I got my first A25's in 1975. They came with standard SEAS alnico woofers and H87 . One year later unfortunately swap them for A25XL. No bad but not that better than previous A25. Middle range less natural, even if more power handling. Soon I sold them and got AR6. Many years later, during 1985 I bought again a pair of A25, in excellent shape. Surprisingly I found inside a ceramic magnet woofer. That one mounted in XL model. Very nice compound! The speakers were much more powerful with a little bit more sensitivity in woofer range. After having renewed the capacitor with a polyester 5uF, I have been using them for years. Recently I was intrigued in some slight mods. So for whom having in their A25 ceramic+alnico mix, I give my tips to make, IHMO, A25 better. First: Place a 6uF capacitor instead standard value 5uF. Second: put a 0.39uF capacitor across the 2.2 ohm resistor series connected with tweeter. The first mod gives a much more smooth mid range. The second one lifts a little ( actually a very little bit) the emission of high frequencies above 12khz. Comparing these modded 25's with other speakers of my collection ( AR3a, KLH six, AR6 and many other) they sound really great, even if not better than AR3a, obviously. If you have a A25 with ceramic woofer, try and listen! Regards
Tunedguy57