I have an old Silvertone amp with an 8 inch, 4 ohm speaker. I want to build a 2 speaker cab and have been looking for reasonably priced AlNiCo speakers. I found one 8 inch, 8 ohm Utah AlNiCo and an 8 inch, 8 ohm Ferrite Utah. Wiring two 8 ohm speakers in parallel will drop the resistence to 4 ohms and allow me to drive the cab with my amp but is there a problem with mixing AlNiCo and Ferrite magnet speakers? Thanks.