I'm going to need to test a quantity of used "raw" (not mounted in cabinets) speakers before I purchase them. In the past I've used "the battery test" with a 9 volt flat battery and two wires touched to the negative and positive terminal on the speaker -- "if it crackles it works."

Is this harmful to speakers? Is there a better way that doesn't involve a meter, etc? :scratch2:

Thanks

Play music through them?

As long as you don't leave the battery connected, it won't hurt anything.

Use a 1.5v battery instead, and check for cone extension. Then use a VOM, Digital or otherwise) on the lowest setting (200?) and see if the resistance resembles the impedance, It won't match exactly, but within 2-3 ohms or so. (This test may not be relevant for some tweets, and definitely won't for HPM super tweets; they will look like they are open)

Although a 1.5 volt battery is the safest way to test a speaker, I for one would like to hear some noise coming from the speaker. Running a speaker line out from an amp is easy to do, but you have to be extremely cautious that your speaker leads do not accidentally get shorted to each other and thereby damage your amp. I avoid that method if I can. I do have a method for testing that requires a cable testing device like this: http://www.mcminone.com/product.asp?catalog%5Fname=MCMProducts&category%5Fname=3830538&product%5Fid=72%2D8090

The little box with this set sends out a repeating tone that is used for cable searching. This tone will also play back through a speaker and also dynamic microphones. I use this device to test speakers and mics when I go out to buy them used. The varying tone can usually be heard through tweeters and woofers and can verify for you that all components of the speaker are active. In your case you would just clip the alligator clips to each speaker you want to test and listen for the tone. It is safe ,easy and versatile. The only thing is that the tone tester will not tell you if there are issues with voice coil rubbing because it is not sending enough amplitude to create much speaker excursion. This is better done by repeatedly connecting and disconnecting a battery quickly. With the repeated motion you should be able to hear any voice coil rubbing. This tone checker I suggested is a great device to have for all sorts of wiring issues. and it has a plug that can be used to test phone lines. It a worthy investment. I picked one up at the flea market for $2 from someone who did not know what it was and have used it for lots of things over the years.