Speaker lining - too many choices!

[zanlation]

I am building a pair of Pensil 7.3's and CGR ken-mar10.2's and I up to the stage of lining the insides. Planet10 recommends 15mm cotton/wool felt. So I went along to the local Spotlight (fabic) store and had a look at what they had. The only cotton/wool felt or wadding they had was about 5mm thick. So, I did some googling and searching through diyaudio and found that a whole range of materials are used:

1. Dacon pillow material
2. Cotton filled mattress protectors
3. Acousta-stuf (which I cannot find in Australia)
4. polyfill of various kinds

I could layer on the cotton felt to reach 15mm, or use an alternative. Suggestions?

[sonokeling]

Hi Zanlation,

There are going to be lots of sensible suggestions here, and some natural-based product would seem a good start (wool). There are people who have suspended the stuff through the speaker at different heights to achieve a more uniform damping effect.

I was just looking at the Pensil 7.3 design, and it appears very similar to some speakers I made around 20 years back. I too was wondering about which material to line them with and ended-up bending a piece of thin plywood to curvie from the top of the front baffle to the bottom, just below my own slot at the base of the speaker, and screwed to top, bottom and back baffle (though I see these Pensil speakers have a detachable back). The idea in my mind being to "guide" the sound down to the port.

I put bits of bitumen on the side walls too, and in no way can suggest that the sound was neutral! However, it was fairly dynamic.

Sorry for this wacky first suggestion. Sensible choices no doubt to follow from wiser heads!

[planet10]

Check out upholstery (car & furniture) shops... or -- at least for the pensils -- given you are in Oz, mug a sheep

dave

[zanlation]

Originally Posted by planet10

given you are in Oz, mug a sheep

dave

That's our cousions across the ditch in New Zealand

I'll try a car auto place and see what they have.

[zanlation]

Originally Posted by sonokeling

Hi Zanlation,
I put bits of bitumen on the side walls too, and in no way can suggest that the sound was neutral! However, it was fairly dynamic.

Sorry for this wacky first suggestion. Sensible choices no doubt to follow from wiser heads!

I am planning on using bitumen to make sure the cabinet is sealed, then applying the lining.

[planet10]

I knre that the concentration of sheep was higher in NZ, but the imported lamb we get is all from Oz (local fresh is preferred -- just had some for supper)

dave

[zanlation]

NZ don't eat their own sheep

[arny1]

Hi ZANLATION,
I had the same problem, tried the poly stuff from spot light but was not happy with it. On a chance I stopped at a carpet store and out the back was a roll of cotton fibre felt underlay, 12mm. Pulled out the polly and lined MAR-KEN12t with it and the difference was night and day. No kidding, my wife and daughter were not happy with the highs with the polly, too jumbled up(they hear the higher notes better). But now, my daughter wants a pair as well. don't bother with anything else.
google cotton underlay/felt, its made in AUS.

arny1

[arny1]

Oh, I just measured the internal lengths, marked it out and cut it in one piece then notched out the bits around the braces and the top/bottom angles. Cut it with pinking scissors. I did not cut the driver circle out, just a vertical and horizontal cut (pie pieces?) and let the driver spiders push the pieces in.

[zanlation]

Thanks Arny1, I will have a look at some local carpet places.