Damping material for speakers

[keith_correa]

Another concept I have seen some people use with good effect is to hang curtains(basically sheets of fabric) of different materials inside the speakers ,one person I know used a sheet of jute ,then thick cotton , then felt ,and finally the back wall had a layer of glass wool.All the hanging sheets had holes made in an alternating pattern and of various sizes so that the holes dont over overlap.He used this treatment for the Midrange section the driver he was using was a paper driver,and I can tell you that it worked brilliantly.

This is novel.
Question: Did the curtains extend completely from side to side or front [back] to back [front]?
Question: When you say that this treatment was used for the Midrange section - how did he manage this? Was the driver used for the mids, in a separate enclosure?

I had used loose bundles of paddy straw for lining the back and sides of my boxes, there was noticeable improvement in the lower mids compared to stuffing with Dacron.

Very very nice "desi" approach. I love it. Especially since Antony claims that it works.
Question: How did you manage to stick the bundles to the sides & back of the boxes?

Hey! How about using sections of straw matting?

 

[t.antony]

Question: How did you manage to stick the bundles to the sides & back of the boxes?

I used Fevicol SR. This type of glue is mainly used for upholstery work.

How about using sections of straw matting?

Of the "desi" fibers I used IMO straw was most effective in taming the internal reflections. The other options tried were jute, coir, grass mat and banana fiber.

It calls for experiment with the type of mat available at your disposal as the raw material used for making these mats vary across region.

Regds...

 

[Adhiraj]

@Keith

The curtains were parallel to the driver IE the baffle ,the were hung loose from the top of the box with an inch of space all around apart from the top.The midrange was in a separate enclosure ,this was a 3 way design,It should work in a 2 way as well imo.Infact it would be a better idea to add a bit of asymmetry by playing with the angles of the curtains and the distances between them,maybe use strips of different fabrics in the same line,you get the general idea.It should work quite nicely ,in principle , to break up the internal standing waves and absorb reflections ,couple this to a non paralell enclosure design and suitable damping with a bit of acoustastuff or dacron thrown in and we might have a winner

 

[keith_correa]

I used Fevicol SR. This type of glue is mainly used for upholstery work.

When you say "bundle", I'm imagining a rolled up bundle of straw and hence my question. I guess it was more of a flat bundle - like a thick mat - right? How was the straw in the bundle held together? Got a pic?

Of the "desi" fibers I used IMO straw was most effective in taming the internal reflections. The other options tried were jute, coir, grass mat and banana fiber.

Very innovative and experimental :clapping:

Wondering aloud: What about rubber sheets bonded to the walls with rubber compound? Any sort of other damping material can be over that rubber sheet. Should work well too.

 

[t.antony]

When you say "bundle", I'm imagining a rolled up bundle of straw and hence my question. I guess it was more of a flat bundle - like a thick mat - right? How was the straw in the bundle held together? Got a pic?

Those were cylindrical bundles of about 2inch dia. The straw was held together by sewing thread at regular intervals.

Regds...

 

[keith_correa]

Those were cylindrical bundles of about 2inch dia. The straw was held together by sewing thread at regular intervals.

Regds...

Thx!