Hi,
Here's your answer. Switch "A" engaged will enhance the upper bass region. Switch "B" will enhance the treble region. Both "off" will give a smoother tube like sound while both "on" gives a combination of enhanced said bass and treble. Note, These are approximate sonic signatures and can be heard with high resolution systems especially when the AC line is clean.
I have 2 in my system.
Here's your answer. Switch "A" engaged will enhance the upper bass region. Switch "B" will enhance the treble region. Both "off" will give a smoother tube like sound while both "on" gives a combination of enhanced said bass and treble. Note, These are approximate sonic signatures and can be heard with high resolution systems especially when the AC line is clean.
I have 2 in my system.