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Soundproofing a genset -- does mass loaded vinyl work?

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Anonymous
January 20, 2005 6:16:30 PM

Archived from groups: rec.audio.tech (More info?)

I am right now soundproofing my generator, see

http://igor.chudov.com/tmp/onan/Diesel/

Running without any enclosure, it produces 85 dB at 10 feet distance.

I built a 1/2" plywood enclosure over it, which tentatively reduced
noise by 5 decibel. The enclosure has some gaps, etc, some openings
(for cooling air) that are not baffled, etc.

I would like to further reduce noise at relatively low cost. I do have
money but I do not want to spend too much.

I am currently leaning towards, first, sealing gaps, and second, using
mass loaded vinyl inside the enclosure. I would rather not use foam
due to, first, space constraints, and second, flammability concerns.

Do you think that it is realistic to expect some 10 dB more reduction?

Any pointers to places where I can buy cheap mass loaded vinyl? Yes, I
did google around quite a bit.

i
Anonymous
January 20, 2005 6:16:31 PM

Archived from groups: rec.audio.tech (More info?)

"Ignoramus1606" <ignoramus1606@NOSPAM.1606.invalid> wrote in message
news:csoi0e$5td$0@pita.alt.net...
>I am right now soundproofing my generator, see
>
> http://igor.chudov.com/tmp/onan/Diesel/
>
> Running without any enclosure, it produces 85 dB at 10 feet distance.
>
> I built a 1/2" plywood enclosure over it, which tentatively reduced
> noise by 5 decibel. The enclosure has some gaps, etc, some openings
> (for cooling air) that are not baffled, etc.
>
> I would like to further reduce noise at relatively low cost. I do have
> money but I do not want to spend too much.
>
> I am currently leaning towards, first, sealing gaps, and second, using
> mass loaded vinyl inside the enclosure. I would rather not use foam
> due to, first, space constraints, and second, flammability concerns.
>
> Do you think that it is realistic to expect some 10 dB more reduction?
>
> Any pointers to places where I can buy cheap mass loaded vinyl? Yes, I
> did google around quite a bit.

If you are running it outside (I hope). you could build a little
"dog house" for it out of cinder block. Massive, fireproof, and
cheap.
Anonymous
January 20, 2005 6:47:43 PM

Archived from groups: rec.audio.tech (More info?)

On Thu, 20 Jan 2005 07:25:15 -0800, Richard Crowley <rcrowley7@xprt.net> wrote:
>
> "Ignoramus1606" <ignoramus1606@NOSPAM.1606.invalid> wrote in message
> news:csoi0e$5td$0@pita.alt.net...
>>I am right now soundproofing my generator, see
>>
>> http://igor.chudov.com/tmp/onan/Diesel/
>>
>> Running without any enclosure, it produces 85 dB at 10 feet distance.
>>
>> I built a 1/2" plywood enclosure over it, which tentatively reduced
>> noise by 5 decibel. The enclosure has some gaps, etc, some openings
>> (for cooling air) that are not baffled, etc.
>>
>> I would like to further reduce noise at relatively low cost. I do have
>> money but I do not want to spend too much.
>>
>> I am currently leaning towards, first, sealing gaps, and second, using
>> mass loaded vinyl inside the enclosure. I would rather not use foam
>> due to, first, space constraints, and second, flammability concerns.
>>
>> Do you think that it is realistic to expect some 10 dB more reduction?
>>
>> Any pointers to places where I can buy cheap mass loaded vinyl? Yes, I
>> did google around quite a bit.
>
> If you are running it outside (I hope). you could build a little
> "dog house" for it out of cinder block. Massive, fireproof, and
> cheap.

Well, remember that the genset needs to be taken out for maintenance,
repairs etc. I doubt that a cinderblock doghouse would be easy to deal
with, but I am open minded.
Related resources
Anonymous
January 20, 2005 6:47:44 PM

Archived from groups: rec.audio.tech (More info?)

"Ignoramus1606" wrote ...
> Well, remember that the genset needs to be taken out for maintenance,
> repairs etc. I doubt that a cinderblock doghouse would be easy to deal
> with, but I am open minded.

Face the door away from your house and make a massive door
out of two layers (in orthogonal orientation) of 2x6 lumber.

Using "indoor" materials like mass load vinyl for an outdoor
application like this significantly decreases the benefit/cost
ratio and makes something that won't last very long outdoors.
Anonymous
January 20, 2005 7:28:19 PM

Archived from groups: rec.audio.tech (More info?)

On Thu, 20 Jan 2005 08:02:11 -0800, Richard Crowley <rcrowley7@xprt.net> wrote:
> "Ignoramus1606" wrote ...
>> Well, remember that the genset needs to be taken out for maintenance,
>> repairs etc. I doubt that a cinderblock doghouse would be easy to deal
>> with, but I am open minded.
>
> Face the door away from your house and make a massive door
> out of two layers (in orthogonal orientation) of 2x6 lumber.
>
> Using "indoor" materials like mass load vinyl for an outdoor
> application like this significantly decreases the benefit/cost
> ratio and makes something that won't last very long outdoors.
>

Good point. How about lead sheet such as this

http://www.soundproofing.org/sales/prices.html

AT LAST! REAL LEAD! THE BEST! ACOUSTICAL DAMPING LEAD METAL
SHEETING & Radiation BARRIER! An economical, extremely effective
barrier to sound. It's the thinnest and most effective acoustical
material known, so is good for installation in/on floors, walls and
ceilings for maximum effect. They give this 1/64" foil material a
rating of STC 21. It weighs 1 pound per square foot! Professionals
apply it to walls, sheetrock/drywall panels with our heavy-duty
adhesive. Also blocks radiation from nuclear attack! Rolls 48"X25'
are 100 Sq. Ft and weigh 100 lbs. $9.15 a lineal foot. Roll price:
$228.75 each plus shipping. (UPS). We now also have it with 2 Pounds
per Sq. Ft! STC of 32. Thickness 1/32" 4'X20': 160 Lbs. $14.85 a
Lineal Ft, $297 per roll plus shipping: (Truck)

I would then line the 1/2" plywood with this lead foil (1/64"
presumably).

Any thought on this?

i
--
Anonymous
January 20, 2005 7:35:05 PM

Archived from groups: rec.audio.tech (More info?)

On 20 Jan 2005 16:28:19 GMT, Ignoramus1606
<ignoramus1606@NOSPAM.1606.invalid> wrote:

>On Thu, 20 Jan 2005 08:02:11 -0800, Richard Crowley <rcrowley7@xprt.net> wrote:
>> "Ignoramus1606" wrote ...
>>> Well, remember that the genset needs to be taken out for maintenance,
>>> repairs etc. I doubt that a cinderblock doghouse would be easy to deal
>>> with, but I am open minded.
>>
>> Face the door away from your house and make a massive door
>> out of two layers (in orthogonal orientation) of 2x6 lumber.
>>
>> Using "indoor" materials like mass load vinyl for an outdoor
>> application like this significantly decreases the benefit/cost
>> ratio and makes something that won't last very long outdoors.
>>
>
>Good point. How about lead sheet such as this
>
>http://www.soundproofing.org/sales/prices.html
>
>AT LAST! REAL LEAD! THE BEST! ACOUSTICAL DAMPING LEAD METAL
>SHEETING & Radiation BARRIER! An economical, extremely effective
>barrier to sound. It's the thinnest and most effective acoustical
>material known, so is good for installation in/on floors, walls and
>ceilings for maximum effect. They give this 1/64" foil material a
>rating of STC 21. It weighs 1 pound per square foot! Professionals
>apply it to walls, sheetrock/drywall panels with our heavy-duty
>adhesive. Also blocks radiation from nuclear attack! Rolls 48"X25'
>are 100 Sq. Ft and weigh 100 lbs. $9.15 a lineal foot. Roll price:
>$228.75 each plus shipping. (UPS). We now also have it with 2 Pounds
>per Sq. Ft! STC of 32. Thickness 1/32" 4'X20': 160 Lbs. $14.85 a
>Lineal Ft, $297 per roll plus shipping: (Truck)
>
>I would then line the 1/2" plywood with this lead foil (1/64"
>presumably).
>
>Any thought on this?
>
>i

Far too thin to be of any soundproofing value. You really need both
mass and stiffness, so a concrete coating would be good. But most of
the annoying sound is doubtless coming out of the holes. The thing
needs air, so you can't close them, but a labyrinth will do a good job
of stopping the noise, particularly if you line it with something
absorbent.

d

Pearce Consulting
http://www.pearce.uk.com
Anonymous
January 20, 2005 7:40:49 PM

Archived from groups: rec.audio.tech (More info?)

On Thu, 20 Jan 2005 16:35:05 GMT, Don Pearce <donald@pearce.uk.com> wrote:
> On 20 Jan 2005 16:28:19 GMT, Ignoramus1606
><ignoramus1606@NOSPAM.1606.invalid> wrote:
>
>>On Thu, 20 Jan 2005 08:02:11 -0800, Richard Crowley <rcrowley7@xprt.net> wrote:
>>> "Ignoramus1606" wrote ...
>>>> Well, remember that the genset needs to be taken out for maintenance,
>>>> repairs etc. I doubt that a cinderblock doghouse would be easy to deal
>>>> with, but I am open minded.
>>>
>>> Face the door away from your house and make a massive door
>>> out of two layers (in orthogonal orientation) of 2x6 lumber.
>>>
>>> Using "indoor" materials like mass load vinyl for an outdoor
>>> application like this significantly decreases the benefit/cost
>>> ratio and makes something that won't last very long outdoors.
>>>
>>
>>Good point. How about lead sheet such as this
>>
>>http://www.soundproofing.org/sales/prices.html
>>
>>AT LAST! REAL LEAD! THE BEST! ACOUSTICAL DAMPING LEAD METAL
>>SHEETING & Radiation BARRIER! An economical, extremely effective
>>barrier to sound. It's the thinnest and most effective acoustical
>>material known, so is good for installation in/on floors, walls and
>>ceilings for maximum effect. They give this 1/64" foil material a
>>rating of STC 21. It weighs 1 pound per square foot! Professionals
>>apply it to walls, sheetrock/drywall panels with our heavy-duty
>>adhesive. Also blocks radiation from nuclear attack! Rolls 48"X25'
>>are 100 Sq. Ft and weigh 100 lbs. $9.15 a lineal foot. Roll price:
>>$228.75 each plus shipping. (UPS). We now also have it with 2 Pounds
>>per Sq. Ft! STC of 32. Thickness 1/32" 4'X20': 160 Lbs. $14.85 a
>>Lineal Ft, $297 per roll plus shipping: (Truck)
>>
>>I would then line the 1/2" plywood with this lead foil (1/64"
>>presumably).
>>
>>Any thought on this?
>>
>>i
>
> Far too thin to be of any soundproofing value.

The sellers list soundproofing STC value of 21, which is pretty good.

Do you think that they are misleading us?

> You really need both mass and stiffness, so a concrete coating would
> be good. But most of the annoying sound is doubtless coming out of
> the holes. The thing needs air, so you can't close them, but a
> labyrinth will do a good job of stopping the noise, particularly if
> you line it with something absorbent.

Yes, I will implement some degree of baffling and noise
redirection. The generator will be installed in a relatively friendly
area, and most of my concern is eliminating sound going in one
direction (towards my near neighbors' house).

i
Anonymous
January 20, 2005 7:44:09 PM

Archived from groups: rec.audio.tech (More info?)

On 20 Jan 2005 16:40:49 GMT, Ignoramus1606
<ignoramus1606@NOSPAM.1606.invalid> wrote:

>On Thu, 20 Jan 2005 16:35:05 GMT, Don Pearce <donald@pearce.uk.com> wrote:
>> On 20 Jan 2005 16:28:19 GMT, Ignoramus1606
>><ignoramus1606@NOSPAM.1606.invalid> wrote:
>>
>>>On Thu, 20 Jan 2005 08:02:11 -0800, Richard Crowley <rcrowley7@xprt.net> wrote:
>>>> "Ignoramus1606" wrote ...
>>>>> Well, remember that the genset needs to be taken out for maintenance,
>>>>> repairs etc. I doubt that a cinderblock doghouse would be easy to deal
>>>>> with, but I am open minded.
>>>>
>>>> Face the door away from your house and make a massive door
>>>> out of two layers (in orthogonal orientation) of 2x6 lumber.
>>>>
>>>> Using "indoor" materials like mass load vinyl for an outdoor
>>>> application like this significantly decreases the benefit/cost
>>>> ratio and makes something that won't last very long outdoors.
>>>>
>>>
>>>Good point. How about lead sheet such as this
>>>
>>>http://www.soundproofing.org/sales/prices.html
>>>
>>>AT LAST! REAL LEAD! THE BEST! ACOUSTICAL DAMPING LEAD METAL
>>>SHEETING & Radiation BARRIER! An economical, extremely effective
>>>barrier to sound. It's the thinnest and most effective acoustical
>>>material known, so is good for installation in/on floors, walls and
>>>ceilings for maximum effect. They give this 1/64" foil material a
>>>rating of STC 21. It weighs 1 pound per square foot! Professionals
>>>apply it to walls, sheetrock/drywall panels with our heavy-duty
>>>adhesive. Also blocks radiation from nuclear attack! Rolls 48"X25'
>>>are 100 Sq. Ft and weigh 100 lbs. $9.15 a lineal foot. Roll price:
>>>$228.75 each plus shipping. (UPS). We now also have it with 2 Pounds
>>>per Sq. Ft! STC of 32. Thickness 1/32" 4'X20': 160 Lbs. $14.85 a
>>>Lineal Ft, $297 per roll plus shipping: (Truck)
>>>
>>>I would then line the 1/2" plywood with this lead foil (1/64"
>>>presumably).
>>>
>>>Any thought on this?
>>>
>>>i
>>
>> Far too thin to be of any soundproofing value.
>
>The sellers list soundproofing STC value of 21, which is pretty good.
>
>Do you think that they are misleading us?
>

Generators produce an audio spectrum that makes these figures a bit
misleading.

>> You really need both mass and stiffness, so a concrete coating would
>> be good. But most of the annoying sound is doubtless coming out of
>> the holes. The thing needs air, so you can't close them, but a
>> labyrinth will do a good job of stopping the noise, particularly if
>> you line it with something absorbent.
>
>Yes, I will implement some degree of baffling and noise
>redirection. The generator will be installed in a relatively friendly
>area, and most of my concern is eliminating sound going in one
>direction (towards my near neighbors' house).
>
>i

How about a small brick wall to block the direct line of sight. That
will stop all the more penetrating HF stuff.

d

Pearce Consulting
http://www.pearce.uk.com
Anonymous
January 20, 2005 8:00:17 PM

Archived from groups: rec.audio.tech (More info?)

On Thu, 20 Jan 2005 16:44:09 GMT, Don Pearce <donald@pearce.uk.com> wrote:
>>>>http://www.soundproofing.org/sales/prices.html
>>>>
>>>>AT LAST! REAL LEAD! THE BEST! ACOUSTICAL DAMPING LEAD METAL
>>>>SHEETING & Radiation BARRIER! An economical, extremely effective
>>>>barrier to sound. It's the thinnest and most effective acoustical
>>>>material known, so is good for installation in/on floors, walls and
>>>>ceilings for maximum effect. They give this 1/64" foil material a
>>>>rating of STC 21. It weighs 1 pound per square foot! Professionals
>>>>apply it to walls, sheetrock/drywall panels with our heavy-duty
>>>>adhesive. Also blocks radiation from nuclear attack! Rolls 48"X25'
>>>>are 100 Sq. Ft and weigh 100 lbs. $9.15 a lineal foot. Roll price:
>>>>$228.75 each plus shipping. (UPS). We now also have it with 2 Pounds
>>>>per Sq. Ft! STC of 32. Thickness 1/32" 4'X20': 160 Lbs. $14.85 a
>>>>Lineal Ft, $297 per roll plus shipping: (Truck)
>>>>
>>>>I would then line the 1/2" plywood with this lead foil (1/64"
>>>>presumably).
>>>>
>>>>Any thought on this?
>>>>
>>>>i
>>>
>>> Far too thin to be of any soundproofing value.
>>
>>The sellers list soundproofing STC value of 21, which is pretty good.
>>
>>Do you think that they are misleading us?
>>
>
> Generators produce an audio spectrum that makes these figures a bit
> misleading.

Great point! That is so because of low frequencies, is that correct?

>>> You really need both mass and stiffness, so a concrete coating would
>>> be good. But most of the annoying sound is doubtless coming out of
>>> the holes. The thing needs air, so you can't close them, but a
>>> labyrinth will do a good job of stopping the noise, particularly if
>>> you line it with something absorbent.
>>
>>Yes, I will implement some degree of baffling and noise
>>redirection. The generator will be installed in a relatively friendly
>>area, and most of my concern is eliminating sound going in one
>>direction (towards my near neighbors' house).
>>
>>i
>
> How about a small brick wall to block the direct line of sight. That
> will stop all the more penetrating HF stuff.

That's a possibility, yes. Thanks for good thoughts. I might make a
concrete wall made out of patio blocks put on their edge and hel;d by
some sort of frame, for ease of disassembly if needed.

i
!