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George's Pro Sound Company George's Pro Sound Company is offline
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Default Speaker overload (tweeter) protection using bulbs (repost)


"Meat Plow" wrote in message
...
On Sun, 16 Nov 2008 04:25:13 +0000, Eeyore
wrote:



Meat Plow wrote:

"George's Pro Sound Company"wrote:
"Meat Plow" wrote in message
Eeyore wrote:

This is a well established technique for preventing voice coils
burning
out under conditions of 'overdrive'.

There is a stage monitor I'm having problems with that uses this
method.

The HF sounds very distorted and almost cuts in and out.

I looked closely inside and found some damaged push-on terminals. Ah,
I
thought, probably a poor contact causing the probelm, replaced them,
checked driver DC resistances etc, reassembled thinking I'd probably
fixed it.

But no, the low level HF and distortion continued.

I'd checked the DC resistance of the protection bulb but later it
occurred to me that it might have 'very nearly' burnt out and have a
weak spot that wouldn't show up on a DVM but passing signal would
heat
it and cause this trouble. I'll be able to find out soon enough but I
wondered if anyone else had ever encountered this ?

In the meantime I brought the HF driver home to check it's not voice
coil rub.

Been using some Wharfedale stage gear for a year or so. The mains are
all protected by lamps. I've replaced two in a year but not
experienced a distorted HF. You'll find problems in the xover or
drive
I would assume rather than the lamp.

or maybe it's time to upgrade from that MI grade junk your using
George

Who, me?


From what I've heard they're well considered and in the IAG group now.
http://www.internationalaudiogroup.com/

The Chang brothers don't believe in messing about AIUI.
http://www.internationalaudiogroup.c...ve_summary.php

Graham



We've been using the Warfe pro-audio stuff for a year and have had few
problems. One 2500 watt power amp we used for our 18" subs got sent
back because it was too sensitive and would fault when pushed hard at
4 ohms. The replacement did not exhibit this behavior under the exact
conditions. I've replaced a couple lamp protectors elsewhere.

I wouldn't call Wharfedale junk. It's usable, sounds good and reliable
and a lot less expensive than other name brands.


I consider W home stereo grade gear, not suitable for Pro Live Sound, below
behringer