I was looking at my speakers I have bought thought the past 4 years that I have tried with this Mesa amp and that Mesa amp. The bulk of my tone quest was centered around two amplifiers: Mark IVb combo, and the Mark V head, then the expense rolled in more when I converted the Mark V head to a combo.
The Mark IVb combo suffered a similar fate as did the OEM speakers in my OS recto cab. My point of reference was the Mark IV. Both combo and cab had the flub issue. I was so tempted to remove the MC90 and install the EVM12L black shadow into it but was unsure if it would fit. I found an old picture of my gear dating August 2011 shortly after moving in to the new home. The Mark III on the left in this over crowded room reveals an EV emblem on the speaker dust cap. That was an EVM-classic. The EVM12L black shadow was in the oak 1x12 cab just below it. When I sold that amp, I returned the black shadow speaker to the Mark III comb and both amp and extension cab were sold to a friend for a reasonable price. Other than 23years of hard use, no mods and countless tube changes, the amp was in mint condition. At this time I was done with playing guitar and had difficulty due to injury and thought I would never play again. That changed in 2012 after I sold the amp. The Mark IVb combo on the right sitting on the Virgin OS Recto 412 both of which were bought in 2000. After selling the Mark III, I missed the amp and character of the EVM12L black shadow I decided to get a recent EVM12L in black label form which is closest I could find to the Black Shadow version. The Classic was different and had softer low and response than the black shadow.
After installing the EVM12L speaker into the Mark IVb combo, I was overjoyed with the performance at moderate to high volume settings (above 3 on the master volume control) but at the same time I was not pleased with the lower volume level character of the EV and thought the MC90 was better. Needless to say the MC90 did not last very long after that due to voice coil damage. Could be from lack of use over a 8-10 year period resulting from injury to tendons in my left arm.
After the MC90 was toasted, the EV went back in, but I front mounted it. Had to modify the grill frame to make it fit. Then I found a FANE resource in the US and bought a Fane Studio 12L which is quite similar to the EV but voiced very similar to the V30.
I actually liked the Fane speaker, I figured if I could get more I could try them in the 412, actually I was thinking of the Medusa 150C but my resource drop the product shortly after I bought the Studio 12L so that became more of a fantasy than a reality. The Studio 12L had to be driven hard to be effective, it was shy when running at bedroom level. Also it was the first speaker I stuffed into the Mark IVb combo that I could run at full volume and it did not break up. EV could not do that.... Cone shape was different and it really projected out, the further away from the speaker the fuller the sound. It did not beam the mid to high frequency in a narrow cone like the V30, it was spread out well and balanced. When I sold my Mark IVb combo, it had the Fane speaker in it. That was an improvement over the MC90 or even EV. I did try it with the Mark V but was not impressed with it as the amp was still pushing ice or broken glass tones. Roadster did not favor the Fane nor did the RA100. Seemed like a good match for the Mark IV combo. Note that the basket was very tall relative to the other speakers. It could not be rear mounted due to the driver touching the power tubes. Also there was no room to change preamp tubes. Since I modified the grill for front mounting, that is how the Fane speaker would fit and allow for preamp tube change without having to remove the chassis. Similar to the EV basket when rear mounted but plenty of room for power tube access.