Page 1 of 2 12 LastLast
Results 1 to 20 of 23

Thread: The quality of broadcast sound on both radio and TV

  1. #1
    Join Date
    Sep 2007
    Location
    England
    Posts
    242

    Default The quality of broadcast sound on both radio and TV

    This thread was suggested to cover the sound we hear at home, originated in a TV or radio studio.

  2. #2
    Join Date
    Jun 2012
    Location
    England
    Posts
    244

    Default Hunting for good quality broadcast sound ....

    My background, and long interest in sound quality cause me to want to start a new thread on the quality currently of broadcast sound, although I suspect that many members of this site do not use their much loved sound equipment for anything other than dedicated music listening, it being perhaps a sacrosanct activity.

    However, in my case, and especially since I do not have any sound equipment between the speakers, my television sits in the centre, allowing watching and particularly monitoring of the stereo sound quality of TV sound from a Humax PVR., and also what I presume to be its accompanying DAB radio.

    This link, http://www.diyparadiso.com/teksten/i...arupdated1.htm especially in the later pictures, shows what I had always thought to be bad practice, especially with valve equipment which is inherently microphonic.

    I listen to R2 at 1900, for the Monday blues programme, the Wednesday folk programme, and the Thursday country programme for new inspired music, as well as R4 for most of the day whilst doing work, and I am surprised, as someone familiar with BBC sound quality in the 70s, at its now very variable quality.

    My memory of those earlier times, is of the sound I had at home showing a markedly consistent quality in broadcast output whilst using; a Garrard Zero-100 SB turntable, with G900SE cartridge, Quad FM3, Quad 33 preamp, Nelson Jones Class A 10+10 power amp, and Tannoy Gold Lancaster15s, and when I recorded from any source to my Revox A77, the output was, at 7.5 i.p.s. indistinguishable from the input, and I had a feeling of having reached ‘perfect professional standards’.

    If you do listen to broadcast sound, to what degree do you think that it is of good quality, and how variable do you find it? I find in particular that actuality speech is very often poor in quality, with accompanying (Library derived) music being obviously much better, it being full bandwidth in contrast with the often muffled speech. (Quad 33 ‘brick wall’ 5kHz filter), and the relative levels of actuality and continuity announcement in a programme may differ by up to 15dB as well.

    The pursuit of good speech reproduction remains central and vital to good sound in my opinion, and this requirement is made more difficult to assess and fulfil because of the dialectical drift which has occurred in announcing standards over that time, and also what I think is poor diction/enunciation.

    I would appreciate much factual information and opinion on this from the HUG.

  3. #3
    Join Date
    Jan 2006
    Location
    South of England, UK
    Posts
    4,183

    Default $$$ reality

    Quote Originally Posted by Pharos View Post
    .... as well as R4 for most of the day whilst doing work, and I am surprised, as someone familiar with BBC sound quality in the 70s, at its now very variable quality .... My memory of those earlier times, is of the sound I had at home showing a markedly consistent quality in broadcast output ... I would appreciate much factual information and opinion on this from the HUG.
    This is a subject I am very interested in. It was as a teenager hanging around "assisting" in BBC Local radio in the early/mid 70s which hooked me on quality audio. Those days are absolutely gone now; the doorway for an amateur into professional sound opened for just a few years then firmly closed. There was no security at all in those days: you could literally walk in off the street, and providing you because a familiar enough face to get past the stern lady on the reception desk/switchboard, you were in, will unlimited access.

    First, before we dive into this one, we need to make one absolutely critical point. Recording sound, filming and editing video and producing broadcast entertainment burns cash at a frantic rate. To give you an idea, have a look here. Broadcasting is a cash furnace with an insatiable appetite.

    That said, we can be a little sympathetic to the reality of trying to produce audio of even basically good quality, when the budget to 'do audio' as a slice of the overall programme cake is so miserably small. We should congratulate producers who still create the most unexpectedly excellent audio in broadcasting. A example is Michael Portillo's Great Train Journeys here and (if you are quick) here. The sound was, despite the difficulties of location, so exceptionally and uniformly excellent that I took the trouble to ring the production company to thank them for making the effort. I have no idea what monitors they were using - but the positioning of the microphones and the careful matching of atmosphere and levels is so vitally important. When care and trouble is taken, the results are a joy to listen to, and memorable to watch too.

    And the secret is largely this: the producer must have a vision of how the programme should sound, makes the budget available to do the job properly, and recruits the best craft experts. It still can be done!

    P.S. I just couldn't resist making a clip of the wonderful Great British Railway Journeys, made for the BBC. When you consider the ambient noises that accompany the train, the sound quality (and intelligibility) is A1, without being at all hard. Incredibly, the presenter's on-location voice is more natural than in his voice-over, recorded in a sound booth! I hope this short excerpt doesn't cause copyright issues - this is just a clip to illustrate a point.

    This beautiful soundtrack is the work of sound recording experts.

    Loading the player ...


    Expert tips to watch out for! (1) At about 0 mins 15 secs voice quality in train; (2) At about 2 min03, on lake side, when he turns his head away from the camera, little change in sound quality - where is the mic? In his hair perhaps? Or is it a boom mic (doing the job properly).

    Alternative download: Download .MOV file here. 51MB (large file needs a few minutes)
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

  4. #4
    Join Date
    Jun 2012
    Location
    England
    Posts
    244

    Default Recording simplicity and quality hand in hand?

    Alans points have raised a few further issues in my mind. If programme making is so expensive, surely the salary of a technician with good ears would not add substantially to the overall cost, but my guess is that the market cares little about the sound quality.

    I have not noticed the sound quality of Great Railway Journeys, probably precisely because the sound was so good that it did not 'get in the way' of the programme content, and I have actually found myself liking Michael Portillo as a result, this when I have felt loathing for him as a politician.

    I also have re-realised that in many instances in life, a job well done goes unnoticed or gets ignored, and it is only when something is well below acceptable standards that it stands out.

    I notice also in construction, that very often it is the preparatory work which is arduous and time consuming, and that when done for others prior to their 'expertise' in applying a specialist task, they hardly notice how well prepared it is, taking it for granted, when it is that work, which has facilitated their following with ease.

    This evening I watched "Aliens", and found the sound poor in terms of realism of acoustics, but one must have sympathy for the demands of the tasks, and getting the right weight with lack of inappropriate bass on speech is probably too much to expect.

    In the area of 'pop', for want of a better word, much music, with the exception of the voice is produced non acoustically. Unlike that which can be obtained with a Blumlein pair, this produces no real image, and in my experience produces a flat sound with little depth in front of or behind the speakers. But it is still a valid art form, and is often very well done from the points of clarity and frequency response, a good example being Dido's "White Flag", which I was given a few years ago. However, although her voice is very pure and clear, on track 2 there is an audible sampler looping click, (non-zero point looped).

    In about '90 a friend recorded a live gig using a pair of PZMs crossed, whilst another used muti mic'ing and a mixer. Both results were taken to a CD producer, and the crossed pair recording chosen in preference.

    On 'Late Junction" (with Shakira) a few years ago there were many examples of world music which had been produced in the simple crossed pair way, this presumably because of finance and convenience, and it being of an ensemble of four or so in the desert using a pair of mics and a DAT machine. Much of this was stunning, and shows just what can be done.

    Kirsty Wark's voice on Newsnight has always been 'quacky' and unpleasant, but on hearing her on R4 a few weeks ago her voice was much more natural. The lavalier electret condenser mics costing a few quid have to be responsible, and this convenience is a sad reality I suppose of the vast nature of consumerism, in this case of media.

  5. #5
    Join Date
    Jan 2006
    Location
    South of England, UK
    Posts
    4,183

    Default The reality of crewing costs and manning levels for sound

    Quote Originally Posted by Pharos View Post
    Alans points have raised a few further issues in my mind. If programme making is so expensive, surely the salary of a technician with good ears would not add substantially to the overall cost, but my guess is that the market cares little about the sound quality....
    This is indeed the mystery. As humans we are visual animals. Once we are watching a moving image some 80% of our mental capacity is absorbed, which means that audio quality can degrade quite markedly before it becomes intrusively objectionable to the average viewer/listener. I guess that argument from the producer's side (he/she who funds the project, pays the bills) is that every cost that can be saved should be saved, that being normal business logic.

    What underpins great audio is great training and skill specialisation. Video skills are distinctly different from audio skills.

    In the good old days up to the 90s, broadcasters (especially the BBC which found itself as the training provider for not only the BBC but its newly permitted competitors) pushed new technical staff through a structured training programme, from a general basic foundation (what is a decibel? what is a tape recorder?) up to very specific hands-on instructions for a mixing desk or studio camera. Then, with the advent of digital technology, studio audio/video equipment became simpler to operate and maintain, and technical colleges and universities seized the opportunity to train, at a price. The result was that where as there were minimum standards of training when the BBC (and before that the Post Office) were the sole provider, uncertainty crept in and employers could no longer be sure exactly what knowledge foundations a candidate had. Much could be learned on the job by observing more experienced hands - no substitute for learning from a craftsman - but as the old guard faded into retirement, a vital connection with the old, sure and expensive ways of the past was lost.

    I often complain (to my TV, my wife, anyone within earshot) about the not infrequently pitiful sound quality of outside broadcast news items. The sound is all too often muffled. Why? First, producers hate microphones in shot. They think they look ugly, technical, visually distracting and need to be handled and pointed by a presenter who should be concentrating solely on looking at camera and conducting an interview and who may have no training in microphone techniques. Again, in the old days that wasn't an issue because overall staffing levels, unionisation, job demarcation, division of skills and specialisations ensured that even for a two-minute basic OB news items filmed in the village post office there would be a big production crew on site ...

    • a film cameraman
    • a sound recordist with his own recorder
    • a boom microphone operator holding the microphone aloft and skilfully pointing it to the mouth of whoever is speaking
    • a technical assistant to operate the clapper board to synchronise the film and sound, take care of the film and tape stock, handle cables etc.
    • a producer's assistant with stopwatch
    • lighting technicians with various lamps and screens
    • driver of OB vehicle
    • runners to do odd jobs and rush film/sound back to base for editing etc. etc.

    That was in the days of film and tape. Then the shoulder-held video camera arrived which captured sound onto the camera itself. So we moved to ....

    • a video cameraman who recorded sound onto his camera
    • a boom microphone operator holding the microphone aloft and skilfully pointing it to the mouth of whoever is speaking feeding sound to the camera
    • a producer's assistant with stopwatch
    • lighting technicians with various lamps and screens
    • driver of OB vehicle
    • runners to do odd jobs and rush film/sound back to base for editing etc. etc.

    Then a dramatic change in manning resulted from the introduction of the clip-on personal radio microphone. So we we moved to ...

    • a video cameraman who recorded sound onto his camera
    • a producer's assistant with stopwatch who clipped-on a personal mic to the interviewer and interviewee and monitors sound levels etc.
    • lighting technician with various lamps and screens
    • driver of OB vehicle
    • runners to do odd jobs and rush film/sound back to base for editing etc. etc.

    With a bit more rationalisation in manning levels, the introduction of satellite up-links to base, miniaturisation of the digital camera, improved camera sensor performance we arrived at ....

    • a video cameraman who recorded sound onto his camera and who takes care of clipping-on microphones, levels etc.
    • driver/production assistant who books and manages a satellite link (timed to the second)

    and now ...

    • a interviewer who carries his own video/sound camera, sets it up on a tripod, positions himself in front of it, clips-on microphones but cannot monitor the sound because he cannot both be in-shot and in-shot wearing headphones and must manage the satellite link too

    or in the extreme-minimisation cost-down situation ...

    • a interviewer who carries his own video/sound camera, sets it up on a tripod, positions himself in front of it, turns on the internal microphone but cannot monitor the sound because he cannot both be in-shot and in-shot wearing headphones and who must manage the satellite link too


    The consequence for sound quality must be obvious. Proof? Evidence? Listen to the sound quality on archive OB material recorded 30 or more years ago, on film, perhaps in B&W: it is shockingly good. Example, Pathe News. Also, British TV shows like Parkinson, Wogan and similar from the 80s, Old Grey Whistle Test where the excellent sound is a tribute to specialist sound skills plus the use of (big) visible proper microphones on stands, not radio mics.
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

  6. #6
    Join Date
    Jun 2012
    Location
    England
    Posts
    244

    Default What was THE reference?

    Alan confirms my worst fears, and I feel grief at the loss of the prevailing ethos that was once regarded as the norm, to be aspired to by all others.

    In the early 70s, the standards of the BBC were held as THE reference, and that great team of engineers who worked on the now legendary series of loudspeakers, the pioneers of high performance loudspeakers represent to me a, sadly lost, golden era.

    I add this link for interest http://www.ips.org.uk/articles/2010/.../#comment-2641

    Is it surprising, given this, and the current state of 'art', that the average household has a system comprising a 9" cube of amp., tuner and CD player, surrounded by two beech coloured 'bricks' immediately adjacent? We are probably all monitoring accurately the prevailing mediocrity; clear 'lenses' looking at the 'dirt' on the other ones, hearing accurately the failings in the sound quality.

    I think that I can actually hear when R2 is using its new studio, and it sounds better than the old, and although BBC4 is a great relief because its content is educational, enjoyable, and embraces the mind more than much other TV, often the sound is very poor.

  7. #7
    Join Date
    Oct 2009
    Location
    Australia
    Posts
    349

    Default Need more great voices and speech

    It’s a bit of a waste if you think how the broadcast industry looks for the “voice” yet occasionally the end result is too much sibilance or comes out sounding tinny, chesty or nasal.

    I’ve got a feeling the ability to subjectively assess slowly diminishes once we start working our way down to internal flat panel tv speakers. Consumers are missing out if they don’t help themselves. On the other hand, might it also be that we now don’t give as much attention to how beautiful the spoken voice can be?

    I’ve heard some voices and am somehow, not wanting to sound harsh, convinced that standards are indeed dropping or the industry no longer tries as hard looking for speech talent and gift. I miss Mr. Alistair Cooke’s great voice and speech.

  8. #8
    Join Date
    Jun 2012
    Location
    England
    Posts
    244

    Default

    But, does the broadcast industry any longer look for the 'voice', I'm not dso sure, and think that there are probably no longer 'prenunciation departments' to advise, correct and coach broadcasters.

    I think the sibilance is often a result of mic artefacts, and I regret to have to express the view that in Britain, along with the increased 'political correctness', general standards of behaviour, articulation and speech have fallen, as well as those of the written word.

    I too miss some of the great voices; articulate, clear, good bass formants and sibilants as opposed to the now ubiquitous 'glo'al stops. Alastair Cooke not only spoke well, his narrative was interesting and engaging, and his intonations and inflexions were correct to convey meaning, and emotion, intelligently.

    In my search for better sound; and yes I am one of those rather sad individuals who spends hours pondering and analysisng, I have made the major decision to upgrade my amplification from expensive, to much more so, in the perhaps deluded belief that I will hear a difference, and if it works out, then I will have an even clearer insight into broadcasting deficiencies.

    My current FM tuner is the AVI S2000, and I wonder if in anyone's opinion, it is worth considering upgrading that.
    Central to this question I cite the Head of Audio Quality at the BBC's response to being questioned by Roger Bolton on the "Feedback" programme on R4 earlier this year.

    He surprised me with his candidness and honesty when he stated that the quality of FM or of DAB were not of audiophile standard, and that it was up to the individual to choose which deficiencies were most acceptable to him.

  9. #9
    Join Date
    Oct 2009
    Location
    Australia
    Posts
    349

    Default Good antenna, great tuner

    Quote Originally Posted by Pharos View Post
    ...and I wonder if in anyone's opinion, it is worth considering upgrading that.
    I reckon if you don't hear any unexpected noises or interference, and have an appropriate and decent antenna it already is a great set up. There is more and more electronic noise nowadays, either from computers, mobile phones or just poorly designed electrical items. If you get a clean clear steady copy, i wouldn't worry about anything else. Ive always owned very affordable decent fm tuners and there never was one which was ever objectionable.

  10. #10
    Join Date
    Jun 2012
    Location
    England
    Posts
    244

    Default FM unlistenable now?

    I'm not convinced about Kittycat's statement, and think that I have reached a stage in reproduction at which FM is virtually unlistenable.

    In a previous listening a couple of years ago my friend and I came to the conclusion that the FM quality I have, and I do live in a difficult position, was more like 'medium wave'. A luminary told me last week that both R1 and R2 are compressed, I think probably Optimod or similar.

    On certain occasions it is stunning, but these are so few and far between that it cannot be relied on.
    One such was of a live set on the Monday blues programme a couple of months ago; I eased the volume up expecting the usual problems to manifest, but it was to my system absolutley clean, and a complete joy.

    Then it is back to the normal for the 98% of the listening experience. Even a tentative explanation of this is difficult with so many variables involved; would a Day Sequerra sort it out?

  11. #11
    Join Date
    Oct 2009
    Location
    Australia
    Posts
    349

    Default FM radio

    Quote Originally Posted by Pharos View Post
    ...and think that I have reached a stage in reproduction at which FM is virtually unlistenable.
    Imho, saying FM is un-listenable is close to saying all modern CD quality is nonsense. Its almost true, but i wouldn’t go as far as to say that, but there are indeed big variances in “quality”. My biggest gripe is that commercial stations, here at least, are too “loud”. Optimised for car listening perhaps?

    There still are decent stations and material around. ABC FM here is of pretty decent quality. They have live programs occasionally. There’s a station here called 4MBS (they also run NPR material) which is possibly the best available. The station is crewed by very experienced announcers, its informative and for some reason it’s not “in your face loud”.

    Getting a better tuner imo won’t make Fm sound better, just like getting a better amplifier won’t make Pink sound any less loud or compressed.

  12. #12
    Join Date
    Jun 2012
    Location
    England
    Posts
    244

    Default FM for the masses

    That was also my opinion re. tuner. I think the real cause is a cultural shift over 40 to 50 years in which the 'capitalism imperative' has achieved primacy at the expense of all else, and has produced a 'Macdonalds' approach even to FM as with so much else.

    I tried to watch a couple of films last night, and found myself irritated by excessive and inappropriate bass noises accompanying so many, both events, and non events. I also don't like being shouted at, and instructed on what to do in ads.

    I view the sound off FM as markedly inferior to CD in quality, but that exception was wonderful.

  13. #13
    Join Date
    Jan 2006
    Location
    South of England, UK
    Posts
    4,183

    Default FM v. DAB v. BBC HD ... what is the sonic reality?

    Driving north this week I had Radio 3, the BBC's classical music service playing in the car. Relating to the thread that recently appeared about audio compression and signal adjustment on the UK FM service, I would like to remind you that whilst FM was, in the 60's and 70s seen as the purest way of delivering high quality audio to the serious home listener, the advent of CD forced FM to completely rethink its raison d'etre. It refocussed on the casual listener in the car and at home/work listening via portable radio.

    And just to make matters more disappointing for the FM fan, the advent of commercial FM radio (a new concept in the UK) plus the progressive deregulation of commercial FM radio (to the point that there were/are no mandated technical standards for frequency response, distortion, signal processing - only absolute maximum transmitted loudness) meant that the primary target market for FM became the casual listener. And the casual listener is listening under non-ideal conditions and is attracted to the loudest sounding station on the band: that was the end of FM as a serious purist delivery medium.

    We, the listening public cannot have it both ways. If we want the convenience of music on the move, then the radio must cut through the ambient noise we're in. If we are unwilling or unable to invest in a new transmission system that can adapt the service to our individual noise environment and are stuck with a 50+ year old legacy system, then it is surely only reasonable to allow the broadcasters to anticipate how much EQ and loudness boosting will improve our reception. And thus we have Optimod which I believe is used by all FM stations in the UK and probably it or equivalent across the world.

    - Is the FM service capable of truly hi-fi sound? No it never has been due to the limitation of the legacy wartime technology.
    - Can it sound acceptable? Yes, most of the time on Radio 3 or 4.
    - Is DAB audibly better? Yes, not a shadow of doubt that the DAB sound (when the bit rate is above 128kb or so) is closer to what leaves the studio for the transmitter in every respect. You may not like that sound; you may prefer the softer, warmer FM (eq'd) sound but that is the fact of the matter.
    - Can DAB sound worse than FM? Yes when the bit rate is low (say, 60kb) but this is not an issue if you are listening non-critically on a portable radio.
    - Is FM redundant? Technically, yes and has been for 20+ years.
    - Is there any technical development of FM? No it is an abandoned format.
    - What is the best delivery format for high-quality 'radio'? BBC HD stream - far better than DAB and obviously incomparably better (that is, closer to what the studio engineers hear over their monitors) than FM.
    - What's the second best choice: BBC iplayer, play on demand.

    Excellent example of the benefits of signal processing/loudness management in making a loud, punchy, ear-catching pop sound by real-time analysis and adjustment of a sound stream from the studio to the transmitter. Note the bar graph at the bottom right shows that this signal is constantly as loud as it possibly can be, within the legal standard for an FM station's maximum signal output. Look carefully at those bars and at the black rectangles between the tip of the L/R bar graphs and the red clip indicators at 0dB. Notice that when the full processing is applied the tips never fall below -3dB or so, leaving the black rectangles from about -3dB up to maximum level, 0dB. Do you know that this means? It means that the dynamic range of the sound is only 3dB. Shocked? You should be. It is pointless having audio equipment, such as DAC or CD or an amplifier, which boasts a noise floor of, say, -100dB when in fact, with this sort of service, only 3dB of that vast dynamic range is being used - 97dB is needless perfection.

    Hope that helps.

    P.S. A friendly recording engineer has given me a copy of the digital master recording as played-out by the BBC studio, and I recorded the same broadcast at home off a good quality FM tuner. I will try and find them and let you hear for yourself how FM mangles the sound.
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

  14. #14
    Join Date
    Jun 2012
    Location
    England
    Posts
    244

    Default A relief

    This reply and the information is a great relief to me because of the sadness I have felt at the poor FM quality I have been receiving.

    I have not worked formally full time in the audio industry for many years, and this of course, if one does not have contacts enabling one to keep up with events in technology, makes harder the pursuit of good sound.

    I feel now that my own system will, especially with new amplification, which incidentally is viewed as unnecessary and inappropriate by many here, will be entirely limited by source quality, and of course high quality sources directly correlate, though not linearly with cost.

    In the conversation with an industry friend mentioned in my last post, he commented that one main difference between FM and DAB was that the ambient acoustic noise was lost on the latter.

    I would like to know more about BBC HD streaming, Streaming was stated a couple of years ago, by the owner of another company which once did, but now does not produce Hi-Fi separates, as the future.

  15. #15
    Join Date
    Jan 2006
    Location
    South of England, UK
    Posts
    4,183

    Default

    Quote Originally Posted by Pharos View Post
    This reply and the information is a great relief to me because of the sadness I have felt at the poor FM quality I have been receiving..... In the conversation with an industry friend mentioned in my last post, he commented that one main difference between FM and DAB was that the ambient acoustic noise was lost on the latter.

    I would like to know more about BBC HD streaming, Streaming was stated a couple of years ago, by the owner of another company which once did, but now does not produce Hi-Fi separates, as the future.
    That opinion about 'ambient noise' is not factually correct. The fact of the matter is that no useful sound can be heard below the noise floor of a recording or delivery mechanism. In other words, hiss obscures and obliterates every musical detail of an energy lower than that of the hiss. So, the absolutely primary quality arbiter of any audio system is 'how hissy is it?'.

    We know that the wax cylinder has a such a high background hiss level that it is a struggle to hear voices unless they shouted; that gave way to the 78 with a lower hiss level and they gave way to the LP with even lower surface hiss. Each time the background noise level was lowered, the useful dynamic range where music can be reproduced increased, and the fidelity with it.

    FM at best, under really optimal conditions near to the transmitter has a signal to noise ratio that is around 55dB compared with LP under optimal conditions of about 60dB. The implication is that (and this was provable when the broadcasters played LPs routinely) you could not hear the surface noise of an LP when played over FM radio because the FM system's noise floor was/is higher than the LP record. Also, the stereo separation is very poor on FM and the overall distortion under peak conditions will be 5-10% THD or more.

    All these issues are sidestepped with DAB which if the bit rate is high has a much lower noise floor (to let us hear those 'ambient sounds'), much lower distortion, far better stereo separation.

    As I said the facts are these:

    - Is DAB audibly better? Yes, not a shadow of doubt that the DAB sound (when the bit rate is above 128kb or so) is closer to what leaves the studio for the transmitter in every respect. You may not like that sound; you may prefer the softer, warmer FM (eq'd) sound but that is the fact of the matter.
    - Can DAB sound worse than FM? Yes when the bit rate is low (say, 60kb) but this is not an issue if you are listening non-critically on a portable radio.
    Studio staff have the means to 'listen to output' to check how their programme sounds in our homes on FM and DAB by sending the signal collected from FM and DAB tuners back to the studio. The FM off-air check has always revealed a dirty, hissy, distorted, poorly separated and often warmer sound than that which leaves the studio about which they can do nothing. DAB is much closer to the source, like it or not.

    So, taking together these last two posts of mine, does your friend have any justification is his belief? He probably does, but for entirely the wrong reasons. Imagine this conceptually: you are a broadcast sound engineer at the control desk in the Royal Albert Hall feeding live to the FM transmitter network, representing 95% of your audience. The music has a very quiet passage, just solo triangle. What do you do? Turn up the loudness of the triangle's microphone so that it lifts clear of the background hiss and we can hear it, then turn it down again when the orchestra picks up? Of course you do. You don't want complaints from the home listener that they couldn't hear anything but hiss. So you have emphasised the quiet sounds, above their true perspective to overcome the limitations of the FM system. These days that job is performed automatically as I illustrated in the previous clip.

    So yes, very quiet sounds near the noise floor are boosted in FM, especially in classical music. There is no need to do that when the system noise floor is lower, as it is in DAB.
    Last edited by A.S.; 19-08-2012 at 09:52 AM. Reason: The reality of FM and hiss
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

  16. #16
    Join Date
    Aug 2007
    Location
    Harrow, UK
    Posts
    477

    Default Radio listening in quiet places ...

    Quote Originally Posted by A.S. View Post
    ...the casual listener in the car and at home/work listening via portable radio
    There is, and always has been, a dichotomy involving radio in the car as well as noisy places in general (or indeed, any area in which listening is casual or secondary to the main task in hand). Alan explained this succinctly in post #13. Although DAB is widely condemned by audiophiles, there is no doubt that the standard BBC Radio 3 service in the UK, running at 192kb/s, is better than FM for the vast majority of listeners. Band II (88 - 110MHz) has now become overcrowded and interference-laden. I live in a difficult location where the signal strength is strong but, because of the height, I pick up a huge number of "competing" signals causing all kinds of intermodulation effects: quiet FM stereo is a near impossibility and, from what I hear, becoming more problematic for many others too. Quite probably, a really well made tuner front end would improve matters but the chances of finding one (except, perhaps, a very old model) are poor. Good quality RF engineering is very mechanical and does not come cheaply; I doubt that it's now possible to obtain a tuner possessed of a top notch RF front end combined with good audio electronics.

    Some of the BBC's on-line approaches are excellent. The 320kb/s AAC R3 stream is as good as any in the world and I seriously doubt whether there is any audible distinction between that format and 44.1kHz PCM.

    But what of the car? Even in Central London, surrounded by high steel-framed buildings and all the electrical interference of modern life, FM reception can be surprisingly good. Car radios typically offer less stereo separation than home receivers and this helps to keep the noise down (NB a given noise performance in stereo requires a far stronger signal than in mono), combined with a stereo decoder that discreetly reduces down to mono should the signal be inadequate at any instant. But in cars we don't really worry about the subtleties of stereophony.

    So how well does DAB work in cars? Radios with DAB support are only just creeping into new models. While DAB 'adaptors' are available, there still remains the issue of providing a DAB receiver with a decent signal. DAB is transmitted at roughly double the frequency of FM broadcasts so the antenna systems are incompatible; you will probably need an external antenna and this is not something added cheaply, unless you are prepared to use a magnetic clamp and run the cable through a door seal - not at all tidy. The nature of all things digital is that they tend to work well with decreasing signal, up to the point where the collapse is catastrophic.

    So has anyone practical experience of DAB in cars? Just how well can it work when driving around a crowded city?

  17. #17
    Join Date
    Jun 2012
    Location
    England
    Posts
    244

    Default Noise floor and FM

    I do appreciate, fully understand, and agree with your analysis of the DR and noise floor relationships. I haven't had DAB for very long, and instinctually do not like using my Humax TV tuner for that, with its audibly noisy fan and HD.

    The industry friend is very prominent and ACTIVE, and I will not be more specific than that because 'fetching and carrying' is not something I am prepared to do. I was not very well, and also very tired during the conversation, and may have not fully grasped the context or some significant factor therin, but I cannot see how.

    If I compare my FM with my DAB from the Humax on R3, the latter is probably 15 or more dB lower in level, whereas in the case of R1, there is barely a dB between them.

    I had no idea that the distortion levels on FM approached that degree of severity.

  18. #18
    Join Date
    Jun 2012
    Location
    England
    Posts
    244

    Default My other worldly experience

    I have had three weeks away from this site - due to the antics and technical incompetence of Talk Talk, and have during that time installed both a new pre and power amplifier into my system.

    The thread on that subject was withdrawn in about mid August, but I have results which are to me amazing, and rather counter intuitive, and since they are audible on both FM and DAB, I will touch on them here.

    I have changed my power amplifier from an ATC SIA2-150, to an ATC SPA2-150, and on my first auditioning, which was of Paul Jones' blues programme on Monday evening on R2, could hear that his sibilants were not only different, but better. I am aware that this may be due to multifold reasons, including the mic. used, but it remains a perception. Later that evening I clearly heard that the applause on the prom. was clearer and cleaner, with greater stereo image positioning of claps.

    A few days later I installed an ATC SCA2 pre, and was astounded by the improvement in sound quality, which was far from slight, and manifest in all parts of the frequency band. The sibilants particularly are better.

    Most surprising to me is that the pips - yes the World at One pips, are audibly cleaner, and this when they are necessarily distorted because they are 1kHz sine waves which have been 'enveloped'.

    The figures on all of the four pieces of equipment are what I would have described as exemplary; the distortion on my old AVI S2000 pre was 0.0001%, and that on the SCA2 5dB worse at 0.00018%, but the latter sounds much better.

    The power amp. differences were similar, but less marked, and similarly both with very good figures.

    It is as though whilst there is an apparent convergance in technical specs. towards the exemplary, something else happens which is very much undefined by these, and which is also very disorientating. The change feels 'other worldly', and I am stunned.
    Last edited by Pharos; 16-09-2012 at 01:12 AM. Reason: Maths from manual wrong; 6 should be 5dB.

  19. #19
    Join Date
    May 2013
    Location
    UK
    Posts
    8

    Default Cost and sound quality in today's broadcasting

    Quote Originally Posted by A.S. View Post
    - What is the best delivery format for high-quality 'radio'? BBC HD stream - far better than DAB and obviously incomparably better (that is, closer to what the studio engineers hear over their monitors) than FM.
    Radio listeners can use either a Digital Terrestrial (Freeview) receiver or a Digital Satellite (Freesat, Sky) receiver to listen to MPEG2 radio streams which are of a higher bit rate than DAB. I find the encoding artefacts on some lower bit rate channels to be unacceptable on DAB, though fortunately the BBC at least tends to use relatively higher bit rates on DAB.

    It doesn't really matter to most people, but there is an additional encoding process applied to BBC FM radio feeds which is due to the fact that the audio is generally not delivered as baseband (ie. raw audio) at the transmitter sites. Most of the audio is delivered as NICAM encoded at the transmitter, before being decoded, and then modulated and radiated.

    My general opinion of audio standards in broadcasting: yes, it has declined. In some respects, there is relatively less money, and cuts often mean that one person has to do the job of two or three. For instance, some of the satellite news gathering trucks are sent out with a single person, expected to radiate a vision and sound carrier to satellite for live transmission, operate the camera and sound equipment, and coordinate the whole process to make sure they make it live on air! It's cheaper to do.

  20. #20
    Join Date
    Jan 2006
    Location
    South of England, UK
    Posts
    4,183

    Default BBC Lunchtime Concert, 10 June 2013

    I don't know if you heard the Lunchtime Concert today on BBC Radio 3 (Beethoven and Britten live from the Wigmore Hall), but the sound quality was absolutely dreadful. Gutless, colored, thin, distant, uninvolving. Perhaps yet another new low? The question we touched on here only recently was, in summary, 'what can we do to encourage youngsters to become interested in good (live) music?'. If this was my first experience, I'd turn my back on it forever. There was nothing whatever to hold ones interest because the sound was just so remote and unbalanced. Without adequate warmth in the sound, my long experience is that the listener cannot immerse himself/herself in the performance. It is, perhaps above all other parameters, the most vital to the 'being there' experience and something that Harbeths are renowned for. But even the M40.1s couldn't have made anything of this broadcast. Real pity: I wanted to hear the Britten.

    Was it my car speakers? Was it the Wigmore Hall, which I am not especially familiar with? Was the mic set-up done in rush? Was there a technical problem? I am well aware that the preferred BBC balance is more distant than typical commercial recordings, but why so coloured and distant? Speaking with no knowledge of the set-up, I was longing to drag the mics closer to the performers and/or to turn down the contribution of ambience mics and/or use some omnidirectional mics. What on earth were they monitoring on?

    Will be available here soon
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •