Studio technologies:  electromechanical devices.

Four devices in a radio studio convert a mechanical effect into an electrical effect, so they can never be perfect.   These devices are

a) Microphones
b) Speakers
c) Pickup cartridges
d) Headphones

All of these have quirks and compromises that you need to understand in order to get the best results – unlike fully electronic devices, which have got about as good as they could get.

In this article John Maizels gives you some practical tips that will help you to work out how to get the best results from headphones.

HEADPHONES

Headphones (or “cans”) are found in every radio studio… although “found” isn’t always true: headphones have a strange tendency to grow legs and leave the studio without warning.

A good pair of headphones is essential to a broadcaster’s craft.

Headphones come in many forms: they can be supported over the head, have a headband around the back, or have no band, in which case they sit just outside the ear canal or (in the case of earbuds) sit in the ear canal.

You might be surprised, but size isn’t everything, and no one type is better than another.  Some designs are definitely more useful that others in specific situations.    In general, for radio work the best option usually is an over-the-head band, but be guided by your personal preference.  You have to be comfortable using them, and that’s what really counts.

1. Should they be closed or open?

This one is simple.   Closed headphones, where your ears are fully enclosed, are the smart bet for radio use.  Open headphones are less claustrophobic, are light, and let conversations in – useful when the mic is off.  But they also let the sound out, which is not so useful when the mic is on.  So go with closed.

2 What do they sound like?

Studio headphones should have a flat and smooth frequency response.   It’s surprising how many “brand” headphones sound like tin cans.   Compare headphones against each other to get a feel for whether they sound open or boxy.  Studio headphones shouldn’t sound tizzy, and shouldn’t sound doofa-doofa.  That might be cool while you’re walking down the street, but it gets very tiring very quickly in a studio.  Plus, if the headphone has a specific peak, that’s where you’ll get feedback when the microphone is open and the headphones are up loud.

For sound mixing you need headphones that don’t colour the sound and are as faithful as possible.  But since there’s no such thing as perfection, a good second best is a pair of headphones that produce reliable sound.  Many sound recordists in film and television use Sony’s MDR-7506 or MDR-V6 (which are identical) for that reason.

3 What connector

That pretty much depends on what connectors you have on your console, and whether the headphones come with an adaptor.   Most mobile phones use 3.5mm (1/8″) sockets.  Most broadcast consoles use 6.5mm (1/4″) sockets.   You can use an adaptor to convert from one to the other, but… most adaptors get in the way.  So there’s no really good answer.  One good solution is to have headphones with 3.5mm plug, and carry a right-angle adaptor which goes from 3.5mm socket to 6.5mm plug.

4 USB = disaster

Some headphones come with USB connectors, and are designed to work straight out of a laptop. That’s a cute idea, but introduces a major challenge for radio work:  USB means digital, and digital processing introduces delays.  If you use a  USB headset to talk to someone else and you don’t hear your own voice, digital delay isn’t a problem.   But in radio we always listen to our own voices and the digital delay of  USB connection will make your voice sound weird  – to you.  it only takes a few milliseconds delay for your voice to sound weird in your head, and a delay of tell milliseconds would be noticed by almost anyone.  

You’re unlikely to be able to plug a pair of USB cans into a console, but you might be tempted to use them with a laptop.  Just be aware that digital delay is not your friend.

5 Replaceable pads

After a while headphone pads get ratty and tattered.  Hardwearing headphones allow you to change the pads when you need to.  Often pads are available on eBay but beware.   Cheap pads don’t always fit the headphones, don’t always last very well, and might not breathe very well – in which case the headphones won’t be very comfortable to wear.  On the other hand, cheap pads might be just fine.   Unfortunately, the only way you’ll find out is by trying different pads.

6 Replaceable other bits

Headphones will break at the least expected time, but most likely while they’re in a bag going to where you need them.  The broken piece will be made of plastic, maybe the hanger clip on the headband which holds the headphones together, or the cord.   Because you’ve paid a lot of money for the headphones, it would be good to know that you can get spare parts.   The major brands will have available spares.

7 Headset microphone

Headsets used in studios or OBs have a microphone built in.  Not all microphones are equal, and not all headset microphones sound very good.  In fact some won’t even interface to a broadcast console without a major fight, so beware.  

The biggest trap with a headset mic is to get it placed correctly, so that it’s not to breathy, not too nasal, and doesn’t get popped on every other word.

8 Sensitivity

Put simply, sensitivity this is how much noise you get out for the amount of electricity that you put in.  Headphones with a higher sensitivity will be louder for the same amount of input.   High sensitivity is quite important if you intend run headphones from a phone or portable player which might not have a lot of output.   But most radio consoles are able to drive headphones quite hard, so a lower sensitivity would be OK

In a studio, what’s more important than absolute sensitivity is that all the headphones that you use should be about equally sensitive.  That’s so that you can swap headphones around and you won’t be blasted by the previous person’s settings, or unable to hear for the same reason.

9 Impedance

The impedance of a pair of headphones determines how much load it will put on the headphone driver, and how well the headphones will match the electrical circuit.  

 High impedance headphones won’t load down the amp as much, and you can have more of them hanging from the same socket before you create a problem.  High impedance headphones might be 100-200 ohms.  Low impedance headphones will be 8-20 ohms, and too many of those built out from the same adaptor will probably cause distortion or low sound… or both.   Many studio headphones sit in the 50-100 ohm range, and that’s pretty good.

The Maiz, John Maizels, is our technical writer and a tech ‘gun for hire.’  He is also an Asia Pacific region Governor of SMPTE.

 You can contact John for consultancy and freelance work at [email protected]

See some previous articles by John Maizels at these links:
 
How to get the most from your Station Tech
 
Latest radio equipment at SMPTE 2013