Guglielmo
10-17-2013, 03:44 AM
HI to all,
I own since new a pair of JBL L166 Horizon whose Xover has been modified to accept a bi-amp set up. In facts an electronic Xover cuts @ 1000Hz the lower way from the upper so a Solid State 50W amp drives directly the woofer while a Vacuum Tube 40W amp the mid/tweeter. Obviously the passive Xover @ 6000Hz is retained.
Since new the woofers performed very well with abundance of bass. After 15 or more years the bass become longer and boomy so I checked under the grilles and I discovered that both woofers were needing reboarding being the original board completely pulverized. A near technical lab took in care the woofer and so the bass started again to perform as new, just the time for the running-in to reach the optimal sound.
Again after 15 years the woofers needed reboarding so this time I got the service from another "specialist" who aesthetically done a good job but from the first hours the bass seemed "dry", absent", too short, so I guesses that it was just a matter of time to break-in the suspension. Unfortunately more that one year is passed without better results, the only hope is that nowadays I don't have much time to listen to these JBLs preferring headphone use.
I have to highlight too that few months ago I changed the 50W Solid State amp (woofer dedicated) to a 100W always SS but the bass results are poor: dry, lacking, dull without power even if I increase the bass amp gain or insist with the bass tones on the preamp...
Question: perhaps the reboarding has not been done as required? May be utilizing some wrong suspension material? What else?
Thanks a lot for help!
Cheers,
Guglielmo
I own since new a pair of JBL L166 Horizon whose Xover has been modified to accept a bi-amp set up. In facts an electronic Xover cuts @ 1000Hz the lower way from the upper so a Solid State 50W amp drives directly the woofer while a Vacuum Tube 40W amp the mid/tweeter. Obviously the passive Xover @ 6000Hz is retained.
Since new the woofers performed very well with abundance of bass. After 15 or more years the bass become longer and boomy so I checked under the grilles and I discovered that both woofers were needing reboarding being the original board completely pulverized. A near technical lab took in care the woofer and so the bass started again to perform as new, just the time for the running-in to reach the optimal sound.
Again after 15 years the woofers needed reboarding so this time I got the service from another "specialist" who aesthetically done a good job but from the first hours the bass seemed "dry", absent", too short, so I guesses that it was just a matter of time to break-in the suspension. Unfortunately more that one year is passed without better results, the only hope is that nowadays I don't have much time to listen to these JBLs preferring headphone use.
I have to highlight too that few months ago I changed the 50W Solid State amp (woofer dedicated) to a 100W always SS but the bass results are poor: dry, lacking, dull without power even if I increase the bass amp gain or insist with the bass tones on the preamp...
Question: perhaps the reboarding has not been done as required? May be utilizing some wrong suspension material? What else?
Thanks a lot for help!
Cheers,
Guglielmo