Audio Buzz/Hum

If you're getting a buzz or hum in your audio mix (hearing in camera headphones), never fear. Here are some troubleshooting steps as well as some recommended gear.

Some cheap ground lifts literally do nothing other than take $10-$20 out of your wallet. Below are ground lifts (and mic splitters) we can verify will clean up a buzz/hum in many situations.

A Quality Ground Lift is considered essential videographers gear! Having 2 ground lifts is recommended!

Basically put the ground lift in between the audio mixer and your camera's XLR input.

• Whirlwind ISO XL Line-Level Isolater ($48.00)

• Pro Co Sound MS-2 1 into 2 Microphone Splitter ($64.00)

• Whirlwind IMP Splitter 1X2 ($98.00)

Keep in mind that beyond inserting a ground lift between the audio mixer and your camcorder, don't forget the golden rules of troubleshooting which is break the complexity down. Strip things down to base level such as:

1. Clean up your cabling. Cables running over power strips or other sloppy cabling can cause buzzes.

2. Wireless lavalier going into audio mixer as ONLY input (pull others out), single output going to camera - how does it sound?

3. How does it sound with Wireless lavalier going directly into your camera xlr inputs?

4. Start slowly adding in audio components one at a time until "there it is!"

1. Sloppy Cabling. Your mic cable routing is sloppy and perhaps a mic cable is right next to a power strip etc. Clean up your routing.

2. Laptop Audio / Direct Box being connected. There is a ground lift switch typically on direct boxes. Flip it

3. Bad Mic (XLR) cable that may need to be swapped.

4. Bad Audio Mixer port (audio mixer output going to your camera)

5. Bad Power Strip (Swap out power strip)

1. POP IN A GROUND LIFT

• Put a quality ground lift in between the audio mixer and your camcorder XLR Inputs

2. BASIC AUDIO MIXER TROUBLESHOOTING

• • • First and foremost make sure you don't have sloppy xlr cabling with a rats nest of XLR cables particularly near or touching power strips etc.

    • Mute or turn down all used audio mixer channels.

      • One by one, unmute (or turn up) channels that have inputs (wireless lav, handheld e.g.) until you when unmuting or turning up one channel the buzz/hum returns in camcorder headphones. | You're identifying which particular channel/cable/component is causing the issue

    • Move the mic cable going into this troublesome channel into another empty input channel on the mixer | May be a bad port on audio mixer

    • Replace the mic cable going from that specific wireless receiver into the mixer | May be a bad mic cable

    • If buzz/hum still exists after switching the identified component (wireless lav e.g.) to a different channel on the audio mixer and swapping cables, ask the venue for a replacement for that component.

3. ADVANCED AUDIO MIXER TROUBLESHOOTING

• • • Try a different output on the audio mixer - such as moving from Aux1 to Aux2 | May be a bad port on audio mixer

    • Try switching from Mic to Line Level or Line Level to Mic Level on your camcorder XLR's. See relevant Camera Mic/Line Level section

    • Swap out all cables routing from the audio mixer (a few feet away) into your camcorder's XLR mic input | May be a bad mic cable

    • Plug wireless lav receiver directly into your camera - is it clear as a bell? | SOLUTION: Ask venue for a replacement audio mixer. It sounds like a bad port on audio mixer / bad audio mixer

    • Plug wireless lav receiver directly into your camera - still a buzz/hum? | SOLUTION: Swap out the power strip where audio mixer, wireless receivers is plugged into.

SOURCE ISSUE
Buzz/Hum when laptop audio is connected to audio mixer that isn't there when laptop audio mic cable is disconnected from that audio mixer.

QUICK SOLUTION
Flip ground lift switch on direct box / laptop interface to see if it gets better/worse

TROUBLESHOOTING STEPS

1. Mute the Laptop Audio channel on the audio mixer - does buzz/hum go away?

2. Unplug XLR from Laptop Audio going into audio mixer - does buzz/hum go away?

3. Unplug the speaker's laptop power cord from the power strip - does buzz/hum go away?

Basically we're trying to identify that the only thing causing the buzz is the laptop audio connection.

ADDITIONAL SOLUTIONS (BEYOND QUICK SOLUTION)

1. (Bad Channel on Mixer) Try plugging Laptop Audio XLR into a different channel on audio mixer

2. (Extra Ground Lift) Insert an additional ground lift between the laptop audio mic cable and the audio mixer.

3. Carry one of these (As only a few bucks) or ask the hotel to plug the speaker's laptop power into one of these. To my understanding this only works when the ground lift tab is broken off.

4. (Bad XLR Mic Cable) Run a quick ungaffered (for speed's sake) XLR/mic cable between direct box and audio mixer to see if bad cable.

5. (Different Circuits for Audio) Have venue route power for the Presenter's laptop to the same circuit/power strip as the audio mixer at your tech area. The laptop at front of the room is probably on a different circuit causing buzz/hum.

BUZZ/HUM MILD
Keep laptop audio muted OR laptop XLR disconnected from mixer UNTIL needed and then either unmute or snap XLR quickly back into channel strip in audio mixer at video clip time.

BUZZ/HUM SIGNIFICANT
Unplug direct box hogging up speaker's laptop audio headphone jack and instruct speaker to place wireless handheld next to laptop speakers when there are video or audio clips. Use this process if the buzz/hum is quite pronounced and impactful.