Blocking up ports to make sealed box.

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   I have a pair of bass reflex  cabs using dual RCF L15P200's at 158L. I want o experiment using them as sealed cabs above some double 18 bass flex. My question is whats the best way to block up shelf ports temporarily? I was thinks about some sort of closed cell solid foam. I don’t want to screw board across the front as it will look naff.

If I just block the exit of port does the port does the volume of the port become part of the box volume? or will it just become a half wave resonator?

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PolymorphicMark Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 27 May 2004 Location: United Kingdom Status: Offline Points: 444	Post Options Post Reply Quote PolymorphicMark Report Post Thanks(0) Quote Reply Topic: Blocking up ports to make sealed box. Posted: 05 May 2018 at 1:01pm
	I have a pair of bass reflex cabs using dual RCF L15P200's at 158L. I want o experiment using them as sealed cabs above some double 18 bass flex. My question is whats the best way to block up shelf ports temporarily? I was thinks about some sort of closed cell solid foam. I don’t want to screw board across the front as it will look naff. If I just block the exit of port does the port does the volume of the port become part of the box volume? or will it just become a half wave resonator?
	Free to do what i WANT

midas Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 27 October 2011 Location: Cumbria Status: Offline Points: 2117	Post Options Post Reply Quote midas Report Post Thanks(0) Quote Reply Posted: 05 May 2018 at 1:10pm
	foam is the easy way. But also entertaining if it is not quite tight enough, pops out like a champagne cork.
	In bass no one can hear you scream!

LunchieTey Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 06 February 2005 Location: Australia Status: Offline Points: 934	Post Options Post Reply Quote LunchieTey Report Post Thanks(0) Quote Reply Posted: 06 May 2018 at 12:44am
	yes, get a very large piece of closed cell foam you have to very firmly squash and pack in the slot!
	Speaker addict

PolymorphicMark Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 27 May 2004 Location: United Kingdom Status: Offline Points: 444	Post Options Post Reply Quote PolymorphicMark Report Post Thanks(0) Quote Reply Posted: 06 May 2018 at 9:44pm
	Thanks for the answers
	Free to do what i WANT

Hemisphere Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 21 April 2008 Status: Offline Points: 2272	Post Options Post Reply Quote Hemisphere Report Post Thanks(0) Quote Reply Posted: 07 May 2018 at 6:48am
	How the port behaves as part of the enclosure volume will depend on how wide and how long it is. I would guess it's a sliding scale between acting fully as part of the enclosure volume (for a big open shelf) and hardly at all for a long thin bendy tube, but how the scale slides I have no idea.
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midas Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 27 October 2011 Location: Cumbria Status: Offline Points: 2117	Post Options Post Reply Quote midas Report Post Thanks(0) Quote Reply Posted: 07 May 2018 at 9:43am
	oh I miss read that. If they are big rectangular ports, I would think about big foam block, squeezed in from inside the box. It won’t matter if there is any not squeezed in the port, it should help remove some of the boominess that wadding does. You could staple it from inside too, to help keep it in place.
	In bass no one can hear you scream!