DAB+

[Owen Smith]

Music listeners on TV must be a fairly small proportion of the population, so I imagine the broadcasters don't spend much on them.

BBC radio on Freeview is very good quality, they use stereo with ample bit rate. I record The Early Music Show on Radio 3 on my HDR Fox T2 so I can listen to it whenever. Sometimes I'm months behind so iPlayer (or Sounds as it now is) isn't sufficient.

GenX are more interested in quantity than quality. Did you miss the memo?

And yet internet streaming is increasingly going lossless and 24/96, and Bluetooth now does hi res and lossless. It's contradictory.

But seriously, if you are an audiophile you will have to go outside the general broadcast realms to satisfy your needs.

My mum and dad would not describe themselves as audiophiles, and yet when I play crappy over compressed MP3 streams for them my mum is the first to say it sounds awful.

My mum has the radio on all day on the hifi. She likes to walk up to it, power on amp and tuner, press 6 or whatever on the tuner for her station, and walk away. Modern streaming needing a smartphone to start it or speaking to Alexa or similar leaves her going "but why is it so complicated?". She's 79, dad is 84.

 

[Owen Smith]

If true, I didn't know that (how do you tell?), but if you're looking to ClassicFM for a concert experience, you won't be using Freeview to do it anyway.

It's pretty obvious on a properly set up hifi that does good stereo imaging. Even easier given I can A/B compare it with the DAB, FM and internet MP3 stream which are all stereo.

More generally check the bit rate and encoding here:

DAB UK Leeds mux list

Bitrate measurements of TV channels and Radio DAB+ DTT FIBER Satellite Cable OTT.

www.digitalbitrate.com

 

[Owen Smith]

Digitalbitrate.com will give you this information, and the bit-rate. Well, for London. But that should do.

Actually quite a few other transmitters are on there too. Greatest Hits Radio on DAB (mum's daytime favourite for Ken Bruce) is in mono on some local DAB transitters and stereo on others. Here it's in mono but I can stream it (can't get it on FM here). Fortunately at my parents it's in stereo on DAB (they can get it on FM but it's subject to interference and stereo is no good).

 

[EEPhil]

Actually quite a few other transmitters are on there too.

Okay. But I wasn't going to link to all of them to illustrate where BH could find whether Classic FM is mono on his TV.

BBC radio on Freeview is very good quality

Agreed. Easy to record as well. Radio 4Extra in (reasonable) stereo rather than mono on DAB.

 

[Black Hole]

Those flappy things on the side of your head.

Like I'm paying that much attention! I don't find it a problem for my purposes, I've never been conscious of it (and the TV doesn't have much stereo separation anyway).

So some services are stereo and some are not. I guess ClassicFM sacrifice stereo (on Freeview) in favour of a higher bitrate mono, which seems like a good compromise.

I am more concerned how they go about mixing stereo to mono; that rarely turns out well in my experience but perhaps the audio industry has a better way to do it than simply (L+R)/2.

 

[prpr]

My mum has the radio on all day on the hifi.

Does that not generate a complaint about the electricity usage?
Or has that been curbed now?

I am more concerned how they go about mixing stereo to mono; that rarely turns out well in my experience but perhaps the audio industry has a better way to do it than simply (L+R)/2.

That's how it's universally done. FM generates M=(L+R)/2, S=(L-R)/2. Reversal is just a repeat.

 

[Black Hole]

When mixing tracks to mono, I often notice a change in timbre due to constructive and destructive interference, particularly with "live" recordings. Studio mixed recordings don't generally suffer, because individual sound sources are individually mic'ed or recorded separately, and then mixed into the stereo field using pan without any phase shift (therefore summing to mono is effective).

Live recordings however, where the mics capture the overall sound field, receive sound sources at multiple mics with different phase shifts at each (this is how binaural works). In the worst case, mixing to mono by simple summation can produce significant cancellation at specific frequencies.

The reason I know this is practical experience: the music at an event I attend regularly didn't sound right, and when I had the opportunity to investigate it turned out the organiser was running a mono mixer-amp by mixing stereo outputs from the sources to mono at the amp inputs (it was worse than that: the L and R signals were wired together!).

I provided cables to do resistive mixing, and that improved things but not totally. When I demonstrated the sound of the same music through a stereo PA system he was blown away! The mono system has since been scrapped, and I specified up a stereo system to replace it.

 

[sine24]

But seriously, if you are an audiophile you will have to go outside the general broadcast realms to satisfy your needs.

He can't be an audiophile. He listens to Classic fm

 

[Owen Smith]

Does that not generate a complaint about the electricity usage?
Or has that been curbed now?

An FM tuner and a modest hifi amp don't consume much power. Now everything is going digital power consumption of basic things like listening to the radio is going up quite considerably.

But my mum has made it clear that having the radio on all day is non negotiable.

 

[prpr]

I agree, but once you've downmixed everything to stereo there is no scope for converting to mono in any way other than what's already been described.

 

[Owen Smith]

He can't be an audiophile. He listens to Classic fm

I listen to a wide range of music from lots of sources. Classic FM is one of them, as is Radio 3. But also so is Metallica on multi channel DVD-Audio.

 

[Black Hole]

I agree, but once you've downmixed everything to stereo there is no scope for converting to mono in any way other than what's already been described.

(cross-posts)

I'm sure it could be done with some clever DSP to mimic room propagation to a mono microphone.

 

[Rodders53]

DAB+ uses the more recent AAC codecs cf the old DAB MP2. So should sound equally 'as good' at the proposed reduced bitrate.
Classic FM is dynamic range compressed (Optimod style) so lossy codec bitrates possibly won't matter too much?

On satellite they use MP2 joint stereo at 192kbit/s;
On Freeview it's Mono MPEG/MP2 at 64kbit/s - so not a good high bitrate {it would = 128kbit/s stereo}.
Streaming I think, from a search, it is 192kbit/s using the more modern AAC codec so will be a slightly superior sound quality to satellite (and significantly better than DAB 128kbit/s MPEG stereo).

(BBC use 192 kbit/s stereo for the main R1-4 services on both Sat and DTT, including R3.... BBC iPlayer is much better quality bitrate using more advanced codecs https://www.bbc.co.uk/sounds/help/questions/features/hd-sound and even dispenses with the Optimod compression on Radio 3 - for the hifi buffs). Even the lowest bitrate mono BBC Radio station is 80Mbit/s on DTT. Only the NAR (audio description) on BBC SD TV channels is as low as 64 Mbit/s MPEG.

For home listening via a hifi or similar, older Echo Dots have an analogue audio out 3.5mm jack socket. Google did a Chromecast Audio (I have two) with digital optical and analogue out via a 3.5mm jack/ toslink connection. Other similar devices exist, I'm sure, to allow streaming of better quality audio. Second user models may be quite cheaply sourced, I'd hope?

BBC at one time used L+R -3dB for mono rather than the more common L+R -6dB... https://en.wikipedia.org/wiki/Peak_programme_meter#M3_and_M6

 

[prpr]

Even the lowest bitrate mono BBC Radio station is 80Mbit/s on DTT. Only the NAR (audio description) on BBC SD TV channels is as low as 64 Mbit/s MPEG.

 

[Owen Smith]

DAB+ uses the more recent AAC codecs cf the old DAB MP2. So should sound equally 'as good' at the proposed reduced bitrate.

No bit rate for Classic FM on DAB+ has yet been stated. I suspect we won't find out until it goes on air.

DAB+ can use either AAC-LC (Low Complexity) or AAC-HE (High Efficiency). For "High Efficiency" read "completely throws some stuff away and just plain guesses what should be there on playback". This works less badly on heavily produced rock and pop than it does on complex content like classical music. Scala using 40kbps will be AAC-HE as there is no way to get down to that bit rate with AAC-LC in stereo. The BBC radio UK high quality streams use AAC-LC at 320kbps and sound pretty damned fine.

Streaming I think, from a search, it is 192kbit/s using the more modern AAC codec so will be a slightly superior sound quality to satellite (and significantly better than DAB 128kbit/s MPEG stereo).

Standard Classic FM streaming is 128kbps MP3, I've checked it just now and this is the best that is available on hifi amps and streaming boxes etc. It actually sounds worse than their DAB at 128kbps MP2, don't know how they manage that as MP3 is supposed to be a little more efficient than MP2. Presumably different processing elsewhere eg Internet stream is dynamic range compressed more.

The Classic FM App in HD mode does stream in AAC and I think I've seen 192kbps mentioned. But it has a rotating security scheme that changes keys every half hour or so such that it is locked in to only being playable in Apps. So you can't listen to it in the browser on a PC, or with a streaming box on your hifi etc. You also have to sign up to an account to get it.

For home listening via a hifi or similar, older Echo Dots have an analogue audio out 3.5mm jack socket. Google did a Chromecast Audio (I have two) with digital optical and analogue out via a 3.5mm jack/ toslink connection. Other similar devices exist, I'm sure, to allow streaming of better quality audio. Second user models may be quite cheaply sourced, I'd hope?

The user interface of such devices is too complex. My dad does not have a smartphone and my mum does but is hopeless at using it. They have explicitly stated they want a hifi tuner to replace their FM tuner from 1997 to go in the hifi rack next to the Arcam Alpha 6+ amp (new in 1995 and still going strong). And they want a tuner that has station buttons so they press one button for each of Radio 2, Classic FM and Greatest Hits Radio. They don't care whether it is DAB or internet streaming behind the scenes, but they want station select buttons and no internet streamer that I can find has those.

 

[Black Hole]

Standard Classic FM streaming is 128kbps MP3, I've checked it just now and this is the best that is available on hifi amps and streaming boxes etc. It actually sounds worse than their DAB at 128kbps MP2, don't know how they manage that as MP3 is supposed to be a little more efficient than MP2. Presumably different processing elsewhere eg Internet stream is dynamic range compressed more.

Suggestion: perhaps they've encoded the stereo MP3 as two separate 64kbps channels rather than (I forget hat it's called) combined stereo.

They don't care whether it is DAB or internet streaming behind the scenes, but they want station select buttons and no internet streamer that I can find has those.

If you're up for a challenge, there are plenty of interesting parts available in the RPi and Arduino worlds – touch screens etc – and plenty of ready-baked code or code modules... it would not be impossible to build bespoke.

 

[Rodders53]

The user interface of such devices is too complex.

Alexa play BBC Radio 2
Alexa play Classic FM
Alexa play Greatest Hits Radio

Once you've set it all up for them.

Or buy a second-user Arcam tuner off eBay? https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=Arcam+tuner&_sacat=0 They seem to have push-button presets.

 

[Owen Smith]

Suggestion: perhaps they've encoded the stereo MP3 as two separate 64kbps channels rather than (I forget hat it's called) combined stereo.

Good point, Classic FM on DAB is indeed 128kbps Joint Stereo which compresses more easily. If the streaming MP3 is straight stereo that might explain why it doesn't sound as good.

If you're up for a challenge, there are plenty of interesting parts available in the RPi and Arduino worlds – touch screens etc – and plenty of ready-baked code or code modules... it would not be impossible to build bespoke.

I'm not up for that kind of challenge. And I can imagine my dad's response along the lines of "why do we need all those boxes, and how much power does all that consume?"

 

[Owen Smith]

Alexa play BBC Radio 2
Alexa play Classic FM
Alexa play Greatest Hits Radio

My parents have a serious aversion to any of that kind of equipment that sits there listening to you all the time. And to be honest so do I.

Plus you haven't seen my parents in action, they can screw up anything with technology in it. The simpler the better. I once got a call from my mum about the tuner not working. She'd pressed Shift by accident and was on station B2 rather than A2. I wish I could disable the shift function, they only listen to 3 stations so 8 buttons is more than enough.

Or buy a second-user Arcam tuner off eBay? https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=Arcam+tuner&_sacat=0 They seem to have push-button presets.

That's what I've done. But only the Arcam T32 handles DAB+ so I've bought two of those. Actually I bought two non working ones very cheap and by transplanting the mains transformers (it has two) made a working one. I then bought another one fully working as a backup once I found how well the repaired one works. My word it sounds good with a strong FM signal (though the 320kbps AAC stream is slightly better on Radio 3, unsurprisingly) and for other stations they can use DAB or DAB+.

The Arcam T32 really is over the top as a hifi tuner, but then it was £500 at launch in 2008:

 

[Rodders53]

I wish I could disable the shift function, they only listen to 3 stations so 8 buttons is more than enough.

Is it not possible to store the wanted stations on both banks, A and B so it doesn't matter if shift is pressed first?