# Hi-Res Audio Question



## Guest002 (Feb 19, 2020)

I don't usually buy Hi-Res music formats because my ears aren't nearly young enough to hear the difference from standard lossless CD Rips.

But a question for those of you who do use hi-res formats: are the recordings considerably quieter than their standard CD cousins?

I ask because I recently purchased an SACD download in ISO format, and I can extract that and turn it into a set of standard 2-channel FLACs that I can play -but the volume is waaaay down, to the point that sometimes its barely audible at all. So then I purchased a standard 16-bit 44.1KHz set of FLACs of the same recording (presumably of the CD mastering, rather than the SACD one) and it sounded perfectly normal: volume level entirely reasonable.

I'm wondering whether by extracting only 2 stereo channels from a 5:1 mastering, I'm losing signal that would normally make a proper surround-sound setup produce the 'correct' volume. Or whether it could just be that SACDs are mastered at a quieter volume, expecting to be played on hifi that can be turned up to 11?!

As it is, I'm having to extract FLACs from the ISO, normalize their volume (i.e., boosting it slightly) and then I'm fine... but I don't like homebrew tinkering with the audio signal like that.

So just wondering: general feature of SACD, or my conversion to 2-channel FLAC is causing the problem? Or are SACDs mastered at a different volume level as compared to standard CDs?


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## Phil loves classical (Feb 8, 2017)

I have these hybrid SACD/CD's. The levels are the same or similar. I believe in your case the mastering was at a different volume.


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## Guest002 (Feb 19, 2020)

Phil loves classical said:


> I have these hybrid SACD/CD's. The levels are the same or similar. I believe in your case the mastering was at a different volume.


OK. But -er, in pursuit of "research" on the matter- I, ahem, obtained a number of SACD ISOs subsequent to my first legitimate go, and all of them are quieter than their "plain CD" counterparts, usually quite significantly. I can't guarantee the masterings were identical in all cases, but the CD artwork seemed identical, etc. so they were as identical as I could possibly get them.

So whilst I'm quite prepared to accept that they are mastered at a lower volume... why would that ever have been done? Are SACD users content to crank the volume knob to the right? Or is it that because of the wider dynamic range of SACDs, they _have_ to be mastered lower so as to stop clipping?

But good to know that in your experience the volume difference is not 'normal'.


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## Simon Moon (Oct 10, 2013)

AbsolutelyBaching said:


> I don't usually buy Hi-Res music formats because my ears aren't nearly young enough to hear the difference from standard lossless CD Rips.


Not to start an entire 'hi-res DSD vs redbook' debate, but many, if not most of the advantages of DSD (SACD) over 16/44.1 is audible even with aging ears.

Most of what I hear in DSD over 16/44.1, are mostly in the (for me, very noticeable) improvement in things like: ambience retrieval, soundstage width and depth, and the 3d quality of the image of the instruments within the soundstage*.

These types of attributes do not seem to be diminished by age, unlike frequency response.



> But a question for those of you who do use hi-res formats: are the recordings considerably quieter than their standard CD cousins?
> 
> I ask because I recently purchased an SACD download in ISO format, and I can extract that and turn it into a set of standard 2-channel FLACs that I can play -but the volume is waaaay down, to the point that sometimes its barely audible at all. So then I purchased a standard 16-bit 44.1KHz set of FLACs of the same recording (presumably of the CD mastering, rather than the SACD one) and it sounded perfectly normal: volume level entirely reasonable.


*DSD is recorded at 6db lower than PCM to prevent overloading the delta-sigma modulator. While not quite an industry standard, it is pretty widely followed.*

*Due to 16/44.1 inability to reproduce low enough inter-aural time differences for what the human auditory system is capable of detecting.


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## Guest002 (Feb 19, 2020)

Simon Moon said:


> Not to start an entire 'hi-res DSD vs redbook' debate, but many, if not most of the advantages of DSD (SACD) over 16/44.1 is audible even with aging ears.


Yeah, let's not start that debate, since I'm not prepared to do battle on the Nyquist theorem. 



Simon Moon said:


> Most of what I hear in DSD over 16/44.1, are mostly in the (for me, very noticeable) improvement in things like: ambience retrieval, soundstage width and depth, and the 3d quality of the image of the instruments within the soundstage*.
> 
> These types of attributes do not seem to be diminished by age, unlike frequency response.


I now see why you think Hi-Res sounds better when its basic stereo audio signal cannot mathematically be better than Redbook: more channels will definitely be "different". But as I say, I really don't want to get into that debate. It's like when one says 'you can't hear better than redbook' and people answer, 'Ah, well, my SACD is a remastering...', at which point we're comparing apples and bananas! I've never doubted that half my CDs will sound better with a more modern mastering, in other words!

(Also: I only have two speakers. More channels doesn't help me! Oh, and I have another half that won't invest... so upgrading is a non-starter, too!)



Simon Moon said:


> *DSD is recorded at 6db lower than PCM to prevent overloading the delta-sigma modulator. While not quite an industry standard, it is pretty widely followed.*


Ah. Now, see, that's a nugget of information I very much appreciate! Do you have a citation for it please? Not that I doubt it, but if I'm going to explain a need to re-normalize extracted SACD audio, I need to be able to cite something authorative!



Simon Moon said:


> *Due to 16/44.1 inability to reproduce low enough inter-aural time differences for what the human auditory system is capable of detecting.


Your bold statement is brilliant. It's exactly what I think I'm hearing. I would be very grateful for a citation to... anywhere, really!

Many thanks for your answer. (At least I know I'm not going mad!! Well, not much, anyway!)


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## Simon Moon (Oct 10, 2013)

AbsolutelyBaching said:


> h. Now, see, that's a nugget of information I very much appreciate! Do you have a citation for it please? Not that I doubt it, but if I'm going to explain a need to re-normalize extracted SACD audio, I need to be able to cite something authorative!
> 
> Your bold statement is brilliant. It's exactly what I think I'm hearing. I would be very grateful for a citation to... anywhere, really!
> 
> Many thanks for your answer. (At least I know I'm not going mad!! Well, not much, anyway!)


Not sure how authoritative you might consider this, but there is a product called "DSD Master" for MAC that has the following to say in their manual:

https://dsdmaster.blogspot.com/p/user-manual.html?m=1

Conversion Options

DSD files are supposed to follow the SACD protocol which requires that the music signals be encoded 6dB down from maximum theoretically encodable (0dB) level. This is because DSD encoders have the potential to go unstable under certain conditions, and if the signal level is kept at least 6dB down from the 0dB level this problem is effectively eliminated. However, the onset of instability is graceful, and many DSD recordings can be found to contain passages which the recording engineer has allowed to exceed this -6dB limit without any obvious sonic penalty. Others, however, are conservatively encoded, and never actually approach the -6dB limit.

Compare this to PCM, which also has a maximum encodable limit of 0dB, but can make use of the full dynamic range, all the way up to 0dB. However, any attempt to drive the input signal above 0dB is not treated gracefully and will be abruptly clipped. It is therefore very important that PCM recordings should not be encoded with levels which exceed 0dB. However, if the peak levels are encoded too conservatively, this results in a failure to take full advantage of the dynamic headroom offered by the format.

The theoretically 'correct' procedure when converting DSD to PCM is to apply 6dB of gain to compensate for the 'SACD 6dB Level'. This is quick and easy to do, but will result in clipping whenever the DSD recording was driven into its 'graceful' overload state. Soft clipping is routinely employed to alleviate this, but at the cost of undesirable dynamic compression. The ideal solution is to read through the file before conversion, and establish in advance what the exact correct gain setting should be, so that the peak of the DSD recording is encoded precisely at the 0dB level of the PCM format. The downside of this approach is that it is slower. This process is called 'Normalizing' and is the approach taken by DSD Master.

ROON also has a default setting in their product to compensate for the -6DB. See the bottom of this image:


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## Simon Moon (Oct 10, 2013)

JRiver also defaults to a 6DB boost during DSD to PCM conversion in their software.


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## MatthewWeflen (Jan 24, 2019)

I have many different formats on my player, including DSD and FLAC files that were originally released on SACD. 

DSD files that were originally released on SACD do seems to be somewhat quieter (I have a Colin Davis/LSO Sibelius cycle that I need to crank up to 70 when my normal listening level is 50). 

Pentatone DSD files are quieter. Pentatone FLAC files originally released on SACD seem to have had their gain boosted when they were converted to FLAC.

But other DSD files I have (such as Michael Jackson's Thriller from Sony) are definitely being packaged at the same "boosted" volume level as my FLAC and MP3 files.

So, long story short, it makes sense that ISO rips from SACD discs would be quieter. Different companies seem to do different things with respect to selling those audio files as downloads.


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## SONNET CLV (May 31, 2014)

AbsolutelyBaching said:


> I don't usually buy Hi-Res music formats because my ears aren't nearly young enough to hear the difference from standard lossless CD Rips.
> 
> But a question for those of you who do use hi-res formats: are the recordings considerably quieter than their standard CD cousins?
> 
> ...


I'll admit I don't know an ISO from a FLAC (or is it a FLAC from an ISO), but I will make a suggestion. Maybe it's time to crank up that volume control knob. No more being polite with the decibel level. Worst that can happen is neighbors will complain. But they tend to complain about everything anyhow, so ....

Best wishes enjoying your music.


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## MatthewWeflen (Jan 24, 2019)

SONNET CLV said:


> I'll admit I don't know an ISO from a FLAC (or is it a FLAC from an ISO), but I will make a suggestion. Maybe it's time to crank up that volume control knob. No more being polite with the decibel level. Worst that can happen is neighbors will complain. But they tend to complain about everything anyhow, so ....
> 
> Best wishes enjoying your music.


An ISO file is just an copy in binary code of everything on a given disc. FLAC, MP3, DSD, WAV and so on are ways of packaging that information as audio for a player to read. Some are more compressed than others, some delete information while others do not, and they can have different bitrates.

https://www.headphonesty.com/2020/04/best-audio-file-formats-explained/


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## Guest002 (Feb 19, 2020)

Simon Moon said:


> Not sure how authoritative you might consider this, but there is a product called "DSD Master" for MAC that has the following to say in their manual:
> 
> https://dsdmaster.blogspot.com/p/user-manual.html?m=1
> 
> ...


Excellent citations and very authoritative for my purposes, so very many thanks!


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