Damping material is useful only in sealed subs? Or will it work in ported subs also?

[mart34]

Damping in bass reflex subs is clearly preferred by some of the best sub manufacturers in the world.

First image - SVS PB13 Ultra, with lots of Polyester Fibre sheet (BAF Wadding)

Second image - RBH 1212, with Polyster Fibre sheet (BAF Wadding) and open cell foam near the port.

 

[Juhazi]

They obviously use stuffing to minimize port resonances from reflecting back to the tube.

 

[mart34]

They obviously use stuffing to minimize port resonances from reflecting back to the tube.

Agreed. I know this wasnt really the subject of the thread starters original post, but damping IMO clearly should be used. I have a build thread with my sub, and I haven't applied any damping so far. My original thinking was, I'd made no compromise in the enclosure size, so didn't need it. But having used it now for two months, I am struggling with upper bass and lower midrange bleeding through the drivers. Theres no box resonance, due to thickness and bracing, but there are definitely reflections. Another issue I've noticed very recently, is that although I dont have port noise/chuffing, the box seems to howl at low frequencies <20Hz), sounds like the sound of the air moving through the box/port. I believe I'll significantly reduce this with lining of the walls.