Easy way to tell if a speaker is blown or not!

This is just going to be a short instructable because of its simplicity. This only works with the speakers that have the positive and negative wires that hook into a stereo. To tell if the speaker is blown or not without taking it apart is really easy. All you have to do is take a 9 volt battery and touch it to the wires. If it makes scratching noises its good. If it makes no sound at all its blown.

Comments

[dog digger]

I'd say the best way is with an ohm meter but DC will kill the speakers. I'd only use a 9v to check polarity on big subs such as my Electrovoice EVX180s.

[survivorwolf]

The only thing wrong with your comment is when you use an ohm meter it actually uses a set DC voltage to test the resistance so if your meter is powered off of a 9v batt. your actually checking ohms with 9v

[DELETED_Troll_Dragon]

(removed by author or community request)

[pfred2]

That scratching noise might just be your cat that wants to come in, or get out of the speaker ... meow?

[pfred2]

Sounds good. I did the math and if W = V^2/R then with a fresh 9 volt battery you're subjecting an 8 ohm speaker to a little over 10 Watts of power. 10 watts doesn't sound like much but distortion seems to do more damage to speakers in my experience than clean signals do. "Scratching noises" is my definition of distortion too.

A lot of times speakers don't have sophisticated crossovers in them, just non-polar electrolytic capacitors, and the caps fail more often than speaker drivers. Although I've burnt out a lot of tweeters over the years myself. Most tweeters can't handle too many watts.

[MikB]

For a PP3, actually getting your full 10 watts (1.125 Amps) isn't going to be very likely. That's quite a load ...

Usually this test is done with a 1.5V cell (AA), just to test polarity (positive battery to positive/red speaker = cone pushes OUT).