Your situation depends more on what type of receiver you have than what type of speakers you have.
On a receiver, you generally have provisions for an “A” pair and “B” pair of speakers. If you are running just the two pairs of speakers, you are working within the guidelines of what the machine was designed for. So in this case, you would need only standard volume controls.
If your receiver has only 1 output provision for speakers, then you should use an impedance matching volume control to maintain the 8 ohm impedance that the receiver likely is requiring by only having one output for speakers, because most speakers are 8 ohms, this is what`s expected.
I’ve read the FAQs, but am still a little unsure about volume controls vs. impedance matching volume controls. My situation is that I have 2 pairs of JBL HTI8 speakers in an open kitchen/dining area and want to be able to control each pair of speakers separately. What product(s) i.e. speaker distribution/inwall speaker selector/volume control/impedance matching volume control do your recommend? Thanks for your help.