Purpose of felt lining in TL ?

What is the purpose of felt lining in a transmission line design?

Does it not affect the cross sectional area?

If it does not affect the CS area because the sound waves pass through it, then what is it achieving?

What the the pros and cons of natural fibres vs synthetic ones?

I will be filling most of the line with stuffing as well.

TIA
 
Hello dublin78

"What is the purpose of felt lining in a transmission line design?"

Dampening reflecting standing low frequencies sound waves

"Does it not affect the cross sectional area?"

Due to the aspects (speed and pressure) of internals LF sound waves, no. Regarding felt thickness don´t exceeds stock 5mm. You won´t need any thicker.

"If it does not affect the CS area because the sound waves pass through it, then what is it achieving?"

See your first question

"What the the pros and cons of natural fibres vs synthetic ones?"

Natural fibres, you mean sheep wool f. ex., are affected by moth. You must asure it was treated with anti-moth by the supplier. Polyesters are cheap and easier to handle.

"I will be filling most of the line with stuffing as well."

Hold one side of cabinet with screws during experiment stage. It´s a long run task.

Search for MJK or Martin J. King posts/links/webpage for a deep aproach.

Hope this helps. Sorry for english mistakes.

Cheers