Recommendation for interior damping material in sub

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Recently finished a sub build and looking for recommendations for a lining material inside the enclosure. I have used good ol fiberglass insulation in the past but wanted to see what folks were using these days. Always wondered if the ports would be spewing fiberglass fibers when it was kicking! It's a fair size ported enclosure of 9 cu ft. Thanks in advance.
 
Is it necessary for a sub? perhaps brace to raise cabinet resonance. Standing waves aren't going to be an issue

Being constructed of 1" MDF, braced internally with 2x2's and 2x4's, screwed and glued with 3m industrial epoxy it is very stiff. I was curious if I should place anything inside as I had read somewhere it may not be necessary. Seems like it couldn't hurt anything as long as it isn't overstuffed.

Is the non-woven fabric something purpose made or something like landscaping fabric? 5mm seems awfully thin, are you saying double the material or??

Thanks in advance for everyones input!
 
If you know the resistivity of the dampening material you can use Hornresp to simulate a lining. The default horn example uses lining.
Some stuffing can remove resonant peaks in the response at the port tuning frequency. I have simulated good results with putting some stuffing in a large cabinet for a Tannoy Gold 15" Dual concentric - But still need to finish building the real thing!
Fibreglass is not regarded as a good material to use - Not only will it get out of the enclosure it is also agresssively abrasive to the speaker voice coil.
 
Being constructed of 1" MDF, braced internally with 2x2's and 2x4's, screwed and glued with 3m industrial epoxy it is very stiff. I was curious if I should place anything inside as I had read somewhere it may not be necessary. Seems like it couldn't hurt anything as long as it isn't overstuffed.

Is the non-woven fabric something purpose made or something like landscaping fabric? 5mm seems awfully thin, are you saying double the material or??

Thanks in advance for everyones input!

You might want to dampen a little to combat the somewhat hollow sound and reduce the reflections back on the cone which will result in distortion.

For the material it is exactly this:

Polsterwatte Vlies 100g/m2

It is cushion/furniture stuff, very cheap and effective and not double. If double the sound will be more dull, not as pronounced then.
It took a week of experiments to get the best sound of it, but well this is subjective. Everyone has her/his own methods. I used this because it was cheap and worked surprisingly good.

In ported enclosures bracing or better: excessive bracing will compromise the sound. Maybe it has something to do with air vortexes. Better is to use more material on the walls or some kind of sandwich.
 
In ported enclosures bracing or better: excessive bracing will compromise the sound. Maybe it has something to do with air vortexes. Better is to use more material on the walls or some kind of sandwich.

I've wondered about this before.

I tried thicker walls this time and much stronger material for inner bracing, in turn less of it is required to be effective. Compared to a puzzle maze of MDF.
 
The exterior walls of the enclosure are 1" MDF, the bracing/stiffeners are all pine. No cnc mdf maze here.
 

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