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PostPosted: 22 Jan 2009, 13:39 
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Joined: 06 Jan 2009, 01:16
Posts: 62
Location: Philadelphia Pa
RiGuy wrote:
Nothing better than a junk speaker to try out a new amp on when you are unsure whether the thing is going to destroy your speakers or not. Well, nothing better except a block of resistors, but I like to hear if the music is getting through. Whether it sounds good or not does not matter, its just a test.

Riguy, why use a junk speaker?
Any speaker could be used, as long as certain precautions were used beforehand.
If the specific amplifier in question was throwing possible B+ into speakers, merely rig a "test" speaker by placing a 50-100uf bippolar cap in series with it to save the voice coil from burnout.
But I always check the amp for signs of DC on the output terminals first, just to make sure it'll work.


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PostPosted: 23 Jan 2009, 08:15 
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Location: Winnipeg, CANADA
I use a speaker dummy load that limits power to the speakers when testing out amps.

http://diyaudioprojects.com/Technical/D ... ummy-Load/

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PostPosted: 23 Jan 2009, 09:18 
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Joined: 06 Jun 2008, 20:12
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Okay. Guess I fail to see where using a busted speaker as a dummy load to test an amp is a bad idea. It seems to work for me everytime and seems to be the perfect dummy load as it actually plays music, not well, but does and this way tells me a bit more than just a block of resistors, so its nice to keep that busted sub around so that I can easily plug into it, fire up, listen and unplug. Dont even have to hook up a DMM and start measureing since the speaker tells me everything I have to know instantly at least for the first fire up so I know if the amp is working to any degree. Another nice thing is that if the amp for some reason is putting out a decent amount of DC I can see that by watching the excursion of the speaker. If its a small amount I wont probably see that but it will also be small enough to not damage the next speaker I hook up and I will see it when I do my next round of testing with a DMM.
Ri

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