Identical cabs but different volume?

[Deaf Ear]

I had a friend today bring over his cab, which is the same as mine, Mesa Oversized Slant. We noticed that they both sounded quite different, which could be age, etc, but what got me was the difference in volume.

My cab was about 3 times louder than his with the same amp. Any clue what would cause this?

 

[53Crëw]

Are you sure they have the same speakers inside? One may have C90's and the other V30's.... I'm not sure what the sensitivity difference is, but a different sensitivity rating for two different speakers would cause a difference in volume, as well as tonal difference.

 

[Deaf Ear]

Yeah, they're both V30 cabs. The only physical difference between them at all is that one is orange and one is black. There must be something wrong with his for it to be so much quieter. That is, unless something could be off about a cab that would make it louder than it should be, which I would doubt.

 

[Deaf Ear]

I stuck a multimeter on the speaker cable for the 8 ohm jacks of both cabs.

His cab measured 8 ohms...

Mine measured 12ish....

This leads me to believe that I may have a speaker out on my cab. Would a blown speaker make a cab over twice as loud though?

 

[JeffTD]

Blown speakers should still have resistance, unless it's become unwired?

 

[Deaf Ear]

Getting out the drill now. I'll report back.

But even if it came undone somehow, would that explain it being ridiculously louder than the other cab?

 

[JeffTD]

Yup, impedance affects volume pretty directly!

 

[Deaf Ear]

Here's what I've been able to determine so far.

The 8 ohm jack measures 12 ohms.
The left 4 ohm jack measures 4 ohms.
The right 4 ohm Jack Measures 8 ohms.

All connections are solid in both circuits.

 

[Deaf Ear]

Blown speakers should still have resistance, unless it's become unwired?

Are you sure about that? Everything I see on blown speakers says they'll give infinite resistance.

I'm starting to think I may actually have a speaker that went bye bye, and I haven't noticed it because the volume actually got louder. I never noticed any crackly blown speaker sound though, so if it went, it just popped.

 

[JeffTD]

Ah fuck me, was confusing ripped with blown; blown actually means the circuit is broken so you're right in saying you'll get a non-reading.


*EDIT* Take a 9v battery and have a friend touch the tip/sleeve of the speaker cable to the positive/negative (doesn't matter which) terminals of it, and see which speakers move when contact is made. The blown one won't move.

 

[Deaf Ear]

It was a blown speaker. I'll order a new one after Christmas madness is over. Thanks for the help solving this one. I've never had a speaker just die before. I'm glad I caught it before it could damage any amps.