8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

JMP/HBE

Well-known member


Ive heard much forum folklore that sez you can run a "safe mismatch" MESA 8 ohm speaker load into a 16 ohm cab.
However my friend & Engineer Obeid Khan sed i run the risk of the NOS 6L6's in my MK III "flashing over" which isn't encouraging. This amp puts out alot of power.
Ive played JMP Marshalls for 40 years & always match impedance for best results as Marshall do not tolerate mismatches at all.
What is the forum folklore here @ SD forum ?
Seems there is never a shortage of un-solicited advice when its not [your] amp that can take the hit/ [no offense].

Obeid said he would build me a loadbox to solve the problem which seems the best route.
I do not want to re-wire my cabs to 4 ohms.
 
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Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

i dont have a ton of mesa experience but i wouldnt risk it. marshalls dont like it, with old fenders you can usually get away with it but there is always risk involved
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

Just from my experience (this is not with Mesa's though) I've run lower impedence into higher impedence cabs many times with no issues. However, this was usually for a gig or rehersal here or there, generally I am matched up 8 - 8. But I have run 4 -8 and 8-16 before without issue.

If you look here: https://mesa-boogie.imgix.net/media/Amplitudes/2013/June/Speaker Impedance Matching and Hookup.pdf You will see they have scenerios of safe mismatching including 8 - 16.
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

My Mesa Blue Angel's manual states that the amp is not very sensitive to mismatches, and won't be damaged by them, but the power tubes will wear faster.
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

I know all my recto manuals say it's fine. never had a mark series though.
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

I know all my recto manuals say it's fine. never had a mark series though.
I called MESA support [which is outstanding i have before] and they assured me 8 ohm > 16 ohm cab is a safe mismatch & will not harm the amp. Im going to take him at his word and use a leap of faith.
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

Running a higher impedance speaker with an amp rated at lower is never a problem. I have had a WGS ET 10 in 16 Ohms in my Subway Rocket Combo for a few years now. Did it to give me a little power soak and also to run a parallel splitter with my 16 Ohm cabs for a true 8ohm load. Where you get into trouble is running a lower ohm load than recommended because it allows more current flow due to the low impedance and will build a LOT more heat.
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.



My MESA MK III purple stripe stomps my 3 channel Dual Rectifier which i hate to say because i love the DR but alas its true. All hail the MK III.
I pulled the EV-12L and lightened the load by 30 pounds i swear.
Using it as a head only.
Thru my 40 yr old Blackback cab it is amazing. Got to goose the volume a bit .... look out !
Never knew the NOS Phillips 6l6 glass could sound so good.
Got NOS Amperex & Blackburn Mullard in da pre.
 
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Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

Those old Boogie transformers are pretty darn stout. That's a jewel of an amp btw... :) I always preferred my Mark amps into a 1x12 EVM, that's it.
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

What you need is the matching Mesa 112 EVM or C-90 Thiele cab. I have three to go with my Mark III, Mark IV, DC-3 and Mark V:35 combos. This makes for a killer rig that can easily fit in the back of a Corolla. The Simul-Class and 100-watt versions of the Mark III combo with a Theile and a pair of EVMs can keep up with any Marshall or Twin Reverb. It can cover any genre, from country twang to jazz to metal. And they're not as finicky to set as some would think.

I have a red stripe, no stripe and a blue stripe combo, and then a no stripe 200-watt Coliseum head. That head thru a Mesa EVM/C90 412 Half-back is my favorite to play on. The red stripe is my fave combo. I haven't worked with the no stripe combo yet. It's a Simul-Class, reverb, EQ, EVM model with the imbuya cab. It is gorgeous, but the amp needs a little work and I haven't gotten to it yet with all the health issues. It should be killer.

Enjoy your Mark III. They are truly great amps.

Bill
 
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Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.



Ive heard much forum folklore that sez you can run a "safe mismatch" MESA 8 ohm speaker load into a 16 ohm cab.
However my friend & Engineer Obeid Khan sed i run the risk of the NOS 6L6's in my MK III "flashing over" which isn't encouraging. This amp puts out alot of power.
Ive played JMP Marshalls for 40 years & always match impedance for best results as Marshall do not tolerate mismatches at all.
What is the forum folklore here @ SD forum ?
Seems there is never a shortage of un-solicited advice when its not [your] amp that can take the hit/ [no offense].

Obeid said he would build me a loadbox to solve the problem which seems the best route.
I do not want to re-wire my cabs to 4 ohms.
I would think that re-wiring a 16 ohm cab to 4 ohms would be fairly easy. Even to make it switchable between the two.
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

The forum folklore is usually an impedance mismatch of one setting, 4 ohm to 8 ohm or 8 ohm to 16 ohm, won't harm anything. Impedance is frequency dependent and varies over the speaker's range, so this seems to make sense. I have never really found a better tone by mismatching, so I don't mismatch.

Here is my standard reply to what really happens and what could go wrong when you mismatch:

https://forum.seymourduncan.com/showthread.php?330426-Marshall-1936-JCM900-212-16-8-ohm-Sounds-Better-When&p=4249229&viewfull=1#post4249229
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

The forum folklore is usually an impedance mismatch of one setting, 4 ohm to 8 ohm or 8 ohm to 16 ohm, won't harm anything. Impedance is frequency dependent and varies over the speaker's range, so this seems to make sense. I have never really found a better tone by mismatching, so I don't mismatch.

Here is my standard reply to what really happens and what could go wrong when you mismatch:

https://forum.seymourduncan.com/showthread.php?330426-Marshall-1936-JCM900-212-16-8-ohm-Sounds-Better-When&p=4249229&viewfull=1#post4249229

+1
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

Obeid Khan made me the coolest loadbox on the planet. The amp will see 8 ohms now as i use my 4x12 cab.
Thanks Mr. Khan.
 
Re: 8 ohm MESA MK III into 16 ohm Marshall Blackback cab.

nice! very cool to have friends like that
 
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