Ac30 speaker wiring negative positive lead..

Red is usually positive I think though it shouldnt make a difference as long as the speakers are wired together right

 

Get some masking tape - or some scotch tape with a little piece of paper - and mark the wires BEFORE removing them from the speaker in the future.

:^)

 

It matters that both are in phase to each other AND to any other amps you may use in a simultaneous multi-amp setup. I try to make my amps follow the industry standard positive voltage = forward cone motion (as defined by JBL, EV and others)

Generally the SLEEVE of the speaker jack (on amps so equipped) is negative and the tip is the positive going signal. On the AC30C2 the red wire is the "end" tap on the output transformer, (either 16 or 8 is available, according to the schematic I saw - you should verify which tap it is on your amp, IMO) The black wire should show continuity to ground of chassis. Easy to check that.

Generally the speakers themselves are marked with a red dot for the lead which produces forward motion with positive voltage applied. Examine them carefully - the markings are often subtle...but almost always there.

If they are not (unlikely) then here is how one identifies acoustical polarity. Obtain a 1.5 volt AA battery and two alligator or similar leads. You will just momentarily connect the battery to the speaker terminals. just "touch it" to move the speaker cone. As you do, simply note the cone direction and trace out how you have it connected to the battery. IF you got forward motion, trace the alligator lead from the battery + terminal to the speaker. THAT is your RED speaker terminal. Mark it now. If you got backwards motion, trace the negative battery alligator lead to the speaker terminal and mark THAT terminal as the RED. Perform the same test on both speakers. Now you know which is which on both loudspeakers.

Series wiring of two loudspeakers.

1. Connect the red wire of the output transformer (coming from the inside of the amp chassis, along with a black wire) to the red + terminal of the left speaker.
2. Connect a JUMPER from the NOT RED terminal of the left speaker to the RED + terminal of the RIGHT speaker. Got it? That's NOT RED LEFT to RED RIGHT with a jumper.
3. Now connect that black wire (which also came from inside the amp chassis) to the NOT RED/NOT POSITIVE terminal of the right speaker.

That's it. Ready to rock, in phase series wiring. Be aware that your amp now sees an impedance which is double that of each individual loudspeaker.

Be aware that excessively high Loudspeaker impedance mismatches can cause output transformer damage in certain designs.

 

3 things.

Red is positive.

Most the time speakers are wired in parallel not series.

You can check to make sure your speakers are in phase by hooking up a 1 1/2 volt battery and note which way the cone moves, forward or backward. They should both move in the same direction.

 

AC30s spkrs wired in series usually. 2 8 ohm spkrs in series connected to a 16 Ohm output.

 

1) As Blues Owl notes, Johnny, 'in general' does not apply to all specific situations. IF one wired these two 8 ohm speakers in parallel and ran them against a 16 ohm tap, one might be putting the amp in joepardy.

2) CBG notes that one wants to make a momentary...part of a second...contact with that battery. One does not want to 'hook up' a battery to a speaker. A constant voltage like that to a speaker will burn the voice coil down in a short period of time. I'm not sure that you meant 'hook up' in a literal sense, Johnny...but we have to be careful because someone might take it that way, right? I am clarifying for the benefit of those for whom this procedure is a new thing.

 

You wouldn't leave the battery hooked up it's only a momentary contact test, I've done it that way for several years and never had a problem.

I don't see why I have to defend myself when I point out a solution to a problem. WHEW!