On Order. 45 Day Lowest Price - 100% Satisfaction Guarantee. This popular bass effect adds a deep note one octave below the note you're playing for a huge, stadium-filling tone. Compare this new MXR Bass Octave to ANY unit on the market (even the European models), and you'll be pleasantly surprised. The MXR tracks instantly with what you're playing, and continues to synthesize useful subtones for lower fundamentals, where other pedals give up.