Posted by MARCOS AUGUSTO on January 30, 2003 at 22:02:44:
In Reply to: Re: It's exciting.... posted by Lew on January 30, 2003 at 11:22:09:
....that is correct, Lew, i had left both bias controls on both speakers set at maximum for over 1 hour, and ,as Dr. West told me, that is definitely a NO~NO~ practice as it strips the conductive coating off the membranes.
i just e-mailed back to Dr. West afterwards as i also noticed that on one of my speakers i was getting tiny electrical sparks when the bias control was maxed out which, according to Roy, a fellow SLOGGER, would seem to indicate that on one of the speakers there happened a "stator wire insulation brakedown "...(by the way, thanks Roy for the explanation).
so, as Dr. West pointed out it is okay to max out the bias control for short periods of time during adjustments procedures, and then backing it down to just below audibility for proper speaker setup.
again, nowhere in the owner's manual there is any mention that maximizing the bias controls for extended periods of time is tantamount to damaging the speaker, which really, really upset me !!!!
i am now seriously considering trying to sell my speakers at whatever price i can get for them (if i can find a buyer, considering their need to be sent to the factory for estimated repair cost of at least $1.000,00 plus another $1.000,00 for shipping both ways !!), and thinking about buying a pair of 76" tall ribbons from Bohlender Graebener (just the ribbons, which would cost me less than $1.500,00 per pair including shipping), and see whether or not i could simply screw the ribbons to the top of my Genesis 928 subwoofers. the BG ribbons are bipoles and rated at 150Hz to 18.5KHz +/- 3dBs, and, according to one review, capable of playing at loudness levels above THX specs, or, louder than 105dBs without any stress.
i still can't believe that my much beloved pair of Sound Lab A-1 speakers apparently lasted me for just 2 years of use, i am still literally in shock, as i expected to own these speakers for at least 10 years!!!
in all fairness, the only reason i started to "play around" with the bias control for extended periods of time was because i noticed that one of the speakers had lost its ability to properly "crackle" as time went on, so i thought there wouldn't be any harm in "crackling" them longer than say, 5 to 10 minutes....if only i had known....if only there was a WARNING in the owner's manual ....!!!