Gentlemen
Be nice - really. The M2!5 is an excellent speaker, beyond dynamic with great tonality. The reason the upper woofer is underneath the M2 waveguide is to get it as close to the Compression driver as possible - the grille goes up underneath the lip on the horn. The woofers used are the JBL 2235H, the modern day offerings form JBL and others needs DSP to go LOW - its by purpose I used this vintage woofer. 12B4A - I doubt that
And while your at it - lets see something that you actually have created.
Good Listening
Peter Noerbaek
PBN Audio
WWW.PBNAUDIO.COM