Two speakers working harder in 4x12?

  • Thread starter Thread starter D-Rock
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D-Rock

D-Rock

Well-known member
I put 4 V30's in my Krank 412 and notice the upper right and lower left speakers flexing and moving more that the other two. They also seem louder. Wiring is the same as stock just a simple speaker swap and re-solder was done.
Do I have a major issue here or what?
 
Yeah all 16 ohm.
Replaced speakers that were all 16 too.
Cab is 16 ohms mono
 
I dunno... I just can't seem to concentrate enough for form a coherant though with your sweet avatar looking at me...
 
Red_Label":3c4tbm52 said:
I dunno... I just can't seem to concentrate enough for form a coherant though with your sweet avatar looking at me...
Click to expand...
Concur.
 
Sounds like you may have the polarity switched somewhere along the way. If you watch closely do the lazy speakers seem to move inward? You could test with a 9v battery, placing the + of the Battery on the tip of the cable, and the - to the sleeve. If the loud speakers move out, and the others in, you'll know it's wired incorrectly.
 
A few things come to mind, assuming it is wired correctly and the speakers are identical in age:

1) Maybe you have a bad solder connection. Measure the impedance (resistance) of the cab with a multimeter. Wired properly, you should measure between 13-15 ohms.

2) Wired in a) Parallel - Series or b) Series - Parallel? While the equivalent load is the same, wired in Parallel - Series off the post, the Parallel pairing is the path of least resistance.

3) As mentioned in an earlier post, it could be a polarity issue, but with a mono wiring set up, it shouldn't be.
 
D-Rock: Time to disconnect the speakers and measure all of their ohm ratings with a multimeter individually. They may be marked as 16 ohms, but it sounds like two are 8 ohms since they seem louder.

And I'll need the large mb version of your avatar sent to my email address asap. :D :yes:
 
If they are all equal as far as impedance and electrically sound, maybe when they were installed they could be binding mechanically if the frames weren't torqued down properly/evenly?
 
I'm having the same issue right now. I have a Splawn 4 x 12 that I had 4 Big Blocks in. I swapped out two of the Big Blocks for Small Blocks--wire-for-wire. The Small blocks, although 55w instead of 60w, seem to have less cone travel and slightly less volume, although that might just be a frequency thing. All of the measurements on the multi-meter are correct. All individual speaker impedance is correct and all of the jacks are showing the correct readings as well. When I check each of the pairs I show 8 ohms (6-7) and when I check the whole cab in mono I get 16 ohms. Both of the bottom stereo 8 ohms jacks are working correctly as well and measure correctly and only drive the correct half of the cab. The 9V test shows that the speakers are not out of phase, neither in pairs nor for the whole cabinet. The Big Blocks just seem to travel farther than the Small Blocks. I'm going to test another pair of Small Blocks and see what's what...

I'll also check the mechanical binding...
 
When speakers start to fail they do lots of interesting things.

1) Get quieter or start to sound off (polarity/out of phase type sounds/less bass/more treble) to your ears.

2) If you use my method to mount your speakers it's pretty hard to overtighten and twist/bend/compress your frames (and therefore your cone), which in turn warps the voice coil out of shape. Remember, there's only .005-.009 of clearance in the voice coil gap (depends on the speaker/coil/spec/etc) and that's a pretty thin margin of error.

How to install your speakers: http://www.scumbackspeakers.com/speakermounting.pdf

3) If you have two speakers with a stiffer spider and two with a looser spider that would explain the travel of the cone being longer/farther on one than the other.

Good luck gents!
 
I went ahead and used the below diagram and just redid the whole wiring.
Looks like the Krank employee (circa 2004) wired the cab wrong. I guess I shouldn't be too surprised by that. It was a damn piss off though.
The positive and negatives were all mixed up. I guess it resulted in two speakers working harder than the other ones.
Anyways, got it done and the cab sounds proper now. (and badass!)

I also rear loaded the V30's (V30's on top, Vet30's on bottom) whereas the cab was originally front loaded. Worked out fine. Just some reverse bolt/screw work needed.

 

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