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Op-ed: 32kbps will become the norm for DAB+


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Old 06-12-2016, 09:09
martinwatkins
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Well indeed, but it would be nice if they just backed it right off. The intense dynamics processing is the problem on a lossy system like DAB, not a few fancy magic tweaks that someone who thinks they know about sound makes.
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Old 06-12-2016, 16:15
AEC2600
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Yes, and I suppose my wider point was that they need to tailor their processing for each form of broadcasting. If you're going to broadcast at 80kbps MP2 mono then you can't use the same type of processing as on FM.
Exactly. It's not as if it would cost them extra, the modern optimods and omnias allow for separate processing for fm, dab and online. I assume other high end processers have the same feature.
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Old 06-12-2016, 16:43
hanssolo
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Well indeed, but it would be nice if they just backed it right off. The intense dynamics processing is the problem on a lossy system like DAB, not a few fancy magic tweaks that someone who thinks they know about sound makes.
If you check the article Jazz FM have kept the online feed clean, but for DAB+ they decided to reduce the dynamic range for noisy kitchens and cars.
Instead, we focused on mobile listeners, in car, on personal sets and in noisy environments like kitchens and workplaces.”
But have added the right amount of processing to ensure the loudness into the encoder does not affect the SBR componant which can get "metalkic" at low ratre like 32k which D2 offered. Ideally if Jazz FM can one day get more national bandwidth as it becimes available and profits increase but seems they have the right compromise.
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Old 06-12-2016, 21:18
clewsy
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Listened to that union jack in the car today it wasn't too bad really and was listenable, however you can tell it's compressed.

I wonder how much it costs them to be on d2? They don't seem to have many adverts on it.
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Old 07-12-2016, 09:11
Inkblot
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If you check the article Jazz FM have kept the online feed clean, but for DAB+ they decided to reduce the dynamic range for noisy kitchens and cars.

But have added the right amount of processing to ensure the loudness into the encoder does not affect the SBR componant which can get "metalkic" at low ratre like 32k which D2 offered. Ideally if Jazz FM can one day get more national bandwidth as it becimes available and profits increase but seems they have the right compromise.
Tried Airplaying the various online streams to my hifi from my laptop and phone. To my ears, the only stream that doesn't have a slight "metallic" blare to it is the one accessed via Radioplayer (linked from Jazz FM's "Listen Live" button). Obviously jazz is more susceptible to that kind of distortion because of the brass instruments, and even Chet Baker's mellow trumpet sounded harsh on some feeds.

Is the Radioplayer feed a better quality one than the ones available via Tunein, the Jazz FM app etc?
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Old 07-12-2016, 11:00
hanssolo
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Tried Airplaying the various online streams to my hifi from my laptop and phone. To my ears, the only stream that doesn't have a slight "metallic" blare to it is the one accessed via Radioplayer (linked from Jazz FM's "Listen Live" button). Obviously jazz is more susceptible to that kind of distortion because of the brass instruments, and even Chet Baker's mellow trumpet sounded harsh on some feeds.

Is the Radioplayer feed a better quality one than the ones available via Tunein, the Jazz FM app etc?
According to http://www.radiofeeds.co.uk/query.as...z+FM+%5BJAZ%5D
there are 3 AAC streams at 24k, 48k, and 128k and one legacy MP3 128k streams.
Presumably the 24k and 48k are for mobile use and use the same filtering and processing as DAB+, and 128k for unprocessed home use?

Shame they don't have a 320k "HD" sound stream
It's not clear which stream the radio player uses but guess it's the 128k AAC one?
Some stations have an option for mobile or "HD" sound, but Jazz FM does not (yet).
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Old 07-12-2016, 17:18
mill9
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In a decade there'll be not that many DAB sets left, surely.
I bought a Pure Evoke-2 xt in 2007 and still in working order and playing right now. Currently there are no DAB+ stations of interest to me so it works for me. However I have another unit plus the car radio which are both DAB+. In fact the car unit also supports DMB so could be used in France. Funnily enough I've just ordered a replacement for the Pure unit with DAB+ so the former could escalate to the kitchen perhaps.
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Old 07-12-2016, 17:59
Inkblot
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It turns out there's a scientific reason why we don't enjoy low bit rate digital radio. According to a scientific study, lossy compression removes more of the positive characteristics and fewer of the negative emotions from music :

MP3s make you less happy, study says

According to a study by the Audio Engineering Library, MP3s and similar low-quality compression formats have a distinct effect on the timbral and emotional characteristics of the instruments involved - strengthening neutral and negative emotional characteristics, and weakening positive ones.
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Old 07-12-2016, 18:34
tghe-retford
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It turns out there's a scientific reason why we don't enjoy low bit rate digital radio. According to a scientific study, lossy compression removes more of the positive characteristics and fewer of the negative emotions from music :

MP3s make you less happy, study says

According to a study by the Audio Engineering Library, MP3s and similar low-quality compression formats have a distinct effect on the timbral and emotional characteristics of the instruments involved - strengthening neutral and negative emotional characteristics, and weakening positive ones.
[TINFOILHAT]So that's why they're putting the bitrate so low, to make us so melancholy that we are not tempted to change the station. [/TINFOILHAT]

In the latest Radio Today eRadio newsletter, there is a piece from Niocast who run the Manchester trial multiplex which backs up what I have been saying within this thread. The fifteen stations in DAB+ are between 32kbps in mono, from 40kbps using parametric stereo up to 64kbps. The DAB+ services are being described as (to quote) "allowing more stations to get onto the multiplex without compromising sound quality. That's got to be great for listener choice!".

48kbps which make up most of the DAB+ stations on that multiplex would sound better and ultimately would allow up to 24 stations per multiplex. But the impression I continue to get is the concept that choice is king and low bitrates are still considered good audio quality (as well as spreading the risk financially if a station fails).
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