Indian equivalents of the following DIY items.

[s_zimble]

Hi,
...well, last week I put a whispy "pad" of fiber fill on the back inerior wall behind the driver (which is half obscured by the tube wall where I have no absorbsion material). Then I packed (pretty tightly) fiber fill iin the top end (closed end) of the tube, about half way to the speaker. This resulted in a more thuddy and less defined sound and I also felt the the already weak mid range suffered even more, although it is hard for me to tell (some hearing loss from loud concerts in my youth). Then I tried a very fluffy lighter stuffing technique in the top end of the tube, coming up closer to the driver. Remember that this is a folded tub so the stuffing is resting in the top end of the tube and rises towards the driver. This resulted in a less thuddy bass.

Now I am wondering if the bloody things sounded best without any stuffing at all. They seemed to have better bass definition before I started messing with this stuffing.

What do you think?

Stuart

[ajju]

Good afternoon Stuart,
Yes the stuffing does tend to muddy the sound especially if the stuffing is too dense...
Try lining the walls alone with the material...!! another important factor here is, if your stuffing is too dense
and less porous that will tend to reduce the internal volume...Law of dimnishing returns. If you have used MJK's math cad sheets, as you increase the stuffing you would see better and better responses...
but we should also consider how practical those densities we specify are...!!

If its a TL, the best use of stuffing would be to reduce ringings etc caused in the tube... you would hear a charecteristic tube like (cave like) sound
when you put your ear close to the open end of the tube...after stuffing these tend to go away. Midrange frequencies should actaully ge a better defenition after stuffing..!!

One experiment you can do is try feeding some impuleses, or chirps to the speaker and notice if you can pick up any ringing...
a good comparisson would be to listen to these first on headphones.. (be cuations to reduce the level before using headphones..)

If you wouldnt have accees to these chirps try these...
Play some music on your CD player...
Forward while the track is playing...at a good speed (may be 4x or 8x)
pause and listen to the speaker...
generally on an unstuffed line...you will hear a charectersitic..."guingggg..." imeediatley after the pause..

Repeat the same after stuffing...the "guing..." should go off or be reduced significantly..!

As a rule of thumb, I would give more importance to vocals than any other band of frequencies..
Stuffing reduces the relaunch of internal reflections through the cone, which I feel is much more important especially while working with smaller drivers...

many thanks
ajju

[gjo]

Hi Folks

I revisited this page today and see that things have evolved a bit. FYI, I have used felt as well as Black Hole for wall lining of my ported enclosures, and fibreglass(messy stuff which I wont use again) as fill, as well as Reliance's dacron for both two ways and subs.

The felt wasnt thick enough so I folded it. Black Hole is very expensive and I suspect we have cheaper options available here.

George

[s_zimble]

Thanks Ajju for the good descriptions and advice.
I will report on my progress. I think I want to get a wool felt army blanket and line the cabinet (or parts) with it.

Cheers, Stuart