LS 4x12 "mod" - MS12

[user 41014]

Fulfilling a long standing desire for a 4x12 of MS-12's.

Heads up: no front loading a LS 4x12 due to the front lip clearance.

There are also 2 MS-12 Black Shadows I just discovered tho some of you may know this.

 

[user 41014]

Oddly which I guess means musicians are odd this was packed with 4x16ohm V30's all of the same Dec '04 date code.

It was wired all parallel for 4 ohm cab which is cool for easily running a full stack.

I'd much prefer a black front grill on these blue LS classics but it would have to be cloth and it doesn't look fun to separate the grill from the frame.

I bought one 6 leg MS-12 which I never opened till just now and didn't catch that it was different, reconed (no ribbing) and which barely fits the back loading on the bottom of the LS cab. The 5 leg frame MS-12's of which I think all my others are will require a little wood brace cutting to fit in on the bottom.

I haven't weighed the MS-12, but the mounting bolts are marginal. They are not good enough for an EVM for sure. I would say for non-gigging use it is ok but for shipping would be a potential danger. I have tons of beefier t-nuts/bolts but for my use it's not needed.

 

[bandit2013]

I would not use T-nuts as they require a larger hole and there is not much wood between the screw hole and speaker hole. It is very easy to remove the original screws and replace them with longer one's. I generally use 10-24 screws. You will have to open up the hole just a bit so the new screw will fit properly. I loaded my OS Recto 412 cab with EVM12L speakers, I needed longer screws and the 10-24 worked out. I think I used 1.5 inch screws, with the allen key head. Black oxide type, steel. I do not see them through the black grill. It may help to use a disc washer between the speaker lip and the locking nut.

 

[user 41014]

When I "modded" and re-enforced a OS and a halfback for 4 x EV 12L these #10 t-nuts were critical. It has to be done carefully but there is no way I would trust a 12L to 4 bolts/nuts.

For those, the #8 bolts stay and the #10 t-nuts get installed in between. Yes, it is a tight fit against the opening but the t-nut prongs if also placed carefully make for a solid install. It can and has been done.

I also use those same black metal oxide allen wrench bolts. They fit in the frame if front loading a driver and I have more of those bolts/t-nuts than everyone on here together could use in a lifetime.

I just found my meter after going on a "feed the disease tour" (west coast mesa gear journey) so I'll ohm match the MS-12's I have today and chisel or cut some wood out to fit the drivers in the bottom.

 

[bandit2013]

I just noticed that there is not much room between the speakers. That is one tight fit. I am so used to the Standard or Oversized Recto cabs I have not considered Lonestar cab to be that much different. I guess it is more of a compact 412 than the traditional Recto 412 cab. Looks like a fun project to work on. Good luck with that.

 

[user 41014]

Yeah, the LS and 3/4 back are a couple inches more narrow and very tight. One of these days I'm going to make a open back piece for a Trad and / or OS.

The 3/4 back 4x12 sounds immense so I'm not complaining but would like to hear a bigger space. I assume it doesn't matter as much being open back but I generally hate a short 1x12 like almost all the Mark combos. The EV is able to roll over the space limitation like a freight train but will still blow away that performance in a thiele.

The longer 1x12's like a ED/5:50/etc sound way better than the 19" with mesa's standard drivers so I can't help but think a OS with cut outs for about 1/4 (holes/roadster like slots/top cut/combination of) would sound killer. I could also compare Creams closed back vs open back that way in a OS.

 

[user 41014]

Chisels turned out to be a good choice with the nails. Then hammer the nails down so not to rub on the drivers.

With no working postal scale I resorted to a homemade counter-balance using bags of flour, rice and sticks of butter so take the weights with a grain of salt....

I'm calling out 3 versions of the MS-12 and I measured a 5xxx with food and then relative to 5xxx:

Early MS-12: 5 legged rough cast 14.5ish lbs
Mid MS-12: 5 legged smooth cast 15.5 lbs
Late MS-12: 6 legged and just grains lighter than the 15.5 lbs reference driver

2 out of 3 aint good for my purchased speakers. Two must have come from a halfback given the consecutive serial numbers, 2xxx with the rough cast. I had to start robbing combos but am trying to leave my 1st IIB, #1532 and my pair of IIC combos as is. There's another MS-12 around here somewhere so the search is on.

The 6-legged #9681 came in at 7.9 ohms DCR, an early #2147 at 12.3 ohms. Aside from those 2 that might have issues, 5 are coming in all very close at 6 2/3 ohms.

With the driver falling right in the middle of the 10.5 lbs standard V30/MC90 that uses the #8-32 and the 20 lb EVM 12L that would laugh at 4 of those #8's the decision and purchase has been made for a middle solution for mounting screws. I'll stick with the 1-1/4" truss head for low profile screws but up it to a 10-32.

There isn't enough exposed wood for in-between t-nuts on the LS cab so if one wanted to take it to 8 lugs it would have to be screws- machine or wood. For the record wood screws that aren't snugged up occasionally have a bad relationship with EVM 12L's in 40 year old cabs with the cab getting both the short and long ends of the stick beating.