Audio Compression on Classic FM.

[trsomian]

I keep hearing the level of background noise varying on Classic FM during pieces of music; it was particularly bad yesterday evening during the broadcast of the previous evening's "live" concert. I assume this is due to over enthusiastic use of a compressor to reduce the dynamic range of the broadcast. I was listening on VHF analogue, not digital or on line.

Has anyone else noticed this?

[Hartley118]

Classic FM is pretty good for its intended purpose - for listening in the car or in other high background noise environments.

For serious hi-fi listening at home, I've always found it a sheer frustration because its enormous compression saps the life out of the music.

I'm afraid it is what it is.

Martin

[paulsherwin]

As Martin says, the audio processing on CFM is optimised for people listening in cars or on kitchen radios. The hifi audience is relatively small and of little interest to their advertisers.

[Andrew2]

I'd agree with Martin & Paul. It's much better than R3 for noisy places at it keeps the level up. Not very pleasant for 'serious' listening due to the obvious compression.
Radio 3 in the car is terrible as the dynamic range allows the quiet bits to sink into the surrounding. Speech on R3 can be very frustrating as the level often gets very low when they have guests so you have to whack up the volume to hear what is being said. Then you change stations and get your ears blown off.....

[mhennessy]

I don't know if this is still the case - I haven't checked recently - but their DAB feeds were unprocessed.

This had an unfortunate side-effect - it offered a clearer window into their workflows, and - to pick just one example - you could clearly hear that they were peak-level normalising all their audio on a track by track basis. That's the usual practice for non-classical radio, but for classical it's a bad idea. You won't notice it at all on FM, but on DAB you get jumps in level between the end of one movement and the start of the next (on the rare occasions when CFM play more than one movement of a piece, of course).

Having noticed this, I searched around and found a document that confirmed what I'd heard. From a quick search, it appears to be no longer on-line, so I've attached a copy here.

As I say, I don't know if this is still the case as I took the DAB radio out of my hi-fi system many years ago. They have refurbed their studios since this PDF was written, but I haven't seen any detailed technical information yet.

[Nickthedentist]

I find even non-serious listening on a portable set is a horrible experience with CFM. It just sounds "wrong", a bit like a Musicassette played without the Dolby B decoding switched on.

[Graham G3ZVT]

Originally Posted by trsomian

I keep hearing the level of background noise varying on Classic FM during pieces of music; it was particularly bad yesterday evening during the broadcast of the previous evening's "live" concert. I assume this is due to over enthusiastic use of a compressor to reduce the dynamic range of the broadcast. I was listening on VHF analogue, not digital or on line.

Has anyone else noticed this?

Just remember that CFM is a Global station. If you think Classic FM is over compressed, try listening to their other brands like Smooth and Heart!

Unfortunately for me that's what SWMBO likes to listen to in the car, I can cope with their playlists, but I find the constant pumping of the volume to strip out any vestige of dynamic range thoroughly fatiguing.

I emailed a complaint to Global about this a few years ago, and guess what?
They didn't reply.

[G8HQP Dave]

CFM is fine for listening in the car, but if you actually like classical music then avoid it at home. If you listen carefully then even in a car you can hear the limiters clipping off the high bits, while the compressor deals with the low bits.

[paulsherwin]

I am actually impressed by how good CFM sounds in its intended listening environment. Sucking the dynamic range out of classical music without it sounding dreadful is quite a technical challenge.

[stevehertz]

In many ways I'm as critical as anyone wrt the amount of compression and the like that stations apply to broadcasts. But sometimes, for me personally, I question why everything has to be 'so perfect' and just get on with listening to the music or show. It's a similar thing with my hifi; do I sit in a chair in that 'perfect stereo' postion and listen to it? Hardly ever, I'm normally walking about doing things with the music as a nice backdrop. Does it detract from my enjoyment? no it doesn't. That doesn't mean to say that I don't try to optimise my radio reception - clearly from posts on here - I do! But sometimes I feel 'you' just have to let the 'c**p' fly over your head and just enjoy what you hear, warts and all. There's so much going on in the world today that detract from the likes of 'us lot on here'. In addition to the above, there's the demise of AM, there's the (eventual) risk of losing FM, poor quality hifi systems and speakers, irrepairable equipment, more and more new 'vintage style' components no longer being made, SMPS hash everywhere, and so on. A lot of this we can do nothing about, you'd go mad if you let it all bother you. I'm not disagreeing with the sentiment of the thread in any way, just my own take on it, how I handle it.

['LIVEWIRE?']

Steve, I agree with much, if not all, of what you say. I listen to Classic FM from time to time, usually on my almost 20 year old Sony HiFi System, and a pair of Sharp 3-way speakers which are O.K., at least to my 75 year old ears, but not ultra Hi-Fi. I sometimes also listen on portable radios. Some people, to my way of thinking feel that the medium is more important than the message, or, to put it another way, treat their equipment as an end in itself, rather than a means to an end. This isn't to say that we shouldn't look for/listen to decent quality sound, but that we should all remember what we bought our radios & stereos for in the first place. Like you, too, I don't sit at the apex of a triangle formed by the two speakers an a chair, but tend to move around when listening to anything.

[G8HQP Dave]

I don't set out to listen to CFM's equipment, but they make it unavoidable. Anyway, it makes a pleasant background noise on a long journey. At home their habit of playing only one movement from a symphony is enough to stop me listening. It is like going to an art gallery whch only displays one corner of each picture.

['LIVEWIRE?']

Dave, you do know about the 'Full Works Concert', every weekday evening between 8 & 10PM (BST)? As it's name implies, that program does play full length works. E'G, yesterday evening's 'F.W.Concert' featured, among other things, Beethoven's Symphony #8 and Haydn's 104th. Symphony, in recordings conducted by Herbert von Karajan. Their other programming, to which, from time to time, I enjoy listening, features mainly short works, and/or excerpts from longer ones. No doubt this is to encourage listeners to go out and buy (or download) the complete work concerned.

[Nuvistor]

I do like Clsssic FM and Jazz FM, I get far more enjoyment from those than the BBC radio network.
Just my preference.

[stevehertz]

But Jazz FM is DAB? Anyway, I like it too, it's my favourite station and the main reason why I recently bought a tuner with DAB+.

[Graham G3ZVT]

Originally Posted by stevehertz

But Jazz FM is DAB? Anyway, I like it too, it's my favourite station and the main reason why I recently bought a tuner with DAB+.

It's "Jazz FM Stereo". The "Stereo" is worth emphasizing, because on their first foray onto DAB they were in "Glorious Mono".

Since the relaunch they have been quite listenable.

[G6Tanuki]

I don't have any issues with the audio processing on Classic FM, with one exception[1].

Indeed, I prefer it to the radio3 experience where they seem to have an obsession with broadcasting unnecesarily long periods of silence [like for 20-30 seconds either side of playing a track] and often really-low deviation for some music - both of which often leave me wondering if there's been an unscheduled interruption to the feed!

[1] their speech feeds for some of their DJs are sometimes horribly clipped/compressed, it's almost like they're still using 64Kbit ISDN for an uplink from a 'home studio'. That might have been OK a couple of decades back for a live-from-the-frontline news report but it just doesn't meet expectations for current mainstream programming.

[lesmw0sec]

I don't mind the quality of CFM too much, but as soon as the adverts start I lose interest and switch off. Same with what passes for television these days!

[Nuvistor]

I don’t notice the adverts on CFM, on the other hand TV adverts are very annoying, perhaps why I watch little live TV.

[stevehertz]

Originally Posted by Nuvistor

I don’t notice the adverts on CFM, on the other hand TV adverts are very annoying, perhaps why I watch little live TV.

I often dream of inventing a 'black box' that would automatically turn down the sound as soon as adverts appear, reverting to normal when your programme resumes. It would display stunning country scenes and aerial landscapes accompanied by great music. Dream on. Anyway, I make do with pressing the mute button and keeping one eye on the tele while I read or use my tablet for five minutes. Some adverts - and the people in them - get right up my nose!