Peavey Firebass cabinets connection

[agedhorse]

I'm not a technician, but I have a digital tester; what could I do?

A "digital tester" is useless for identifying this issue.

Look up speaker battery test and speaker polarity. Positive voltage on the + terminal should cause the speaker to move outward.

 

[Gene871]

A "digital tester" is useless for identifying this issue.

Look up speaker battery test and speaker polarity. Positive voltage on the + terminal should cause the speaker to move outward.

A "digital tester" is useless for identifying this issue.

Look up speaker battery test and speaker polarity. Positive voltage on the + terminal should cause the speaker to move outward.

If not, is it enough to reverse the connections?

 

[agedhorse]

Ideally you identify the NON-conforming speaker and swap the leads of that one. That's why I mentioned the battery test (twice).

 

[Gene871]

Ideally you identify the NON-conforming speaker and swap the leads of that one. That's why I mentioned the battery test (twice).

Ok.
Thanks

 

[toughluck]

If not, is it enough to reverse the connections?

As in run them to Peavey first and Mag next? It won't help.

Are your cabs actually matched? Do they have the same nominal impedance? If one is 4 Ω and the other is 8 Ω, the 4 Ω one will receive twice the current of the 8 Ω one.

I'm assuming that by "digital tester" you mean a multimeter.
Unplug the cables first.
Things to check:
1. Cable short.
- Check resistance between tip and sleeve at one end and at the other. It should be infinite.
- If it's not, the cable has a fault and there is a small current leak between the leads.
- If you don't know how to check for faults in more detail and how to fix the cable, don't bother.
2. Cable resistance.
- Short the tip and sleeve at end 1.
- Check resistance between tip and sleeve at end 2.
- Short the tip and sleeve at end 2.
- Check resistance between tip and sleeve at end 1.
- If your meter is not very sensitive it will show a short. If it's sensitive, it will show you the exact resistance of the cable.
3. Cable polarity.
- Check resistance between the tip at end 1 and tip at end 2.
- Check resistance between the sleeve at end 1 and sleeve at end 2.
- The meter should show a short (or very low resistance).
- If it doesn't, the cable switches polarity.
Repeat tests 1-3 for both cables.

If one cable switches polarity and the other doesn't, use the cable that switches polarity between the amp and the first speaker. Use the good one between the cabs.

4. Check resistance of cabs.
- Plug a known good cable into the cab
- Check resistance. It should be close to nominal impedance of the cab.
- Repeat for the other cab.

If resistance is much lower (or higher) than nominal impedance, it might have a crossover and/or speaker fault.

 

[Gene871]

I meant the internal connections of the speaker. However, the cabinets are both 4 ohm.
As soon as I can, I will do the checks you suggest.
Thanks

 

[agedhorse]

As in run them to Peavey first and Mag next? It won't help.

Are your cabs actually matched? Do they have the same nominal impedance? If one is 4 Ω and the other is 8 Ω, the 4 Ω one will receive twice the current of the 8 Ω one.

I'm assuming that by "digital tester" you mean a multimeter.
Unplug the cables first.
Things to check:
1. Cable short.
- Check resistance between tip and sleeve at one end and at the other. It should be infinite.
- If it's not, the cable has a fault and there is a small current leak between the leads.
- If you don't know how to check for faults in more detail and how to fix the cable, don't bother.
2. Cable resistance.
- Short the tip and sleeve at end 1.
- Check resistance between tip and sleeve at end 2.
- Short the tip and sleeve at end 2.
- Check resistance between tip and sleeve at end 1.
- If your meter is not very sensitive it will show a short. If it's sensitive, it will show you the exact resistance of the cable.
3. Cable polarity.
- Check resistance between the tip at end 1 and tip at end 2.
- Check resistance between the sleeve at end 1 and sleeve at end 2.
- The meter should show a short (or very low resistance).
- If it doesn't, the cable switches polarity.
Repeat tests 1-3 for both cables.

If one cable switches polarity and the other doesn't, use the cable that switches polarity between the amp and the first speaker. Use the good one between the cabs.

4. Check resistance of cabs.
- Plug a known good cable into the cab
- Check resistance. It should be close to nominal impedance of the cab.
- Repeat for the other cab.

If resistance is much lower (or higher) than nominal impedance, it might have a crossover and/or speaker fault.

Multi-meter isn't going to help diagnose a reversed polarity speaker.

 

[toughluck]

Multi-meter isn't going to help diagnose a reversed polarity speaker.

Absolutely. I'm not saying it will. But a reversed polarity speaker is just one hypothesis. I'm suggesting other things to try and check to rule out other possibilities.

The third step will detect a reversed polarity speaker cable. It's very unlikely, perhaps even impossible, for cables sold commercially, but I did see botch jobs where somebody resoldered a broken jack incorrectly, but since they were only using a single cab, they never actually detected this issue until they sold the cab with the cable and somebody hooked it up to their sound system.

I just think that there may be other possibilities apart from reversed polarity that may be checked,

 

[agedhorse]

Absolutely. I'm not saying it will. But a reversed polarity speaker is just one hypothesis. I'm suggesting other things to try and check to rule out other possibilities.

The third step will detect a reversed polarity speaker cable. It's very unlikely, perhaps even impossible, for cables sold commercially, but I did see botch jobs where somebody resoldered a broken jack incorrectly, but since they were only using a single cab, they never actually detected this issue until they sold the cab with the cable and somebody hooked it up to their sound system.

I just think that there may be other possibilities apart from reversed polarity that may be checked,

Maybe a 1% chance, which is why we test for the most likely things first.

 

[toughluck]

Quite so, but I think it's even more likely that one or more speakers in the cab are broken, maybe the crossover has a fault.

 

[agedhorse]

Quite so, but I think it's even more likely that one or more speakers in the cab are broken, maybe the crossover has a fault.

And the battery test is the most logical and easiest first step.

There is a high pass filter for the horn, but no low pass filter for the woofers, just directly wired.

I'm trying to help the OP identify the problem, I work with players and dealers all the time to get this kind of thing sorted out quickly and easily, without distractions.

 

[GtenderG]

I gigged with a Firebass for several years. Lots of great features. I did a lot of gigs with 2x 4ohm cabs (was asked to 'turn down!' once or twice). At 52lbs it became a bit much to lug around. Now my cabs weigh cabs weigh 1/2 that!
Rock that Firebass!

 

[Gene871]

Good morning. I'm getting back to the Firebass discussion with this question: I have a Peavey 1x15 BX BW cabinet to connect to it, and to complete the rig, I'd like to get a 2x10 Peavey from the same period. What I find through web searches is the 210 TVX, which has 175 watts RMS. Can anyone tell me why it has such a low capacity? Yet I see so many photos with the Firebass and these speakers underneath; in theory, at high volumes the 210 would take 350 watts compared to its 175... Is there something I don't understand?

 

[agedhorse]

The TVX is a different series, lowest cost and lowest performance. Nothing like your other cabinet.