Tidal Lossless Streaming

[zilch0md]

Mike, thanks for the explanation , but I am a little bit confused.  Hopefully i learn something.  If i play a file from an X5 DAP via digital coax out to my DAC, and the same file from another DAP to the same DAC, are you saying the should sound at the same SPL. Does the GAIN variations means reducing bit depth.  I think there are other variable that could account for the difference. sorry just playing devils advocate but seems like apples an oranges comparison. Just because the file is the same resolution if they come from different sources the volume could vary.  lol not sure. I am sure there has to be other methods of testing resolution besides spl variation. good discussion though. 
Ismael

In response to the bolded portion of the quote... Yes, if the DAC > amp > headphone components remain constant, there should be no change in volume when switching between SPDIF sources using the same file. I'm selecting the same Artist/Album/Song in Tidal HiFi as I have in 44/16 WAV format, but I am consistently hearing a lower volume when streaming the allegedly identical file from Tidal HiFi.

If Tidal has reduced the bit depth, the volume would be reduced. What other variables could account for the difference in volume when the DAC > amp > headphone chain is a constant?

As the article at the link I provided explains, reducing the volume in software (digitally, instead of with an analog attenuator) is accomplished by reducing bit depth. And given Tidal's obvious bandwidth limitations, one way to reduce the amount of data being streamed would be to reduce the bit depth. Thus, I can imagine they have an incentive to do so, but I'm only conjecturing in the absence of any other reasonable explanation for why I'm hearing reduced volume coming from Tidal HiFI's 44/16 tracks in each of two entirely different A/B tests. (See my earlier post, above.)

Mike

 

[Maelob]

I understand the whole concept of digital attenuation and you might be right about TIDAL, but I still disagree with your assumption that all SPDIF outs from different sources should sound that same without variation. You are assuming that bits are bits that different transports will output the digital information the same and that there should be no difference in gain or spl level, and I disagree with that's assumption. and I am not a technical guy, but for example I read that jitter can affect the sound, etc etc. Again you are assuming all digital outputs will output that data perfectly and I am not sure that's the case. Have you tested your assumption with an A/B test using different sources/transport? . For example take the same file and use different DAPs. Ill bet they will have sound slightly different. Each transport could have variation in the way that data is transferred thru the digital output. . Same way you can compare the same file streamed via digital outputs of different brand of streamers, lets say a SONOS digital out vs Auralic Vega, Blue Sound, Sony, or any high end streamer and Ill bet you will have some variations.

 

[Zoom25]

I understand the whole concept of digital attenuation and you might be right about TIDAL, but I still disagree with your assumption that all SPDIF outs from different sources should sound that same without variation. You are assuming that bits are bits that different transports will output the digital information the same and that there should be no difference in gain or spl level, and I disagree with that's assumption. and I am not a technical guy, but for example I read that jitter can affect the sound, etc etc. Again you are assuming all digital outputs will output that data perfectly and I am not sure that's the case. Have you tested your assumption with an A/B test using different sources/transport? . For example take the same file and use different DAPs. Ill bet they will have sound slightly different. Each transport could have variation in the way that data is transferred thru the digital output. . Same way you can compare the same file streamed via digital outputs of different brand of streamers, lets say a SONOS digital out vs Auralic Vega, Blue Sound, Sony, or any high end streamer and Ill bet you will have some variations.

I agree with your disagreement. For example, sending optical out from my TV to Emotiva DC-1 vs. PS3 to Emotiva DC-1 yields different results aside from jitter. For one, I have to turn the volume higher through my TV to reach the same volume. I also found it true with my Marantz and Philips CD players when using their digital out. I'm not attenuating the digital out in anyway.
 
On the other hand with all my studio gear via AES, all their output volume is same for each source file. I guess they have it standardized.

 

[stuartmc]

This has me really puzzled. I agree with you Mike on the effect of bit depth, but I'm thinking that there must be other factors in play that can affect perceived loudness. I'm running Tidal on a Xiaomi Mipad and its volume buttons definitely work. Surely it is not lowering volume by reducing bit depth. My DAC also has a digital volume control with set steps that incrementally reduce volume. Since voltage amplitude is both encoded in the data stream and can also be externally increased or decreased across the board, it begs the question as to whether all hardware has a uniform zero point for amplitude. I would think that it does, but hey, you never know. I'm sure that one of our electrical/digital gurus here on head-fi could easily clear this up for the technically challenged, like me.

Bottom line for me is that the Tidal feed is extremely close to what I hear from my tricked out Rega CD transport and that is much better than I expected.

 

[zilch0md]

Hey Stuart,

My observations exclude any adjustments of any volume controls, digital or analog.

Take any combination of DAC > amp > headphone with the analog volume control set to a comfortable SPL.

Now don't touch the volume control again.

Supply the DAC with a "real" 44/16 file of your choice via Coaxial, Optical, or USB input.

Now, using the same input to the DAC, play Tidal HiFI's version of that same track.

The volume will be lower when the digital signal is received from HiFI. Why?

I've reproduced this with two completely DAC > amp > headphone chains, as follows:

Tidal HiFi > iPad 3 > Pure i-20 Coaxial Out > Metrum Octave MkII > Metrum Aurix > HD800
vs.
44/16 WAV > FiiO X5 Coaxial Out > Metrum Octave MkII > Metrum Aurix > HD800

And...

44/16 WAV > Windows 7 > Foobar 2000 > USB > CEntrance DACmini CX > LCD-2 rev.1
vs.
Tidal HiFi > Windows 7 > USB > CEntrance DACmini CX > LCD-2 rev.1

I'm still open to the possibility that it's just a coincidence that Tidal HiFi's files reproduce at a lower SPL in both of these comparisons.

In other words, it's possible that in the first comparison, the iPad 3 or Pure i-20 dock is somehow causing a loss of SPL at the headphones in its handling of the SPDIF data. And It's possible that in the second comparison, the Tidal HiFi app is somehow causing a loss of SPL at the headphones in its handling of the data.

Mike

 

[stuartmc]

Mike, I feel your pain brother. This kind of stuff can be frustrating, if not maddening.  I decided to run a similar comparison with my gear to see if the Tidal feed produced a lower volume.  The consistent part of my chain is the Gustard X12 DAC > Gustard H10 > HE-560's.   I used a very familiar track from Holly Cole's "Temptation" that I happened to have on CD, a 44/16 flac file and also on Tidal. The variable source components were the Rega Apollo R playing CD into the X12 coax input, the Hidizs AP100 dap playing the flac file into the AES input, and my Xiaomi Mipad streaming Tidal (through a Gustard U12 usb interface) into the I2S input. The X12 DAC makes for easy comparisons because  the front panel button cycles though AES, I2S and Coax in that order.  So, I cued up the Holly Cole track on each source device ( it wasn't easy to get them all to start at the same time) and I sat back and did the 'ole one, two, three button push to cycle through the sources.
 
I found the volume to be very close between all three. I tried to do it blind by cycling very quickly so I forgot which input was in play.  Here is what I came up with -  The source with the lowest volume was the Hidizs AP100 playing the flac file, next came the Tidal feed and the loudest was the Apollo R playing the CD.  I would put this at close to the 1db threshold for hearing a difference in sound between the three. Maybe at most a  1.5 db difference between the Hidizs as the lowest and the Apollo R as the highest. In my test, the Tidal stream is clearly not the lowest volume and it certainly is much less than 1.5 db off of the loudest.

 

[zilch0md]

Thanks for all that effort Stuart.

Is there any way you could come into the DAC on the same input (with both Tidal and the CD coming in on the Coaxial input - one at a time, of course)?

Update: I'd like to withdraw that request. It's not worth any more of your time.

When it's all said and done I'm still concerned that after volume matching, Tidal HiFi via Coaxial input still sounds flat or compressed compared to the "real" 44/16 files into Coaxial.

I'll have to defocus my attentions for awhile and revisit this later - with volume matching.

Thanks!

 

[stuartmc]

No problem Mike. In the spirit of good methodology, I just switched the two into the coaxial input on the DAC. This time I decided not to trust my ears and used my trusty db meter with average and peak readings.... and the results are..... Drum roll....

Exactly the same average and peak readings!!

I did it a few times to be sure and it was bang on each time. The difference I heard before was most likely a product of the DAC input and not the source. It's late so I didn't use the db meter to check the various inputs, but I probably will tomorrow.

 

[stuartmc]

I think I can say rather conclusively that Tidal is not lowering the volume through reduced bit depth or otherwise.

 

[zilch0md]

Thanks Stuart!  
 
When I had repeated my initial observation in an entirely different hardware comparison, the coincidence was overwhelming, but in the end, too small a sampling to reach any conclusions.  Thanks for all your effort.
 
Going with your conlcusion that Tidal HiFi's files  (after decompression from FLAC format) are identical to my 44/16 WAV files, it's obvious that my source hardware (two instances) is somehow causing the reduction in SPL - despite the fact that it's just sending digital data via Coaxial or USB output to the DACs.
 
Mike

 

[Maelob]

Probably a good topic for another thread, but there is long running thread on Computer Audiophile about bits and digital data transmission. Very interesting stuff,

http://www.computeraudiophile.com/f8-general-forum/bits-aint-bits-modest-proposal-23202/\

 

[zilch0md]

Probably a good topic for another thread, but there is long running thread on Computer Audiophile about bits and digital data transmission. Very interesting stuff,

http://www.computeraudiophile.com/f8-general-forum/bits-aint-bits-modest-proposal-23202/\

http://www.computeraudiophile.com/f8-general-forum/bits-aint-bits-modest-proposal-23202/

Thanks!

 

[Moosi]

Just found a diamond album from Tidal. Billy Joel's Greenvale New York live album remastered 1977. New York state of Mind... eargasm cause his voice in his 30s was more raw and just rips the song in this album. EDIT: nvm. this WHOLE album is pure gold

 

[zilch0md]

  Just found a diamond album from Tidal. Billy Joel's Greenvale New York live album remastered 1977. New York state of Mind... eargasm cause his voice in his 30s was more raw and just rips the song in this album. EDIT: nvm. this WHOLE album is pure gold

 
In the U.S., this album is not available on Tidal HiFi, so far as I can tell - I've searched every way I can imagine...
 

 

[Baroninkjet]

it isn't on Spotify in the US either.