I just purchased a pre Magnavox (Circa 1970) B-15 N. It is the four input variety. Here is my issue: Whenever I play an E note in the bottom two octaves it makes a horrible rattle that over powers the note. This happens at moderate volumes or above. Moreover, it does not happen on any other...
If you are looking for lows, look no further than a 1972-1977 Telecaster bass. This is the model with the humbucker in the neck position. Run one through an SVT and you will crack your house's foundation with lows.