Cable snake causing clicks on recorded audio?...at the end of my tether!

[Studio101]

Hi all,

I have been experiencing some issues in my studio recently where audible 'clicks' have started appearing (seemingly at random) on my raw recordings. Would be very grateful if anybody might be able to give me some advise about it!

I have managed to compile from test recordings some examples of what has been happening in the audio file from the link below to illustrate what I have been going through!

http://we.tl/yhIYIkh44K (Wetransfer link to audio file).

Listen out for it at
-00:01.05 On the word 'Times'
-00:02.31 Just before 'That'
-00:05.13 Just after 'London'
-00:05.79 Just before 'The'

Kind of a 'static' sound...don't think it sounds like digital clicks caused by clock issues/jitter...(?) As you can hear, the sounds occur at varying degrees of intensity.

In my studio setup I have a separate 'control' room and 'tracking' room. The signal flow is:
[mic] -> breakout box/cable snake -> FW mixer (A+H Zed14) -> iMac running Logic

In an attempted process of elimination, I have tried different mics, xlr cables, different audio interfaces and even different computers and experienced the same issue each time.

I thought the cause could be my electricity supply, however the problem was still evident when using a laptop running off the battery.

This leaves my cable snake as the only common denominator. Could the problem be caused by this? The snake is not particularly old and has barely moved since it has been installed - I am of course reluctant to go through unnecessary trouble and expense to replace it!

If anyone has experienced this kind of problem before I'd really appreciate some advise. If any more details are required please let me know!

Would really appreciate help to get to the bottom of this as it is frustrating as I am sure you can all imagine.

Cheers

[Hugh Robjohns]

It's quite possible that your snake is acting as an aerial and picking up unwanted RF interference. Brief sparks from old and corroded switches on lights, boilers and other mains-powered devices often generate RF spikes that can radiate quite far and be picked up by cables. The problem can be made worse if the mic preamp/interface has poor RF immunity... Which is not uncommon on budget gear.

However, clicks can also happen if data transfers are briefly interrupted in the computer. Given that you've tried different computers that's probably not your problem, but it is common. Clicks can also come om the source itself, of course. I once spent ages trying to find a source of radio interference generating clicks on a radio mic lavalier I'd placed on a female guest. Eventually discovered it was her bra underwrites creaking!

Tracking down these kinds of problems can be frustrating, and you have to be very methodical. I find using a steady tone source is a far better diagnostic tool than random musical sources. A 3kHz sine wave is ideal -- clicks become very obvious, whereas it's easy to miss some clicks with music sources. Regular clicks imply some digital clocking problems or computer processing issue, for example.

It is worth recording the tone source into the computer directly via the interface first, to prove that is fault-free, and then again via the snake. Obviously, if you're using a line level tone source, you should pad it down to mic level, perhaps via a D-I box.

That will help to reval of the problem is getting in at the interface, or via the snake, for example.

H

[Mike Stranks]

Two questions:

1) Have you tried a different voice?

2) Do you live in the country or a city/town?

[Studio101]

Thanks a lot for replies chaps, will try the test tone idea

To answer your questions Mike:

The issue has occurred with different vocalists and I live in a town.

[Mike Stranks]

Thanks a lot for replies chaps, will try the test tone idea

To answer your questions Mike:

The issue has occurred with different vocalists and I live in a town.

Ah! That's my two 'first-thoughts' out the window then!

I've had a quick look (as well as listen) to the clicks. It's interesting that they are not at a constant volume - which adds strength to the idea of an RF problem rather than an 'internal' system-glitch. The test-tone-test will be interesting....

[Richie Royale]

When I listened to this my first thought was that the click was coming from the person speaking; the action of opening the lips causes a similar click, but if you are getting it on all sources then that may not be the case. I suggest, as Mike says above, using something clean and repeatable like a test tone or sample.

[Exalted Wombat]

I'm hearing mouth noises too.

My personal bugbear is mouse noise - I seem to have a habit of tapping it on the desk if I tweak anything while recording. That's not the problem here though, I think.

[molecular]

Thanks a lot for replies chaps, will try the test tone idea

To answer your questions Mike:

The issue has occurred with different vocalists and I live in a town.

Ah! That's my two 'first-thoughts' out the window then!

As someone who lives very much in the country, I'm now intrigued...

[Mike Stranks]

Thanks a lot for replies chaps, will try the test tone idea

To answer your questions Mike:

The issue has occurred with different vocalists and I live in a town.

Ah! That's my two 'first-thoughts' out the window then!

As someone who lives very much in the country, I'm now intrigued...

Happy to de-intrigue you...

Having working with/in semi-pro studios in rural locations I know that electric fences and heavy-duty farm machinery including automated milking parlours can cause problems in nearby properties.

[molecular]

Gotcha. None of that stuff around here, thankfully!