# Splitting a signal



## achstechdirector (Jul 13, 2009)

This may sound like a stupid question but I've never worked on this side of the rope...

How do you split a signal to send one to a monitor mixer and the other to a Main/FOH Mixer?

Please enlighten me.

Thanks for any answers


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## tech2000 (Jul 13, 2009)

I work for a high school theater so my resources are pretty limited...I would plug the source into one of the mixers, probably the FOH mixer first and then use the direct out on that channel and plug it into the monitor mixer.
For those that do sound in the professional world, please correct me if I am wrong or if there is a better way to do it! I know there are other ways, but this is the way I would do it.


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## AlexD (Jul 13, 2009)

You can use an aux send to send a certain channel (or multiply channels) to a monitor and just use the main outs to do the FOH 

There should be on the mixer an aux 1,2 or more outs (they are normally ¼” jacks) so u will send that to the monitor because an aux send will not be affected by any fader it will stay at the same volume.

I think I’m right


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## tech2000 (Jul 13, 2009)

Just make sure (when using aux sends) if you want a constant output from the mixer (uninterrupted from the faders) you may have to hit the "pre" button. Some boards have them, at least our old Mackie board has them.
On my mackie, if you don't hit the pre by the aux knob, the sound will come out the send but is controlled overall by the channel fader.
We also have a newer (analog) yamaha that doesn't need the pre to send the audio. It depends on what type of board you have.


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## achstechdirector (Jul 13, 2009)

Thanks for the help, we are planning a very large battle of the bands and would like to do this (mostly to involve all of our techs). I thought that maybe there was some type of equipment that split it before it got to the FOH. That works. Just lots of 1/4" cables...


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## AlexD (Jul 13, 2009)

Well yes if u want you coul chain the speakers together. Most have inputs and outputs. And there will be spliters around (i dont know what they are called though) that will plug into the main out befor it gets to the amp or speaker i dont know if there is a power isue there.


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## tech2000 (Jul 13, 2009)

There are signal splitter boxes and adapters, but I have not used them before so I don't know how good they would be.
I would try to get in to your theater before you guys actually start setting up your event and try our suggestions first. It would save you money as long as you have all the cables. If they don't work, you could try one of these. They should also be available at your local audio store as well as online.


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## epimetheus (Jul 13, 2009)

OP, use a mic splitter. These are designed to do exactly what you describe. Let me rephrase, the correct way to do what you are asking is with a mic splitter in the stage rack. Your monitor console is normally at the stage. Mics/other sources to splitters, one splitter output to monitor console, other splitter output to FOH console. This is model we use at my church, but it's a permanent install. I'm sure you can find rackmount splitters that are fully connectorized as well. In your case the isolated split output would connect to front of house (somebody correct me if I'm wrong on this point).


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## derekleffew (Jul 13, 2009)

See this PDF from Whirlwind on Mic Splitters.


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## museav (Jul 13, 2009)

It sounds like what you need are splitters. One potential problem with using a direct out or any other send from one console, and also with active splitters, is that certain changes or adjustments at one device then affect everything downstream. For example, if you use the direct out of one console to feed the other then adjusting the trim/gain at the first console will affect the level the other console receives. Imagine the FOH mixer tweaking the gain on a channel only to send the monitors into feedback and everyone looking at the monitor mixer as though it was their fault (or vice versa).

Another aspect to consider is phantom power. This is one area where 'Y' cables, direct outs, etc. can potentially be a problem, if someone activates phantom power on the second console that then feeds the phantom power back into the first console. With active or transformer based passive splitters the phantom power is passed through from only one console or a separate phantom power supply is used with the phantom from both consoles being blocked.

Ground loops and isolation is another potental issue, if you wire directly between the consoles or hardwire split the mics then you greatly increase the chances of experiencing ground loop prblems betwee the monitor and FOH devices. Conversely, a transformer based split can isolate the two consoles/systems and eliminate such problems.

So a 'Y' cable or using a direct out on one console can work, but has some limitations and represents several potential problems. Active splitters can be a good choice for some applications with the understanding that these devices usually include cirucuitry and controls that would impact the signal to both consoles. Passive mic splitters are often a good choice and are available in a variety of physical form factors and a range of prices, you might look at Jensen Transformers, Radial Engineering, Wirlwind USA, ProCo and others for models.


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## rwhealey (Jul 13, 2009)

You want a splitter, or a splitter snake.

How many channels will you need? We just did some research into this same problem. We felt the best solution for us is to install a splitter snake sometime in the future, but we expect that to cost a lot.

This is probably something you want to rent if it's a once a year thing. Call your local SR company- they should have something.


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## mbenonis (Jul 13, 2009)

As folks have said above, there are two main ways to split a signal--directly and with isolation. Direct splits work fine in situations where you do not need to run phantom power, and this essentially involves tying the two console inputs together (literally, two wires come off of the input, one to each console). In an isolated split, the second console is fed through a transformer, which blocks the DC signal from reaching the primary console.


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## Chris15 (Jul 14, 2009)

Like normal, there's more than one way to skin a cat.

By definition, a passive split will result in signal loss. An active split however can have unity gain or even positive gain. This can be useful where you have a long core run to say FOH and by boosting your mics to line level for that run you end up with more headroom and less noise. Note however that you are then forced to have the sound of the active splitter's preamps not those of the console. You can get caught out by some active splitters though. Say with the XTA DS800, feeding phantom back into the monitor output will switch in a 10dB pad on the channel (affecting all feeds)...

Traditionally splits go at least 3 ways for an event of any size, FOH, Mons, and Broadcast. Except for a handful of specific times, you give broadcast a transformer isolated split. This being because they are so often on a different power supply and normally some cable distance away. The exceptions normally relate to things like your Australian Idol TV shows where Broadcast get the direct feed and FOH & Mons get isolated feeds. That way the audio director retains phantom control etc. and when TV is involved, the audio director is above FOH and Mons by a country mile.

Brad, I'm curious about these active splits with phantom pass through. All the ones I've seen have all outputs at least electronically if not transformer balanced and the phantom supply comes from the splitter itself to the mics.


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## museav (Jul 14, 2009)

Chris15 said:


> Brad, I'm curious about these active splits with phantom pass through. All the ones I've seen have all outputs at least electronically if not transformer balanced and the phantom supply comes from the splitter itself to the mics.


I probably worded it poorly, I meant that both passive and active splitters prevented being tied to two phantom power sources and/or phantom passing from one console to the other. However, being able to pass phantom power from one of the console applies to passive splitters while using a separate phantom power supply, either internal or external to the splitter itself, may apply to both passive or active splitters.

I should add that phantom power into a console input is not a problem for most consoles and that having two phantom power supplies in parallel is not a problem for most mics. But "most" is the operative word here and I had a client who found out the hard way when they used hardwired splits to add a new recording console to an existing house system. Luckily for us, the house mixer and installed mics we were involved with had no problem with phantom power from the new console. Unluckily for them, their new console started losing inputs the minute they turned on the house mixer.


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## FMEng (Jul 14, 2009)

Chris15 said:


> Like normal, there's more than one way to skin a cat.
> 
> By definition, a passive split will result in signal loss. An active split however can have unity gain or even positive gain. This can be useful where you have a long core run to say FOH and by boosting your mics to line level for that run you end up with more headroom and less noise. Note however that you are then forced to have the sound of the active splitter's preamps not those of the console. You can get caught out by some active splitters though. Say with the XTA DS800, feeding phantom back into the monitor output will switch in a 10dB pad on the channel (affecting all feeds)...
> 
> ...



A transformer splitter can be built to pass phantom power a couple of ways. Most common is for one console to be fed directly from the mic, with the transformer primary parallel across the mic line. All phantom is supplied from the directly connected console, and the transformer secondary(s) feed another console(s) with isolation.

Less common is for the primary winding and one secondary winding to have center taps which are tied together, which allows the transformer to pass phantom. I've never seen the wisdom in this, because there doesn't seem to be any advantage to it over the method described above. The tapped secondary would not provide isolation.

As for transformer splitter loss, I have never found it to be a factor. Most mic preamps have higher input impedance than they did a few years ago (no 150 ohm inputs) so loading just isn't a big deal. A resistive splitter could have significant loss, but then I would avoid using one anyway, because it provides no isolation. I dealt with an active splitter exactly once, and it was a disaster full of noises. Give me a nice Jensen transformer split any day.

I would be very skeptical to making Y cord splits and getting away with it in most situations. Grounding and power distribution would get very picky to prevent hum. Touring systems sometimes get away with it mostly because they connect the system in exactly the same way every time, and every last connection has been carefully engineered.


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## Anonymous067 (Jul 14, 2009)

AlexD said:


> I think I’m right
> [/COLOR][/FONT]



I think I'm a genius.


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## BillESC (Jul 14, 2009)

A split snake is the Pro way of doing the task. Unless you will do this often, it may be however too much of an investment.


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## Anonymous067 (Jul 14, 2009)

Bill, those look like multipin connectors, for adding length to the run and such?

Do you have the model/brand of the particular one you just posted offhand?


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## Thefoxygranpa (Jul 14, 2009)

BillESC said:


> A split snake is the Pro way of doing the task. Unless you will do this often, it may be however too much of an investment.



Use this snake often at my work. If I remember right, its called MASS connector.
Whirlwind / Multipin Connectors

The ends are asexual so its pretty sweet. It has a 25' monitor split fanout, and 10' FOH Fanout thats kept on our main FOH board, and a 200' run.

Its a wonderful snake and the asexual ends are a great idea.


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## TimmyP1955 (Jul 15, 2009)

It's very rare that a passive (hardwired) split - or even multiple splits - will result in enough signal level loss to be of importance.

It's also very rare (I've yet to hear of an instance in which the problem was not because of faulty gear) for phantom power to be a problem when two consoles' inputs are connected via a passive split. The consoles' phantom supplies are isolated from each other by 6.8k Ohm resistors in each console. Phantom can be run from either console or both with no trouble. (If the shield is lifted one of the consoles, no current will flow from phantom power on that console.


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## epimetheus (Jul 15, 2009)

It's not signal loss that I would be concerned about with a passive (hardwired) split, it's isolation. With any installed sound system, there's a very good chance that the destination device of the 2 outputs of the split are going to have different power sources, whether it be a FOH/recording split or and FOH/monitor split. I stick with splitters with one or both outputs isolated and let the splitter supply the phantom power. With the splitter supplying the phantom power I don't have to worry about somebody accidentaly sending phantom power from the board to a mic or source device that can't handle it.


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## FMEng (Jul 18, 2009)

Let's clarify a little. There are three kinds of passive splitters:

1. A Y cord split. Works well only in some circumstances. Very cheap.

2. Resistive split. The two outputs are isolated to a small degree with a resistive pad on each output. Lossy and often troublesome.

3. Transformer split. With high quality transformers and proper design, the isolation is very good. Low loss (< 1 dB). Recommended, but expensive.

The latter method can be built to pass phantom from one output and block phantom from the others. Or, it can be built with an internal phantom supply, blocking phantom from all outputs. In any case, phantom applied to any or all outputs will not harm anything.


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## CenterSpot (Jul 18, 2009)

Might I recommend an excellent resource that I got a copy of in 1989 or 1990 ?

The Yamaha Sound Reinforcement Handbook

It answers a great many questions that are still relevant today and is an excellent teaching guide I used to coach many an aspiring audio mixer and audio system technician many years ago.

Digital aside from all that.


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## mixmaster (Jul 20, 2009)

Thefoxygranpa said:


> Use this snake often at my work. If I remember right, its called MASS connector.
> Whirlwind / Multipin Connectors
> 
> The ends are asexual so its pretty sweet. It has a 25' monitor split fanout, and 10' FOH Fanout thats kept on our main FOH board, and a 200' run.
> ...



Yep, those would be MASS connectors. We use basically the same system here, although I had them build my FOH trunk with the fan-out at the house end instead of another MASS connector w/ a seperate fan-out. The connectors run 3-400 bucks each. Sturdy, well built connectors, but assembling them from scratch is not something a short tempered or impatient person should do. 
To the OP, W'wind (and similar companies) make a variety of splitters, your budget is really the limit. Check the W'wind site for everything from passive splits as above to rack mounted active splitters and everything in between. I know they used to make a 24 ch xlr in, xlr out passive splitter that could be used with some fan to fan snakes for a less expensive way to do it.


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## Chris15 (Jul 21, 2009)

mixmaster said:


> Yep, those would be MASS connectors. We use basically the same system here, although I had them build my FOH trunk with the fan-out at the house end instead of another MASS connector w/ a seperate fan-out. The connectors run 3-400 bucks each. Sturdy, well built connectors, but assembling them from scratch is not something a short tempered or impatient person should do.



A lot depends on your individual application, but to me if you are going to skip one of the multipins on a core, you do it at the stage end. That way you can leave the tails in the doghouse and roll the core back up. Having to unplug all the tails seems painful... Thought this does depend on the number of channels we're talking about...

I would not recommend you even contemplate multipins until such time as you are well at home with less complex connectors. You will also find that there is a degree of specialised tool set to some multipins and that can be pricy... I don't know if MASS connectors come pre pinned - if so ICK. If not you are looking at an insertion tool and an extractor for when things break or you stuff up inserting them...


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## SjonRokz4u (Jul 22, 2009)

Go To Audiopile.net and look up splitter snakes. If Im reading your post right, thats what you want


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