DRC on Radio 3 HD Stream?

[Guest]

Hello!

I have a simple PC audio setup consisting of a Windows 10 desktop (standard integrated Realtek sound) connected to a Phillips Micro System and old Pioneer speakers. This sounds surprisingly good from most sources (primarily Spotify Premium). However to my ears Radio 3 on DAB @ 192kb/s MP2 sounds better than the 320kb/s AAC HD stream (via the BBC website on direct through VLC) which doesn't make any sense. The DAB version has a noticeably wider dynamic range and is generally a punchier and more pleasant listen at higher volumes. I tried a browser based 16 bit dynamic range tester which reproduced the full 96dB range without any problems and all my other PC audio sources sound fine so I don't think there's anything wrong with my setup.

Is it possible that the BBC has quietly reintroduced dynamic range compression to its Radio 3 HD stream when it switched over to HLS?

Any thoughts or suggestions would be greatly appreciated.

Thanks!

[Bryn]

Hello!

I have a simple PC audio setup consisting of a Windows 10 desktop (standard integrated Realtek sound) connected to a Phillips Micro System and old Pioneer speakers. This sounds surprisingly good from most sources (primarily Spotify Premium). However to my ears Radio 3 on DAB @ 192kb/s MP2 sounds better than the 320kb/s AAC HD stream (via the BBC website on direct through VLC) which doesn't make any sense. The DAB version has a noticeably wider dynamic range and is generally a punchier and more pleasant listen at higher volumes. I tried a browser based 16 bit dynamic range tester which reproduced the full 96dB range without any problems and all my other PC audio sources sound fine so I don't think there's anything wrong with my setup.

Is it possible that the BBC has quietly reintroduced dynamic range compression to its Radio 3 HD stream when it switched over to HLS?

Any thoughts or suggestions would be greatly appreciated.

Thanks!

I might try a comparison between this afternoons Prom in DAB (hopefully 192kbps mp2 rather than the degraded 160kbps all too often imposed) and iPlayer 320kbps aac-lc. However, from past experience I think the problem you perceive may well lie with the Realtek integrated audio circuitry. Given the content and venue of this afternoon's Prom, I will try tonight's Prom too.

[beauchampboiler]

I might try a comparison between this afternoons Prom in DAB (hopefully 192kbps mp2 rather than the degraded 160kbps all too often imposed) and iPlayer 320kbps aac-lc. However, from past experience I think the problem you perceive may well lie with the Realtek integrated audio circuitry. Given the content and venue of this afternoon's Prom, I will try tonight's Prom too.

Thank you for your response. I'm working tonight unfortunately so would be very interested to hear your thoughts. It should give me an indication of whether the problem lies at my end or not. In the meantime, I'll play around with the Realtek drivers and see if I can improve things.

[kernelbogey]

Can't respond at a 'technical' level, but suggest your experiment by listening to the HD stream via iTunes. I would be interested in your comment.

[beauchampboiler]

Can't respond at a 'technical' level, but suggest your experiment by listening to the HD stream via iTunes. I would be interested in your comment.

Thanks for the suggestion, will give it a go in the morning. I've already got a slight improvement by removing the Realtek drivers and using the default Microsoft ones instead.

[Bryn]

I have now closely compared the iPlayer (320kbps aac-lc) and DAB (unfortunately 160kbps mp2) of Reich's Music for a Large Ensemble form this afternoon's Prom. Taking the quietest .504 seconds of ambient ending 6.915 seconds before the leading edge of the start of the music itself, and adjusting the iPlayer's level to that of the DAB, the peak level of the iPlayer version is just 1.4 dB higher than that of the DAB, both sharing a overall RMS of -20.6 dB. So, the difference is marginal, but the iPlayer version appears to just have the edge in terms of dynamic range, though I would say the margin of error is possibly as great. I chose Music for a Large Ensemble since has the most, and greatest variety of, instruments of the works included this afternoon. Tonoght's concert will, hopefully, be at 192kbps on DAB.

[ChrisBennell]

I also have a desktop PC with integrated Realtek sound playing through an S220 Logitech speaker system. Although reasonably happy with the sound, I improved it by investing in an external sound card about 2 years ago. (A Creative Sound-Blaster Omni Surround 5.1) This connects through a USB port, and converts the internal digital signal to analogue to drive the speakers directly. This works fine (using the default Windows 10 drivers) and resulted in a noticeable improvement in sound quality. I can also record any broadcast from it using Audacity software. At around £60 I think this was an excellent buy. Just a thought!

[beauchampboiler]

I have now closely compared the iPlayer (320kbps aac-lc) and DAB (unfortunately 160kbps mp2) of Reich's Music for a Large Ensemble form this afternoon's Prom. Taking the quietest .504 seconds of ambient ending 6.915 seconds before the leading edge of the start of the music itself, and adjusting the iPlayer's level to that of the DAB, the peak level of the iPlayer version is just 1.4 dB higher than that of the DAB, both sharing a overall RMS of -20.6 dB. So, the difference is marginal, but the iPlayer version appears to just have the edge in terms of dynamic range, though I would say the margin of error is possibly as great. I chose Music for a Large Ensemble since has the most, and greatest variety of, instruments of the works included this afternoon. Tonoght's concert will, hopefully, be at 192kbps on DAB.

Thank you so much for doing this, it seems to confirm that the problem lies at my end.

[beauchampboiler]

I also have a desktop PC with integrated Realtek sound playing through an S220 Logitech speaker system. Although reasonably happy with the sound, I improved it by investing in an external sound card about 2 years ago. (A Creative Sound-Blaster Omni Surround 5.1) This connects through a USB port, and converts the internal digital signal to analogue to drive the speakers directly. This works fine (using the default Windows 10 drivers) and resulted in a noticeable improvement in sound quality. I can also record any broadcast from it using Audacity software. At around £60 I think this was an excellent buy. Just a thought!

It's good to know that a dedicated sound card/dac made a noticeable difference. It'll probably be the first upgrade I make to my system.

[Bryn]

It's good to know that a dedicated sound card/dac made a noticeable difference. It'll probably be the first upgrade I make to my system.

If you only need 2 channel stereo, keep an eye open for Richer Sound half price offers on the USB powered Cambridge DacMagic XS. They are normally around £100 but every now and they get reduced to £50 or less. They are aimed at the headphone market and in USB Class 2 mode can handle sample rates up to 192kHz and incorporate a volume control. For the price they are excellent, though not up to standard (or size) of the Cambridge DacMagic Plus (£250). I have 3 of the little blighters and one of those is used to feed a hi-fi system from an Acer laptop. It gives considerable improvement over the onboard Realtek offering.

Ah, just checked. They are on offer at £49.95 at the moment.

[johnb]

This thread reminded me of remarks made by Jim Simmons (Senior Product Manager) earlier this year in the BBC Blog: http://www.bbc.co.uk/blogs/internet/...1-09890a8fed8f

We have been working with the Audio Engineering Society (AES) in drawing up a standard for loudness in online streaming. We find that the headphone level protections in mobile devices which are designed to cope with the consumption of commercial music, don't always sit well with the lower loudness targets that broadcast production often work to. The net result is that some programmes and podcasts can can be too quiet to hear in noisy environments when listening on mobile players. The AES recommendation seeks to address that. We will look to apply the new recommendations across all our online streams so that our radio output is consistent and when you are listening to programmes online from across the BBC you won't need to adjust the volume level on your player as much.

IMO this is a really bad idea for Radio 3 as the perceived low volume level of Radio 3 is a direct result of the much greater dynamic range used by Radio 3. As I see it, the only way to equalize the Radio 3 'loudness' to that of other channels would be to introduce some form of Dynamic Range Control (e.g. the Optimod which is used with FM) in order to reduce the dynamic range of R3 online.