Posted by MARCOS AUGUSTO on January 20, 2003 at 18:19:25:
In Reply to: CLUELESS posted by Joe S on January 20, 2003 at 10:34:46:
Hey Joe S,
......I tend to agree with the general assessment of your evaluation of Sound Lab speakers, as i an the owner of a pair of "used but pristine" A-1's which i bought about two years ago, meanwhile still finding myself struck by their amazing clarity and unmatched transient response.
however,about 4 months after my purchase, i noticed that the "crackling noise" on one of the speakers had basically stopped and changed to a low-level "growl" as well as a somewhat louder "popping sound"....... after lowering the bias as recommended by the factory and playing music through the speakers i could tell that both of them sounded exactly the same, so, i figured, what the heck, as long as the "defective" speaker sounded like the other one that still exhibited the "crackling noise" when over-biased, i could just live with that and forget about the problem.
now, some 18 months later, i just noticed that the defective speaker has gotten a lot worse : still no "crackling noise", and it is exhibiting playback levels well below the other speaker....plus, i found out that the remedy for this more recent problem is that every time i plan on using the speaker i have to max the bias control for awhile then lower it back to normal to finally be able to listen to music, albeit during soft passages i can still hear a low-level "ping, ping, ping" from the bias control as played through the speaker.
to make matters worse, today i started having similar problems with the other speaker : i had raised the bias control to maximum on both speakers. the one that had functioned properly up to now simply stopped making any "crackling noise" whatsoever and, upon lowering the bias control to normal, the speaker is now playing at much lower levels and sounds distorted!!!!
i have now disconnected both speakers from the wall outlet and plan on reconnecting them again tomorrow to see what happens, although i don't have any hopes that this will fix the problem(s)...
prior to Sound Labs i owned two pairs of Acoustat speakers and never had any problems with their bias controls or whatever, with the exception of their built-in amps, which the factory wisely decided on changing to external amps...in over 20 years of ownership of Acoustats, they never gave me any more problems !!!!
i now wonder whether or not i made the right decision purchasing these Sound Lab A-1's : i was aware as to how fragile they can be during shipping but i didn't expect to get so many problems with their bias controls and who knows what else....i just wish that Sound Lab connoisseurs in this site had warned me concerning their overall "fussiness" and fragility.
....oh, and by the way, anyone here has any suggestions as to what is wrong with my speakers ?? i also noticed that when raising the bias control to maximum, one of the speakers started displaying tiny electrical sparks... is that to be expected ?? and, if not, could i possibly fix it with the "heat gun treatment for loose membrane" as suggested by Sound Lab ??? could these problems be traced back to the transformers, to the mylar membranes or to both ??
thanks for any suggestions, ......Marcos