Wiring a 4x12 cab- UPDATE!!

Wiring a 4x12 cab- UPDATE!!

Hi everybody!  I decided I needed to post this update to my earlier blog about wiring a four-speaker cabinet.  Sometimes a man has got to admit when he's wrong - and this is one of those times. An extended member of the WGS family has done a fantastic job of dissecting the pros and cons of the two methods of wiring a 4-speaker cabinet ... and I want to share it with you!  In a few days I’ll be bringing you the best Marshall sleeper amp of all time - this is the amazing deal you all want!  Until then, read on for some valuable, and extremely well thought-out info on setting up a 4-12 cabinet.

From: Randy Eichman 

Hello, I just read the blog entry on wiring up 4x12 cabs, and had a few observations that folks might find useful.

First, I agree that the Series-Parallel (S-P) method is probably the preferred over the Parallel-Series (P-S) method of wiring.  But the reasoning as to why, and what happens in the event of a speaker failure, is slightly inaccurate.

In the P-S wiring, a single speaker failure would not cause the cab to stop working; you would be left with 3 speakers working, and the cab would change from 8 ohms to 12 ohms, because you now have a single 8 ohm speaker in series with the 4 ohm combination of the other two speakers.  Also,  the distribution of wattage among the speakers would change... the single 8 ohm speaker would now be handling more power than the other two speakers in the good pair.  If you were pushing 100 watts into the cabinet, the two speakers in the good pair would drop from 25w each to about 10w each, and the other single speaker would go from 25w to about 40w (not good if your cab is 25w greenbacks).  Obviously, all this is bad -- your amp now sees 12 ohms, not 8, and your speaker power output is unbalanced.  The only advantage to using this wiring method, it would seem, is if you must have two separate 4 ohm loads in the cab that you need to use in a stereo mode.

In the S-P wiring, a single speaker failure would cause 2 speakers to stop working, you'd be left with two working speakers, and your cab would go from 8 ohms to 16 ohms.  Your output power would drop quite a bit, but most heads would let you switch to 16 ohms temporarily until you could repair the cab.  And the speakers themselves wouldn't be suddenly handling more power.  Definitely the better way to go, in my opinion.

Another thing to consider is how you pair the speakers up; if all are the same type, it doesn't matter, but if you mix different types, like two ET65's with two Vet 30's, it would be good to put one of each in the series pairs in the S-P setup, so if one speaker fails, you still have one of each type working.   Randy

P.S.  I just ordered my first WGS speaker -- a Green Beret -- a few days ago, and can't wait to try it out in my 2x12, alongside the Eminence Private Jack.  I'm removing the Red Fang and replacing it with the Green Beret; the Red Fang didn't seem to like my plexi reissue very much, and wasn't recording very nicely when mic'd.  I may end up putting another GB in there, or maybe mix the GB with a reaper or something else.  What would you suggest for a good combo with the GB, for a 50watt Plexi head, in a big 2x12 cab?  (I like ZZ Top and Zeppelin tones, classic british crunch.)

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Hi Randy, and thanks!

You have a given this more thought and done a better job of running the pro’s and cons than I have.  Yes, I will share your wonderfully thought out insights with the WGS family on my blog.

As for the pairing with a GB in a "big" 2x12 cab - my normal response would be to go with an ET65 for the extra meat that it would give you on the bottom.  However, if you already have an oversized cab, plus you specifically mentioned that you were going for classic British crunch, I think in your specific case, I would suggest simply pairing with another Green Beret (if that meets your power handling needs), or maybe a Vet 30 or Retro 30.  The Reaper would be a fine choice, but if you go that route, it will take it a tad bit away from the classic British sound.  The reaper has one foot in classic Britt soil, and one in classic Yank soil!    -Vaughn-

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