thermionic
Well-known member
- Joined
- Jun 3, 2004
- Messages
- 1,671
Hi,
I should preface this by saying that I'm a goody-two-shoes, in that, in the 30+ yrs I've been tinkering with audio equipment, I've never knowingly blown a driver. I've always felt the signs of impending destruction to be blatant and have adjusted the gain accordingly. Hence, I do not consider myself an expert in loudspeaker failure modes. I have seen a few blown drivers - always manifested in the form of a siezed or damaged coil. I've seen / witnessed the chatter effect of worn surrounds many times. One great area of satisfaction for me has been replacing foam surrounds early, before damaging the coil, to see the driver have a new lease of life (one has to get one's kicks where one can in this business...)
Anyway, a couple of weeks back I attended a party in a small, private venue. The speakers used (in conjunction with powered subwoofers) were these large main studio monitors, consisting of a Scanspeak-type HF dome + ATC mid driver (think along lines of a Boxer or ATC 300 kind of scale) and a pair of 15" Gauss bass drivers. The monitors came from a famous studio. They weigh a ton, supposedly had input from Roger Quested and, to my ears, have always sounded good. Ideal for a small, private bar.
It was a hot evening. About 1am, 2 hours into the party, both HF drivers failed... (I should add that this isn't an installation of mine - and the *limiters* were switched to bypass....). As the usual engineer wasn't there, muggins got called upon to inspect damage. The x-overs confirmed the issue to either be with the amps, or speakers. This author did not feel popular, with about 70 party-goers standing around whilst he fumbled around amp rack with a maglite...
Without a load of tools, all I could do was cite HF amp failure. Both channels had gone - it'd be odd to blow both tweeters at once, right?
This is the weird part: upon inspecting the monitors, one of the 15" Gauss drivers had completely torn its cone. What's odd is that it had not only detached about 200-degrees from the centre dust cap, but also from the surround...the cone thus flapping, like a narrow strip....
How on earth could a cone detach from both the dust cap and surround? Heat? Certain parties wondered if riff-raff had gotten into party and caused vandalism, as this had happened before. I wish I had a photo.
You could see that the cone was torn - it was not a clean break along the glue lines.
According to the engineer who looks after the installation, both tweeters were blown - not the amps.
What makes me curious is that the coil in the Gauss driver felt perfect - like new. The dust cap and 160 degrees of remaining cone could push in and out, feeling the same as the undamaged speaker...
Have you ever seen a cone detach at both sides, i.e. dust cap and surround? Melted glue? Vandalism? Where would you point the finger?
I should preface this by saying that I'm a goody-two-shoes, in that, in the 30+ yrs I've been tinkering with audio equipment, I've never knowingly blown a driver. I've always felt the signs of impending destruction to be blatant and have adjusted the gain accordingly. Hence, I do not consider myself an expert in loudspeaker failure modes. I have seen a few blown drivers - always manifested in the form of a siezed or damaged coil. I've seen / witnessed the chatter effect of worn surrounds many times. One great area of satisfaction for me has been replacing foam surrounds early, before damaging the coil, to see the driver have a new lease of life (one has to get one's kicks where one can in this business...)
Anyway, a couple of weeks back I attended a party in a small, private venue. The speakers used (in conjunction with powered subwoofers) were these large main studio monitors, consisting of a Scanspeak-type HF dome + ATC mid driver (think along lines of a Boxer or ATC 300 kind of scale) and a pair of 15" Gauss bass drivers. The monitors came from a famous studio. They weigh a ton, supposedly had input from Roger Quested and, to my ears, have always sounded good. Ideal for a small, private bar.
It was a hot evening. About 1am, 2 hours into the party, both HF drivers failed... (I should add that this isn't an installation of mine - and the *limiters* were switched to bypass....). As the usual engineer wasn't there, muggins got called upon to inspect damage. The x-overs confirmed the issue to either be with the amps, or speakers. This author did not feel popular, with about 70 party-goers standing around whilst he fumbled around amp rack with a maglite...
Without a load of tools, all I could do was cite HF amp failure. Both channels had gone - it'd be odd to blow both tweeters at once, right?
This is the weird part: upon inspecting the monitors, one of the 15" Gauss drivers had completely torn its cone. What's odd is that it had not only detached about 200-degrees from the centre dust cap, but also from the surround...the cone thus flapping, like a narrow strip....
How on earth could a cone detach from both the dust cap and surround? Heat? Certain parties wondered if riff-raff had gotten into party and caused vandalism, as this had happened before. I wish I had a photo.
You could see that the cone was torn - it was not a clean break along the glue lines.
According to the engineer who looks after the installation, both tweeters were blown - not the amps.
What makes me curious is that the coil in the Gauss driver felt perfect - like new. The dust cap and 160 degrees of remaining cone could push in and out, feeling the same as the undamaged speaker...
Have you ever seen a cone detach at both sides, i.e. dust cap and surround? Melted glue? Vandalism? Where would you point the finger?
