Do you need a mixer?

Do most of you guys use a mixer to connect the MA-7A or MA-15D monitors? Since I know that the MA-7A and MA-15D has built in tone controls that mixers have and also has inputs. Roland says about this about the MA-7A monitors.
 
"The MA-7As offer conveniently placed Volume and Tone controls. Adjust the volume and tone directly from the front of the speaker. While a large studio setup typically uses a mixer to control output level to the speakers, compact desktop setups can rarely afford the space a mixer requires. This is not an issue with the MA-7As. You can adjust your output volume and tone on the front of the speaker."
 
 
So I thought that means you don't need a mixer and you plug directly to the monitors.