Joe's Dark Secret.

[Mark Hennessy]

Yes, the DTV services use higher bit rates, but sadly they still use Joint Stereo, which ruins the stereo image on any half-decent setup. Personally I find that pretty much as objectionable as the "roughness" that results from low bit rates. Only Radio 3 via DAB is discrete stereo AFAIK.

Back in 2006 the BBC installed newer more efficient coders in BH. Then they dropped the bit rates! After a listener campaign, they restored the bit rates (for the majority of time), but apparently put the old coders back in*.

* I can't name my source, or indeed verify this claim at this stage, but I certainly wouldn't have been surprised if they returned the new coders for a refund.

Although I am uncomfortable with people making claims like Jeffrey referenced, I would agree that low bit-rates are only part of the problem. Poor reception causing "bubbling mud" is what most people complain about, and the heavy dynamic range processing and poor quality control at the studio end of things is what offends me the most; and ironically, the increased transparency of DAB, even at low bit rates, makes this more obvious. Same problem with CD showing flaws in the master tapes that vinyl masked, which in part explains why a lot of people prefer vinyl, despite the unarguable flaws in the medium. Not to mention the differences in mastering, which people always seem to discount in the CD vs vinyl arguments. But I guess that's a separate thread...

Sadly these days, technical standards will always be second place to production values - that's just the politics of broadcasting. And production values aren't exactly universally high! Please do make the most of the BBC while we still have it :D

Oh, and check out R3 streamed at 320kb/s - and send lots of positive feedback to the BBC. This simple development signals a slight hope of reversing the current trend - the man behind it even got a internal award for his efforts (quite right too!). Let's do what we can to raise some momentum :D

Mark

[Joe]

The problem I've found with CDs are the things that were orginally on record and they've obviously used the same masters and the sound just seems very 'thin.' 'Born in the USA' is a prime example as my own CD copy of the LP seems much better than the proper CD.

'Never Mind the B*ll*cks' is just too quiet and that was supposed to be 'Digitally re-mastered.' I tried copying it and turning the level up but that just caused distortion so it's not just plain volume that it lacks.

You raise an obvious but no less valid point about comparing like with like as far as quality goes. My £20 MP3 player has more background noise than a valve radio but that isn't the coding's fault. Strangely the little five quid from Tesco one has far better sound quality. Luckily I'm not an audiophile and it's plenty good enough for me and far better than tapes of tapes of tapes of your pal's brother's cousin's record and the like that I grew up on!

It's nice to learn about the workings of these things so thanks for sharing your knowledge, Mark.

Cheers
- Joe

[big band heaven]

Interestingly, the digital remaster of the Beach Boys 20/20 album sounds very good. Nice crisp punchy sound which makes the original 60's vinyl copy I have sound quite flat in comparison. Curious. I suppose its all down to the sound re-engineering.

[tiv48]

ok here is a picture of what i use to compair the two systems, because i was begining to belive i had become a ludite ,so i decided to get other people round and do blind listeng tests, please note that the fm tuner is a buget nad 4020a and not the leak that i prefer,the dab ithink is in the same range, on radio 2 and radio 3 every one prefers fm.radio 4 it was about 50/50
the rest of the system is a beard valve preamp ,an icon audio 30watt valve amp feeding tanoy lancaster speakers
not shore what this proves . but if you are happy with what you have dont go and listen to some thing that may sound far better, or your ears will crave that you upgrade
rob t

[Mark Hennessy]

Interesting observations. Just in case it's not clear to all, "mastering" is what happens to the mix before it's committed to CD or vinyl. One of the jobs of the mastering engineer is to modify the recording to suite the limitations medium; arguably for CD, there's nothing or very little that needs to be done. But for vinyl, you have much less dynamic range and you have to be very careful to avoid producing levels that will overheat the cutter head or cause the needle to jump out of the groove on replay - in other words you have to limit the HF and LF energy. There are more subtle effects too, which means that you are limited with the bass end; you should put loud bass sounds in the centre of the image.

These limits are pretty rigid, but early on record companies discovered that making their records sound "louder" than the competition was advantageous; especially as a lot of reply was via jukeboxes with fixed volume settings. The Phil Spector Wall of Sound being an obvious example...

The most commonly used technique is to apply multiband compression to the final mix at the mastering stage to produce a version that is optimal for vinyl. And, as compression makes things sound louder, you can be forgiven for thinking that the vinyl version of an album has more bass or "punch" or whatever when you compare the vinyl to the CD.

In the earlier days of CD, most were produced more or less directly from the master tapes. So, lacking the processing that was done for the vinyl master, early CDs could sound slightly anaemic by comparison. Despite the fact you were hearing what was heard in the control room while the recording was originally mixed down, many preferred the "lo-fi" version that was committed to vinyl!

BTW, I've no problem with people preferring the sound of vinyl to CD; you can't argue with personal preference. But I always endeavour to explain that technically, vinyl simply isn't better than CD in any objective measure, and the reason most people prefer the sound is that they prefer the processing that's been added at the mastering stage - to overcome the shortcomings of vinyl. Ironically...

Personally, I get my kicks from knowing that I'm hearing something akin to the mix engineer. That's why I use studio monitors at home. Sometimes that's not good because monitors ruthlessly expose faults in bad recordings, but given a good production, the sound is sublime. By comparison, a lot of so-called "hi-fi" speakers present a much more "average" sound that flatters the poorer recordings while failing to do justice to the best. And I thought that "hi-fi" was meant to be about accuracy...

Having said that, we enjoy vinyl a lot, especially the kids (and their friends). There's something magic about playing old singles, despite the distortion and background noise. It's much more of an organic experience - and the kids love choosing the record, placing it on the multichanger and watching the needle drop. And of course, this tactile interaction with the hi-fi is part of the blend for those staunch pro-vinyl fans. And why not?

Back to CDs and mastering. These days, most CDs are compressed at the mastering stage to compete with other recordings. Given that 0dBFS is a fixed limit (ignoring reconstruction-filter created excursions beyond that), compression is the only way to make things sound louder. But, like any tool, compression can be used badly and it has ruined many a great recording in recent years. Just google "loudness war".

Many remastered recordings are compressed to give the illusion of a louder mix - but done well, this can be very effective. But overcook it and it's horrible. The thing is, if there are no quiet bits, how can you have loud? Google "Metallica Death Magnetic"...

Hope this hasn't strayed too far OT, but any discussion of audio quality inevitably leads to these fundamental principles.

Mark

[Mark Hennessy]

ok here is a picture of what i use to compair the two systems, because i was begining to belive i had become a ludite ,so i decided to get other people round and do blind listeng tests, please note that the fm tuner is a buget nad 4020a and not the leak that i prefer,the dab ithink is in the same range, on radio 2 and radio 3 every one prefers fm.radio 4 it was about 50/50
the rest of the system is a beard valve preamp ,an icon audio 30watt valve amp feeding tanoy lancaster speakers
not shore what this proves . but if you are happy with what you have dont go and listen to some thing that may sound far better, or your ears will crave that you upgrade
rob t

Hi Rob,

One of the difficulties with this sort of comparison is that the FM and DAB feeds are treated differently in BH basement. There are separate processors for each, and they are set up differently for each feed. Which means that this isn't a genuine test of the medium (DAB verses FM). It is, of course, a valid test of the BBC's DAB verses FM "offer", to use the jargon...

Mark

[tiv48]

my bigest problem is we are being spun a tale ,crystal clear sound for as little as £24 pounds,there are problems with portables for one the power consumption compaired to an fm set this is why they have tiny 1 watt amps and 2" non hifi speakers, who pays for the adverts? not the makers, some do soud ok ie pure roberts,ect but look at the price.the other bug bear i have is there are no longer simucast tv and radio for obvious reasons and soud out from a sky box or freview is just bad.nicam was imo better. i shall miss watching the proms ect whilst listening on high quality fm
rob t

[Joe]

Hope this hasn't strayed too far OT, but any discussion of audio quality inevitably leads to these fundamental principles.

We don't do OT here!

You're quite right about the CD versus vinyl argument. Like anything there are pros and cons for both and as Rob rightly says if you like it that's what matters.

Interesting you mentioning Phil Specor who always maintained that mono bet stereo.

I prefer CDs for other reasons like portability and being able to hop through to the tracks I want to hear. Besides that you can't pile a load of junk on the lid of a CD player. Perhaps I ought to get a radiogram with the deck in a cupboard, but I'd probably fill that up too.

I've also been interested to learn about MW being deliberately hobbled. I'd just assumed that there was a direct correlation between frequency and quality and had been surprised by how good that MW transmitter I made sounded.

Cheers
- Joe

[Steve_P]

The human ear can filter out most things. But it is an Analogue device. So Analogue problems can be effectively ignored by the human ear and, if unlike me you have one, the human brain.

This is why digital sound, unless well set up, will be more noticeable as a digital feed. The digital errors can be more noticeable. Same with DTV, as the eye and brain can find it easier to ignore analogue noise than digital drop-outs.

Basically, humans are analogue. Digital has to do more to keep up with this, and the bean counters make it harder still.

At least we don't get Aliasing. Much...

Cheers,

Steve P.

[tiv48]

which of corse explains listener fatigue when listening to cd and mp3
rob t