Use old speakers out of a Sharp stereo

Can you post a picture of what you are talking about?

On 10/23/2009 3:54 PM Eggbert spake thus:

Numbers on speakers of this type are absolutely no help. They're put there by the manufacturer, and usually cannot be traced at all.

Forget all this nonsense about "three cords" (by which I assume you mean wires).

The speaker has two terminals. Connect those two terminals to the corresponding channel's two output wires. Use whatever means is best for you (soldering, using existing push-on terminals, etc.) That's it.

(This is assuming a single speaker with no crossover, etc.)

It sounds to me as if what you have here is a stereo speaker system.

The "two cords with black insulation" are the common (ground) side of the speaker connection. It's a three-way connection, with the ground contact on the plug going to one speaker and then another wire continuing to the other speaker.

Each speaker then has an independent "hot" wire - one grey and the other brownish-red, apparently. Each of the hot wires goes to an individual contact on the plug.

This is very much the same sort of arrangement you'd see with a stereo headphone setup. If you look at the plug for such a headphone (usually a 1/8" mini "phone" plug) you'll see three contacts... the tip (at the end) which is normally the left-channel "hot" connection, the ring or collar (right-channel "hot") and the sleeve or base (ground or common).

See

There is no extra cord.

Each individual speaker needs two wires. If the signals (and amplifiers) were independent and isolated, you'd need a total of four wires to drive two speakers - two wires for the left speaker and two wires for the right speaker.

Commonly, though, the amplifier is set up so that one "common" wire is connected to the amplifier's ground, and can serve as the signal return for both speakers. This eliminates the need for one extra wire, and you can get away with three - one ground, one left-channel hot, and one right-channel hot.

Monaural headphones only need two wires, because the left and right channels are being fed with identical signals. That's not what you'd want for an MP3 player.

See the Wikipedia article above - it should give you enough information to wire this speaker up for normal stereo use with a 1/8" miniphone plug (which is what most MP3 players use).

It is questionable, however, whether a standard MP3 player has an amplifier powerful enough to drive a loudspeaker. Mostly, they're designed to drive higher-impedance headphones (32 ohms or above) at relatively lower power levels. Loudspeakers need more power to drive... either an amplifier in the stereo, or (in the case of computer A/V speakers and most external speakers for MP3 players) an amplifier built into the speaker itself.