Speaker protection?

[jrmintz]

Hi all,

How do you protect your studio speakers from excessive peaks or power amp failure, if you do? I spoke to the American importer for Quested and they recommend against fusing speakers because of the sonic degradation. Has anyone done any careful listening to fuses or other methods of protection? I believe some people put large caps inline to block DC in the event of amp failure. Is there a sonic penalty? This something I've always been meaning to explore but never seem to have time for.

Thanks,

:thumb: :sam: :guinness:

 

[daArry]

not sure if it applies here, but on the gainclone amp i done a 'zobel' resistor can be placed on the output for protection - low value/high wattage...

 

[PRR]

> How do you protect your studio speakers from excessive peaks or power amp failure

Use speakers louder than you or your clients could ever need, and reliable power amps.

If the speakers can't do what you want, you WILL blow them, no matter what "protection" you put in there. And modern power amps are very reliable.

 

[jrmintz]

Use speakers louder than you or your clients could ever need, and reliable power amps.

Thanks PRR. I never thought of it quite so straightforwardly, but that is what I've always done in practice. I've only ever blown one tweeter. I was just wondering what other people do, if anything. I like to work softly most of the time and if my clients want to monitor loud I leave the room. I'm concerned about catstrophic amp failure, although I've never had a problem. I do have good amps, so I'll worry about something more immediate - like dressing for success. I'm really hurting there.

:thumb:

 

[CJ]

Just make sure that if your fuse opens, that the pwr amp won't self distruct.

 

[thermionic]

Are you using a home-built amp or a commercial design such as a Quested? A commercial amp such as a Quested should have DC protection as standard, I would be very surprised if it didn't.

If you're still nervous you can install a module such as one of these: http://www.velleman.be/Downloads/0/Infosheet_K4700_stereo.pdf between amp and speaker.

The Velleman kit is simple, cheap and easy to make, but not as sensitive as some may require (it waits for 1V DC I believe). Velleman kits can be bought for the US here: http://www.vellemanusa.com/

I've probably got a few protection schems on file if you need any more ideas, the one I'm planning for my own amps is from Randy Sloane's excellent book (ISBN: 0-07-134119-6) "HIGH POWER AUDIO AMPLIFIER CONSTRUCTION MANUAL".

I've been lucky to get away without DC protection on my amps, but Sloane's protection circuit is top on the list of projects to do - if one of the ops fail drain to source that'll cost a lot in new drivers...

Justin

 

[jrmintz]

Justin,

I have a Bryston amp, so it ought to be as reliable as they come. Early in my days of learning to repair things (two or three weeks ago :green: ) I actually set fire to a pair of speakers with an amp I thought I'd fixed. Nothing like that has happened since, but I do keep a fire extinguisher nearby in the studio.

 

[CJ]

I set fire to some KLH's with a Macintosh solid state amp.
There was a nickname for that amp, as it was notorious for doing this. Bill Robertson knows but where the heck is he?

The stupid fire chief reported that the fire was started from the outside in, by a cigarett on the cone!
How do you get a ciggy to stick to a vertical plane that is vibrating back and forth!
sheesh!

 

[SonsOfThunder]

[quote author="cjenrick"]The stupid fire chief reported that the fire was started from the outside in, by a cigarett on the cone![/quote] Unbelieveable, CJ! There is a good safety reason not to have speakers with paper cones!

Peace!
Charlie

 

[jrmintz]

Well, if you're going to smoke you just have to give up listening to music...

 

[CJ]

That happened at UC Davis while we were on acid playing Pink Floyd thru a moog 3 panel!
My keyboard player just stopped playing and pointed to the speaker.
Then he put the flaming cabinet on his shoulder next to his curly hair, and walked down the second story corridor of the music building and heaved it off the balcony! As luck would have it, all the students were getting out of class! Oh, if I had only had a camera to preserve the stunned looks on those freshman!
What a way to end a cool jam! Actually I think we were playing How Many More Times by Led Zep. You know the riff, da da d d da, da da da d d....
Oh Rosie... Oh Girl....
:razz: