We have received requests from customers who have purchased the Waves MaxxBass 103 unit who wish to better optimize and tune the device for their car. Below is information that will allow any competent technician to replace one or two resonators on the main board, in order to achieve this aim. Waves will provide technical support via email, if needed.

Disclaimer: 
Waves Audio Ltd. cannot be held responsible in any way for any changes that are made to any Waves products.

The MaxxBass corner frequency control is set by a simple resonator. Here is a link of one of many places where you can get them.  We linked here the page of the exact part number you need. 
see http://dkc3.digikey.com/PDF/T051/0769

Selection of the Crystal is approximately so that 5Mhz will set the maxxbass corner frequency at 50Hz,  3Mhz at 30Hz etc etc.  The semiconductor inside is specd to work down to 25Hz so you should not use a resonator lower then 2.5 Mhz.

Instructions:
Open the Waves MaxxBass 103 box. Unscrew the 4 side screws and remove the      circuit board. The two resonators are circled in the      picture: You will need to un-solder the resonators      and replace them with the new part. That’s it. Thank you for using the Waves           MaxxBass 103!