Mackie active speaker problem

[Stefan Toftevall]

Hello all,
A Dj came into my shop with one of his active speakers, a Mackie
ART300A.
He was very dissapointed in its reliability since it had caused him
much hassle over a short time.
The problem is, it actually **blows** the speaker element. Now it's
the 3rd time this happens. The unit has got no DC protection, I can't
understand why the design is so cheap. I don't know if DC is the main
reason for blowing the speaker but I can assume it. After a brief
inspection of the amplifier module I found a blown fuse (F1, this is
for the high positive rail voltage, it's a class H output stage). I
guess the amp output very high DC level and therefore also this fuse
blown. The thing is, I can power up the amp today without any DC on
the output. And when I've installed the new speaker, I don't want this
to happen again, so I'll implement a DC-protection circuit.
But for my real question: I want to know why the speaker blows so
frequently, my customer has 3 of these active speakers, and only this
one fails.

Best regards
Stefan

 

[Jerry G.]

I would get in touch with Mackie. Their products are supposed to be good and
reliable.

--

Jerry G.
=====


Hello all,
A Dj came into my shop with one of his active speakers, a Mackie
ART300A.
He was very dissapointed in its reliability since it had caused him
much hassle over a short time.
The problem is, it actually **blows** the speaker element. Now it's
the 3rd time this happens. The unit has got no DC protection, I can't
understand why the design is so cheap. I don't know if DC is the main
reason for blowing the speaker but I can assume it. After a brief
inspection of the amplifier module I found a blown fuse (F1, this is
for the high positive rail voltage, it's a class H output stage). I
guess the amp output very high DC level and therefore also this fuse
blown. The thing is, I can power up the amp today without any DC on
the output. And when I've installed the new speaker, I don't want this
to happen again, so I'll implement a DC-protection circuit.
But for my real question: I want to know why the speaker blows so
frequently, my customer has 3 of these active speakers, and only this
one fails.

Best regards
Stefan