Which remplacement speaker ??

[Kelu]

I got a Mesa Boogie roadready 15' cab
The original speaker is :
ELECTRO VOICE OEM series 3400 15
400WATTS

Which speaker should i put in
I tried with a 600w eminence LF series, but the box is too small for it..

 

[lbwdog]

EVM 15B if you can find one. I don't know if they still make 'em..