# How to make a Marshall MG412 cabinet useable



## JCM900MkIII

I have owned an MG412A slant cab since 2005, but didn't use it much. Couldn't decide whether to sell it (loose money), keep it for practice only, or change out the G12-30MG speakers (use it Live). Even Marshall's lower end MG cabs are made very well, and are very sturdy even though the speakers aren't that great. Somewhere I read that Celestion G12-30MG speakers are just cheapo Vintage 30's with ceramic magnets. The MG412 cabs have a predominant loud upper midrange, piercing highs, and a mediocre, flabby bottom end. I had 2 Eminence Red Coat Wizard, 8 ohm, 12" speakers that I wasn't using. They are very articulate, lower midrange speakers, with a tight bottom end, smooth highs and longer transition to break up. The Wizards are very efficient, 103dB (1W/1m), where the Celestion G12-30MG's are only 96dB (1W/1m). With that in mind, if you load the 2 Wizards in an X-pattern you will just drown out the less efficient Celestion G12-30MG's. I loaded the two Wizards on the bottom to take advantage of the great bottom end in a closed back cab and to not blast people right in front of the cab. I left two Celestion G12-30MG speakers in the slant top so they would project more and balance out the heavier Wizards and lucked into a great combination. It is similar to a Celestion Vintage 30's & G12H-30's combination. By investing in 2 Red Coat Wizards, you can turn that MG412A cab into a good gigging cab. Keep in mind the Wizard speakers will add 16 lbs. (magnets weigh 56 oz. each, baskets are stamped steel), to the 65 lbs. weight of the MG412A cab.


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## scat7s

my mg cab sounds much diff than yours. those 'celestions' are celestion in name only, from what ive read. and my ears agree with that theory. 

i find them to be extremely dark and inefficient, like a fucking blanket over the cab. horrible speakers. 

ive tried to balance them out too, by replacing a pair w/some eminence speakers. much improved, but still leaves much to be desired imo. 

about the only thing i can think of that the MG speakers would be good for is to build an attenuator or to use as a load for servicing your tube amp. 

not trying to be argumentative, but i dont think they are in any way designed to be a vintage 30. my personal theory was that they voiced them dark and muffly maybe to counteract the thin overbearing highs in their SS MG amplifiers. a counterbalance.


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## JCM900MkIII

scat7s I did say "cheapo Vintage 30" (Vintage 30's cost $145 to $150 each now). I'm not boasting about any great tone coming out of G12-30MG speakers, but the (2) Red Coat Wizards really make the cab passable, where as before mine was collecting dust. In addition, I am using a Marshall 50w Tube amp, not a thin sounding (ss) MG100DFX and that makes a big difference. If I can find a couple of used 8 ohm, Celestion Vintage 30's, for a good price I may replace the other 2 G12-30MG's later.


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## chuckharmonjr

I lucked into a tore up crate blue doo-doo cabinet for 60 bucks last summer. WhenI say tore up, I mean the grey carpet crap was half tore off, a handle had literally been torn out...and the wood of the box itself was broken off in one corner. The good news?...There was 4 perfect G12M-70's in it and the kid that had it needed money bad. I put those real Celestions in place of the Chi-lestions in my MG412A, and sitting on top of my 1960B the setup sounds fantastic. Looks a little funny being smaller, but sounds great!


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## JCM900MkIII

Celestion G12-30MG speakers have small ceramic magnets to keep the weight of the MG412 cabs to 65 lbs. If I put (4) Wizards in the MG412A cab it would weigh 90+ lbs., hard to handle.


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## scat7s

that was why i bought that cab in the first place, it was a little smaller, easier to handle by myself. my back aint what it used to be haha. 

and jcm900mk111, i wasnt trying to bust balls, i just found my MG to be very different sounding than you described, opposite, actually. 
nor was i trying to imply you were playing an MG head, i was just sharing my theory of why they install such dark speakers in that cab, to balance the shrillness of the SS MG.

thats all. no disrespect intended...


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## mike Kill Wolfe

I have an old mg412 that i use for practice when i dont feel like lugging my beast of a mesa around.. but anyway... i took the back off from it. and it made it a little bit better. the low end is a lot louder.. still sounds like shyt but its better than it was..


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## zenfly

Look into WGS speakers.. "and thats all I have to say about that" 

F. Gump

http://www.marshallforum.com/cabinets-speakers/48731-warehouse-speakers-experience.html


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## gjohnson

Buy some used G12T75's. They're abundunt and $cheap$. Your rig will sound like a monster compared to those MG speaks.


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## GIBSON67

I made mine usable by replacing all the speakers with Greenbacks. It's a little boomy sometimes but sounds really good overall. I also screwed down the rear panel to the center post.


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## Micky

GIBSON67 said:


> I made mine usable by replacing all the speakers with Greenbacks. It's a little boomy sometimes but sounds really good overall. I also screwed down the rear panel to the center post.



Or, you could load it with some Eminence or WGS speakers.

The cab itself, though made of MDF may be heavy, but slam some casters on it and load it up. Could very well be the best investment you ever make...


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## B.Gloob

I think that the MG412's make lovely end tables.


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## GIBSON67

I'd really like to try it as a 2x12 and just plug the other 2 holes. 

One day, I'm either going to get another MG412AR and make it a 2x12 with the new Creambacks, or sell my MG and get a 1960TV or a Mode 4 and load it with Greenbacks.

I really wish they made the Red S&P like mine in a B cab...


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## paul-e-mann

The way to make an MG cab useable is sell it to someone with an MG head. Go buy yourself a 1960 cab.


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## elrostro87

Thanks for this man. I just bought this amp and was looking for a way to improve it. What do you think if I do the Eminence speakers on the Bottom and some Celestine vintage 30's or Grenbacks on top?


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## MesaMan50

You can do searches in this forum for opinions on the MG 4x12. I'm happy with mine but I replaced all 4 speakers. 

Your idea sounds reasonable, I believe there is a 3 Db difference between this 2 speaker types. Put the louder ones on the bottom. 

Secure the mid post to the back with a 2" screw. Do not over tighten the speaker retention screws it will strip the MDF quickly.

Good Luck


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## Ufoscorpion

I'm with pedecamp , sell it and buy a 1960 . The 1960b I got about 3-4 months ago that's in great condition cost me £ 150 . It costs more to buy two new 75's on their own , and they won't even be nicely broken in like used ones . Gotta make sense surely ?


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