Internet radio stations & other alternatives to Radio 3

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  • Dave2002
    replied
    Originally posted by Caliban View Post
    Dave thanks - one of the things that occurred to me is that the reason the Airport is so useful is that it's enabled a Naim amp. to be used with iTunes, but only by means of an analogue cable from Airport to amp. The Airport's internal DAC is doing the work - and I've read that "The DAC is however limited to CD quality output (16-bit PCM encoding at 44.1 kHz sampling rate) which means if you send it a higher resolution encoding it will be down sampled to 16-bit/44.1 kHz."

    Now I don't really understand your "didactic bit" sufficiently to know how that impacts on the above.

    Does it mean that there is unlikely to be any difference between the two grades of streaming you describe, or is it irrelevant?

    And turning to downloads, is there no point in me spending money on anything higher res than 16bit/44.1 kHz, as it is just going to be compressed to that value anyway in the DAC?
    It's perhaps slightly more complicated, but maybe not too much.

    Your link will "reduce" everything to CD quality - 44.1 kHz sampling at 16 bits. Some people claim that higher sampling frequencies and more bits are better. It is certainly the case that for producing the CDs there are a lot of advantages in using higher sampling rates and more bits per sample, or other techniques such as DSD. However, for the final produced article many engineers and mathematicians would argue that 44.1 kHz at 16 bits is good enough. Most humans can't hear above 20 kHz, so 44.1 kHz sampling should be enough.

    Some equipment may work better with higher sample rates, or more bits, or may simply be better made. It's very difficult to tell IMO.
    My personal hunch is that having a few more than 16 bits may give improved sound quality - it will reduce the noise floor, and in turn that may increase the apparent loudness of the sound.

    Oddly that is where mp3 and similar systems may do slightly better than 16 bit PCM, as it's quite easily possible to enocde masters at 20 bits or 24 bits using these compression forms. However, most lossy compression algorithms introduce significant artefacts/noise, which would tend to have the opposite effect on perceived audio quality. You may remember the R3 DAB bit rate debacle from quite a few years ago, when the DAB bit rate was reduced to 160 kbps. Many people complained, and said it was clearly inferior to the 192 kbps streams. DAB was designed to work at 256 kbps, but by reducing the bit rate broadcasters can fit more stations on to the same transmission system. DAB uses a codec called mp2, which in terms of audio quality is considered less good than mp3. For example we might establish a rough equivalence of 160 kbps DAB (mp2) with 128 kbps mp3, and 256 kbps DAB (mp2) with 192 kbps mp3. AAC is considered to sound better than either of these for a given bit (data) rate. This means it actually discards more data than other codecs, but it only attempts to discard data corresponding to sound which we probably wouldn't hear anyway. At 256 kbps and above, most lossy codecs should sound more or less indistinguishable to most people, but at lower bit rates there are clear differences, and noticeable quality loss.

    I am more sceptical about the use of higher sampling rates.

    At very low bit rates, quality suffers a lot, and lossy codecs might only be considered suitable for speech, or very limited (comparable to AM radio perhaps) audio, and stereo isn't great either. One of the problems is a loss of high frequencies, which really dulls the sound. However, quite a few years ago, a system called SBR (Spectral Band Replication) was developed, which "regenerates" the missing high frequencies to give a more acceptable result. It doesn't actually regenerate them - it's a fake process, but fools the ear into thinking that the sound is closer to what the original might have been. This has been developed into AAC-HE which can give passable results for many not too critical listeners.
    This way the broadcasters can send out more channels without using up all the spectrum they have available. There are other trade offs possible. For example, rather than trying to send out two very high quality channels, they could perhaps transmit 5 or more somewhat lower quality channels for surround sound systems using the same overall data rates. It is possible that many users would prefer that - if they had appropriate playback equipment.

    If you are happy with your system as it is, then don't worry too much about it. The Airport express link should be capable of delivering much higher quality (CD quality) than the streamed audio from the BBC. However, you should try to pick up the best of the R3 streams - which others seem to have now confirmed is a 320 kbps compressed stream. If you find you are picking up a lower bit rate stream you might notice the lower quality.

    One other thing - it would not be worth spending a lot more for studio master downloads at (say) 24/192, as with your link these would be transformed down to 16/44.1 - though if you ever got equipment which could play 24/192 you might then get a benefit. If you are always going to use that link, then don't even try to improve quality by buying any so-called hi-res files - they may sound OK, but shouldn't be any better than regular CD quality. That should answer your last point.

    Despite all this, do remember that perceived audio quality isn't always determined by bit rates and all this technical stuff. A relatively poor technical system may be capable of giving very musical results on some material (may depend on the instruments and music), and in contrast, no matter how good technically the transmission system is, if the basic recording is **** then the replay will also be ****.

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  • Bryn
    replied
    Thanks for that, John. I was, as usual, accessing both 'Listen Again' and the live stream via a Windoze laptop.

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  • johnb
    replied
    I use the Logitech Touch (together with the Logitech Media Server with "Triode's" iPlayer plugin) and the Radio 3 live feed has been replaced by a message "explaining" the changes.

    The Radio 3 Listen Again (on the Touch) is still working though, and appears to be at 320 kbps AAC-LC.

    This is pretty devasting news for me (and many others who use "Triode's" LMS plugin). Whether "Triode" can rewrite his plugin to cope with the new developments and whether the LMS can be developed to incorporate any necessary changes remains to be seen.

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  • Bryn
    replied
    I am having some trouble checking the data rate of the current iPlayer stream but today's Afternoon on 3 and Choral Evensong are definitely available at 320kbps AAC-LC via the iPlayer's 'Listen Again' facility.

    [O.k., using Bandwidth Monitor it appears that the live stream is also still at 320kbps.]
    Last edited by Bryn; 11-02-15, 19:21. Reason: Update.

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  • Phileas
    replied
    Originally posted by Dave2002 View Post
    If you are right about the 320kbps AAC then there is less to worry about, but I can see that changes have been made, and some people have been affected. Maybe it's only people who use some formats with some devices (eg. some Microsoft formats, and Android phones) - and chances are that unless the codecs are in hardware, that new apps will appear which will sort out the issues. What I would definitely be against would be a move to downgrade the audio across all possible player devices or systems.
    I've edited my post slightly Dave. I'm actually still trying to find out the exact details of the changes, so don't take my word for anything.

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  • Nick Armstrong
    replied
    Originally posted by Dave2002 View Post
    Not everyone will be able to tell the difference, but 320kbps streams should provide a significantly higher quality level than 128 kbps. At the current time I think the 128 kbps streams - which I believe use aac encoding - deliver a quality level roughly comparable to 192 kbps mp3. Most of the time it'll sound OKish, but at critical moments it probably won't work for anyone with good quality equipment and good hearing. Most of the time compression methods such as aac deliver audio quality which is good enough for speech, and also for "casual" music listening - such as R4 programmes about music, but for high quality reproduction I'd suggest that 320kbps is preferable, and should be the norm for R3.

    [didactic bit - kbps = kilobits/second which for lossy compressed formats does have an impact on audio quality.So called hi-res audio masters - 24 bits/192 kHz -> 9.216 Mbps for 2 channels or 23.040 Mbps for 5 channel (surround) master tapes. These bit rates are far too high for most normal broadcast streaming, so compression methods are used to compress the bit stream. 16 bits/44.1 kHz -> 1.4112 Mbps CD quality - uncompressed - or 1.536 Mbps for basic 48 kHz/16 bit audio. It is only possible to get a factor of about 2 reduction by using lossless compression, such as FLAC, which would get CD quality audio down to around 700 kbps. Lossy compression does "better" by throwing some of the data away, hopefully in ways which are not detectable by most people - but that's where there can be significant arguments.]
    Dave thanks - one of the things that occurred to me is that the reason the Airport is so useful is that it's enabled a Naim amp. to be used with iTunes, but only by means of an analogue cable from Airport to amp. The Airport's internal DAC is doing the work - and I've read that "The DAC is however limited to CD quality output (16-bit PCM encoding at 44.1 kHz sampling rate) which means if you send it a higher resolution encoding it will be down sampled to 16-bit/44.1 kHz."

    Now I don't really understand your "didactic bit" sufficiently to know how that impacts on the above.

    Does it mean that there is unlikely to be any difference between the two grades of streaming you describe, or is it irrelevant?

    And turning to downloads, is there no point in me spending money on anything higher res than 16bit/44.1 kHz, as it is just going to be compressed to that value anyway in the DAC?
    Last edited by Nick Armstrong; 11-02-15, 18:47.

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  • Dave2002
    replied
    Originally posted by Phileas View Post
    I assume if you use the iPlayer app on e.g. an iPad, you still get the 320kbps AAC stream?

    If you use the Shoutcast streams, accessible in various ways on Internet radios, you will get 128kbps MP3 (but this will be switched off at some point in the future). Not sure about 128 kbps AAC?
    If you are right about the 320kbps AAC then there is less to worry about, but I can see that changes have been made, and some people have been affected. Maybe it's only people who use some formats with some devices (eg. some Microsoft formats, and Android phones) - and chances are that unless the codecs are in hardware, that new apps will appear which will sort out the issues. What I would definitely be against would be a move to downgrade the audio across all possible player devices or systems.

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  • Beef Oven!
    replied
    Originally posted by Dave2002 View Post
    Not everyone will be able to tell the difference, but 320kbps streams should provide a significantly higher quality level than 128 kbps. At the current time I think the 128 kbps streams - which I believe use aac encoding - deliver a quality level roughly comparable to 192 kbps mp3. Most of the time it'll sound OKish, but at critical moments it probably won't work for anyone with good quality equipment and good hearing. Most of the time compression methods such as aac deliver audio quality which is good enough for speech, and also for "casual" music listening - such as R4 programmes about music, but for high quality reproduction I'd suggest that 320kbps is preferable, and should be the norm for R3.

    [didactic bit - kbps = kilobits/second which for lossy compressed formats does have an impact on audio quality.So called hi-res audio masters - 24 bits/192 kHz -> 9.216 Mbps for 2 channels or 23.040 Mbps for 5 channel (surround) master tapes. These bit rates are far too high for most normal broadcast streaming, so compression methods are used to compress the bit stream. 16 bits/44.1 kHz -> 1.4112 Mbps CD quality - uncompressed - or 1.536 Mbps for basic 48 kHz/16 bit audio. It is only possible to get a factor of about 2 reduction by using lossless compression, such as FLAC, which would get CD quality audio down to around 700 kbps. Lossy compression does "better" by throwing some of the data away, hopefully in ways which are not detectable by most people - but that's where there can be significant arguments.]
    Thanks for the explanation. I enjoyed last night's broadcast and thought the sound was superb. I have bad hearing and good equipment.

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  • Phileas
    replied
    I assumed if you use the iPlayer app on e.g. an iPad, you still get the 320kbps AAC stream?
    Also, if your internet radio is compatible with the new Flash-wrapped AAC streams?

    If you use the Shoutcast streams, accessible in various ways on Internet radios, you will get 128kbps MP3 (but this will be switched off at some point in the future)?

    Just trying to determine all the details of this change at the moment.

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  • Dave2002
    replied
    Originally posted by Beef Oven! View Post
    I streamed it through the Wifi/Apple Airport thingamajig last night and it sounded wonderful. I didn't know that Kbps had been cut. What difference does it make? (what's a Kbps?)
    Not everyone will be able to tell the difference, but 320kbps streams should provide a significantly higher quality level than 128 kbps. At the current time I think the 128 kbps streams - which I believe use aac encoding - deliver a quality level roughly comparable to 192 kbps mp3. Most of the time it'll sound OKish, but at critical moments it probably won't work for anyone with good quality equipment and good hearing. Most of the time compression methods such as aac deliver audio quality which is good enough for speech, and also for "casual" music listening - such as R4 programmes about music, but for high quality reproduction I'd suggest that 320kbps is preferable, and should be the norm for R3.

    [didactic bit - kbps = kilobits/second which for lossy compressed formats does have an impact on audio quality.So called hi-res audio masters - 24 bits/192 kHz -> 9.216 Mbps for 2 channels or 23.040 Mbps for 5 channel (surround) master tapes. These bit rates are far too high for most normal broadcast streaming, so compression methods are used to compress the bit stream. 16 bits/44.1 kHz -> 1.4112 Mbps CD quality - uncompressed - or 1.536 Mbps for basic 48 kHz/16 bit audio. It is only possible to get a factor of about 2 reduction by using lossless compression, such as FLAC, which would get CD quality audio down to around 700 kbps. Lossy compression does "better" by throwing some of the data away, hopefully in ways which are not detectable by most people - but that's where there can be significant arguments.]

    Leave a comment:


  • Beef Oven!
    replied
    Originally posted by Caliban View Post

    It's the amount of data passing per second so in theory the higher the rate the better the sound. But it all varies depending on the individual, the kit, etc etc. I agree, listening to the now-normal R3 stream sounds fine on our Airport/Naim combos - whether one would tell the difference switching from the current 128Kbps to 320Kbps and back, I don't know. I suppose it's like choosing between a 3.0 litre engine in a car, and a 4.2 litre - in extreme circumstances, there's a difference but for normal sensible use, the 3.0 is going to get you where you want to go quite quickly enough...

    I'm only aware of it since I had made a playlist of the dozen or so internet stations on iTunes that I listen to, for ease of access - and the R3 item in the playlist had ceased to function as it was the 320Kbps stream. Going into the main internet radio section and playing the 128Kbps Radio 3 stream works, as you say, perfectly well.
    Thanks for the explanation Caliban.

    Can't wait to listen tonight, through our Airport/Naim combos

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  • Nick Armstrong
    replied
    Originally posted by Beef Oven! View Post
    I streamed it through the Wifi/Apple Airport thingamajig last night and it sounded wonderful. I didn't know that Kbps had been cut. What difference does it make? (what's a Kbps?)

    It's the amount of data passing per second so in theory the higher the rate the better the sound. But it all varies depending on the individual, the kit, etc etc. I agree, listening to the now-normal R3 stream sounds fine on our Airport/Naim combos - whether one would tell the difference switching from the current 128Kbps to 320Kbps and back, I don't know. I suppose it's like choosing between a 3.0 litre engine in a car, and a 4.2 litre - in extreme circumstances, there's a difference but for normal sensible use, the 3.0 is going to get you where you want to go quite quickly enough...

    I'm only aware of it since I had made a playlist of the dozen or so internet stations on iTunes that I listen to, for ease of access - and the R3 item in the playlist had ceased to function as it was the 320Kbps stream. Going into the main internet radio section and playing the 128Kbps Radio 3 stream works, as you say, perfectly well.

    Leave a comment:


  • Beef Oven!
    replied
    Originally posted by Caliban View Post
    Does this have anything to do with the fact that the 320Kbps stream of Radio 3 on iTunes is no longer available, just the 128Kbps version?
    I streamed it through the Wifi/Apple Airport thingamajig last night and it sounded wonderful. I didn't know that Kbps had been cut. What difference does it make? (what's a Kbps?)

    Leave a comment:


  • Nick Armstrong
    replied
    Originally posted by Radio64 View Post
    Nice try.. Mai lamentarsi del brodo grasso! ..

    (deliciously OT!)
    Yum!

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  • Radio64
    replied
    Originally posted by Caliban View Post


    Gallina vecchia fa buon brodo? Oh no, that's something else...

    Ah... our Italian cousins!
    Nice try.. Mai lamentarsi del brodo grasso! ..

    (deliciously OT!)

    Leave a comment:

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