decouple speakers from any surfaces, you will have the isolation for the suggested listening level.
however, the space will be cramped. there are also power issues + if you're running the engine all the time - wear and tear + carbon monoxide (and perhaps CO2 if that bothers you), vehicle theft (once people find out you have a rock and roll machine like the Scooby crew), parking tickets/costs, etc.
depending on your budget (factor in the high price of gasoline about to happen, parking costs, insurance, discomfort, etc. ) it might be equal to getting a monthly rehearsal studio rental for the hours you intend (say 9pm-3am) @ $25/day - then you have all kinds of listening options etc.
this highly rated android app is reading an average of 84 dB, peaking at about 90 dB from about 3 or 4 feet away from the speakers.
That sounds about right. Just checking though..... many meters default to dBA which hears no bass. Are you using dBC or dBZ? Are you using Fast or Slow Weighting or Leq?
gullfo wrote:
packed with rockwool, 1x layer of 1/2" ply + 2x 5/8" type x drywall. on the floor just use 3x 3/4" ply. corner trapping + ceiling soffit (lights, air - even people listening to loud rock music need oxygen), comfy chair, and decouple speakers from any surfaces, you will have the isolation for the suggested listening level.
Why rockwool opposed to the pink fluffy i typically see recommended for air gaps? Also, how wide of a gap between the exterior wall and first layer of ply?
Should the layers be sandwiched or spaced? Green glue if sandwiched?
There will be a solar setup for power, so no running the van! And I will already need to buy and insure the van regardless, so that expense is unavoidable
this highly rated android app is reading an average of 84 dB, peaking at about 90 dB from about 3 or 4 feet away from the speakers.
That sounds about right. Just checking though..... many meters default to dBA which hears no bass. Are you using dBC or dBZ? Are you using Fast or Slow Weighting or Leq?
I will double check once I can crank the speakers again!
while the light insulation does work better for LF absorption - it's contextual. in your space you need more mass than not since you don't have the luxury of enough air space in the walls. so the rock wool will be better at the necessary damping factor you need. and the mass will have to do the bulk of the LF containment/absorption.
gullfo wrote:while the light insulation does work better for LF absorption - it's contextual. in your space you need more mass than not since you don't have the luxury of enough air space in the walls. so the rock wool will be better at the necessary damping factor you need. and the mass will have to do the bulk of the LF containment/absorption.
Understood. Would you alter your original plan if this were to be done in a larger van such as a sprinter given that there would be more interior space?
unless i was in a 16' x 7' (or larger) truck, i'd stick with the more mass. remember that the "heavy" stuff is still pretty light compared to drywall, lumber, etc.
gullfo wrote:unless i was in a 16' x 7' (or larger) truck, i'd stick with the more mass. remember that the "heavy" stuff is still pretty light compared to drywall, lumber, etc.
You also wouldn't consider MLV for the purpose of increasing usable space/conforming to irregular wall shapes?
