Re: The right speaker for digtal/ digital modelling amps..
I think the Blue Marvel is a crunchy 40w speaker that definitely has a voicing. Not flat at all.
If I were looking for a speaker to use with a modeler I would primarily be looking for a high wattage speaker, as cone break up introduces unique speaker characteristics.
If a speaker has and abundance of high mids or low mids or a big bass, or a bright treble... that's less of a concern as eq freq's can be matched, reduced and increased where needed. Where as you cannot remove, hide or accurately replicate specific, unique cone breakup properties.
Speakers I would look at would be the Mesa MC90, Eminence Delta Pro, Electro Voice EVM12L and the WGS ET90.