how to tell + from - on a speaker

[Jimbilly]

I've got an old empty Univox u4044 cabinet, and enough 12" 8ohm 'vintage' speakers to load it with, but some are not marked + or -, and might not be correctly labeled anyway.  Is there a best way to figure out the pos and neg on these? I think I remember something about a 9v battery and watching which way the cone moves?

[Dave Scepter]

10 minutes ago, Jimbilly said:

I've got an old empty Univox u4044 cabinet, and enough 12" 8ohm 'vintage' speakers to load it with, but some are not marked + or -, and might not be correctly labeled anyway.  Is there a best way to figure out the pos and neg on these? I think I remember something about a 9v battery and watching which way the cone moves?

Yes, positive will thump outward 

[BoogieMKIIA]

I just loaded two Tone Tubbies in a cab, using the red dot for + as my guide. Seemed odd that one red dot was on the right side, one on the left side. Test driving the cab, bass was lacking.  Used a AA battery to check and found the problem, fixed it.

[Jimbilly]

4 hours ago, BoogieMKIIA said:

I just loaded two Tone Tubbies in a cab, using the red dot for + as my guide. Seemed odd that one red dot was on the right side, one on the left side. Test driving the cab, bass was lacking.  Used a AA battery to check and found the problem, fixed it.

I once had a '66 Showman with 2x15 cab, one of the JBLs had been reconed the wrong way, it was surprisingly not loud wired out of phase.

[Jimbilly]

A very nearly dead 9v battery works just fine.

[hamerhead]

....and don't forget to label it - correctly - once you figure it out.

[Cboss]

I'm always learning something useful on this wonderful site