Chadeffect,
using some sticky black bitumen stuff for the dampening of the cylinders. Did that tweak some 10 years ago. don't remember the brand. it was stuff used in cars in dampen resonances. keep the original foam in place inside the cylinders. however, after removing the rear covers of the horns I removed the rear cover foam so I can see the driver when standing behind the speaker. this way the back wave doesn't bounce back and forth. sounds more open if you will.
Johnk,
using lyngdorf corner subs especially designed to be put into corners behind main speakers. not really bass horns but way better than the 225 subs imo. also mid and high frequencies improve when the vibrations from the 225 subs are removed.
using some sticky black bitumen stuff for the dampening of the cylinders. Did that tweak some 10 years ago. don't remember the brand. it was stuff used in cars in dampen resonances. keep the original foam in place inside the cylinders. however, after removing the rear covers of the horns I removed the rear cover foam so I can see the driver when standing behind the speaker. this way the back wave doesn't bounce back and forth. sounds more open if you will.
Johnk,
using lyngdorf corner subs especially designed to be put into corners behind main speakers. not really bass horns but way better than the 225 subs imo. also mid and high frequencies improve when the vibrations from the 225 subs are removed.