Zoom H4n - Signal Out?

[Alec Moreno]

I had an issue with the Zoom H4n that I'm hoping someone can help with.

On a wedding shoot, I asked the DJ for an audio feed. He had a cable available that he always has connected to his system for this purpose. When we plugged in my H4n, one of his two speakers went totally silent. His other speaker sounded fine and I was getting a signal to my recorder. He switched something around on his end, and then the other speaker cut out, while the first one suddenly had audio again. When we unplugged the Zoom, the DJ was not at first able to get both speakers working at the same time. After shutting down his system though, he was able to get both speakers working. During the shoot though, he mentioned that one speaker or the other continued to cut out from time to time.

The connector he allowed me to tap into was a male XLR. I attached a splitter to this so that I could send the same feed to both 1/4 inch inputs on the H4n. This worked on my end as I was able to get a signal to both channels.

The DJ was real nice about it and mentioned that my recorder must have sent something out to his system. The only thing I know of that can come out of the 1/4 inch or XLR connections on the H4n is phantom power. I never use this feature though, and I verified that the phantom power was indeed turned off.

Is there any chance that the H4n can do this to a DJ's system in the manner I described, or was this just a very odd coincidence that I plugged in at the same time that something in his system failed on its own? I've never had an issue connecting the H4n to a DJ's system, but I would like to find out if there is some setting that I can change to avoid this in the future.

We're both very interested in finding out what happened, as he works with videographers quite a bit (who also use H4n recorders) and I work with a lot of DJs. He mentioned one more thing...that this happened to him once before. That time also involved an H4n. Apparently, there was some setting that the videographer later discovered that had caused the issue, but the DJ could not remember what that setting was.

Any help is appreciated.

Alec Moreno

[Steve House]

How exactly is the splitter you used and the cable he provided you wired? I'm thinking that one of the pins of his board's output either got shorted to ground or had signal hot and signal cold shorted together when your splitter was plugged into it. Depending on the design of the board this might cause a signal loss. An XLR-M output is going to be a balanced mono signal. Signal hot is pin 2, signal cold is pin 3, signal ground is pin 1.If the wiring of your splitter ends up connecting pin 2 to pin 3 of the XLR, pffft that channel goes out.

If your splitter has ONE XLR-F splitting to two 1/4 phone, unless you're plugging into a mono out that's a mix of the two stereo channels, even if it's wired correctly it's likely any music you record is missing one channel. My Mackie board has a TRS mono out that is a mix of stereo left and right but not all boards do.

[Rick Reineke]

I concur with Steve, a mis-wired cable is likely the issue, but without knowing what board and other specifics, the exact cause can't be determined.
Be aware that the H4n's 1/4" line input is unbalanced and the DJ board's XLR is most likely balanced, so the cable/connection must be wired accordingly.

"The DJ mentioned that my recorder must have sent something out to his system"
> Sent out what.. a virus? This is not possible.

[Alec Moreno]

The way that I split the signal was by plugging in two items between his cable and my recorder...

-DJ's female XLR connected to...
-my long cable (female XLR to male 1/4 inch balanced) connected to...
-my splitter (female 1/4 inch to two male 1/4 inch unbalanced) connected to...
-my Zoom H4n (1/4 inch inputs)

I am aware that mixing balanced and unbalanced connectors may not be optimal for quality, but this exact setup has never done me wrong in the past. I was positive up until this shoot that this setup could not possibly damage the DJ's system.

Note that the DJ was the one who actually plugged my cable into his system, and this was after I had already powered up my recorder. Still though, I don't know how his XLR pins might have been bridged with this setup.

Does my description provide any more clarity?

[Steve House]

If the splitter was designed to take a stereo TRS with left on tip, right on ring, ground on sleeve into two separate TS plugs with one having the signal left on its tip and the other the right signal on its tip, as most off-the-shelf splitters are built to do, when you use it to unbalance a mono XLR you've set the stage for XLR pins 2 and 3 to get shorted together. At the very least your recorder's two tracks are going to be 180 degrees out of phase with each other. To properly unbalance a balanced TRS, the tips of both male plugs need to connect to the tip connector in the female jack, their sleeves need to connect to the female's sleeve, and you need to bridge the ring connector in the jack over to the sleeve connector.

[Alec Moreno]

Steve,

I'll admit that your description of how to properly split a balanced mono XLR signal is beyond me. So, I showed your description to a couple of local audio guys, and they told me that there was no possible way that I could short out a DJ's system regardless of the types of connectors and splitters I might use.

Their conclusion was that the DJ's system had some minor problem from the start, and plugging in my recorder made the problem surface. One of the DJ's explained that he has experienced the same thing...that for some reason, a system might have a hiccup of sorts when music is playing and then an additional device is connected to one of the outputs. He said that on a good working system, this would not be a problem, but that when it does happen, it's commonly because the music was not turned down when plugging in the device. He explained that he's seen this result in one of the two speaker outputs going silent. It would make sense then that when the DJ switches the two speaker cables from one output to the other, the working speaker would go quiet and the other would work of course. Powering down the system and then kicking it back on again would then reset the system and both speakers would work.

The description above seems to match up pretty well with what happened to us on this shoot so I'm inclined to believe this. I understand that you're saying I set the stage for shorting the pins on the DJ's XLR. Can you please clarify this for me? By this do you mean that this connection would definitely short these pins, or are you saying that going from a male TRS to a splitter (female TS to dual male TS) is a connection that is "likely" to create a short...depending on the build quality of the connectors possibly?

____________________

In the future, it sounds like the best way that I can be sure of connecting everything correctly is to simply stick with whatever type of connection I'm given. If the DJ hands me an XLR connector, then I'll stick with XLR connectors all the way to my recorder. If I get a TRS connector, then I'll stay with those all the way, and so on.

Will this protocol ensure that I'm connecting everything safely on my end?

[Steve House]

Your audio guys are correct, the connector/splitter combination per se won't short ... what I'm thinking is that when they are plugged into the inputs on the recorder there's a possibility there could somehow be an internal connection made between the two male tips inside the recorder. If one tip carries XLR pin 2 and the other XLR pin 3. there's your short. I'm just guessing because I don't have the recorder's schematic but let's say you are setting the recorder for mono and when you do, the recorder mixes the left and right inputs by connecting them in parallel inside the recorder. That would do it. I don't know that this is what's happened but it's something to consider.

[Roger Gunkel]

I don't see that what your audio guys are telling you is necessarily correct.

A connection from the board to your recorder could have a number of different problems including left and right connected, a balanced to unbalanced connection or a phantom power rather than audio connection to one side.

Unplugging a lead from the speakers while the system is on, is a totally different situation and if the speakers are passive and the lead is carrying a power signal from an amp, the output overload protection on the amp could either blow or shutdown on that channel while there is no load. That would have no relation to your own problem.

Roger

[Rick Reineke]

Your audio guys are correct.. in a perfect world at least
Most mixer's outputs are isolated (a main out XLR and 1/4" for instance). In this case an improperly wired plug would not cause another output to go down. OTOH, I've encountered outputs that were wired together, and that could cause a problem. So w/o knowing the mixer's architecture, it's impossible to say for sure.
The DJ's mixer could have another issue, and the loss of signal could be a coincidence.

[Steve House]

Here's my assumptions and logic ...

1: The XLR to 1/4 TRS male cable is an off-the shelf cable intended to connect a balanced, mono, XLR output to a 1/4 TRS balanced mono input. This cable would connect XLR signal hot (pin 2) to TRS male tip, XLR signal cold (pin 3) to TRS male ring, and XLR ground (pin 1) to TRS male sleeve.

2: The splitter is an off-the-shelf Y intended to take a single TRS 1/4 unbalanced stereo feed and split it to feed two separate 1/4 unbalanced left and right mono inputs. The TRS female jack would have left signal on its tip, right signal on its ring, and common signal ground on its sleeve. In the splitter it would connect signal left to one plug's tip, signal right to the other plug's tip, and signal ground to each plug's sleeve. If the plugs are TS that's it, if they're TRS their rings are unused.

Now combine them, plugging the cable's male TRS into the splitter's female TRS jack. The result is the XLR pin 2 connects to left male TS tip while the XLR pin 3 connects to the right plug's tip. If you plug them both into any device such as a recorder that for some reason parallels the two TS plugs inside the device, tip of left gets connected to tip of right, thus shorting XLR signal hot to signal cold.

[Alec Moreno]

Thank you all so much for your help. I'm going to pass along a link to this thread to the DJ I was working with so he might be able to put it all together along with his knowledge of his system.

Also, since it was brought up that my recorder may have had a short in it...I contacted Zoom customer support to see if the H4n recorder is capable of causing such a problem (just to make sure). According to them, there is no way that a short can occur within the recorder. They also verified that 1/4 TS connectors are perfectly acceptable to use with it.

Since I've summed up Zoom's response, there's no great need to read the following two messages between the Zoom representative and myself, but I'm pasting them below for the sake of completeness.

Thanks again everyone.
____________________

MY MESSAGE TO ZOOM:

I have an H4n loaded with System Version 1.72 and Boot 1.01.

Recently, I got an audio feed from a DJ's board (while filming a wedding) and
split that feed into two. I then connected these two signals to the 1/4 inch
inputs on the H4n, which was already turned on. When we did this, the feed
came through to both channels of the H4n just fine, but one of the DJ's
speakers went silent. We then disconnected the H4n and were able to get the
problem speaker working again, but the other speaker went silent instead.
After powering down his system, the DJ was able to get both speakers working
again, though the speakers had the same problem from time to time throughout
the night.

The DJ mentioned this had happened to him once before when another person
tried to plug in their H4n. He recalled that they had discovered a setting in
the H4n that was to blame, but he could not remember what that setting was.

My first question...
Is it possible that my H4n could have sent anything (power or a signal of
some type) into his system to cause this problem? The only thing I can think
of that can possibly come out of the inputs on the H4n is phantom power, but
I never use this function. I keep it turned off at all times, and I verified
this when the problem occurred.

My second question...
Is it possible that the cables I used to connect to his system were
incompatible with the H4n? Below is the exact series of connections that we
used:

DJ board (male XLR output) connected to...
cable (female XLR to male 1/4 inch TRS) connected to...
splitter (female 1/4 inch TS to dual male 1/4 inch TS) connected to...
both H4n 1/4 inch inputs

I've used this same setup with other DJs in the past without any problems, so
we're really interested in finding out where the problem stemmed from. Thank
you for any information you can give us.

Alec Moreno

ZOOM'S MESSAGE TO ME:

There is no setting on the H4n that would cause this to happen. Most likely this is an issue with the DJ equipment or cables you are using. Some mixers can be set to mute when output to a recording device. Also, when sending signal to an H4n all you need are two cables XLR to 1/4" mono. The more adapters and splitters you use the more problems you might encounter.

[Alec Moreno]

Slight typing error in my description of the connectors used...the DJ's XLR that he handed me was male (of course, since I plugged it into my female XLR connector).

Also, I verified that the splitter is female TS to dual male TS, and it is an off the shelf splitter I bought at a local musicians' store.
____________________

Here is the more complete description of the connections I used:

-DJ's male XLR connected to...
-my long cable (female XLR to male 1/4 inch TRS) connected to...
-my splitter (female 1/4 inch TS to two male 1/4 inch TS) connected to...
-my Zoom H4n (1/4 inch inputs which are compatible with TS connectors)

[Steve House]

I'd be willing to bet good money that your splitter is female TRS, not female TS. Get a multimeter and check to see if tip of one male is connected to the tip of the other. If they are, she's TS. If they're not, she's TRS. TS would be a mono splitter, TRS would be a stereo breakout adapter (which is what I suspect you have).