New Home. Need help deciphering speaker wire setup

[Tango2]

I just moved into a new home and had some in ceiling speakers installed by the builder.
There are 5 ceiling speaker locations in the main family room that I have all working with my new home theater just fine.
I also have 6 other speaker locations on the main floor.
Coming out of the wall near the TV hookup are 5 white speaker cables with just red/black wires inside the jacket. I believe this is 16/2? I'm obviously a novice here.
There are also 3 black, thicker cables coming from the wall. These have 4 wires inside the jacket (red, black, green, white). I believe this is 16/4?

The 5 speakers in the main family room are connected to the 5 white 16/2 wires. All is fine and working.

However, I'm trying to connect the remaining 6 speakers throughout the house and having trouble getting any sound.
I've assumed each of the 3 black wires went to one of the 3 speaker 'zones', each with two speakers.
The confusion I have is when I went to wire the ceiling speakers at those 6 other locations, there is only white 16/2 wiring (red/black only) there in the ceiling.

Is it typical that 16/4 is run through the ceilings to a 'zone' and then split/spliced into 16/2 just before the individual speakers?
Is the black 16/4 intended for 2 separate speakers since there are 4 colored wires inside? or am I completely off base?

I'm sure there is something basic I'm missing here.

Thanks for any help.

 

[jinjuku]

If you have distributed audio throughout the rest of the house you will want to pull down one of the speakers and see if there is a 70v transformer.

If that is the case you will need a distribution amp like the Crown CT series.

 

[highfigh]

Get one of these- it doesn't need to be this brand.

The chance that your speakers have 70V transformers is slim if it's not a large house but it's not impossible. If you connect the tone generator and you hear sound from more than one speaker, that means it is possible, or that they just wired them together and you may end up with a bit of a nightmare.

If you have a multi-meter, measure the DC resistance on each speaker cable- if you don't have one, buy one and learn to use it if you don't already know (it's not difficult).

Is there any way to contact the previous owner and find out who installed the speakers? If they were in use before, have you seen any wall plates or volume controls near the light switches in the rooms where the speakers are in the ceiling?

The color of the speaker cable jacket and insulation mean nothing, other than red/black or red/black & white/green corresponding to Pos/Neg (in both pairings I mentioned). If one wire is blue, use that as Neg for whatever it's connected to (it's not a common color for speaker wire, but it's out there). Check the speakers that are closest to the head end for the connections- it is possible that the 4 conductor cable goes to the first speaker and the 2 conductor cable is spliced to the corresponding pair in the 4 conductor cable.