Audiofile

What bit-rates are used around the world?

31 posts in this topic

Interesting that Sydney has half usable bit-rates...

128 would at least qualify as FM or better standard I guess.

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On 2017-4-7 at 5:36 PM, McDigital said:

For those in Melbourne, for former Magic now TalkingLifestyle station was always crap after it went down from 96kbps to 64kbps. Even SEN is not what it used to be at 56kbps

The problem with SEN is the STL I think. The internet stream on their new app is also AAC+ (not sure the bitrate) and sounds alot better than the DAB+ broadcast. If they were to improve the STL their DAB+ broadcast might sound better even at 56kbps .

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STL? Well it looks like these bitrates are here to stay anyhow....

Sent from my SM-T710 using Tapatalk

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11 minutes ago, Audiofile said:

STL? Well it looks like these bitrates are here to stay anyhow....

Sent from my SM-T710 using Tapatalk
 

Studio-transmitter link (STL). Most likely a microwave link to Mt Dandenong from their Swan St studios that then also feeds their 1116 AM transmitter. The artefacts sound like MPEG layer 2 at a low bitrate to me. The re-encoding to AAC+ for the DAB+ broadcast then just adds to the already low-fi feed. I'm just assuming this is the case as I would think all the encoding for the various stations and then mux-ing into the DAB+ multiplexes happens at the transmitter site.

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Nath85.

If an microwave STL is used pointed at Mt Dandenong, it will not feed their AM transmitter at Lower Plenty. It has to be a separate Microwave link because the beam is too narrow to hit both sites.  Many stations have abandoned microwave systems and use IP on dedicated lines from the telcos.

The AAC encoding should only occur once and would be done at the studios. The DAB+ muxing with the other broadcasters will be done at the transmitter site. It has no effect on sound quality. It is purely switching between the program sources in turn. There is no advantage in using MPEG-1 layer 2 compression between the studio and the DAB+ transmitter, because AAC is more effficient and is required for transmission anyway.

Alanh

 

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Sounds like DAB+ is going the same way as free to air TV in Australia. More channels, less bitrate and poorer quality :-(

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