Help w/speaker wire connection pos vs. neg

[Newbie-Doo]

Hi,

I picked up a beat to death and non-working Peavey Combo 300 amp today and thought I am a complete wiring electronics newb, I was able to find a broken connection and solder it back. So now it's working! Woohoo!

The only problem is, when I was taking it apart I didn't pay attention to which speaker wire went to negative and which went to positive.

One wire is yellow and one is blue. I put the blue on the negative and it works, but I want to make sure that is right so I don't fry the thing.

Thanks for you help!

 

[miroslav]

The wire that goes to the tip of the plug goes to the positive connection of the speaker....the wire from the sleeve goes to the negative.

 

[Newbie-Doo]

The wire that goes to the tip of the plug goes to the positive connection of the speaker....the wire from the sleeve goes to the negative.

I think these pics will give you a better idea of what I'm working with.

The ends of the twined yellow and blue wires go into the positive/negative clips on the speaker. I want to make sure I'm putting them back into the right ones.

Thanks for your help!

 

[MajorTom]

It doesn't matter which one, an analog audio signal does not have any polarity, it is AC. There is no such thing as the "right" way, Whichever way Peavey designated which color lead went to which terminal was arbitrary, and it can't hurt anything either way you put them. If there are 2 or more speakers, they all need to be wired the same way so that they are all in phase - meaning all cones are pushing out and pulling in, in unison. If one is out of phase with another, one cone will be pushing out while the other is pulling in, the result being that they are cancelling each others actions, and the 2 speakers together will actually be quieter than if there was just one. Some freq's will be cancelled more than others, and that will cause in a hollow thin sound.

 

[Roguetitan]

^What he said^

 

[miroslav]

It doesn't matter which one...

...If there are 2 or more speakers, they all need to be wired the same way so that they are all in phase - meaning all cones are pushing out and pulling in, in unison.

True...but the standard IS to wire Tip to Positive/Red...it just makes for more consistancy across audio gear...don't you agree?

 

[dintymoore]

It's not ac, it's dc, and it does matter.

I'd follow the wires back to the pc board and see if there's any markings there or phone Peavey and they'll tell you.

If I were guessing I'd say the yellow was positive (red terminal) and the gray is the negative (black). That would be a more normal setup than the opposite. Most often a color like red, orange, yellow... anything bright will be the positive and a color like black, green or grey (dull colors) will be used for the negative.

 

[Lt. Bob]

It's not ac, it's dc, and it does matter.

that's not correct ......... an audio signal is AC.
In fact, one of the ways a power amp can toast a speaker is by putting DC into it.

And it makes no difference as long as you're only using a single driver.
As soon as you have multiple drivers, they have to be the same so their cones are going in the same direction all the time because otherwise they'll cancel out some bass freq's.
But if it's only a single driver ...... then there's no cancellation.

Actually, to cover all bases, there are those that feel the very first pulse or attack of a note needs to push the cone forward. So it MIGHT make a little difference even with one driver. But the difference is small.
And you absolutely won't harm anything regardless of which polarity you use.

 

[ggunn]

True...but the standard IS to wire Tip to Positive/Red...it just makes for more consistancy across audio gear...don't you agree?

Well, no, actually. JBL speakers, for example, are reverse absolute phase from most other speakers, i.e., applying a positive pulse across the speaker terminals causes the cone to jump the opposite direction, which can be a problem when mixing brands of speakers. Even within an amplifier (my old Fender Super, for example), different channels may have opposite absolute phase.

Absolute phase doesn't matter with a single speaker, and the red/black color coding may or may not be a reliable way of matching polarity between speakers.

 

[Lt. Bob]

Well, no, actually. JBL speakers, for example, are reverse absolute phase from most other speakers, i.e., applying a positive pulse across the speaker terminals causes the cone to jump the opposite direction, which can be a problem when mixing brands of speakers. Even within an amplifier (my old Fender Super, for example), different channels may have opposite absolute phase.

I was gonna say that about JBL but I feared I might have remembered it wrong and would suddenly be declared stupid.


And yes, as you add stages of gain, you usually get phase reversals so if one channel has an extra stage of gain it'll have opposite polarity of the other channel.

 

[ggunn]

DC is how I check a speakers polarity where there's no marking.
A quick tap with a 1.5v battery. If the cone moves outward I consider where I put the battery positive to be the (+) of the speaker terminal. Don't know this is a standard way of doing it, but I picked this up somewhere years ago.

Hmm, I was typing when 2 posts appeared......

I use a 9V battery to do the "thump test"; It's OK if it's just for a second or so. If you leave a 9V battery connected to a speaker, though, it will eventually fry the voice coil.

 

[miroslav]

Well, no, actually. JBL speakers, for example, are reverse absolute phase from most other speakers, i.e., applying a positive pulse across the speaker terminals causes the cone to jump the opposite direction, which can be a problem when mixing brands of speakers. Even within an amplifier (my old Fender Super, for example), different channels may have opposite absolute phase.

Absolute phase doesn't matter with a single speaker, and the red/black color coding may or may not be a reliable way of matching polarity between speakers.

I haven't seen that specifically with the JBLs...interesting….but most every guitar/monitor speaker that I have seen had the Tip (or Hot on the XLRs) going to the speaker terminal marked with a + (usually also Red color).
Maybe it's just the JBLs that are odd (just like some TASCAM gear use to run Pin 3 as Hot instead of the more wider norm of Pin 2 Hot for balanced lines).

Anyway...I agree it doesn't *matter* with a *single* speaker, but I prefer to stick to a norm...'cuz let's say you track some guitar through that single speaker wired in reverse polarity.
Then you decide to double or triple track the same guitar part, but you use different cabs for those other passes or maybe decide to reamp that first track through those different cabs.
When you combine the three tracks...the reverse one will be out of phase with the others since all three passes are playing the same part.
So I figure...you might as well stick with a "norm"...and never have that come up.

Thanks for the heads-up on the JBLs though....

 

[ggunn]

Then you decide to double or triple track the same guitar part, but you use different cabs for those other passes or maybe decide to reamp that first track through those different cabs.
When you combine the three tracks...the reverse one will be out of phase with the others since all three passes are playing the same part.
So I figure...you might as well stick with a "norm"...and never have that come up.

If you play the track again on another amp with reversed absolute phase, phasing won't be a problem because there is no way that the waveforms will be synched and similar enough for speaker polarity to matter. Even with reamping, even though it starts out as the same waveform, I doubt you'd hear the difference. If one of your cabs has JBL's, it will be reversed, anyway.

 

[Victory Pete]

If you play the track again on another amp with reversed absolute phase, phasing won't be a problem because there is no way that the waveforms will be synched and similar enough for speaker polarity to matter. Even with reamping, even though it starts out as the same waveform, I doubt you'd hear the difference. If one of your cabs has JBL's, it will be reversed, anyway.

Interesting point. Please note: The following is VP's own personal opinion.
What makes double tracked guitars produce a chorus effect is because even though the same amp may be used, which is in phase with itself, The 2 guitar tracks are out of phase anyways because the 2 different guitar performances will never be in phase.
VP

 

[Newbie-Doo]

Thanks guys!

I am planning on buying an ext. 2x10 cab at some point, so using the "right" wire will be important. Now that I know I won't hurt it I can jam away with peace of mind. Woohoo!

For now I'll stick with the darker blue wire as the "negative" and shoot an email off to Peavey to confirm.

Thanks for making my day. You are The Mans! ha

Thanks again!
D

 

[ggunn]

Interesting point. Please note: The following is VP's own personal opinion.
What makes double tracked guitars produce a chorus effect is because even though the same amp may be used, which is in phase with itself, The 2 guitar tracks are out of phase anyways because the 2 different guitar performances will never be in phase.
VP

You are correct, sir, possibly even more than you know. Many folks use the word "phase" when what they mean is really "polarity", and I will admit to sometimes playing fast and loose with the terminology myself. If a waveform is exactly the same as another except that it is precisely opposite in magnitude, then it's reverse polarity, or 180 degrees out of phase for all frequencies which is a unique case of phase agreement.

If you play the same part twice, it is indeed out of phase because only the exact same waveform perfectly time aligned could possibly be completely in phase with the original. The chorus effect you are alluding to happens because portions of the second signal are in phase (both in the time and frequency domains) and others are not.

 

[miroslav]

...because only the exact same waveform perfectly time aligned could possibly be completely in phase with the original.

Agreed if the same part is played there might not be real issues since no one can play twice identically anyway ...but I think if you play the part only once using a reversed polarity speaker and then reamp that same part using a different, non-reversed speaker...
...those two parts are exactly the opposite of each other polarity-wise).
And often, people DO like to time-align doubled tracks up perfectly....no?...since the reversed polarity sound wave begins on the negative side while to second will begin on the positive side, that will be a problem.
While they won't cancel each other completely out as they won't be perfect mirrored copies (two different speaker flavors)...I still can't see how that would be a "good" combined sound VS having both begin on the positive side (or at least on the same side ).

Just seems like it would be a better practice all around to always wire everything the same...no?
Sometimes guys like to connect a second cab...why wonder which is which...?
Like I said...every speaker I've ever seen, (not counting the mentioned JBL) has always been wired the same way. I'm just seeing that as some sort of general norm/standard.

 

[Victory Pete]

Agreed if the same part is played there might not be real issues since no one can play twice identically anyway ...but I think if you play the part only once using a reversed polarity speaker and then reamp that same part using a different, non-reversed speaker...
...those two parts are exactly the opposite of each other polarity-wise).
And often, people DO like to line doubled tracks up perfectly....no?...since the reversed polarity sound wave begins on the negative side while to second will begin on the positive side, that will be a problem.
While they won't cancel each other completely out as they won't be perfect reverse copies (two different speakers)...but I can't see how that would be a "good" combined sound VS having both begin on the positive side (or at least on the same side ).

Just seems like it would be a better practice all around to always wire everything the same...no?

I would want all my speakers in my studio to all be in phase with each other, it is simple that way. There must be a standard reference, I assume all manufacturers use this standard and mark their red and black accordingly.
VP

 

[Newbie-Doo]

Here She Is!

Here is my Peavey Combo 300 Bass amp that I picked it up last night. If you can believe it, I got it for $30 plus tax. I found this same model for sale on Ebay for almost $700!

I needed something loud enough to play with a band but I just don't have the money for it. I asked the Lord if he could help me find something and he has provided!

It was absolutely filthy and all the screws were missing. The head was bobbing around loose and falling out. The power light came on but it wouldn't produce any sound at all. Not even buzzing or hum.

I took it home, took it apart, found a broken connection and soldered it, then I scrubbed and cleaned and added about $7 worth of screws to hold it together.

For about $40 total I have an awesome amp and I'm ready to rock with a band! Woohoo!

Thanks again for your help!
D

 

[Victory Pete]

Here is my Peavey Combo 300 Bass amp that I picked it up last night. If you can believe it, I got it for $30 plus tax. I found this same model for sale on Ebay for almost $700!

I needed something loud enough to play with a band but I just don't have the money for it. I asked the Lord if he could help me find something and he has provided!

It was absolutely filthy and all the screws were missing. The head was bobbing around loose and falling out. The power light came on but it wouldn't produce any sound at all. Not even buzzing or hum.

I took it home, took it apart, found a broken connection and soldered it, then I scrubbed and cleaned and added about $7 worth of screws to hold it together.

For about $40 total I have an awesome amp and I'm ready to rock with a band! Woohoo!

Thanks again for your help!
D

Good for you! I just retired one of those, we used it for years. It is currently for sale here. It was replaced with an Ampeg SVT Classic with 8-10 cab. Good luck, it is a workhorse.
VP