Tuning a back loaded horn

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

Rodmann - I put about 5/8 of a pound of polyfill packed quite tightly behind each driver.

The bass that was bugging me is greatly reduced, and somewhat to my surprise, the speakers seem to have more snap, more detail and improved midrange!

Man, back loaded horns are the bomb!

Thanks
Paul