Physical Media (CD) audio quality notably better than Streaming

[Tjf120]

I'm doing some testing of my system. Using 2 songs/discs. Creep by Radiohead and Bohemian Rhapsody by queen (they have quiet & loud portions).

CD signal - Panasonic UB820 > Denon 4700 H (Pre Amp Mode) > Amp > Revel 328Be & SVS 3000 PB
Streaming signal - Apple TV, Apple Music Lossless > Denon 4700 H (Pre Amp) > Amp > Revel 32 Be & SVS 3000 PB

While playing physical media (CD), the sound quality is audibly better vs streaming. Using 'Pure Direct' on receiver for both signals, everything the same except cd player or streaming. One simple difference, I can literally feel the bass in my chest when playing CDs and moderately loud vols. Vols setting ~72 (of 99) on receiver, ~75-90 dB at the listening position on SPL. It's not even close, even my wife can hear (&feel) the difference of the CD vs streaming.

Why wouldn't a lossless streaming signal sound as good as physical media (with all the equipment staying the same)?

**Update - In theory the 'same' source material/master - ie Creep from Pablo Honey CD (same selected on streaming) and the Queen 2007 Platinum Collection Release**

 

[Chester]

Maybe they are the same album but mastered differently. Maybe one is louder than the other before it gets to your volume control.

 

[JustJones]

Is apple employing volume normalization? I think they call it sound check.

 

[Petrushka]

As others have pointed out, there are many possible reasons besides streaming itself.

 

[Digital_Thor]

I tried to play 3 versions at the same time, CD, streaming and YouTube. Streaming was suddenly worse, almost like YouTube. Then I double checked everything, and found out that my streamer had set some mp3-setting instead of sending out the full untouched signal. When set back to normal, the difference between CD and streaming disappeared.
I use tidal with picoreplayer on a pi3 with digi one HAT.
I know that mp3 can be really good, but even when I let some randomly set YouTube and streaming to two different inputs, I clearly hear bass being more defined and higher frequencies being more clear, and easily choose whatever input has the streaming/CD.

 

[Mort]

While playing physical media (CD), the sound quality is audibly better vs streaming.

Do you think you could tell the difference blind 19 out of 20 times?

 

[dan_uk]

I'm doing some testing of my system. Using 2 songs/discs. Creep by Radiohead and Bohemian Rhapsody by queen (they have quiet & loud portions).

CD signal - Panasonic UB820 > Denon 4700 H (Pre Amp Mode) > Amp > Revel 328Be & SVS 3000 PB
Streaming signal - Apple TV, Apple Music Lossless > Denon 4700 H (Pre Amp) > Amp > Revel 32 Be & SVS 3000 PB

While playing physical media (CD), the sound quality is audibly better vs streaming. Using 'Pure Direct' on receiver for both signals, everything the same except cd player or streaming. One simple difference, I can literally feel the bass in my chest when playing CDs and moderately loud vols. Vols setting ~72 (of 99) on receiver, ~85 dB at the listening position on SPL. It's not even close, even my wife can hear (&feel) the difference of the CD vs streaming.

Why wouldn't a lossless streaming signal sound as good as physical media (with all the equipment staying the same)?

**Update - In theory the 'same' source material/master - ie Creep from Pablo Honey CD (same selected on streaming) and the Queen 2007 Platinum Collection Release**

What about a FLAC of the albums vs physical CD?

 

[Robin L]

I use my CD player frequently, usually stream Tidal., sometimes You Tube. It all depends. A good mastering job sounds good because it's a good mastering job. And a louder signal will always seem better than a quieter signal. I just experienced this—was listening to a High-Rez Tidal version of Bob Weir's (RIP) "Ace" and decided to link "Cassidy" here in the celebrity RIP thread. Tidal's stream was from a 2022 remaster, I don't know the source for the You Tube stream, but the stereo spread narrowed and the level was significantly lower in level. Which is to say there are multiple reasons why one stream would sound different from another and that a stream might sound different from a CD. All things being equal, they should sound the same, but all things are not equal.

 

[RDoc]

I'm doing some testing of my system. Using 2 songs/discs. Creep by Radiohead and Bohemian Rhapsody by queen (they have quiet & loud portions).

CD signal - Panasonic UB820 > Denon 4700 H (Pre Amp Mode) > Amp > Revel 328Be & SVS 3000 PB
Streaming signal - Apple TV, Apple Music Lossless > Denon 4700 H (Pre Amp) > Amp > Revel 32 Be & SVS 3000 PB

While playing physical media (CD), the sound quality is audibly better vs streaming. Using 'Pure Direct' on receiver for both signals, everything the same except cd player or streaming. One simple difference, I can literally feel the bass in my chest when playing CDs and moderately loud vols. Vols setting ~72 (of 99) on receiver, ~85 dB at the listening position on SPL. It's not even close, even my wife can hear (&feel) the difference of the CD vs streaming.

Why wouldn't a lossless streaming signal sound as good as physical media (with all the equipment staying the same)?

**Update - In theory the 'same' source material/master - ie Creep from Pablo Honey CD (same selected on streaming) and the Queen 2007 Platinum Collection Release**

To compare sound, you really need to accurately get the volume level of the two signals the same, even very small differences are significant. If you notice that much of a difference in the bass, something is very different between the two sound streams.

 

[goat76]

I have recently analyzed a track from Tidal to the same track I've ripped from a CD (which I knew was the same mastered version), and the null test I did was dead silent. That means that as long as the track is the same version/master, it will sound the same, regardless of whether it's streamed from Tidal or if it is ripped from a CD.

The sound files sound the same and look the same, so Tidal doesn't mess with the sound at all. If you hear a difference, it's either a different mastered version, not the same loudness when comparing the tracks, or something else on your end.

The picture below shows the CD rip on top and the same track from Tidal, and as I said, when playing these tracks and phase shifting one or the other, it becomes dead silent.

 

[Mr. Swordfish]

As others have pointed out, there are many many things that can be done to the audio during the mastering process; if it's a different master, then it will sound different even if the encoding theoretically makes no difference.

I recently downloaded a digital copy of the early Elvis recordings compiled on The Sun Sessions and the digital version sounds quite different than the version I already had on vinyl. The reason as far as I can tell is that the vinyl issue has a lot more of that old-school tape-delay slapback echo that Sun Records were known for. I'm not sure whether additional echo was added for the LP release or whether they found some less-echoey original tape for the cd version.

EQ, compression, etc. can make more difference than the subtle differences between redbook CD, and 256k mp3.

 

[Mr. Swordfish]

What about a FLAC of the albums vs physical CD?

Redbook standard CD audio is 16bit linear PCM at 44.1khz sampling. FLAC is designed to produce the same string of ones and zeroes as would be read from the CD, so in theory it will sound exactly the same.

Start mucking around with EQ, compression, etc. i.e. things that are intended to make it sound different, and it will sound different.

 

[Somafunk]

I could try this with my apple SuperDrive but I’m lazy, can’t be arsed.

The past week I’ve been listening to a mix of stuff from an old hd I found in a drawer that has 90+ dj sets/mixes that I recorded from 2000 through to late 2000’s on my laptops at the time using the audio outs of the mixers we used, Bunch of stuff with bad mp3 compression through to decent vbr or 320kbps and sometimes bad clipping - at no point whilst listening very happily to the sets have I ever gave a thought to the audio quality or bit rate.

But streaming is just so easy so that’s a win from me compared to the hassle of cd’s.

 

[TurtlePaul]

Almost certainly volume normalization. Apple Music normalizes to -16 dB LUFS. This prevents volume differences between different tracks from different artists. If the CD is -14 dB LUFS - which isn’t even TOO compressed - then when you A/B the CD is 2 dB louder and therefore sounds fuller.

 

[Tjf120]

Yep, it’s some sort of volume normalization. To get the exact same SPL meter reading’s at the listening position, I was at 71.5 dB with the CD playback, and 77 dB with the streaming on the pre-amp. That was a ~90 dB peak at the ‘loud’ portions of the same song (range of 75 to 90 dB through the track).

Could feel the bass vibrating the couch slightly at that level. Tightened up how I was looking at the SPL reading’s (ie, same time on the track of the song) and mounted it on a tripod.