Determining speaker polarity

[Oldmactech]

Reassembled a Peavey amp after replacing power transformer. Works fine, sounds a bit wonky, brittle.. I took a pic of the speaker wiring connection and put it back that way. Yesterday, I reversed the polarity and seems to sound better. I know this amp was apart before so before I assume the polarity was correct, is there a way to test without having to disassemble again. I know how to test the speaker but not the speaker cables.

[Jon Snell]

Plug the speaker lead into the speaker cab. Use a PP3 9volt small battery and the speaker cone should push out from the magnet if the positive battery terminal goes to the tip of the jack plug and the negative to the sleeve.
Test momentarily and observe the direction of the cone.

[g1]

If it's a single speaker amp, polarity to the speaker should have no noticeable affect on the sound.
Unless one of the speaker terminals is connected to the speaker frame, that could create some potential issues.

[mozz]

It won't sound any different no matter which polarity, as long as it's a single speaker as was said. If you heard a difference, it's your mind playing tricks.

[eschertron]

Yesterday, I reversed the polarity and seems to sound better

"If it sounds better, it is better" - Benjamin Franklin, or maybe Enzo

Your perception of the sound is all that matters. caveat: there is an argument that LF energy, like kick drum wavefronts, are sensibly different when the phase is reversed. You would need to calculate (or measure) the phase relationship between the input jack and the speaker jack. Having done that, there's no real guarantee that a (near) zero phase between input and output really is the version of 'better' that you hear.

[Helmholtz]

there is an argument that LF energy, like kick drum wavefronts, are sensibly different when the phase is reversed.

Maybe, but don't forget that sound spreads by spatial waves. And the phase of the wave periodically reverses with the distance from its origin (speaker).
E.g. a 400Hz sound wave reverses phase every 17"of increased distance from speaker. Different frequencies reverse phase at different distances.

[The Dude]

Generally speaking, though there are a few exceptions, chassis ground is speaker ground. So, if you want to know which amp wire goes to speaker ground, use your meter and see which wire is at chassis ground potential.

[Oldmactech]

Thanks. I replaced the 3 12ax7’s with groove tubes. (Had something called Ruby in it).
Sounds better still. Put the speaker wires back to the position I found them, sounds “betterer.”

or maybe not, who knows.

thanks again.

[Enzo]

Neither Groove nor Ruby make their own tubes. Ruby is a large seller, I used them for years. But they don't hide the fact their tubes are JJ or Sovtek or EH or SHuagang..Groove tube as well sells you 6L6s that are really Sovteks. it isn't secret.

[Pedro Vecino]

Peavey normally uses blue and yellow wires to the speakers. Blue is the one that is connected to the negative.

[Enzo]

So, we hinted... is this a single speaker amp? Or is it a 2x12 or other multispeaker arrangement?