Damping in small, ported subs - verdict?

[Surtsey]

Does anybody have an opinion on damping in ported subs? If you'd asked me a few years ago it'd be a hard no, but I'm beginning to come around. I have a Mordant-Short MS308. I had to open it fix a fault. To my surprise I found enough damping material to make a small sofa.

I have two identical smaller subs: 10 x 8 x 8. Any damping material reduces cabinet volume but I feel the one with the damping sound "better".

Thoughts?

 

[chris661]

Here's an article from Rod Elliott on the subject: Volume filling a reflex box

Damping material can sometimes increase the effective cabinet volume, although that applies more to sealed boxes.

Chris

 

[Surtsey]

Here's an article from Rod Elliott on the subject: Volume filling a reflex box

Chris

I didn't get it. In the introduction he discusses the low frequency driver being responsible for frequencies between 80Hz and and 3kHz. He's talking about the satellites not the sub.

 

[Brian Steele]

IMO lined or stuffed bass reflex boxes being used for full range duty sound considerably better than those that are not lined or stuffed. Even for subwoofer duty a bit of lining usually produces better results.

However, a stuffed bass reflex box will also suffer from reduced output from the vent (due to increased losses caused by the stuffing). This may not necessarily be a bad thing, particularly if taken into consideration in the design.

 

[conanski]

The rule of thumb is strategic lining for reflex or horn loaded boxes and stuffing for sealed only, in all cases the added material will reduce output SPL but that may or may not be a bad thing. Small sub drivers in particular have to work much harder for any given SPL which can create undesirable sounds like driver vent noise, so while box lining isn't technically required for a subwoofer it may help produce a better end result.