Say No > Digital Radio Plus: NOT - Say no to DAB+ and its minuses
Digital radio was introduced to the world since the early 2000s. More recently (2007 and onwards), a push is gaining momentum to try to get listeners to switch over to digital. However, digital radio is not all that it is striked up to be.
Promises of so-called 'better' sound quality, better reception, station name display etc are usualy marred by problems such as higher cost and limited transmission ranges that plague digital transmissions. As such, digital radio will only compliment analogue radio. It will never replace it.
Worse than FM quality. The DAB+ bitrate, usually 64 Kbps for nearly all stations, is dismal. Most shared DAB transmitters try to cram more 'stations' onto the one DAB frequency, leading to lower bitrates for each station, and subsequently the audio equivalent of image pixellation. The owners of DAB transmitters make more money by having more radio stations 'subscribe' for allocation on their digital services.
As one DTV forum member rightly pointed out:
Yes, HE-AAC shows its strength at 48kbps (actual). Unfortunately it is still only good enough for talk back radio and news at 48kbps (nominal) for my ears. I find the "writhing" and "hollow" basic sound, and the bursts of artificial treble, distracting and unpleasant.
We are seeing a lot of the DAB+ broadcasters in Australia using 64kbps (nominal). That produces a reasonable quality, but unfortunately still below the quality of FM in a good reception location with a medium price range FM tuner. With careful listening, there is almost continually noticeable artifacting of speech. Much music suffers too. Classical music in particular is noticeably compromised at 64kbps (nominal). However for casual listening, particularly at low volume levels, 64kbps (nominal) would be quite acceptable for many people.
There is nothing that sounds quite like analogue - DAB+ can have a harsh sound resulting from encoding artifacts due to the underlying AAC audio compression codec being used. Unless the DAB+ stations use at least a 128Kbps AAC allocation, the full potential of digital radio (i.e. CD quality audio) simply cannot be realised. It is not unlike listening to badly encoded MP3 audio by some pirating, iPod owning kid who should know better. In fact, some stations, notably Magic 1278 in Melbourne, have audio quality on DAB that is not much better than their analogue transmissions. And others, such as 3AW, have a 'normal', high quality station, along with a '3AW+' station which simulcasts the AM transmissions with much reduced quality. Why bother? What's the point?
The crispness and clarity of FM transmissions and the mellow sound of AM transmissions on the MW band simply cannot be replicated on digital transmissions that use lossy codecs such as AAC+ - especially at low bitrates.
DAB+ (on the majority of stations, as of 2010) can be described as an audio signal that has been split into a two bands, with the low (bass to mid) band sounding muffled (as if you had pillows or several sheets over the speaker), combined with an overly accentuated and crunchy high (treble) band for good measure. It may re-create some of the original sound timbre, but the results are disaterous for music such as a orchestral pieces (the stringed instruments lose most of their nuances). ABC Classic FM on DAB+ does no justice to the music.
Unless you enjoy the horrible 'tinnyness', raspy, metallic, youtube-like sounding audio compression used on DAB+ (in the current state of allocations), it would be better to stick to FM.
Delayed audio and latency. Nearly all AM/FM stations who simulcast on DAB+ will incur a delay of up to 7 seconds for the digital version. This is because the transmitter must encode the audio and 'buffer' a few seconds of it before being sent to the transmitter, and the receiver also needs to hold its own buffer of 1 - 2 seconds. Only a rare few stations deliberately delay the analogue signal so both analogue and DAB signals will be in better sync. But the delay on DAB+ can be very annoying to listeners who have the radio commentary running alongside their TV when watching live sporting events. In this case it is better to use an anlogue receiver.
Higher power consumption - portable receivers are available on the market that can receive analogue as well as decode digital transmissions. When running in analogue mode, batteries can last for days or even weeks if used infrequently. But when in digital mode, battery life suffers significantly, by the order of 5 to 8 times less. The decoder circuits (microprocessor, DAC, RAM, etc) are all power-hungry devices. DAB+ uses the AAC codec which is complex to decode, leading to increased signal processing requirements and the need for a powerful microprocessor. It means the receiver can only run for several dozen hours on battery power.
In analogue receivers, most of the electrical power is used to run the audio amplification stages. Very little is needed to run the receiving end of the radio. The opposite is true for DAB+ radios. Most of the electricity is used in the receiving and decoding stages, whist comparatively little is used for audio output. So running a DAB radio at low audio volume will not significantly enhance battery life as it does for an analogue radio.
When used a couple of hours a day, most analogue pocket transistor radios running off a pair of AA cells will last at least two to three weeks. DAB radios, even with their high-capacity lithium rechargeable batteries, will last at most two or three days away from AC power.
In short, portable DAB+ units simply can't compete with analogue sets when it comes to battery life.
Bulky receivers. At present nearly all DAB receivers are bulky, and only a rare few (such as the Sangean DPR-34+) would be classed as truly portable. The popular 'Pure One Mini' comes close, but you would still be struggling to fit that in an overcoat pocket. The good old compact analogue transistor radio will be with us for some time to come.
Weak signals unusable on DAB, less reach - whilst a weak, distant analogue radio station can still be received with some level of intelligibility (albeit with some background noise and static), a digital receiver will be unable to decode the weak signal, resulting in no audio at all. In marginal cases, the audio will cut in and out.
At the end of the day, digital radio is either all or nothing - when you have a good signal, you will have great sounding audio. You get nothing when the signal is even the slightest bit too weak for the radio's liking. If you want uninterrupted reception, stick with analogue. At least with analogue, the audio quality will gradually taper off as the signal gets weaker, rather than cut out entirely.
No ability for DXing. Dxing (or long distance listening) is a hobby some radio listeners engage in. The AM signals on the medium wave band can propogate several hundred kilometers (especially at night). With a suitable antenna, distant signals can be picked up with good clarity. Listening in to another MW radio station from a neighbouring state or town is not difficult.
However, because DAB uses VHF, signal propogation only allows for local listening, unlike medium wave. VHF communications generally require a near-line-of-sight path for a good useable signal, and more so for digital modes. It is near impossible to listen to a distant DAB+ signal.
Another gadget to clutter your car. Car manufacturers have been reluctant to install DAB radios in vehicles, and for good reason. DAB technology is still in its infancy, and there is no guarantee the technology won't be superseded with something newer in a couple of years time. Analogue AM/FM has been around for many decades, is a tried-and-tested technology and will be with us for the long haul.
To listen to digital radio whlst driving, an in-car DAB+ receiver is needed, which retransmits its audio on an 'empty' FM requency so your car's existing receiver can pick it up for playback. But such a thing will clutter your car, competing with the GPS, cell phone charger, etc, for power from the cigarette ligher socket. You now have two things to turn on in order to listen - first, your car's built in radio, and second, your DAB receiver. Probably more trouble than it's worth, so you may as well just listen to analogue AM/FM.
When travelling to rural areas, DAB signals will be a rarity. You'll end up listening to the local analogue station (with no intention of switching to DAB anytime soon) or the stronger AM powerhouses back in town, whose signal actually has decent reach and coverage. Try that with DAB - not a chance! DAB is for local coverage only. No DXing.
Very susceptible to interference - Electrical impulse intererference generally poses no major issues to an analogue receiver, only causing pops or crackles to appear on the received audio. Such EMI (electromagnetic interference) exists in many places, especially in the modern home, office and industrial settings. But on a digital bitstream, electrical interference can easily disrupt and corrupt the precise 1s and 0s being transmitted. The end result ranges from garbled sound for a split second to complete audio muting for several seconds. But in AM or FM, the only effect would be a slight fuzz, pop or crackle in the audio. With DAB, you end up missing out on bits of audio, but on analogue, you can still quite easily make out the programme material from any interference or noise.
Increased greenhouse gases and electronic waste (e-Waste) - as more consumers purchase DAB radios, perfectly working analogue receivers, clock radios, portable 'walkman' type receivers etc will be thrown out, adding to the problem of increasing e-waste. Moreover, the higher power requirements and component complexity will all generate more greenhouse gases in both production and usage. The factory manufacturing the radios will use more resources to produce a receiver. The receiver itself needs more power to run its power hungry decoder circuitry.
Loss of radio hobby and education - 'crystal sets' were one of the first easy to build AM radio receivers that an electronics hobbyist could construct. When all radio stations move to DAB, such a thing will not be possible. This will lead to the erosion of the electronics and radio hobby. More and more people will simply take radio for granted, rather than have an interest in the underlying circuits that make them work.
Can be expensive to switch over. Avid radio listeners will have several radios scattered around living and work areas. One in the kitchen, lounge room, bedside, garage/workshop, car, office, pocket, etc. Replacing all of them could cost hundreds of dollars.
Of course, one could connect a personal FM transmitter (such as a Belkin TuneCast) to the DAB receiver so the digital station can be re-transmitted to other analogue receivers in the home, but there is still a problem with listening to it away from home.
Don't put all your eggs in the one basket. When a DAB+ transmitter fails, it takes all the stations on the multiplex with it. With some DAB transmitters cramming up to 20 stations onto the one multiplex, a transmitter failure can cause widespread disruption. Wheras in analogue radio, a failure of a transmiter would only cause an outage for the affected station. All other stations would still be on air.
With several popular radio sations being designated as 'official information stations' in the event of natural disasters (e.g. bushfires), switching off analogue transmissions is highly dangerous and could potentially risk lives. If a DAB transmitter fails during such an emergency, the public could be left in the dark if they cannot receive broadcasts of vital safety information.
Digital technology prone to change. When newer technologies are developed, DAB+ in its current form may be phased out quicker than expected. This could result in further e-waste issues as another wave of mass dumping of DAB receivers occurs.
Analogue radio has not changed significantly for nearly a century due to its reliability, simplicity, robustness and worldwide universal acceptance.
Because analogue receivers can be found almost anywhere, Analogue radio will be here to stay. Video may have killed the radio star. But DAB will never kill the analogue star.
Quote from Media Spy - Digital Radio - Forums
"Radio bosses are kidding themselves if they think digital radio is going to be paying dividends or scoring significant market share in the next few years. And experience from digital TV has shown that market adoption of the technology is slow and in TV's case it took almost a decade just to get to 50% market penetration. And so far DAB+ is only in capital cities. Radio I reckon will take a lot longer just by the fact that there are so many more radio tuners out there and people are not going to discard the transistor radio they bought for $5 twenty years ago in favour of a digital radio for $150 to hear mostly the same radio with a few extra stations thrown in. Prices are going to have to come a long way down and more models such as car radios have to become available before DAB+ becomes an option for the casual or everyday radio listener. Radio bosses should surely have seen that as the reality before they started digital?"
See also: Don't turn off Analogue TV
External Link: Consumers Prefer FM & Analogue Than Digital Radio - From Channel News. They say digital radio "is suffering from poor reception and in many areas there is no reception", which is the reason why uptake has been slow.