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Is lossy outdated in 2019 & onwards?

Soniclife

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Error spectrum. Most music has little or nothing below 30 hz and above 15 khz. Streaming with its codecs if subtracted from the original signal would have more and more annoying residue than FM.
How many stations are analogue only these days? The BBC was using something like 14 bit nicam* in their FM chain a while ago for all their stations, that may have improved.

* The FM sounds better than CD advocates were perplexed when they discovered that.
 

Blumlein 88

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How many stations are analogue only these days? The BBC was using something like 14 bit nicam* in their FM chain a while ago for all their stations, that may have improved.

* The FM sounds better than CD advocates were perplexed when they discovered that.
I don't know. All my FM tuners are analog so that is what I had in mind. Not digital FM.
 
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Yeah, I find good live acoustic music recordings typically have a noise floor around -60 to -80 dB; that's what digital VU meters read when playing the quiet parts between movements which is just recording the ambient room noise.

Some of these performances have actual music with PPP levels that get down to the ambient room noise level. Others don't. It would be nice to have a measurement that indicates the minimum level of actual music (call it something like "max dynamic range actually used") but it's hard to devise a way to measure that.

To me, incidental sounds like the musicians breathing or clothes rustling as they move is part of the performance, captured by the best recordings and enhances the realism of the experience.
Ahh live recordings:) a different world. Great artists captured in a great space:)
 

garbulky

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Yeah, I find good live acoustic music recordings typically have a noise floor around -60 to -80 dB; that's what digital VU meters read when playing the quiet parts between movements which is just recording the ambient room noise.

Some of these performances have actual music with PPP levels that get down to the ambient room noise level. Others don't. It would be nice to have a measurement that indicates the minimum level of actual music (call it something like "max dynamic range actually used") but it's hard to devise a way to measure that.

To me, incidental sounds like the musicians breathing or clothes rustling as they move is part of the performance, captured by the best recordings and enhances the realism of the experience.
What are PPP levels?
 

amirm

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I was driving my friend yesterday and he was telling me about a new radio station that he had discovered. When I asked him whether they stream it online he said: “But they broadcast it on FM and surely in terms of audio quality that is superior to any streaming!” I was skeptical about his claim but I didn't know the frequency range and throughput of a typical FM station signal, hence the question. FM signal attenuation aside, is there a way to compare the quality of CD vs FM in ideal conditions? Thanks!
Analog FM has far worse channel separation than any digital streaming. Soundstage is substantially limited in analog FM. And depending on quality of FM receiver, can suffer from terrible multi-path distortion.

Digital FM in US solves the channel separation issue and increases bandwidth so you get more highs too. Unfortunately the most commonly used channels are low bit rate (64 kpbs?) which also has to have forward error correction. This means actual bitrate is even lower, resulting in fair bit of compression artifacts. In balance it is better than analog FM due to lack of multipath but for someone like me who suffers from lossy compression artifacts, the experience can be a bit rough. Needless to say, its fidelity is definitely worse than streaming.

Bottom line, your friend is wrong. :)
 

MRC01

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... Digital FM ... In balance it is better than analog FM due to lack of multipath but for someone like me who suffers from lossy compression artifacts, the experience can be a bit rough. Needless to say, its fidelity is definitely worse than streaming.
Bottom line, your friend is wrong. :)
Amir: which sounds better to you overall: analog FM, or digital HD ? Assuming good clear reception for either.
To me, it goes either way depending on the station.
 

amirm

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Amir: which sounds better to you overall: analog FM, or digital HD ? Assuming good clear reception for either.
To me, it goes either way depending on the station.
Same here. When travelling far, I like HD FM better since reception is constant until it is lost.
 

DDF

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Don't listen to radio any more but the few times I have it on in the car I find the audio quality appalling.
I recall visiting the engineering area of (then) Toronto's #1 FM station, back before digital. A VU meter monitoring the direct feed to the transmitter was completely pinned, you could barely notice it move. The engineers told me that Program Directors insist on maximizing compression for that critical car audience, and to be heard above the other stations.
 

syn08

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Unfortunately the most commonly used channels are low bit rate (64 kpbs?) which also has to have forward error correction. This means actual bitrate is even lower, resulting in fair bit of compression artifacts. In balance it is better than analog FM due to lack of multipath but for someone like me who suffers from lossy compression artifacts, the experience can be a bit rough. Needless to say, its fidelity is definitely worse than streaming.
Digital radio doesn’t have to be that bad; most new digital systems (satellite radio being one) are implementing an advanced modulation schema like 8-16-24-QAM or PSM which allows multiple bits per symbol, effectively increasing the bit rate. That, and combined with Viterbi code, approaches the Shannon limit for a channel capacity. Today is a matter of a few chips and a few lines of software, almost trivial.
 

amirm

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Digital radio doesn’t have to be that bad; most new digital systems (satellite radio being one) are implementing an advanced modulation schema like 8-16-24-QAM or PSM which allows multiple bits per symbol, effectively increasing the bit rate. That, and combined with Viterbi code, approaches the Shannon limit for a channel capacity. Today is a matter of a few chips and a few lines of software, almost trivial.
You are speaking of the physical layer. At logical level, all that is available is 96 kbps. That can be used as a single channel using HE_AAC codec but it rarely is. Instead, the channel is subdivided as such depending on the station programming:

1566960697859.png


First line for example is two stations, each getting only 48 kbps!

At that rate, AAC codec severely limits audio bandwidth in order to keep compression artifacts in check. To compensate, a technology called Spectral Band Replication (SBR) is used to synthesize missing high frequencies. Modelling of the content is used as encoding time to provide hints to the decoder as to how to extend the bandwidth at playback time.

At first blush, SBR makes miraculous improvement compared to not using it. Without it, lack of high frequencies makes the sound quite dull. However, with a lot of content the extension of high frequencies can be grating and harsh.

Even at 64 kbps, SBR is needed to get to "CD" bandwidth as without it, the bandwidth likely will be 11 kHz.

With bandwidth being fixed with very low buffering opportunity, difficult parts of the content can get butched bad. Vocals often get impacted and sound bad to my ears especially in lower bandwidth channels.

All in all, it is a miracle that we can using advanced modulation cram so much data into the limited power and bandwidth we have. Fortunately mobile internet provides a great alternative. We have unlimited plan so I almost always am using that to stream high rate music and use FM broadcast for news and casual music listening.
 

syn08

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Are you describing some sort of digital FM standard in the US? In digital radio over satellite, all US providers (Dish Networks, DirecTv, etc...) are using 192Kbps AAC encoded streams. True, this is in the Ku band, hence the question about the standards.

Set aside the advanced modulation and Viterbi, they also use statististical multiplexing of the encoded MPEG2TS, which emulates almost real time a VBR streaming, allowing the total bandwidth required for say 10 digital channels running through the same encoder to be greatly reduced.
 

digicidal

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What is XM using? Because I can't even listen to it because it sounds so horrible... even 96kpbs mp3 sounds much better.
 

amirm

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Are you describing some sort of digital FM standard in the US?
Correct. It is the "HD Radio" standard for US terrestrial broadcast.
 

amirm

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What is XM using? Because I can't even listen to it because it sounds so horrible... even 96kpbs mp3 sounds much better.
It sounds horrible to me too. Typical of satellite transmission schemes, a single, 4 Mhz channel is multiplexed dynamically into the number of channels broadcast. Each channel can get from 4 to 64 kbits/sec dynamically. Likely the channels that are core programming get the most bitrate, not necessarily what needs it. I had heard that most common rate for music just 32 kbps. SBR is used together with preprocessing to make the content easier to encode. Great example of quantity over quality.
 

Julf

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Out of curiosity do you store your files in a lossy format? If so which one? Do you find it adequate for your use?
I store my music in lossless so that I can keep converting to suitable formats as needed. In the car and on the move I use mp3 (for compatibility reasons). I use mp3fs on linux that automatically mirrors the FLAC files as mp3.
 

Julf

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The digital world is all math. Everything done to the original wave file has an affect on the signal due to quantization or how the math is rounded. Even a simple level change has some effect. Bit depth minimizes this quantization effect. Most daws process at 32 bit depth with some plugins process at 64 bit.
They process at 32 or 64 bit floating point, mainly because that is the most efficient format for modern processors. 32 bit floating point only has 24 bit precision ("resolution").
 

Blumlein 88

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It sounds horrible to me too. Typical of satellite transmission schemes, a single, 4 Mhz channel is multiplexed dynamically into the number of channels broadcast. Each channel can get from 4 to 64 kbits/sec dynamically. Likely the channels that are core programming get the most bitrate, not necessarily what needs it. I had heard that most common rate for music just 32 kbps. SBR is used together with preprocessing to make the content easier to encode. Great example of quantity over quality.
I can't listen to XM. Even voice from talk shows gets under my skin.

An example of quantity eventually being at so low a quality it doesn't matter. I don't see how they stay in business. Yucky sound even for a few minutes. Pocket transistor radio AM from the 1960's blows it away in satisfaction for music listening.
 
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