Using XLR Y splitter cables

G

gelojtaboada

Member
Will using an XLR Y cable (XLR F to dual-XLR M) affect my audio.

Say I'm plugging my ME66/K6 with the XLR Y into 2 different channels on a Zoom H6, this to have a backup -padded- channel if the other one clips.

And plugging my Sennheiser G3 wireless kit, with the same deal...

Will this affect my audio, would I have a signal loss??
 
Its my understanding - and Im not a sound guy, that if you do this you also split the incoming signal. i.e. -6db for each channel. I have been told outright not to do it.
 
I've read that splitting 1 mic signal to 2 separate channels has no loss, or minimal loss.

But using a splitter to connect 2 mics into 1 channel gives you that -6dB loss.

Thus, all the articles I read online are not very clear, and there's not much out there about this... I want to be sure about it.

"and other issues can raise their heads as well", what other issues??
 
Phantom power, not happy with a splitter.

I'm not sure where you read that adding more signal will lower the signal but I would question anything else you saw there.

What exactly happens with a splitter depends on what is getting connected. BTW your second example would actually be a joiner not a splitter (though mechanically the same).

There can be problems either way. Hard wired Y cables as splitters are really for sending a relatively high powered signal to more than one place, not for playing around with mic level signals.

Trying to join two mics with a Y can result in the higher out put mic sending signal TO the other mic.
Splitting a mic to two inputs with a Y cable will cause problems with Phantom power, and may have a variety of other issues. A mic in is expecting a mic signal and it's electronics are matched to that expectation. If you split it with a Y then both inputs are seeing part of the mic signal and also each other. This will throw the whole thing out of kilter. How bad that is really depends on the design of the mics and the inputs and is hard to predict, but generally it's not good.

The transformer splitter mentioned above keeps everything isolated so you don't have the interaction problems but you should see a signal drop since you are splitting it.

Not sure where -6dB came from, I would expect a -3dB drop since that is 1/2 the strength (about).

You could get a loss with two mics IF they were mis wired or placed so that they canceled each other out. But it would not be an straight loss, it would be frequency dependant. So if the mics or the source were moving you would get a flanging sound, if they were stationary a comb filter sound. How bad depends on what frequencies were canceling out.
 
I just made a test with this setup

Zoom H6, ME66, XLR Y, no phantom power
Then,switched to a normal XLR cable, kept the same gain level on the same channel.

Sound exactly the same, I dropped the files into Audition and armed a sequence to compare the differences.
They sound really, the same, the levels are equal, I hear or see any difference at all... Then I amplified the signals to see if they were affected... and nope, still mantained the same levels.

What do you think?

I read on a forum, that is possible to run phantom without problems with a splitter, thus, I don't trust that, seems like a terrible idea, too risky.
I would never use phantom with a split signal.

"Basically the Y cable splits the audio output of the microphone into 2 paralleled paths. This means that the 48 volts DC supplied from each XLR connector on your field recorder is also in parallel. Without diving to far into electrical theory, two equal DC voltages in parallel remain the same voltage. If you wanted to test this out at home you could hook 2 fresh batteries positive to positive and negative to negative and place a volt meter across the terminals. If you’ve done everything correctly your volt meter will read the same voltage value as either of the individual batteries."
 
gelojtaboada said:
What do you think?
Click to expand...
I think you have successfully debunked this misinformation floating around the internet. Congratulations. Good show!

SIGNAL LOSS results from "overloading" the source (the microphone in this case) with more of a "load" than it was designed for.
Or from deliberately taking 1/2 the signal and sending it two different places (as from a pad or transformer, tec.)

A modern condenser microphone has a quite low source impedance . In the specific case of your Sennheiser K6, it is rated at 200 ohms.
a modern microphone input typically has a rather high load impedance (i.e. a "bridging" load).
In the specific case of the Zoom H6, 6500 ohms. Two of those inputs connected together with a simple Y-cable would present a load of 3250 ohms.
This is still significantly higher than 10x the source impedance (which is the traditional definition of "bridging").
So you do NOT "split the incoming signal -6dB" with a simple Y-cable.

PHANTOM POWER THROUGH A SPLITTER in SOME cases can potentially pose a problem.
However the ONE configuation where it is virtually never a problem is when you are sending the same signal to two inputs ON THE SAME DEVICE.
I purposely did not use the word "splitter" because you aren't really "splittig" the signal. If you insist on a single "S" word, you can use "sharing".
And please note carefully that this special case applies ONLY to inputs on the SAME DEViCE!!!!!!

IME, a very reliable rule of thumb is that paralleling a mic to two different inputs on THE SAME DEVICE is almost never a problem, and very low risk to try.
HOWEVER, sending a mic signal to two different pieces of gear, has quite high risk of failure and even damage depending on exactly which gear you are talking about.
And ESPECIALLY if the two pieces of gear are far apart and/or powered from different sources. Or if you are a guest dealing with someone else's system.
THIS case is why splitter/isolation transformer products were made.
 
with my tascam i can record dual mono and set the level anywhere from 0 to -12db. does the zoom not have this feature?
 
Hooray! I have responded to every topic on this subject, and in my world of live audio splits are simply everyday work. Passive splits work fine and realistically everyone has a gain knob, that could have a tiny tweak applied, but the talent moving in or out from the mic causes far more change in level! Even phantom is far less of a problem. Richard said this quite accurately, but in the years I've been doing it, feeding phantom power up the spout of a device not expecting it causes either no issue at all (most common) or occasionally a strange oscillation, which you hear straight away, or non-audio issues like led meters behaving very oddly. For instance, using a split on a Yamaha and Soundcraft in parallel makes the Soundcraft led meters all go full scale, if the Yamaha supplies the 48v, but if the Soundcraft supplies power, the Yamaha happily ignores it. A Soundcraft supplying 48v plugged into one model of allen and Heath made the A&H produce a HF oscillation. Until we went digital, we used regularly a three way passive split box, which either would work with our two mixers and the incoming show's mixer or not. The only make of mixer that caused nasty problems was a soundtracs mixer made in the late 90s. This would make nasty bangs when the mic pad was switched in. Never had this before or again. When we first started using splits, we were worried, having heard doom and gloom tales, then we realised that so many of these stories are based on thin air. All desks with phantom must have blocking capacitors to prevent their own 48v getting into the preamp, so the issue is simply paralleling two supplies, but as the phantom design provides the voltage as current limited across the balanced line, the only thing that changes is the result of a current loop with the multiple paths, giving the possibility of instability, but in my experience, it's very rare, and has never in all the years I have been doing it, caused any damage. I suppose that connecting a poorly designed device could feasibly cause a problem, but microphones are very sensitive devices and phantom power very prone to connection issue, and I can't remember anyone damaging a mic. Connecting a mic with phantom on, also considered a doom and gloom process, often connects 48 v briefly to the capsule of a dynamic when pin 2 connects a fraction before pin 3 and produces a Big Bang, and the sound guys yell and shout at each other, but speaker comes don't fly across the room and the mixers don't die, and the mic seems to not object.
 
Wow, glad you never tried that in any of my theatres. The school of "if it doesn't burst into flames, it's OK" is the fear of every house sound tech with outsiders coming in. I had a designer who wired up this weird cable that "sounds really cool" and blew three amps in a row, "never happened before...".

Broadcast splitter boxes are transformer isolated and not simple Y cables, so that is a different issue. Phantom into non phantom mics is not a speaker problem, unless someone was stupid enough to hot patch into an open channel, it's a mic destroying problem. Few ribbon mics will survive it and dynamics may or may not be damaged depending on a number of issues.

One problem that can come up with phantom and a splitter, even on the same device, is if there is more resistance on one leg. Dodgy solder joint, dirt, different length, etc. This can cause a voltage differential that will give you a current loop. Richard is right that on the same box it's probably OK, it really depends on how the phantom is distributed etc.

An issue in general with a Y splitter is that a normal one will create a ground loop when installed. Again depending on where you are how the inputs were designed etc. this may be a problem or not, but it is a weakness. I'm assuming this dual record is for filmmaking so you are going to be in the field in possibly RF unfriendly locations so you have set up a potential problem that you wouldn't have otherwise.

One reason you will get a "Just don't do it" from a lot of folks who have been around, is that having no problems with the Y is based on everything working the way you expect it to and nothing being "wrong". One thing I would do when coming into a new theatre and using their cables (for anything) was to check them. Universities were the worst but even in decent theatres I would find mis wired cables or ones with broken wires. Classics in theatre are mic cables that have been use with the intercoms. Those cable are hopeless twisted rats nests and often have a bunch of issues.

So like many things the more you know the more you can get away with.

Based off of your post I'm assuming you should not count on getting away with a lot.

There is a difference between can something work, and will it work every time. There is probably not a pro around that hasn't done just about everything you are not supposed to do and gotten away with it, at least once. There are plenty of things I would do in the studio where I can check and change if needed that I would not do in the field except in an emergency. A Y splitter on a mic is one of those, unless I was only going from my stuff to my stuff and I had tested it out ahead of time. I still would look to a more proper way to do it, probably.

It looks like your tests are working so as long as you remember that the Y is the weak link and the first place I would look for problems, you are probably OK. However I still wouldn't recommend it to someone who asked tomorrow. Though I might point them to this thread.

BTW, maybe I have been around stranger people but I have seen a SM58 destroyed with a combo of bad cable and Phantom power. I have seen a ribbon mic have to be re ribboned because of phantom power, and I have seen speakers destroyed by an idiot hot patching, and of course all those amps. Mixers do die, I've had my share, including a 24X16 Neotek that blew it's power supply between sound check and show time. I don't think any of the mixer failures had anything to do with a specific patching/ wiring/ etc. but stressing them out can't be a good thing. So I don't know if I have just done a lot more shows, been around unlucky people, or Paul is just one of the blessed, but things do go wrong. And usually at the worst time possible. Most pros are fairly conservative about these kinds of things because they are hired to get it done. It doesn't matter much why "it went wrong", if it went wrong on your watch it's your fault. So they tend to stay away from things that might work 90% of the time because they can't afford the 10%.
 
Last edited:
Sorry Scott, have to disagree. Passive splitters have been used over here alongside transformers splits for quite a while, and the one I use regularly, is one of a pair built by the BBC in the 80s, and has parallel wired male/females on the main panel with a Harting multi on the side. I have never had a problem with ribbons, as they all have a transformer that is centre tapped and therefore phantom is not a problem, and I have never destroyed any microphone by connecting it to a phantom supply. I'm not suggesting you change your opinion, I egularly work with people who insist on turning all their amp controls to fully anticlockwise before powering up and down, but it don't do that either.

I have lost a couple of HF drivers over the years, one PA and one studio monitor, by plugging in a phantom powered mic with the gain up, so fader down is a rule I do follow.

I don't think I'm lucky, I suspect the people who suffer were unlucky. I do try to avoid patching anything through a live PA simply because of the noise, but maybe I just run my systems less than full tilt, so have a bit more slack in the system?

Back to to the splitter issue, I think the only real problem for me is when faced with a mixer combination that doesn't work, and the few that become unstable are a headache. It's quite common in the theatre I run for people to ask to use our EAW system, which works nicely for the building, and it avoids a very long walk with the gear as unloading is 400yds or so from the stage. It's common for people to bring in their desk and monitors, and leave the PA in the truck. In most cases, they just hand us a left and right, and go into our mixer, FOH on a couple of channels. If we are elsewhere, they often do it themselves, we don't mind, and as phantom to the nearest channel strips is usually left on as we use those for off stage mics (SM86), they remove two xlr a and plug themselves in. This is often interesting, because it's where odd thing happen. LEDs full on, or sometimes just the PFL meter, or on one LS9, a pulsing display! Other LS9s just ignored it.

one band who had agreed to use the house PA in the contract, fitted a Y-splitter to all our mics that we had preset for them, and ran them to a Behringer X32 rack mixer, so they could use their in ear system. Drum overheads and a few others had phantom applied, and no grief of any kind.

Of course, there is science to say it is all doom and gloom, but for me, history has been very positive, and I no longer think about it.

I would love to hear first hand from a ribbon user, who had destroyed one with phantom power. I hate ribbons on stage, live anyway, because I have damaged two in the past when a cable pulled a stand over, and every crash to the deck leaves me holding my breath. I know the physics says it could happen, but centre tapped transformers should, and seem to, stop it happening.
 
It comes down to this: With modern microphones and mic inputs, using a "dumb" Y-cable will often work just fine with no significant side-effects, just as paulears says.

HOWEVER, there is a significant possibility that it will not only NOT WORK, but actually DAMAGE one or both of the mic inputs.

The reason people are reluctant to endorse wide use of Y-cables is because you can easily suffer very significant damage if you don't know exactly what you are doing.
And, for better or for worse, people who come to public forums asking about Y-cables are typically NOT in a position to properly judge whether it will work for a given situation.

It takes years of experience AND knowledge of the internal circuit configuration of each input to properly evaluate each specific case.
That is why using a proper transformer-based, ISOLATED mic splitter is very popular to avoid all of the intrigue and hazards from a hard-wired "Y-cable".
 
You must log in or register to reply here.
Back
Top