JBL 4645
02-09-2007, 05:15 PM
Note: Now I know the sub bass extension isn’t a JBL but if I had a choice I’d change the sub bass driver over to one of the newer 12” JBL high powered sub bass drivers.
It struck me last year when I was toying around with extending the sub bass (http://www.hometheaterhifi.com/forum/showthread.php?p=25697#) frequency response when experimenting with carpet tubing placed over the (air duct port).
This time I used a different approach with a small piece of plastic tubing about 7” long and 4” in diameter. To hold it secure (http://www.hometheaterhifi.com/forum/showthread.php?p=25697#) over the (air duct port) and to prevent any damage to the cosmetic look of the Eltax R-12 A I used silicon to hold the tube down.
Has you can see it takes around 30 minutes for it to dry off and thou I could easily remove it without any damage what so ever, if it sticks to your fingers it washes off without fuss!
I repositioned the sub bass extension afterwards into a different location. The overall result was an impressive (6db boost):applaud: and lesser noise from the air duct port at the lowest frequency when playing hard!
http://forum.stereophile.com/photopost/data/500/3677IMAG0017-med.JPG
http://forum.stereophile.com/photopost/data/500/3677IMAG00191-med.JPG
http://forum.stereophile.com/photopost/data/500/3677IMAG00201-med.JPG
http://forum.stereophile.com/photopost/data/500/3677IMAG00251-med.JPG
It struck me last year when I was toying around with extending the sub bass (http://www.hometheaterhifi.com/forum/showthread.php?p=25697#) frequency response when experimenting with carpet tubing placed over the (air duct port).
This time I used a different approach with a small piece of plastic tubing about 7” long and 4” in diameter. To hold it secure (http://www.hometheaterhifi.com/forum/showthread.php?p=25697#) over the (air duct port) and to prevent any damage to the cosmetic look of the Eltax R-12 A I used silicon to hold the tube down.
Has you can see it takes around 30 minutes for it to dry off and thou I could easily remove it without any damage what so ever, if it sticks to your fingers it washes off without fuss!
I repositioned the sub bass extension afterwards into a different location. The overall result was an impressive (6db boost):applaud: and lesser noise from the air duct port at the lowest frequency when playing hard!
http://forum.stereophile.com/photopost/data/500/3677IMAG0017-med.JPG
http://forum.stereophile.com/photopost/data/500/3677IMAG00191-med.JPG
http://forum.stereophile.com/photopost/data/500/3677IMAG00201-med.JPG
http://forum.stereophile.com/photopost/data/500/3677IMAG00251-med.JPG