4818 wbin without reflex

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   hi everyone, i have 2 4818 wbin that i want to use from 65\70 hz to 120. if i mount a front panel without holes can i obtain a better performance in spl? i don't need to go lower than 60 hz because i'm building 4 hogs

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mikelink Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 21 November 2012 Status: Offline Points: 63	Post Options Post Reply Quote mikelink Report Post Thanks(0) Quote Reply Topic: 4818 wbin without reflex Posted: 01 February 2016 at 9:54pm
	hi everyone, i have 2 4818 wbin that i want to use from 65\70 hz to 120. if i mount a front panel without holes can i obtain a better performance in spl? i don't need to go lower than 60 hz because i'm building 4 hogs

VECTORDJ Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 11 June 2006 Location: United States Status: Offline Points: 515	Post Options Post Reply Quote VECTORDJ Report Post Thanks(0) Quote Reply Posted: 02 February 2016 at 3:23am
	The port adds some output from appox 40 to 50 Hz. By sealing the chamber you might gain a dB or two (maybe) between 75 and 100 Hz, but you will get a tighter sound with more punch. The ports have some group delay. I have found that two way bass needs a very good active crossover. Many seem to have a phase problem at LF and cancel some output around 75Hz cross points. They claim they sum in phase but I have found that is not always the case. Try adding a 3 or 4 ms time delay to the infa subs. VECTORSONICS

KidCreole Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 06 November 2013 Location: London (East) Status: Offline Points: 3600	Post Options Post Reply Quote KidCreole Report Post Thanks(0) Quote Reply Posted: 02 February 2016 at 1:26pm
	Seal up the ports and make the chamber smaller. Stick polystyrene in there to take up the volume. Add and subtract poly until you like the sound
	Mykey Wattco

KidCreole Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 06 November 2013 Location: London (East) Status: Offline Points: 3600	Post Options Post Reply Quote KidCreole Report Post Thanks(0) Quote Reply Posted: 02 February 2016 at 1:27pm
	You could also change drivers to a higher EBP value
	Mykey Wattco

mikelink Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 21 November 2012 Status: Offline Points: 63	Post Options Post Reply Quote mikelink Report Post Thanks(0) Quote Reply Posted: 02 February 2016 at 1:32pm
	thanks vector, another question, should i put some glass wool on the back?

VECTORDJ Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 11 June 2006 Location: United States Status: Offline Points: 515	Post Options Post Reply Quote VECTORDJ Report Post Thanks(0) Quote Reply Posted: 04 February 2016 at 5:40pm
	Line the inside chamber with foam that goes under carpet (1/4 to 1/2 inch). Glue in place with contact cement. Then lightly 1/2 fill chamber with poly pillow stuffing. Keep this away from cone. Do this with some glue or thin netting stapled in place. VECTORDJ

_djk_ Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002	Post Options Post Reply Quote _djk_ Report Post Thanks(0) Quote Reply Posted: 05 February 2016 at 7:22am
	"You could also change drivers to a higher EBP value" And end up with less output overall. The EBP of the D130 is much higher than the 2226, and it thus has more output above 200hz or so. The higher x-max of the 2226 insure that the maximum output will be at least 6dB higher. It's seldom a good idea to use a driver with a mass corner (mass corner is 2x EBP) higher than your intended crossover point.
	djk

KidCreole Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 06 November 2013 Location: London (East) Status: Offline Points: 3600	Post Options Post Reply Quote KidCreole Report Post Thanks(0) Quote Reply Posted: 05 February 2016 at 9:18am
	Open backed flh Small sealed chamber flh 65 - 120
	Mykey Wattco

mikelink Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 21 November 2012 Status: Offline Points: 63	Post Options Post Reply Quote mikelink Report Post Thanks(0) Quote Reply Posted: 09 February 2016 at 11:31pm
	should i add polystyrene like this?