Dynamic Range Compression/Fader Fiddling on iPlayer/Sounds

[Bryn]

Unless we are talking about different things I thought the maximum permitted level employed by Uk broadcasters was +8dBu - which is 6 on a PPM ....

I was taking 0dB as the saturation point where clipping kicks in with digital audio and distortion increases sharply with analogue. If you use something like get_iPlayer to capture the HD Sound stream you will find the peak level generally tends to top out approaching -6dB. I was not referring to balanced versus unbalanced analogue (+4dB versus -10dB).

[Ein Heldenleben]

I was taking 0dB as the saturation point where clipping kicks in with digital audio and distortion increases sharply with analogue. If you use something like get_iPlayer to capture the HD Sound stream you will find the peak level generally tends to top out approaching -6dB. I was not referring to balanced versus unbalanced analogue (+4dB versus -10dB).

You might find this interesting. Looks like dB’s are going the way of handloom weaving ..

http://downloads.bbc.co.uk/radio/commissioning/TechnicalSpecificationRadio.pdf

There’s also a really interesting technical brief in sound mixing for telly...

[Bryn]

You might find this interesting. Looks like dB’s are going the way of handloom weaving ..

http://downloads.bbc.co.uk/radio/commissioning/TechnicalSpecificationRadio.pdf

There’s also a really interesting technical brief in sound mixing for telly...

The closing paragraph of 3.6.5 is of relevance to the remit of this forum:

A notable exception to the above is Radio 3 digital. This has no dynamics processing applied to its output. To remove the possibility of clipping, a protection limiter prevents peaks exceeding -2dBFS from reaching the inputs to the emission encoders. Whilst this 2dB headroom is less than on our other services, the nature of Radio 3’s output is such that the average peak level is significantly lower.The extended working range is only used to accommodate exceptional transients such as those on musical crescendos during live concerts.

[Ein Heldenleben]

The closing paragraph of 3.6.5 is of relevance to the remit of this forum:

Yep it also means that when I listen on digital I am forever adjusting the volume control on my amp ...which is why , despite its other flaws , I prefer FM...

[Bryn]

Yep it also means that when I listen on digital I am forever adjusting the volume control on my amp ...which is why , despite its other flaws , I prefer FM...

I am fortunate in having generally quiet neighbours and low traffic noise. I, therefore, do not share your need to adjust levels during digital listening. I have pretty decent FM reception here, despite perching and pecking birds having dislodged and broken off the reflector of my FM Yagi. I have not bothered to clamber up to the chimney stack to replace it since FM's days are numbered and I simply do not use it except very rarely, preferring the dynamic range of DAB/Freeview, its lower tonal fidelity notwithstanding. Most of my Radio 3 listening, though, is to the HD Sound Internet facility (on-demand, rather than in real-time).

[jayne lee wilson]

Yep it also means that when I listen on digital I am forever adjusting the volume control on my amp ...which is why , despite its other flaws , I prefer FM...

No surprise that its the opposite for me of course - with the web stream I can usually just set the volume level and leave it, (always remembering to check the online level is set to 11 - Spinal Tap has a lot to answer for).

I went a long way with FM - finally an 8-element Triax aerial, latterly 7.5 after a gale loosened and a Magpie pinched. So quieting was always achieved, even off a briefly owned Leak Troughline/Valve Decoder which needed 4 mV! I still use the Magnum Dynalab for Radio 4 (or for comparisons....).

During the 2005 and 2006 Proms with the lovely Magnum in place, compression became so prevalent on the live relays I found myself turning pps down and ffs up..... a reluctant human decompressor.

This, during a performance of Turangalila.... well that couldn't go on could it? Having already abandoned DAB (the Arcam Alpha 10 ended up in Mum's bedroom - she couldn't hear the HF distortion...), I gave up on Radio 3 Concerts after that until the 192 kbps aac stream began in 2009. I read about it in the tech section of the Guardian, then rushed into town the same day to buy a Cambridge DacMagic from Richer Sounds, and by midnight was experiencing le grand rapprochement, swooning to a performance of Stravinsky's Orpheus off iplayer, with the BBCSSO and Volkov....

My beloved Proms were back! I was starry-eyed for days.....

[johnb]

Yep it also means that when I listen on digital I am forever adjusting the volume control on my amp ...which is why , despite its other flaws , I prefer FM...

Out of curiosity - how do you cope with CDs? (The dynamic range of CDs is at least as wide as iPlayer/Sounds and can be significantly wider.)

[johnb]

As far as FM vs DAB vs iPlayer/Sounds is concerned I gave up on FM (Sugden, Meridian, Magnum tuners) almost a decade ago because I found the compression very frustrating indeed. If I set the volume for the quiet passages the climaxes were weak and anemic, and if I set the volume for the climaxes the soft passages boomed out. Not only that but Optimod really mangles the relative dynamics. So, with all its drawbacks I preferred listening to DAB (at 192 kbps true stereo). Of course the 320kbps iPlayer/Sounds stream knocks the socks off both FM and DAB/Freeview.

Out of curiosity I've compared the Prokofiev 5 from the 320 kbps Listen Again stream with both the 1985 Neeme Jarvi recording and the more recent Jansons/RCO live. (I know, I know - it's just displacement activity to avoid working on the house.)

The R3 Prokofiev stacks up pretty well, all things considered (though some of the Jansons' quiet passages are somewhat softer).

                                                      R3         Jarvi        Jansons
1st mvmt overall                                     -22 dB      -20 dB         -23 dB   (RMS)   
3rd mvmt overall                                     -26 dB      -24 dB         -27 dB   (RMS)
3rd mvmt quiet bit: 3 secs before 1st clar' entry    -37 dB      -40 dB         -47 dB   (RMS)        
3rd mvmt quiet bit: 3 secs after 1st clar' entry     -38 dB      -41 dB         -40 dB   (RMS)

R3 Prokofiev Symphony No 5 normalized to -0.40 dB in order to make the comparisons valid.

(With the 1st and 3rd movement "overall" figures - the larger the negative, the more it indicates a wider dynamic range.)

[Ein Heldenleben]

Out of curiosity - how do you cope with CDs? (The dynamic range of CDs is at least as wide as iPlayer/Sounds and can be significantly wider.)

To be honest live listening on Radio 3 displaces CD listening by a ratio of about 50 to 1 . You would be surprised at the lack of dynamic range on some CD’s. I have to watch sound levels because of tinnitus and because of that I very rarely listen on headphones. I don’t want to start any hares racing but I prefer the sound of FM live relays and indeed the HD prom relays of a few years back to CD’s and iPlayer. I don’t know why but I do - perhaps I just like hiss and a bit of compression! There is something about digital which is just too clean and clinical - though obviously CDs played on Radio 3 will be digital most of the way to the FM transmitter as will those Proms relays . I think I’m a bit like the guitarists who prefer Marshall Amps , the rock engineers who will only work on Neve desks and the millennials who spend a fortune on vinyls.
I also prefer live performances to recordings - a very large percentage of CDs I’ve bought I’ve only played a few times. I just like the idea that anything can happen...and to answer your question I am also doing a lot of overriding when I listen to CD’s ..

[Ein Heldenleben]

For those who wish to revisit the iPlayer vs FM discussion or for those who simply like good Bruckner performances there is a fine Bruckner 8 performance on now given by Donald Runnicles and the BBC SSO. Evident compression on the blaze ups but heigh ho ....

[Bryn]

. . . Evident compression on the blaze ups but heigh ho ....

On FM, HD Sound or both?

I note from the BBCSSO site (though not the Radio 3 listing) that it's the 1890 edition as edited by Nowak. The Radio 3 listing merely mentions the year.

[Ein Heldenleben]

On Fm - superb performance: really playing out of their skins . He is such a good conductor...I’m not following with score so can’t confirm edition.

[Another Howard]

Just discovered and joined this forum. Hello. Great to know that others care about their music dynamics, too! There are difficult choices, having seen that vivid comparison trace by johnb between FM and other. I do prefer the FM texture to grainy DAB, but share others' frustration with FM's squashed peaks. Working range was about 20 dB on the Bruch concerto with BBC Phil today: same spec as 1950's AM!

[Ein Heldenleben]

Just discovered and joined this forum. Hello. Great to know that others care about their music dynamics, too! There are difficult choices, having seen that vivid comparison trace by johnb between FM and other. I do prefer the FM texture to grainy DAB, but share others' frustration with FM's squashed peaks. Working range was about 20 dB on the Bruch concerto with BBC Phil today: same spec as 1950's AM!

Welcome to the forum . Good to hear from a fellow “ anti-compressioner”. There should be something like a 40db range on R3 FM . But there is something funny going on . I have had a very poor FM signal in the last few days - so much so that I’ve gone over to Sounds. I wonder whether poor atmospheric conditions are affecting FM reception and they are upping compression on FM?

[jayne lee wilson]

Just discovered and joined this forum. Hello. Great to know that others care about their music dynamics, too! There are difficult choices, having seen that vivid comparison trace by johnb between FM and other. I do prefer the FM texture to grainy DAB, but share others' frustration with FM's squashed peaks. Working range was about 20 dB on the Bruch concerto with BBC Phil today: same spec as 1950's AM!

Hi Howard..... how do you feel about the 320kbps aac feed on Sounds? It is well ahead of the others technically - and audibly....

No obvious FM reception problems today with the lunchtime concert or the current Liszt relay..... but there's a rather important football match on soon so I can't listen extensively to offer a subjective DR view....
(7.5 element Triax aerial aimed at Holme Moss (60km distant). It was an 8-element but Magpies removed a gale-weakened part of it)...

I used to communicate regularly with BBC Engineering about this in the 1990s. One producer, mistakenly thinking I expected CD-style dbs from FM (I didn't even own a player) told me sternly that the max DR on FM was 30db. Around the same time, Reg Williamson in the HIFiNews showed that it could have a workable DR of 50db+.....

But thanks to auto-Optimod, it must be a few years since that was ever possible, yet alone approached. Shame because, at least with a large aluminium sculpture on the roof, FM always had great potential and a wonderful design tradition especially in Japan, UK and USA.......