Hello, I'm Rob with Crutchfield's commercial and pro audio team, and today we're going to talk about parallel wiring in your commercial 70-volt audio system. For this demonstration we're going to be looking at the Atlas SM 52 speakers, a pair of the Atlas AT100D wall-mountable volume controls, the Atlas A50 commercial amplifier, and I've gone ahead and pre-cut some speaker wire for us to use in our demonstrations.

So first thing I want to do is talk about the concept of parallel wiring. Parallel just means that the same connectors are being used across multiple units, and by that I mean that when we trace the common the ground line, it's the same terminal on every piece of equipment that we're using whether it's speakers whether it's the volume controls or any combination of those. So there's two sort of concepts: home running, which is going from a speaker directly back to the amp, the source or from your volume control back to the source, or daisy-chaining, which is taking a line from one unit to the next unit to the next and so on and so on.

So our first configuration is our daisy chain, direct daisy chain situation. On the back of our 70-volt amplifier you'll notice that I've wired up the red into the 70 volt and the black needs to be common ground, and what we do want to do is just follow that through the whole system. So our 70 volt is our positive, our common is our negative. So when we get to our first speaker we want to make sure that we've got positive and negative set up for our red and black wires, respectively, and then what we're going to do is you see here I've got two lines coming in and out of that same set of terminals, and what we do when we jump from one speaker to the next is just line up those terminals again, red to our positive, black to our negative, and that's what we call a daisy configuration from the amp, speaker, speaker and you could continue this process on out to however many speakers you have in your system.

The next configuration we're going to take a look at is if you've got two speakers, but they're both, say, instead of having this and it makes sense to run from one speaker the next, maybe it makes more sense for you to have one speaker on one side of the room the other speaker on the other side of the room, and the amplifier started in the middle of the room, and we're gonna do two home runs back to the same amplifier, also still technically in parallel. I'll show you that. All right, so now we've got our system still wired in parallel, but with two home runs. One from one speaker, one from the other speaker, and we're just matching up that positive to the 70 volt positive to the 70 volt, that's our red wire on each, and then the minus to our common on each of those two runs. Still in parallel, still able to control the volume of both speakers from one location.

Now what if you need to have a separate volume control zone, say this speaker is in your main restaurant, and you want to have that independent from your rest room speakers or your lounge area. What we would then do is introduce volume controls in-line, and we'll show that in the dual home run configuration, and then we'll show a daisy-chained configuration for that as well, and I'll walk you through the wiring for that. So now we've got a situation where we've got our source coming from our amplifier out to our first volume control. That's going to control our first speaker, our first speaker zone, and the volume controls are labeled amp minus and plus and speaker minus and plus, setup so the red goes to our positive, black goes to our negative, and then daisy-chaining the input from the volume control to the next volume control means that this is not attenuating this volume control at all. So the same signal is passing from the amp basically in parallel, daisy-chained, then will control the volume at our next speaker, and this could go on and on and on, however many volume control zones you have, and then these speakers, just as we showed before it could be daisy-chained multiple speakers in each volume control zone.

And now I'm going to show you a dual home run setup with the volume controls and the speakers, and this will be our last set up for this demo. All right, so now we've got our dual home run setup here. So as you can see we've got both home runs wired out to our inputs on our volume controls, following that same parallel wiring, making sure all of our positives are in the positive, all of our common is in the negatives, and then from the outputs of each volume control out to our speaker zones, so this will allow us to have our master volume here our individual zone volumes at each location, but without having to necessarily daisy chain them same as our speakers. Of course if it makes sense for you to daisy chain on from this one to go to multiple zones off in that direction, or from this one in that direction or multiple speakers in each volume control area, you can do that. That's what 70 volt distributed audio systems are really great for. And of course, if you have any questions about any of this you can always contact us at the commercial audio department at Crutchfield. Thank you for watching.