I had not realized the Blackbird in the CT combo was 40W. Was not aware they made it in a 40W format. Since I got the extension cab shortly after I got the combo, they are the same speaker without the bell cover. The one I used in a Mark V90W was the 100W version. Took a very long time to break it in. I installed it in a widebody open-back 112 cab. Once I heard the two speakers loading the amp to 4 ohms, it made sense why Mesa did that with the 212 CT cabinet.
Interesting, I just checked the speakers in my combo and extension cab. Same speaker as the Blackbird 100W I removed the bell cover from. Large diameter and thick hockey puck magnet. Looks nothing like the images on Mesa's website or Jensen site for the 40W version. No square shaped loop.
I know for a fact this is the 100W blackbird.
This is how the combo was delivered. Magnet looks the same as the 100W blackbird above.
Here is a back shot of the extension cab and combo. Stock speakers as supplied by Mesa Boogie.
Tried to get a close up of the label that is on the speaker magnet. Could have been better if I removed the back panel.
https://www.jensentone.com/jet-series/12-blackbird-40
I guess I got lucky then. If it is 40W speaker, it has a huge magnet similar to the 100W version.
Not sure if Jensen will sell the speaker without the bell cover, once you remove it, there is no label on the magnet. Wonder how different the 40W sounds compared to the 100W version. At least the risk of overheating the 100W voice coil with a 40W amp will not happen anytime soon. For now, the stockers sound great as they have bloomed with more treble and sparkle. I no longer have to push the treble up on the amp.