Rewire 4x12 as 2 * 2x12 for purpose of...

sidepartings26

Senior Member
Joined
Mar 19, 2009
Messages
416
Reaction score
7
Helloooo

Thinking of rewiring my Marshall 4x12 1960BHW as two separate 2x12 circuits.

The reason being I can then sell my OCD V3 pedal for £150 and buy a used Tiny Terror for £200 (approx +$75). If I stick the terror on the spare out of my Voodoo lab amp selector I can then have the 1987x and the tiny terror through the 4x12 and the Twin reverb on its own, all switchable on/off/combined. Also I could run two outs from the 1987x and use all 4 speakers if need be some times (I think?)

This will make the tiny terror an infinitely better extra overdrive option than a pedal right? Plus then I have a better nasty amp for home use and small gigs etc i.e. versatility. I can pull the Marshall volumes back a bit with my Webber Mass Lite if needs be - or will it still be WAY louder?

The cab has 4x Celestion G12H-30 which according to the website are nominal impedance 8 and 16 Ohm - I guess I have to check which it is, the overall impedance of the cab is 16 Ohms currently.

As you can tell I am no impedance matching specialist but I think I could figure it out. The main problem I can think of is I would need a new or two separate backplates with no conductive material between. I assume the wood with tolex is good enough?

Just wanted to see if this is a good idea? If my assumptions are correct in specific areas e.g. still being able to use two outs from 1987x into two separate 2x12 circuits and adjusting the Ohm setting on the amp (4/8/16)? Plus, is this actually a good thing?!!!!

Would love to hear some feedback.

Peace all
 

Cygnus X1

Senior Member
Joined
Jul 18, 2009
Messages
6,570
Reaction score
2,967
I wired my Peavey 5150 cab (4x16 ohm) with two jacks, one stereo with internal cutoffs.
So I have 4 ohm mono, and 8 ohm stereo in the cab.

You can use this resource to figure it out:
Wiring a 4 X 12 Speaker cabinet
 

sidepartings26

Senior Member
Joined
Mar 19, 2009
Messages
416
Reaction score
7
Thanks for the link I think this is the best page on it that I found too. What do you mean 'with internal cuttoffs' - and how did you add another jack?

Do you regret it or are you happy? Do you think it IS a good idea and that I can get the setup I described?

Also you are saying that you looked at the 4x12 configuration on that page and used something like 'mono/stereo in same cabinet'. I was looking at the 2x12 page and treating them totally separate. Does it make sense to treat it as a 4x12 as opposes to two 2x12?
 

Cygnus X1

Senior Member
Joined
Jul 18, 2009
Messages
6,570
Reaction score
2,967
Since I frequently switch to test different amps...I love it.
Mono/stereo in same cab.

You need to have a double cutoff type stereo jack (as described in that site) to
get it to work.

Sacrilege, but I put a blank in the hole in the back and put the
jacks into the side handle!
I have the cab backed up to a wall and got tired of having to pull it away from
the wall to switch plugs.

(So murder me or something...it actually doesn't look bad).
 

sidepartings26

Senior Member
Joined
Mar 19, 2009
Messages
416
Reaction score
7
Since I frequently switch to test different amps...I love it.
Mono/stereo in same cab.

You need to have a double cutoff type stereo jack (as described in that site) to
get it to work.

Sacrilege, but I put a blank in the hole in the back and put the
jacks into the side handle!
I have the cab backed up to a wall and got tired of having to pull it away from
the wall to switch plugs.

(So murder me or something...it actually doesn't look bad).
So you must have used a normal jack and one of these (the stereo 3 position one):
1/4 dpdt jack

They're not expensive at all!

Like he says though you can get external DPDT switches.
 

Cygnus X1

Senior Member
Joined
Jul 18, 2009
Messages
6,570
Reaction score
2,967
So you must have used a normal jack and one of these (the stereo 3 position one):
1/4 dpdt jack

They're not expensive at all!

Like he says though you can get external DPDT switches.
I don't like to explain things in detail for this very reason.

You, looked, you understood, and you nailed it!

:applause:

Thus you have learned.

:cool:
 

sidepartings26

Senior Member
Joined
Mar 19, 2009
Messages
416
Reaction score
7
I don't like to explain things in detail for this very reason.

You, looked, you understood, and you nailed it!

:applause:

Thus you have learned.

:cool:
You overestimate me!

I don't really see the advantage of the 4x12 setup. If I do two separate, simple, 2x12 setups and use an external switch to say what is on/not on at the same time i.e. my Voodoo Lab amp selector pedal isn't this the same thing except I control the switch on the fly without having to unplug and plug in jacks at the cab.

Then, if I wanted to connect the Marshall 1987x head to all 4 speakers, it does has two speaker out jacks. So if each 2x12 circuit has 2*8 Ohm speakers in series then each presents a load of 16 Ohms i.e. it is the equivalent of the head seeing two separate 'cabs' at 16 Ohms i.e. set the head output at 8 Ohms and use both outputs. (If I have 16 Ohm speakers I can wire each 2x12 circuit in parallel to present a load of 8 Ohms * 2 'cabs' = 1987x set to 4 Ohms right?)

I know it sounds crazy but I like the idea of not having the tiny terror and 1987x signals 'mixing' electrically while in stereo mode. I am way out of my depth. So please tell me if I am on/off track. Would appreciate your input Cygnus!

Either way. I am going to have to get some sort of jack plate fitted / mutilate the back of my cab. boooooooo

If any one wants to make a general comment about whether they think this is a cool idea or not please do....
 

opalburn

Senior Member
Joined
Aug 12, 2008
Messages
801
Reaction score
159
i think that if it is something that you can get use out of, then it is a good idea. you will have the option of using the cab for two heads, or hooking one head up in stereo, so you aren't really losing any fuctionality with the cab... so i say go for it...
 

sidepartings26

Senior Member
Joined
Mar 19, 2009
Messages
416
Reaction score
7
Say I use one of these for the second cabinet input:

Marshall, Dish Assembly V12X

(that's ok isn't it - no need for a large panel)

How far away does it need to be from the existing input panel? Obviously they cannot be mounted together on a conductive surface but I guess the birch cabinet is not conductive enough to cause any problems?

I was thinking of removing the existing large rectangular plate and replacing it with two of these within the same area (so the flight case fold down flap will still expose the cabinet input section and the new input will be available too). Will this be too close, or will I escape conductivity issues?

Thanks all
 

sidepartings26

Senior Member
Joined
Mar 19, 2009
Messages
416
Reaction score
7
Conductivity

According to this wood seems neither conductive or non conductive. Maybe an idea to somehow use rubber to mount the new input....
 


Latest Threads



Top