So you have bought a Bose Wave radio, advertised as
having Incredible Sound, and you have realized that
they have a large resonating pipe that causes just
about any male voice on NPR to sound so boomy you
can barely tell what the person is saying.  There
is no electronic bass control because the radio is
a resonant chamber-- it is a physical property, simply.

Here is how you can reduce this annoying booming bass
and find yourself with a Bose radio that sounds just
great. Step 1. Find an old sock and cut off the top
four inches or so. That is what you will use. 
Next, take a Phillips screwdriver and unscrew the
three screws on the top face of the Bose radio. If you
have a CD player, two are near the back and one is under
the CD cover plate.  The top is a one-piece plastic
cover that will slide up and off, as soon as you 
turn the radio over and, using a flathead driver,
pry forward the bottom, forward latches at the lips.
This frees the front and then the whole top shell lifts
off.  Be careful- it is still connected because the CD
player controls run a ribbon cable to the screen front.
The screen front can also be slid up and out easily. Now,
roll up the sock tube lengthwise and push it into the
opening just inboard the right speaker.  This is the boom
bass exit.  By pushing the sock deep into this, you will
change the air mass and the tube length, thereby defeating
their resonance chamber.  Close up your Bose Wave radio and
enjoy much more balanced bass and treble on NPR.