Thursday 3 December 2009

Pack up your radio towers, the Broadcast Era is nearly over!

I'm just back from a nice holiday away in Republic of Ireland visiting friends and relatives, enjoying Irish hospitality, buying Christmas presents and being blown about by 50mph winds. The things I do for a delicious Dublin-brewed Guinness!

Listening to local radio is great but there are a couple of UK stations I miss when I'm away. Not this time! My iPhone, sat in a JBL powered speaker stand, happily tuned into the Today programme on BBC Radio 4 each morning, and the odd dose of happy dance music from Gaydar Radio at various times during the day. Using the iTune.FM iCarRadio iPhone application both stations came through loud, clear, and very high quality. Very high quality.

In fact the sound quality was so good that it was noticeable, so I looked up their bit rates and compression methods in order to work out why.

No wonder: BBC Radio 4 uses 128Kbps AAC ('advanced audio coding') compression, one of the most advanced compression methods around in terms of the sound quality it offers for a given bit rate. Radio 4 on DAB digital radio often uses 80Kbps (mono) MP2 compression method for part of the Today programme in order to accommodate other services. It sounds awful despite being a speech programme thanks to this limitation of radio broadcasting.

Just for clarity, the greater the number of digital bits that are streamed in a second from an audio source, the better the sound quality because more sound information can be encoded with more bits. Not only that, but more recent compression methods (known as 'codecs') have the ability to compress the sound more efficiently compared to older codecs and thus get more of the audio into the same bit rate compared to older codecs.

Combine a modern compression method and a decent bit rate, and the reproduced audio quality can be as good as Hifi standard.

The UK's digital audio broadcasting service ('DAB') has to use a really old codec because of its original specification. Stations can't just start using a more modern efficient codec because many DAB radios would not know how to decompress the audio stream to recover the sound!

But the Internet? Well, anything is possible because computer software and other internet-connected devices are easily upgradeable to take account of the latest codecs. On my iPhone I download a compatible internet radio receiving application and next I have access to 13,000+ radio stations around the world.

That's not all - I have just taken delivery of a Pure Avanti Flow radio which picks up FM, DAB, and 13,000 internet radio stations, all easily accessible by Country, Genre, or station name. Now my presets include the two stations above, plus BBC Radio Solent (a local station serving the area I grew up on the south coast of Britain), Air America (a great liberal-minded talk/news station from the USA), Classical music stations KDFC 102.1 from San Francisco and WGBH in Boston (with its own orchestral recording studios) - all coming through with stunning, reliable, consistent sound quality.

Switching between DAB and Internet equivalents is the difference between night and day in terms of audio quality. Internet versions are not just a little bit better, they are way better. There is more 'presence' and less 'mush' of higher frequency sounds.

So now, in my home, I no longer listen to radio broadcast the conventional way - over the air. It all streams over the internet in a better quality than I get on FM or DAB, and I get to listen to stations all over the world rather than only those within signal range. Now that's pretty game changing.

There's more: I listen to internet radio reliably in my car! I use the iCarRadio application on the iPhone, plug the iPhone into one of those small FM transmitters with 10ft range so I can pick up the iPhone audio on my car stereo, and drive. My drive to work is mostly by motorway and the 3G coverage from O2 is good enough to provide continuous coverage all the way from Hendon to Welwyn Garden City.

Since iCarRadio buffers the audio (that is, it stores the audio for a few seconds before playing it), it means that any interruptions to the digital coverage that occur momentarily (normally due to the iPhone being 'handed over' from tower to tower as I drive) does not interrupt the audio.

I've been astounded as to how reliably this works in my car. Of course I accept that driving through a rural location will not be reliable, and coverage can be inconsistent if a cellular tower is busy with calls. Even then, I take advantage of the fact that many internet radio stations offer a lower bit rate (and thus audio quality) option where network congestion is causing reception problems. Of course using the iPhone and its headphones allows me to listen to internet radio when walking out and about, and in the office too.

So let's summarise. I now enjoy radio stations more by listening to them over the internet, in my home, car and wherever my iPhone gets 3G or Wifi coverage, with better sound quality and from all over the world. Hmmm! So I'm going to make a prediction here:

Conventional radio broadcasting over the airwaves has been around for about 90 years now.
I give it another 10.

Footnote: my next door neighbour plays in a band. In a discussion on this subject of internet radio, he decided it would be fun to broadcast his own station for an hour once a week where his band plays live, and his friends and relatives can tune if they want to listen using internet radio receivers. I'll be helping him with all the technical bits and streaming software required, and we think we can accommodate 20 simultaneous streams - more than enough for a trial. My research has uncovered that there are streaming suppliers that can receive a single audio stream from my server and rebroadcast it to thousands of potential listeners at low cost. So let's get this right: we are setting up our own radio station, no OFCOM (UK radio regulator) licensing permission, frequency allocation nor broadcasting costs required. Now that's what I call game-changing!

2 comments:

  1. Cell phones CAN CAUSE brain tumors over long-term useage...

    ..does your EAR tell you that??

    ReplyDelete
  2. I also don't listen radio on my car. I always tunein to my stereo.

    ReplyDelete

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