The Jensen AlNiCo Series were stock speakers at the rare TWEED Fender amps of the late 40's, the 50's and the very early 60's. Leo Fender used Jensen Speakers since the late 40's. AlNiCo Speaker are light weight due to the enormous magnetic power of the AlNiCo alloy and is very efficient. Their sparkling trebles and the dirty midrange when driven are synonym to the `vintage' guitar tone at all. Fender Tweed amps of the 50's with Jensen AlNiCo Speakers are the most collectible vintage Fender amps