Help Installing Speaker Volume Controls ...

["M100C" <nospam@xxxxxxxxxxx>]

All,
I need some help understanding how volume control impedance calculates into
the load seen by the amplifier.  Here is my scenario, using just one amp
channel for illustration purposes:

I have an amp rated to drive loads from 6 to 16 ohms ... ideally, I would
like to present the amp with an 8 ohm load.

I have three, 8 ohm speakers, all with home runs back to the amp.  When
connected in parallel, they will provide this channel with a load of 2 2/3
ohms (1/Rt = 1/8 + 1/8 + 1/8), which is clearly too low.

This is where I start to get a little fuzzy about how the volume control
impedance works ...  I know need to create another 6 ohms of impedance to
bring the total impedance for this channel to just over 8 ohms, but here are
my questions:

1) Are I seeing this correctly?  If so, I have not been able to identify any
volume controls which would create the proper "make-up" impedance.  Your
suggestions are welcome.
2) Ideally, I'd like to have a volume control with an "off" setting.  In
this case, I assume that there might be a make-break switch which removes
the speaker from the circuit and adds the additional impedance needed to
replace the speaker ... is this correct?

Thanks for the education,

Chris