Audio Quality on Radio Today


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But no-one seemed to bother to tell audio editing-types that, after opening an MP2 file in their new-fangled PC-based editing software, they should be very careful when saving the resulting audio as an MP2 because it could cause the software to compress it further.

The cost/capacity of hard-disk storage has, of course, become far more realistic in recent times; so most if not all computerized playout systems now store the audio as linear, non-compressed files. But I do still see a lot of use of MP3 files on air, which disappoints me greatly.

I know of at least one FM station, who rejoice in an 'all-digital' transmission chain, where commercials are received as MP3 files via email, opened by a person employed in commercial traffic in Adobe Audition, topped/tailed, trimmed and normalized, and saved again as an MP3. The warning that pops up to alert of the tragic consequences of saving to a lossy format isn't even read. It probably isn't even seen, before being summarily okayed.

This file is then imported into the playout system that converts it to a WAV file.

It's a WAV file, therefore good quality, right? Wrong. That poor audio has by then been subject to at least one particularly vicious bit-rate-reduction process, which if the MP3 was at 128kb/s, means it now contains only one eleventh of the data it did when virgin.

The plight of all those bits of audio that no longer exist seems to be of no interest. I feel for them, however; Mother Nature, after all, decided that they were all needed for us to accurately perceive the sound they represent - so who are we to discard them with such gay abandon?

Of course, whether we actually notice their absence is debatable. In the example above though, most people can notice the difference. Data reduction of a factor of eleventy-one is pretty severe.

I have seen, with my own fair eyes, someone playing a song on air off YouTube. The appalling swirliness of the audio on air seemed to matter not a jot, if it was even noticed by the bold presenter.

I do not have a propensity for physical violence, but upon witnessing this I can tell you, my perturbation was palpable, and had I been of pugilistic tendency, blows may have been wrought.

If you're just saving your legally obtained album to your iPod, and you're going to listen to it on loudspeakers so tiny that they fit right in your ear, then it probably doesn't matter.

But we - and I mean us, in the broadcast industry - are imparting that audio to our customers. Surely it's beholden upon us to do so in the most accurate way possible?

Besides, that poor, stripped-down piece of audio may well subsequently be squeezed down a studio-transmitter link that reduces the bitrate again. It might be converted from digital to analog and analog to digital several times before it presents itself, exhausted, to our faithful listeners.

You know those excellent novelty birthday cards, which impart mirth and joy by means of a built-in recording of someone singing 'happy birthday'? You know how crunchy and distorted they sound? Well I routinely hear commercials on FM radio that rival that quality for awfulness.

Audio processing

Which reminds me to write of the hoary old chestnut that is audio processing. I am a great fan of it; but only when done properly.

When the venerable Optimod-FM 8100 came amongst us in the early 1980s, it was actually quite difficult to put one on air and make it sound bad. There were varying degrees of niceness attainable, but with only five knobs, it was practically impossible to set the unit up to sound horrid.

"Give me five knobs, and I will give you the world," someone once said. Possibly.

The clever stuff was by dint of the properties of resistors, capacitors and inductors - those esoteric old analog components used in particular configuration to great effect by Mr. Orban, father of the Optimod.

But when the ones and zeros came along, it became much easier to add myriad other controls - as you didn't need a physical knob for each one, all million of them could be represented by a picture on a display. Later, more unruly progenies of Mr. Orban and his competitors had adjustments rejoicing in such nomenclature as Delta AGC; MB Release; HF Enhance; Sideways DownUp - all there on a nice LED or some other display and all nicely messuppable.

"Give them lots of knobs, and they will turn them," someone else said, maybe. And turn them they do, until they've knotted themselves up in a conundrum within an enigma, the audio sounds like it has passed through a vacuum-cleaner pipe, and no one is happy.

- continued on page 3



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