Do you worry about your recordings being affected by magnetic fields?

David Mellor

David Mellor is CEO and Course Director of Audio Masterclass. David has designed courses in audio education and training since 1986 and is the publisher and principal writer of

Monday September 11, 2006

Perhaps you should worry about magnetic fields.

There are magnetic fields all around. Fortunately, the Earth's field is too weak to affect recordings. But electric motors emit strong fields (watch out where you sit in an electric train - you could be sitting on top of a motor). So do loudspeakers. And sometimes technicians like to carry magnetized screwdrivers around with them - great for picking up screws, but death to some types of recording.

What types of recordings can be damaged? The most sensitive are analog recordings. The tape has a low coercivity meaning that it is very sensitive to magnetic fields. NEVER put an analog tape on top of a loudspeaker.

Digital tapes however are very much more robust. You are unlikely to damage a DAT tape anywhere in the studio, but loudspeakers still really should be a no-go area just to be sure. Even if a DAT tape is not audibly affected, the error rate may be higher and further use and abuse could just push it over the top into glitching.

Hard disks too use magnetism to store data, but the coecivity is high so they are likely to be safe, but best to be careful.

Some digital storage devices use magneto-optical technology, such as Minidisc. However, the surface is only sensitive to magnetism when heated by a laser, so they will not be damaged at all by external magnetic fields in normal use.

One last thought - remember to take off your watch when using a bulk eraser (device for erasing tapes a whole reel at a time). Certain types of watch will run at up to 60 times their normal speed!

Like, follow, and comment on this article at Facebook, Twitter, Reddit, Instagram or the social network of your choice.

Come on the Audio Masterclass Pro Home Studio MiniCourse - 60 great hints and tips to get your home recording studio MOVING

It's FREE!

Get It Now >>

The Internet goes analogue!

How to choose an audio interface

Audio left-right test. Does it matter?

Electric guitar - compress before the amp, or after?

What is comb filtering? What does it sound like?

NEW: Audio crossfades come to Final Cut Pro X 10.4.9!

What is the difference between EQ and filters? *With Audio*

What difference will a preamp make to your recording?

Watch our video on linear phase filters and frequency response with the FabFilter Pro Q 2

Read our post on linear phase filters and frequency response with the Fabfilter Pro Q 2

Harmonic distortion with the Soundtoys Decapitator

What's the best height for studio monitors? Answer - Not too low!

What is the Red Book standard? Do I need to use it? Why?

Will floating point change the way we record?

Mixing: What is the 'Pedalboard Exception'?

The difference between mic level and line level

The problem with parallel compression that you didn't know you had. What it sounds like and how to fix it.

Compressing a snare drum to even out the level

What does parallel compression on vocals sound like?

How to automate tracks that have parallel compression

Why mono is better than stereo for recording vocals and dialogue

Clipping and compressing a drum recording to achieve an exciting sound texture

What can we learn about room acoustics from this image?

Can you hear the subtle effect of the knee control of the compressor? (With audio and video demonstrations)