Monitor wiring and impedance

[drumcat9800]

Hi again folks. Great forum here, still learning a ton.

So my question is about hooking up our monitors. We have 3 Peavey PV12 monitors and 1 older Peavey "something" in our band and are using a Nady XA900 (I know, not good) to power the monitors. Currently we're running it in parallel.

 

So when we hook them up, we are only using 1 of the aux sends off the board and we all get the same monitor mix. All 4 of the monitors are daisy chained together. Peavey says the PV12's are 8 ohms each. Assuming our other monitor is 8 ohms, we're looking at a 2 ohm load on the amp.

 

I guess I am wondering if daisy chaining is really parallel wiring? Its not series? Because unhooking 1 cable kills everything else after that(series). Although we still have signal before that point(parallel). Just want to make sure I'm figuring the load on the amp correctly. I'm assuming I'm not running a 32 ohm load (series).

 

I'm thinking its a better idea to use both of the amp's channels and just run 2 monitors on each, with a more appealing 4 ohm load on each channel. Don't need to be blowing any speakers. Thanks !!

[Shaster]

I would be worried about the Peavey something amp - is it supposed to go as low as 2 ohms?

 

I didn't understand your question. How could a speaker keep working if you unplugged the cable before it?

 

Anyway that's a 2 ohm load, assuming all speakers are 8 ohms - and it's a real 8, and not 6.3 ohms or something.

[drumcat9800]

Sorry, I should have been more clear. The Peavey "something" I was referring to is another monitor. I'm just not sure what model, or impedance it is right now, I'll have to check into it.

 

What I was trying to get at with the monitor connections is, since they are all daisy chained together, say I unplug the cable from the 2nd monitor to the 3rd monitor. Then the 3rd and 4th monitor stop working (obviously). I was relating that to a series circuit.

 

But the 1st and 2nd monitor (still hooked up) are still functioning. I was relating that to a parallel circuit. Maybe I'm making it too complex. I was just looking for an expert to tell me that daisy chaining monitors is indeed hooking them up in parallel.

[tlbonehead]

Sorry, I should have been more clear. The Peavey "something" I was referring to is another monitor. I'm just not sure what model, or impedance it is right now, I'll have to check into it. What I was trying to get at with the monitor connections is, since they are all daisy chained together, say I unplug the cable from the 2nd monitor to the 3rd monitor. Then the 3rd and 4th monitor stop working (obviously). I was relating that to a series circuit. But the 1st and 2nd monitor (still hooked up) are still functioning. I was relating that to a parallel circuit. Maybe I'm making it too complex. I was just looking for an expert to tell me that daisy chaining monitors is indeed hooking them up in parallel.

 

Well, c'mon, if you unplug the send between the 2nd and 3rd speaker, what makes you think the last two would keep making noise?

[agedhorse]

If you are running all 4 monitors off of one channel of the Nady amp, I suspect that your perormance will pretty much suck. When I tested one, at 2 ohms reactive load the amp sounded terrible when it clipped and I wouldn't want to do that for very long for fear of a magic smoke release. It's 400 watts/channel at 2 ohms which is 100 watts per box and barely that because you don't want to clip the amp (actually it's currenmt clipping due to the VI protection which sounds worse than regular clipping)

 

I would recommend running 2 boxes per channel and it should hold up ok.

[samkokajko]

I see where you are trying to go with the idea of a series circuit. What you have to keep in mind though is that the speaker "wire" isn't a single conductive wire (that would not only be series, but an incomplete circuit), it's a cable with 2 conductors in it. Each time it goes into a speaker cab it is jumpered over to the other speaker jack (in parallel) and also to the speaker itself. It doesn't go through the speaker before going out the other speaker jack.

 

If you carefully draw it out on paper you may get a better picture of it but yes it is really parallel. Hooking up speakers in series actually takes quite a bit more thought, parallel is easy.

[drumcat9800]

 

I see where you are trying to go with the idea of a series circuit. What you have to keep in mind though is that the speaker "wire" isn't a single conductive wire (that would not only be series, but an incomplete circuit), it's a cable with 2 conductors in it. Each time it goes into a speaker cab it is jumpered over to the other speaker jack (in parallel) and also to the speaker itself. It doesn't go through the speaker before going out the other speaker jack. If you carefully draw it out on paper you may get a better picture of it but yes it is really parallel. Hooking up speakers in series actually takes quite a bit more thought, parallel is easy.

 

 

 

Thanks ! This is pretty much what I was asking about. Thanks for clearing that up. I actually do electronics for a living as a tech, but this PA stuff is basically all new to me. I've never had a need to get into it before, so i'm just trying to get a hold of things....

 

I'll make sure we aren't running 2 ohms with that amp, and get 2 monitors on each channel.

[samkokajko]

It just doesn't make sense to cram them all onto 1 channel and leave the other one doing nothing. You can use a Y cable on the input (I don't know if that amp has a parallel mode but that would be fine too) and still use just one mix from the board if that was the concern. Then your amp isn't have to work so hard to do essentially the same thing.