BBC HD Sound,will it kill Dab?

reboot

Just when you thought Digital Quality was at its best with Dab radio,and maybe having spent a few bob,along comes BBC HD sound .Enough already,or an exciting new development?

Dolby digital? Thats all it is.
Thats been around for ages.
The bbc radio channels are just ordinary stereo,at least thats what my amp tells me.
Not all programmes are in dolby digital on bbchd either.
Most movies and some U.S programmes are.Thats also the case with itv1 hd.

watty

DAB isn't high quality, hasn't got the bitrate for the MP2 Codec. It's not yet "taken off" so hard to kill...

Some channels on Satellite may use 256k MP2 stereo rather than 128k MP2 stereo of DAB.


For similar, nearly but not quite CD quality, but probably good enough you need
256k MP2, 192K VBR MP3 and 128K AAC. Most UK DAB is 128K or less.

DAB+ testing here was of course experimenting with "as cheap as possible" Not improved quality, i.e. 32k to 46 k AAC approx.

Note that only "produced for Cinema" has complete Surround Sound, which is nothing to do with "HD", high quality or true "being there surround sound" but is more about artifical effects and post production mixing.

There is nothing whatsoever "more hifi" about Dolby Digital compared with high enough bit rate for full HiFi for whatever codec you use.

Dolby Digital is the common version containing up to six discrete channels of sound. The most elaborate mode in common usage involves five channels for normal-range speakers (20 Hz – 20,000 Hz) (right front, center, left front, rear right, rear left) and one channel (20 Hz – 120 Hz allotted audio) for the subwoofer driven low-frequency effects. Mono and stereo modes are also supported. AC-3 supports audio sample-rates up to 48 kHz. Batman Returns was the first film to use Dolby Digital technology when it premiered in theaters in Summer 1992.

Dolby Digital is NOT about quality, per se, it's about Cinematic Audio effects.

DD 2.0 = Stereo using Dolby Digital, which means AC3 codec rather than MP2, MP3, or AAC.

Use of Dolby Digital (stereo or surround versions) AKA AC3, basically is paying Dolby Labs licence Royalty, instead of other holders for other Codecs.
E-AC-3, Enhanced Dolby Digital, or AC3+ is only going to be used on Discs, it's up to 6.1Mbps, so too "fat" for broadcast.

DD, aka Dolby Digital aka AC3 is only used on Broadcast where it's the preferred or only soundtrack. It's designed for Cinema and Disc playback, so takes up more space for same quality of AAC. There is no value in DD 2.0 compared to "ordinary" Digital Stereo.

Also -ANY- stereo (i.e. two channel) system, even analogue, if recorded suitably, it matters not if storage/transmission is DD/AC3, MP2, AAC, MP3, Red Book CD, Analogue Vinyl or MPX FM stereo, you can analogue or digitally process the two channels to get an almost true Centre, a basic Sub woofer (the .1 of 5.1) and quasi surround left & right rear. This has been done very successfully since the 1970s in analogue and is now better on many Home Theatre Surround Amps... NO MATTER WHAT kind of stereo signal is used as long as the original "mix" to two channels was done properly!

Currently for quality vs bitrate (the most important thing for Broadcast) the AAC standard is best. it's used in Nordig 2.0, Optional on UK HD DTT, mandatory on Saorview, only codec on Digital Radio Mondial (DRM) and preferred codec for DAB+

MP2 - There is no commercially used "near CD quality" Bitrate used. 256K is the highest I have seen, about similar to 192k MP3, but depends on Content. Most Satelliteand DTT TV & Radio uses MP2 today.
MP3 - 320kbps VBR is very near CD quality.
Red Book Uncompressed CD Audio - 1,411.200 kbps
AAC - 192kbps to 256kbps is alleged to be near CD quality. However it's usually deployed to greatly reduce bit rate at similar quality to older MP2 systems. All the most recent Satellite & Terrestrial TV and Digital Radio systems all specify AAC

bkehoe

watty wrote: »

DAB+ testing here was of course experimenting with "as cheap as possible" Not improved quality, i.e. 32k to 46 k AAC approx.

The only DAB+ test that I know of, in the South-East, had a service at 80k for a long time and currently has a service at 64k, so yeah as cheap as possible...not...

watty

I'd guess they found that even to bean counters less than 64k was terrible!

64k even on AAC is not an FM Radio replacement. Some Internet streams are better. Though the RTE "DAB" station streams I was listening to yesterday via "vTuner" on Archos where reported as 32k, may not be correct of course.

80K AAC is not good enough for FM Radio upgrade. 128K AAC or 256K MP2 ought to be minimum, otherwise what is the point? I have a FM Radio I bought for 60c that runs of 2 x AAA cells. I get better audio on it if I listen to an €8 "iTrip" type gadget playing 256K MP3s from my own CDs.

mossym

Deleted User wrote: »

Dolby digital? Thats all it is.
Thats been around for ages.
The bbc radio channels are just ordinary stereo,at least thats what my amp tells me.
Not all programmes are in dolby digital on bbchd either.
Most movies and some U.S programmes are.Thats also the case with itv1 hd.

it's nothing to do with it being dolby digital, so that's not all it is is. it's a higher bitrate version of the channel, which should give improved sound quality for those with a system able to take advantage. it has nothing to do with multichannel, or dolby digital tracks on tv


off topic
little experiment i carried out once( was trying to see how differing bitrates messed up dolby prologic II music). get any audio cd with a track you are very familar with, get an audio ripper with a selectable sampling rate. rip the same song at 8, 16, 32, 64, 128, 192, 256kbps..play over any decent stereo system

the higher ones are difficult to tell the difference, but once you start getting down to the lower ones you'd be amazed what they sound like...once you get to 8 it's hardly even music...

watty

Exactly.

Though comparable subjective quality vs bitrate varies with codec used, quality of encoder, CBR vs VBR, type of program material.

At highest bitrates there is less value in difference between AAC, AC3 (Dolby Digital), ATRAC, MP3 or MP2. At lowest bitrates, then at same lower bitrate
AAC is Best, better than MP3 or MP2. Unlike AC3 it's designed for broadcast.
MP3 better than MP2
AC3 /DD not designed to do low bitrates.

But we don't want the "lowest" bitrate. We want to have at least FM Multiplex Stereo quality. Less is obviously a backward step.

The Broadcasters are not going to use the "highest bit rate". Thus AAC offers better hope for future than AC3/Dolby Digital or MP2. (MP3 is rarely used by Broadcast)

Mike 1972

watty wrote: »

DAB isn't high quality, hasn't got the bitrate for the MP2 Codec. It's not yet "taken off" so hard to kill...

HD sound wont kill DAB
FM radio will kill DAB

rlogue

The future of radio isn't DAB or DRM it's delivery over the Internet. TV will ultimately go the same way.

Tom Slick

rlogue wrote: »

The future of radio isn't DAB or DRM it's delivery over the Internet. . .

What kind of internet connection have you got in your car?

Can I have one?

Mike 1972

Ten years ago most people didnt have an internet connection in their house
Even five years ago most people were still on dial up

in car internet is hardly the stuff of science fiction. Broadband is available on mobile phones right now for crysakes.

Having said that I do think it will be a long time before it replaces conventional broadcasting completely.

watty

Tom Slick wrote: »

What kind of internet connection have you got in your car?

Can I have one?

I had one in my car when I was in Dublin. An experimental one. My boss had DECT phone on his with a real fixed number


But you are right. Internet is complementary to Broadcast. Even with universal FTTH, Broadcast is cheaper.

Also "Mobile" Internet is seriously ungreen compared to DAB, DTT, FM Radio. Between 800W to 2.5kw per listener/viewer!

http://www.boards.ie/vbulletin/showthread.php?t=2056068467

1KW Terrestrial can serve 100,000 people
Satellite can serve 4M to 40M people, energy cost is launch.
Fibre to Home is the MOST efficient Broadband at under 1W per person, (excluding home Modem etc, maybe 10W to 15W), but is not Mobile and about 60 times more power consumption than Broadcast per person (30kW for 50,000 homes).

Broadcast isn't ever going to go away, it's complementary.

Also you can now record an entire rolling week of TV of all your favourite channels from Broadcast, and decide AFTER what you want to keep. HD VOD on Fibre is nearly 10,000 times more expensive per user than Broadcast!

rlogue

A 3G connection so I can run the RTE Radio app while I drive to and from work in and about London.

watty

You do realise Caps are due to fall and prices rise by x3 or more on 3G data as it's up to 97% subsidised by voice calls?

Assuming it doesn't get hit by a "carbon tax" for being effectively 800W to 2kW approx PER PERSON using it... That's terribly un-environmental way to to listen to Radio.

I think Ofcom are refusing to release the UK part of the Europe wide terrestrial part for the ne pan-european mobile Satellite Radio that would be ideal for RTE. They want to charge local 3G licence rates instead of the pan European satellite spectrum rate for spectrum licence.

rlogue

Frankly I don't give a stuff about how much carbon credits I use up!

Bottom line for me is that I have RTE Radio in the car - the amount of data I download to listen to Lyric FM is neglible and doesnt affect my download cap and the sound quality is way superior to hissy old FM in London. As we are plagued by FM pirates here the quality of the FM signal I receive in the car is poor. Also it's a bit hard to pick up Lyric on FM here.

bkehoe

If even 10% of people in their cars did the same as you the cell networks would collapse. Mobile internet isn't a viable means of delivering content to a mobile audience.

watty

Actually less than 0.01% of drivers...

Complain to Ofcom and your MP about the way Ofcom is treating the new Mobile Satellite Radio Operator, who has a pan European licence for Satellite + terrestrial fill in, but without the UK.

It's a logical and cheap method for RTE to deliver Radio across Europe and Ireland to car drivers.

rlogue

Then the operators need to be planning forward and anticipate future demand.

rlogue

Watty the pan European satellite radio option would be good if it happened but the kit would need to be affordable and RTE would need to be on there.

From my point of view using my phone to get an RTE radio signal is easy and provides a good quality audio on my way to and from work.

Many Internet streams are of a far higher quality than DAB too. DRM might have been an option bit where are the receivers?

mossym

rlogue wrote: »

DRM might have been an option bit where are the receivers?

DRM won't offer anything more in terms of quality than current FM, it was about saving bandwidth, and having longer transmission ranges, it would not be higher quality than existing FM

watty

DRM is more a LW/MW/SW replacement that gives near FM quality.

There are DRM receivers, but not many, (only seen table-top models) and RTE seems to have stopped overnight LW DRM tests. There are some on SW and some tests on MW, not from Ireland though.

DRM+ is only an alternate proposal to FM on Band I (Someplace in 45 to 60MHz instead of 88 .. 108 of VHF -FM or 200MHz approx of DAB & DAB+)

No-one is really offering "better" than decent signal FM with any terrestrial Digital proposal. Only Satellite systems are likely to ever have higher quality audio and not often.

Oddly I'm in Limerick and wakened by R4 LW. I then hit FM memory 4 (the "iTrip" on a Satellite Receiver as that might reset in middle of night when power cuts). Then 7:15 I hit FM memory 1 for RTE. After the 7.30 traffic news I go back to R4 "FM" via Satellite and "iTrip" gadget.

I look forward to a Car radio with DRM and BBC on DRM

fat-tony

reboot wrote: »

Just when you thought Digital Quality was at its best with Dab radio,and maybe having spent a few bob,along comes BBC HD sound .Enough already,or an exciting new development?

I listened to the live BBC Radio 2 concert from the Roundhouse last night (Elton John) on the net in wonderful 320kbps AAC stereo. I used my Altec Lansing speaker setup to listen and also monitored for a while on high-quality headphones. My impression of "HD sound" - meh! It didn't help the comparisons with the regular 128k AAC stream that the overall sound level on the "HD" audio stream was way down. I would say that the 320k stream was free of the slight warbling artefacts present on the 128k stream, though. My jaundiced view is that the 320k stream is just another way of using up my bandwidth more quickly!

According to the BBC Radio 2 web page, the HD stream was for UK listeners only, but I had no problems accessing it through my ISP connection (no proxies etc.). I went back to the satellite broadcast version (48KHz, 192kbps MP2) playing through my home audio system from my Freesat receiver. Certainly as good/better than the internet "HD" stream. I filled out the BBC questionnaire on the website and gave them my feedback.

My view - listen to radio or watch tv via broadcast. All this i-player stuff is just crowding out the available internet bandwidth:rolleyes:

reboot

reboot wrote: »

Just when you thought Digital Quality was at its best with Dab radio,and maybe having spent a few bob,along comes BBC HD sound .Enough already,or an exciting new development?

I think I may have confused a few folk over my BBC HD Sound thread.
I was referring to the BBC Press release 29th Oct."BBC launches HD sound for Radio".
It would seem that in order to avail yourself of the improved encoding and higher bit rates,you would need to connect your computer to the HI-fi.
It was also pointed out that better headphones for your Laptop would prove an advantage.
I just don't get it,and hope I won't need to.
Seems they don't know what to be at next.
If you are a listener to Radio three and the Proms,I don't mind paying for BBC HD Radio streaming your way,yeah right.

fat-tony

No confusion here, reboot!
I suppose the Beeb are trying to improve the user experience for streaming audio by using high bit rates and good quality codecs like aac.

What hacks me off is that even our fledgling digital broadcast platform Saorview is launching with reduced quality video (544x576) on RTE 1 tv. On the radio side of DTT, RTE Radio 1 is in mono and has a bit rate of 96kbps:eek: Where's the quality remit here?

watty

maybe that is the LW feed of R1 ?

fat-tony

Quite possibly.
<rant> It's been like that for weeks. R1 Extra is the same. It may be just an error or maybe it's to shave some bandwidth off the multiplex (like the 544x576 on the TV channels) to give more headroom to the HD channel. Who knows? The clock on the multiplex is 30 seconds out (slow). It was two minutes fast a couple of weeks ago. I didn't mind so much when the thing was just a technical test. Now that it is supposed to be available for public consumption you'd think that someone would be in charge of getting things right.... </rant>

watty

It's all short of bandwidth. Even when 2nd Mux running it will be tight for space when all the main channels are HD (2013?). Hence AAC. I suspect the radio and TV sound will have to change to AAC stereo to save space instead of current MP2. It's in the minimum spec.

reboot

fat-tony wrote: »

No confusion here, reboot!
I suppose the Beeb are trying to improve the user experience for streaming audio by using high bit rates and good quality codecs like aac.

What hacks me off is that even our fledgling digital broadcast platform Saorview is launching with reduced quality video (544x576) on RTE 1 tv. On the radio side of DTT, RTE Radio 1 is in mono and has a bit rate of 96kbps:eek: Where's the quality remit here?

Thanks for that,I just thought the thread had gone off in all sorts of directions perhaps due to my assumption that everyone knew of the launch of HD sound on Radio.Also the fact that I had no idea what some folk were talking about.
I sometimes reflect when it comes down to sound quality,how many of the boards contributors can hear much above 8k?Present company excluded of course.

watty

Quality isn't just Frequency Response. Most older people should hear up to 10kHz

It also includes Distortion, Signal to noise, Artefacts (of Codec system) and Dynamic range.

reboot

watty wrote: »

Quality isn't just Frequency Response. Most older people should hear up to 10kHz

It also includes Distortion, Signal to noise, Artefacts (of Codec system) and Dynamic range.

I am told we are the only animal that cannot regrow the hairs we lose in our ears.
If someone is selling any snake oil,I'll buy some.

watty

I only believe reviews that used statistically meaningful results (i.e. MUCH better than chance) of double blind A-B tests.