home insulation in doors?

[Jeffdachef 5,000+ posts]

Home insulation is going to mold. It's impossible to seal the door. The rubber trim that is on the door edge is designed to let water roll down the window and into the door. That's why there are drainage holes at the bottom of every door. Also why there is a moisture barrier (plastic held with butyl rubber adhesive) on the inner door skin.

thats why in the guides, it tells you to wrap and seal it with 1 mill painters cloth to shield it from moisture and double up with aluminium tape on weak spots. Done right, there will be no moisture or mold.

 

[boxpunch]

thats why in the guides, it tells you to wrap and seal it with 1 mill painters cloth to shield it from moisture and double up with aluminium tape on weak spots. Done right, there will be no moisture or mold.

Then there's no dampening going on. Your sound waves are bouncing off of plastic sheets causing the plastic to resonate. Just never found home fiberglass insulation to be useful in a car, especially when they have rubber pads designed for that specific use.

 

[boxpunch]

Dbl post fail

 

[winkychevelle 10+ year member]

Dbl post fail

well if you use mineral wool it wont mold or you can use ceramic based fiberglass that also doesnt mold.

in my car adding the insulation makes a tremendous diffence for anything above 100hz.

i dont have my insulation wrapped though and my doors dont allow much water in at all.

 

[Lockdown801]

Wouldn't insolite/closed cel foam have the same effect?

 

[winkychevelle 10+ year member]

Wouldn't have the same effect?

no as it would just block the rear waves from exiting the car door and send them reflecting back to the rear of the speaker cone possibly making matters worse. open cell foam would work but it grows mold over time since it holds water.

the idea here is sound absorption not deflection. insolite/closed cell foam makes a good barrier though to keep the rear wave that do reflect back from going through the door card when applied behind the door panel

 

[Jeffdachef 5,000+ posts]

[quote name='CandeShop']Then there's no dampening going on. Your sound waves are bouncing off of plastic sheets causing the plastic to resonate. Just never found home fiberglass insulation to be useful in a car, especially when they have rubber pads designed for that specific use.[/QUOTE]

rubber and foam have horrendously weak absorption properties from my experiences with them. With the insulation wrapped in plastic, when its only 1 mill thin, its not bouncing off anything, the insulation still does a waay better job waay job of absorbing the rear wave then any foam or rubber crap they mass marketed. Dont knock it unless you've tried it.

if you want to go into more detail @keep_hope_alive ; can elaborate more.

 

[Lockdown801]

Ah I got my closed and open cell mixed up. They sure try to market overkill like it absorbs them.

 

[whitedragon551 5,000+ posts]

Closed cell foam is meant to be used between vibrating panels. It puts pressure on the opposing panels and prevents them from rubbing against each other. Its not meant to stop sound waves from entering into the cabin or the audio from being heard outside the car. Thats what mass loaded vinyl is for.

 

[trumpet 5,000+ posts]

Then there's no dampening going on. Your sound waves are bouncing off of plastic sheets causing the plastic to resonate. Just never found home fiberglass insulation to be useful in a car, especially when they have rubber pads designed for that specific use.

Try it and see for yourself. The materials are so cheap it's down to your time to acquire them and put the bagged insulation into a vehicle. Surely you're open to a better way to get a vehicle sounding good.

 

[keep_hope_alive Premium Member]

Then there's no dampening going on. Your sound waves are bouncing off of plastic sheets causing the plastic to resonate. Just never found home fiberglass insulation to be useful in a car, especially when they have rubber pads designed for that specific use.

I still use sound damping products on the metal, and I still seal the doors up. I use CCF to isolate the door from the panel to prevent rattles, and I even use CCF on each clip so the clips don't rattle in their holder. But you NEED sound absorption inside the door cavity or you have a resonant chamber for the speaker, and sound from the rear of the speaker bounces around inside the door them comes back out through the speaker cone later - presenting phase interference that gets worse the louder you play. speaker cones can push air but cannot block sound well at all. the best speaker enclosures prevent the rear wave from ever coming back to the cone by controlling reflections and providing a lot of absorption. a car is no different in the need, we just haven't seen the application.

sound transmission is based on the thickness, mass, and material properties of the material relative to the wavelength of sound. 1 mil plastic easily lets midrange and midbass pass through, and though it will reflect high frequencies we don't care about that inside a door. the plastic is just there for water protection. I cover the entire rear door skin and get as much as possible in the door - you cannot have too much because the door is such a large volume compared to the speaker.

using them in vehicles I have gotten lower midbass response, smoother midrange response, and overall better imaging and a more defined sound stage - all compared before vs. after. the reasons for the improvement are because that much fiberglass will absorb rear midbass which would otherwise cancel out, and better imaging is from getting a single source and not a reverberant source.

 

[boxpunch]

the reasons for the improvement are because that much fiberglass will absorb rear midbass which would otherwise cancel out.

Wrong, the reason why you hear any difference is because you have now shrunk the volume of the "enclosure" the driver is playing in.

In doing house remodels, I've done tests of walls with insulation and without. The difference is minimal as to how much sound can be reverberated to the other side. It's done in the ceilings of houses to avoid heat/cold transfer thus allowing your home to stay at the desired temperature more easily.

Using home insulation is no different than using poly fill, except for the fact that one can cause itchiness, molds easily and over time deteriorates with various temperature changes, age and weather. The other loses no volume due to deterioration and has no properties that'll cause histamine reactions nor does it mold. Tbh the home insulation idea is just about the same as people presenting peel and seal as a sound deadener.

 

[winkychevelle 10+ year member]

Wrong, the reason why you hear any difference is because you have now shrunk the volume of the "enclosure" the driver is playing in.
In doing house remodels, I've done tests of walls with insulation and without. The difference is minimal as to how much sound can be reverberated to the other side. It's done in the ceilings of houses to avoid heat/cold transfer thus allowing your home to stay at the desired temperature more easily.

Using home insulation is no different than using poly fill, except for the fact that one can cause itchiness, molds easily and over time deteriorates with various temperature changes, age and weather. The other loses no volume due to deterioration and has no properties that'll cause histamine reactions nor does it mold. Tbh the home insulation idea is just about the same as people presenting peel and seal as a sound deadener.

One where is your data for your statement Keephopealive has data in has thread supporting his statements

Two making the enclosure volume smaller would raise the fc of the box and not allow the mids to play as low.

three making the box smaller also wouldnt smooth the response but rather raise the peak frequencies to a high point in the octaves.

Four the mold issue is taken care of by uusig the 1mil drop cloth

Five the frequency band of which the sound wave bounce off of the 1 mil drop cloth is much higher than the 3.5khz lowpass used on midrange drivers

Six fiberglass works better because the micro fine fractures and slivers that cause itching increase the surface area higher than the same amount of polyfill due to polyfill have a smooth surface.

 

[boxpunch]

One where is your data for your statement Keephopealive has data in has thread supporting his statements
Two making the enclosure volume smaller would raise the fc of the box and not allow the mids to play as low.

three making the box smaller also wouldnt smooth the response but rather raise the peak frequencies to a high point in the octaves.

Four the mold issue is taken care of by uusig the 1mil drop cloth

Five the frequency band of which the sound wave bounce off of the 1 mil drop cloth is much higher than the 3.5khz lowpass used on midrange drivers

Six fiberglass works better because the micro fine fractures and slivers that cause itching increase the surface area higher than the same amount of polyfill due to polyfill have a smooth surface.

Uh huh yea ok! I'm not gonna get into a big bickering war.. Go check out an sq comp and ask all the competitors what they're using in their doors and kicks, then report back with your data.

 

[winkychevelle 10+ year member]

Uh huh yea ok! I'm not gonna get into a big bickering war.. Go check out an sq comp and ask all the competitors what they're using in their doors and kicks, then report back with your data.

Ok man ill do that but wait ive already done that and yea maybe you should actually try it before you dismiss it because by what ever way it affects the speaker I can say it works. And you are quick to shur me up because why? You have no proof at all you are just speaking out of your *** because you are a shop.

really I dont care if you agree with me imma use this method because I know it works.