Tuning a back loaded horn

Thanks for the response John. I try some Madisound wool.

Would I start by putting some wool in behind the driver or close to the mouth of the horn? I have a sachiko design (from the Frugal Horn website) with 206 fostex, and I want to bring the upper bass down just little bit.

I am thinking I need to start close to the mouth of the horn.

thanks
Paul

Stuff the area behind the woofer tightly, and progressively looser towards the vent. The object being to convert acoustic energy to thermal and reduce peaks/nulls in the cabinet response. In other words: Add 1/2lb/ft3 of fiberfil to the coupling volume(area directly behind the woofer), and reduce that to 1/8lb/ft3 of
fiberfil to the first one third of the horn’s length.

PS: Polyester is nice because you don't have to worry about moths and their larva.

The real wool is treated you will not have a moth problem. You tune a BLH from the driver down you shouldnt need to damp mouth but this all depends on cabinet design and driver choice. I could help you more if I knew this.

Third attempt to respond to Johnk question.

John, the speakers I use is at http://homepage.mac.com/tlinespeakers/FH/download/Sachiko-map-1v0-230307.pdf. I use Fostex 206E drivers.

Thanks
Paul