Blew my 12".....AGAIN!!!!!

[Scottkarch]

I do not run the cabs connected together. They are on different/completely separate outputs, but the short answer is no. Speaker is wired correctly

It's not that one or the other is incorrect. But if they are wired oppositely, any overlapping frequencies will cancel each other our... the jack to the speaker could be opposite on one even if your speaker wires are fine.

With opposite polarity and playing the same note, one speaker will be pushing OUT at the same time the other is pulling IN. Happens all the time. It will kill a lot of the response.

Try the old 9v battery trick. Plug a speaker cable into one of the cabs. touch a 9v battery across the contacts of the speaker cable ( if you're using speakons you may need to make a short pigtail to attempt this ). Watch which way the speaker goes.. and note which contact you connected the + and - wires to. Then do the same with the second cabinet. The speakers on both cabs need to move the same direction when given the same signal/power.

Used alone either will sound fine, there is nothing WRONG with either one. You won't notice it until you use them together. If that';s the case, the easiest fix is to rewire the 112 cab.

 

[B-string]

I do not run the cabs connected together. They are on different/completely separate outputs, but the short answer is no. Speaker is wired correctly

It is also possible that the 4X8 is wired in reverse polarity than the Avatar. If you lost low end and apparent volume with both cabs in full range this would indicate that one cab is of opposite polarity.

 

[David Jayne]

I do not run the cabs connected together.

I didn't say connected. I said USING together. If the cabs are out of phase with each other, you'll have no low end. Easy to check.

 

[Scottkarch]

9v

I do not run the cabs connected together. They are on different/completely separate outputs, but the short answer is no. Speaker is wired correctly

You might not know this, but multiple outputs on the back of the amp are wired in parallel exactly there same as if you daisy chain multiple cabinets together. Electrically, there is no difference. And the best ways to check polarity is to either take them both apart and look/test, or try the battery test. Unless you did that test, they might be wired out of phase to each other. Neither of which is necessarily "incorrect", just different from one another. If the sound is as bad as you say together, that sounds more like two out of phase cabs than 2 differently voiced cabs together.

You have multiple people here coming up with the exact same advice... give it a shot.

 

[David Jayne]

9v


You might not know this, but multiple outputs on the back of the amp are wired in parallel exactly there same as if you daisy chain multiple cabinets together. Electrically, there is no difference.

In this particular case there is, because it's a dual-mono amp. Out of phase is just as possibile regardless.

 

[Scottkarch]

In this particular case there is, because it's a dual-mono amp. Out of phase is just as possibile regardless.

Aaah Interesting.. dual mono each channel could be out of phase with each other at the output?

Is the easiest way of testing to swap the polarity of the 112 and see if that makes an immediate difference? I can't think of a way to test visibly. Thanks So, you can also ignore my two outputs on one amp being in parallel bit too. I was assuming putting an amp into mono would just dump one big mono signal across both output jacks in parallel like in a non stereo amp. Thanks for the tip.

My hunch is on the 112 being out of phase with the other cab... I'm only guessing because I think I'd have noticed more of these out of phase posts with regards to running stereo amps dual mono... but I've been wrong plenty of times before. Now I'm really curious what's up.

 

[David Jayne]

Aaah Interesting.. dual mono each channel could be out of phase with each other at the output?

Very unlikely, but possible. I'm just saying the cabs could be out of phase regardless of how or what they're attached to.

 

[delta7fred]

Thanks for getting back to us.

Just for the hell of it, and to quell our curiosity, can you reverse the phase on one of the cabs and try running them as you did before (full range, one from each amp output).

If it sounds way better then one of the cabs (or amp (unlikely)) has a 180 phase shift (i.e swapped wires), If it sounds way worse then the phasing was correct and they are not suited to run together.

 

[Downunderwonder]

As well as the polarity experiment you should try shifting the crossover point with both polarity options. You might find a similar alignment of phase as you found so pleasant with the old cab.

 

[agedhorse]

The reason I bring this up is because not all drivers are manufactured with what is now considered (bass/PA) industry standard, with positive voltage on + terminal moving the cone forward (positive acoustic pressure).

I have encountered this more times than I would have expected (other than the well established legacy JBL inverted standard), sometimes due to the magnet being charged backwards (magnetizer polarity can be inverted to reverse the magnetic field) to be used with a reverse wound voice coil, a batch of voice coils being wound backwards, etc.

The acoustic polarity of a speaker can be reversed at manufacture/repair by:

1. Reversed magnetization

2. Reversed voice coil winding

3. Reversed leadout wires off the VC to the tinsels

4. reversed terminals (hard to do on most speakers, but very easy on some like differential drives)

Also, some driver manufacturers, especially in Asia and India, don't really follow the standards on anything, including speakers.

 

[pb9717]

It's not that one or the other is incorrect. But if they are wired oppositely, any overlapping frequencies will cancel each other our... the jack to the speaker could be opposite on one even if your speaker wires are fine.

With opposite polarity and playing the same note, one speaker will be pushing OUT at the same time the other is pulling IN. Happens all the time. It will kill a lot of the response.

Try the old 9v battery trick. Plug a speaker cable into one of the cabs. touch a 9v battery across the contacts of the speaker cable ( if you're using speakons you may need to make a short pigtail to attempt this ). Watch which way the speaker goes.. and note which contact you connected the + and - wires to. Then do the same with the second cabinet. The speakers on both cabs need to move the same direction when given the same signal/power.

Used alone either will sound fine, there is nothing WRONG with either one. You won't notice it until you use them together. If that';s the case, the easiest fix is to rewire the 112 cab.

112 is wired correctly. Without a doubt. But I understand now.

 

[pb9717]

The reason I bring this up is because not all drivers are manufactured with what is now considered (bass/PA) industry standard, with positive voltage on + terminal moving the cone forward (positive acoustic pressure).

I have encountered this more times than I would have expected (other than the well established legacy JBL inverted standard), sometimes due to the magnet being charged backwards (magnetizer polarity can be inverted to reverse the magnetic field) to be used with a reverse wound voice coil, a batch of voice coils being wound backwards, etc.

The acoustic polarity of a speaker can be reversed at manufacture/repair by:

1. Reversed magnetization

2. Reversed voice coil winding

3. Reversed leadout wires off the VC to the tinsels

4. reversed terminals (hard to do on most speakers, but very easy on some like differential drives)

Also, some driver manufacturers, especially in Asia and India, don't really follow the standards on anything, including speakers.

Ok...I'll put a battery to it and confirm.

 

[mbelue]

Ok...I'll put a battery to it and confirm.

This is only half the picture. Whatever the 12 is, should be the same as your 4x8. Ideally check them both and match them.

 

[pb9717]

This is only half the picture. Whatever the 12 is, should be the same as your 4x8. Ideally check them both and match them.

Will do....ideally they both should( and I believe are) wired correctly ( as I wired them both) so drivers in the cabs push out when connected to the 9V.
Then my findings are correct, that the two cabs simply don't sound as good as the Avatar alone.

Off to the bench......

 

[agedhorse]

Wiring doesn't matter if the drivers do not conform to the current industry standard. The acoustic polarity is the ONLY thing that is important, the batter test will confirm the proper acoustic polarity.

 

[will33]

Read like 13 pages of this stuff the other day, not reading 7 more.

You're expecting too much from a 112. ANY 112. The End.

 

[CL400Peavey]

Will do....ideally they both should( and I believe are) wired correctly ( as I wired them both) so drivers in the cabs push out when connected to the 9V.
Then my findings are correct, that the two cabs simply don't sound as good as the Avatar alone.

Off to the bench......

Take a look at what Agedhorse has to say about this, both his previous comments, and the one below. It isnt really about the cabs being "adequately" wired, but making sure they move in the same way given the same signal.

Wiring doesn't matter if the drivers do not conform to the current industry standard. The acoustic polarity is the ONLY thing that is important, the batter test will confirm the proper acoustic polarity.

I would daisy chain the cams together if possible, and test them at the same time. That way you will see them both move in, or out, at the same time if they are wired "correctly". Or they will move in different directions, and you will need to flip the leads on the 12.

 

[pb9717]

Read like 13 pages of this stuff the other day, not reading 7 more.

You're expecting too much from a 112. ANY 112. The End.

Yes. Agreed.

 

[Roxbororob]

Wow. I have to say, after reading all 21 pages with great interest over the past few days, that this is in fact a great thread. What a lively debate, all parties (all parties) had some contribution to make. Much appreciated that some of those a few notches up there stayed with it. Kudos to the stubborn OP who never really lost his cool and came round in the end. Im Scottish/Irish stock so this kind of discourse is to my liking.

Im really anxious to hear about the polarity results....

 

[bobcruz]

Wow. I have to say, after reading all 21 pages with great interest over the past few days, that this is in fact a great thread. What a lively debate, all parties (all parties) had some contribution to make. Much appreciated that some of those a few notches up there stayed with it. Kudos to the stubborn OP who never really lost his cool and came round in the end. Im Scottish/Irish stock so this kind of discourse is to my liking.

Im really anxious to hear about the polarity results....

I agree about the utility of this thread. The information that a driver can have reversed polarity even though it appears to be wired correctly is complete news to me and could save a person a lot of frustration if the problem occurs. Thanks, Mr. Horse, for that insight.