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Polyfill placement question in monitor speakers.

I have a pair of Acoustic Energy AE-2 speakers that I am refurbishing. I had to remove the poly-fill batting while working on them and never thought to make note of where the poly-fill was originally placed. Now I have to put it back in.

I am wondering if there is a most beneficial area to place the poly-fill. Behind the mids? Around the ports? Pack the tweeter area? Really have no memory of where it was before.

These speakers have 2 mid drivers one tweeter and 3 ports. I am only putting back in what came out. There is not a ton of it so it does not fill the entire space. In fact I'd say there was only about as much to fill 1/4-1/3 of the volume.

These are excellently designed monitors and I'd like to have the damping working as designed. 
128x128oharchie
6 responses Add your response
johnk's avatar
johnk
1,975 posts
 
I would install wool or acousta stuff and fully fill but loosely pack the total cabinet with it. Seems what you had has settled with time and from being removed.
geoffkait's avatar
geoffkait
23,365 posts
 
As it turns out almost everyone puts way too much stuffing in speakers. Didn’t anyone ever think, geez, isn’t that suffocating the sound? I guess not. Monkey see, monkey do. You might be surprised to know speakers will sound much better -  more open, better bass and more musical - if you remove all (rpt all) the filler and replace it will only a grapefruit size ball of hollow fiber wool, like lamb’s wool. Check it out.
oharchie's avatar
oharchie OP
31 posts
 
I'm pretty sure this is Acousta-Stuff (how does one know?) unless they didn't make that in 1987.

These are pretty brilliant speakers. I'm probably not going to go the route of making obtuse changes.

I'd still like to find more about how/where this was dispersed. In the meantime I'll try to evenly fill the cavity.
mijostyn's avatar
mijostyn
8,570 posts
 
Oharchie, It does not mater where it goes as long as it is not touching a moving cone. The fill effectively increases the size of the enclosure or lowers the "Q" You want to fill the enclosure without packing in the fill or in  other words it should loosely fill the enclosure. I paint the inside of the enclosure with contact cement which keeps the fill from shifting. Over years the fill will compress due to its own weight. The contact cement will also keep this from happening. The best fill is cotton batting. Some manufacturers used fiberglass insulation. There is now synthetic stuff that you can get from Parts Express.  
oharchie's avatar
oharchie OP
31 posts
 
Thank you Mijostyn

This is helpful! But did you mean decreases the size of the enclosure? From my limited understanding the mass of the batting subtracts from the void of the enclosure... the more fill added the less air there is in the space.

I know that Proac speakers limit the port flow with straws and such to increase box resonance... I’d be interested in understanding the basics of the purpose for the fill and how to maximize the purpose of fill in the dimensional design.







bdp24's avatar
bdp24
9,788 posts
 
The fill is put in the enclosure to achieve a few ends. One of them is to "slow down" the sound waves traveling through it, the effect of which is to make the enclosure behave as if it were larger. Unless you want to change the sound the speakers' designer created, put back into the enclosure the same amount of fill you removed. To do otherwise is to re-engineer the speaker.
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