ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Got a BL4 in a link room that just started squealing a continuous high pitch sound. I've removed it from it's ceiling mount mount and plugged it in with a new cord and PC input and it continued squealing which confirmed that it was not the Active box or cable issues. Obviously, it will need to either be replaced or repaired but as I've never had an active speaker fail or cause any problems in the past I'm curious if this is a common or known type of speaker failure. Power supply? Ice amp failure? Any of you tech guys have a thought?
Thanks.
-Michael
I'll take a stab at this since no one has responded yet. When the Class D ice amps are functioning normally they actually produce an extremely high frequency that is inaudible to the human ear. It sounds to me like something is out of whack on the ice amp. I've heard of the standby transformers taking a dump but this is new to me at least...
BeoCentral page on the BL1 says the following:
The switching frequency must be high enough not to generate audible harmonic signals in the output, and in the case of the “Ice Power” amplifier it is 384KHz, nearly 20 times higher than the most sensitive ear can detect. To operate at this frequency, highly efficient power transistors are needed, and it was possibly the availability of new ranges of power devices that combined a wide useable bandwidth and excellent switching performance that had re-awakened the interest in class “D” amplifiers for audio in the time leading up the launch of the Beolab 1.