Digital Radio - Technical

Splitting out the Digital Radio into two threads as per @Moe’s idea .
Technical aspect discussions to DAB+ etc here.
The old thread.
The new Digital Radio- Content thread.

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I’m sure I’ll get a chance to ramble on about DRM+ soon - but I’ll try to be more helpful with the opening post here, and point people to DABList - I noticed the newst updates to the DABPlayer software auto upload (if you opt in) the station data to that website, which makes it a pretty good resource for checking/comparing bitrates,

The site has all the Australian multiplexes on it, not sure if all of them are perfectly up to date, but the common ones should be - https://dablist.org/welcome.php

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cool bananas

Will jump this over here -

So the answer here kinda varies as a “48kbps” stream can vary quite considerably based on how much of that is actually audio.

You always lose a small amount to overheads, but from there it can depend a lot on how much is used for data - here’s a worse case scenario (plus a fun error) - over a third of the nominal rate is used on slideshow/data

There’s no real pattern here, other than the ABC and Community Radio being poor at it - SEN have been good with it in Melbourne, while Magic loses 20% of their 96kbps to data, but don’t even do a slideshow.

2CH currently have slideshow info from the last post I saw, so I wouldn’t be surprised if their rate is less than ideal - especially if they didn’t reconfigure much from data rates that would have made sense at 128kbps.

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http://www.astrosurf.com/luxorion/qsl-drm.htm

i just found this gem on the interwebs… :sunglasses:

About 16Kbps less :+1:

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NTS back on in Sydney at 40kbps.

Drops 2UE to 72kbps.

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2GB is also down to 80 kbps

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FUN is also back on air…first time in a long time

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They were promoted how the audio quality was improving with the move to 9c but now it is lower than before. It’s the sign of the times. I would imagine there was a time people would call people/companies out for this.

That adds up to 192kbps? What are they doing with the other 64? Have they sold it off?

Melbourne is 96/96/48 - which is fine. Though 128/80/48 would be a better split, keeping music at the high rate.

No doubt I’ve said this before, but how has that station managed to survive at least three (Fairfax, Macquarie, Nine) eras of ownership?

It’s by far the biggest waste of space on DAB+ and rarely used for anything productive.

Not sure. Aside from the return of NTS, there aren’t any additional stations as a result of these changes.

If it’s at all possible, I’d try and go for a 96/96/64 split myself.

Yeah - I’ve been meaning to check if it ever does stuff like taking the Andrews Press Conferences live or anything like that - I don’t think it’s been used for overflow sport in ages either.

They really should just do a “Nine News Radio” station rather than “NTS” branding if they wanted to keep it - run rolling loops of news bulletins, with the occasional extra interview stuff if they really need it.

Oh yeah, my maths is awful such that I didn’t notice 96/96/48 isn’t the full 256k either - still better than what’s happening in Sydney.

I can only think if it’s not for trading elsewhere, it is just to save transmission/data costs? But again - there’s very likely to be companies willing to pay them to use it.

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Now I’ve thought about it, could the 64kbps be going to Pacific Star/Crocmedia/SEN/whatever this company is actually called these days?

It seems that they’ll soon need room for five DAB+ stations on the Sydney multiplexes (presuming the plan is SEN 1170, SEN Victoria, SENTrack, Niche Radio/Radio Italia and 2CH DAB) - 192kbps is enough to fit in up to six 32kbps streams. With only 128kbps, you’d be looking at 24kbps stations! :open_mouth:

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I suppose a question for Sydney people - how good is their reception of 2SM’s digital stations - when they work obviously?

They all run at EEP 4A - a lower protection level configuration that means you can get higher bitrates, while sacrificing coverage. I did a video a while back showing what occurs with reception on the cliff - but I don’t know how many areas are in practice on that edge.

The 128kbps that stations get is actually 96 CU - There’s a useful calculator here that lets you convert them for different bitrates at different levels - but it allows for basically infinite ways of slicing it.

Examples for 2CH/SEN
Station Bits EEP
SEN 1170 32kbps 3A
2CH 48kbps 3A
SEN Track 32kbps 3B
SEN Vic 32kbps 3B
SEN 1170 32kbps 3B
2CH 56kbps 3A
SEN Track 32kbps 3B
SEN Vic 32kbps 3B
SEN 1170 32kbps 3A
2CH 40kbps 3A
SEN Track 32kbps 3B
SEN Vic 24kbps 4A
Niche 24kbps 4A
SEN 1170 48kbps 4A
2CH 64kbps 4A
SEN Track 32kbps 4A
Niche 48kbps 4A

RSN Carnival 2 runs at 24kbps in Melbourne - for exclusively speech content, it’s borderline listenable, while the 16kbps that SEN3 runs at is not.

This would be I think the best balance, assuming they want SEN Vic, that could swap for Niche if they need to.

SEN 1170 40kbps 3A
2CH 56kbps 3A
SEN Track 32kbps 4A
SEN Vic 32kbps 4A
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Not great in Western Sydney, I had lots of trouble with Gorilla but have long since given up on it

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I had issues too but sometimes it was not signal issue but something wrong at the source. Fun was ok last night in the car. No song title or artist. I don’t like the low bit audio but at least it’s back. I suspect Crocmedia have done a deal with nine for Digital spectrum. I have no idea why NTS is back. Hope they put some real content on it.

Does any station in Aus run at a higher protection level than EEP 3A?

What style of error protection does DRM+ use?

Thanks @Moe for the video, I recall seeing your demo when you produced it, great to see again. The CU calculator was interesting too.

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No - but I’d absolutely think there’d be good uses for it. Like for example Coast/Wave in Mandurah absolutely should ramp that up to EEP 1A - they could do their current 2x 64kbps feeds within their allocation at that much higher protection level, and potentially getting much further up into Perth

Similarly, perhaps doing that for ABC Local Radio in each city, just to potentially push that out a bit further to overcome the artificial limits of license areas that have been imposed.

Reducing the crazy high levels of data allocated to slideshow data on the ABC stations could gain them back the necessary data to do that.

I believe it’s the same/similar but uses different terminology - though aligned with DVB in describing different levels of QAM and code rates, I’m not 100% sure how to compare them.

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Agree @Moe, would be great for Mandurah and any adjacent metro market.

ABC definitely need to use it, however, I bet they are more focussing on being available on digital TV now. Doesn’t help for handheld/mobile reception.

Surprised ABC hasn’t got the message of their largely unseen slideshows.

I suspect there’s an informal policy, especially among commercial licensees not to ‘jump the line’ on EEP 3A to continue their argument for protectionism.

Me either, that’s as far as I got too! Thanks again @Moe

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