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[arthur071169]

Hi all, I hope someone has been down this path and can assist.

I have my dac working in USB 2.0 mode (24/192) and it sound great.
What I would like however is for different files recorded at different bitrates to playback at differenet output rates to my dac.

EG,
I want anything less than 44,100 (IE lower quality MP3's) to play back at 44.100
anything 44,100 to playback at 88,200
anything at 48,000 to playback at 96,000
etc.
The thing is when I set the settings as required, every mp3 track plays to the dac as 88,200
96 khz plays back as 192 as expected, and flac plays back as 88,200 as expected.
it is almost as if all mp3s are being auto upscaled to 44,100 before playback and when sent to the dac it then performs the double again?

I am using my Dac in ASIO USB 2.0 mode.
Help???
thanks,
Arthur.

[JimH]

You can probably do what you want in MC's DSP Studio/Output Format.

[Vincent Kars]

Often people are confused by bit-rate and sample rate.
If audio is compressed (lossy or lossless) you will get a lower bit-rate (amount of data read in bits per second) simply because the file is smaller

All compressed audio will be decompressed at playback time .

E.g. a 320 kbs MP3 contains (most of the time) audio with a 44.1 kHz sample rate
At playback time you see a bit rate of 320 kbs and a sample rate of 44.1 kHz

Hope this helps

[connersw]

Just to clarify, as Vincent said, since almost all MP3s are compressed from CDs, they will almost always have a Sample Rate of 44.1kHz, regardless of Bitrate (320kbps, 128kbps, VBR, etc).  So when you see all MP3s played back at 88.2kHz, it is working the correct way for how you have set it up.

[arthur071169]

Thanks to Vincent and Connersw.
That helps.
It is very confusing to the relatively uninitiated as this would mean (in real world terms)...
All mp3's will effectively be presented as 44.1, therefore the option in JRiver MC for 'Less than 44,100 Hz' is 'mostly' redundant?

I previously thought this would have allowed me to leave poorly encoded (128, 192 etc) mp3's untouched and pass straight through. 
Upon hindsight this makes no sense as how would my DAC know what to do with it (aside from lowest common denominator?)

So to recap,
all CD's or CD based media rips (mp3 regardless of bitrate, all flac, or wav ripped from CD, etc) will always be 44,100?

I initially hated (very) the overly complex nature of Media Center 19 (I am an IT manager in a school so not frightened by software or hardware setups from 'scratch') but the feature that kept me going is the IOS remote (much nicer that the overly feature rich windows based interpretation) and having my ipad/iphone as an actual media device to listen on was a bonus. 

I am migrating away from my Sonos investments due to their refusal to accept change and support above 48. 
Are JRiver going to consider adopting the 'Wizard' setup idea in future for those who are getting confused - eg Myself? 
There are so many options and functions (having to enable DNLA was not the most obvious either!)

Once again, thanks for the answers.

Arthur.
 


 

[6233638]

"128k" or "192k" MP3 files are referring to the bit-rate in kilobits per second (kbps) which is an indicator of how compressed the file is.
 
"44.1kHz" "48kHz" etc. refers to the sample rate of the audio in kilohertz.

[Vincent Kars]

all CD's or CD based media rips (mp3 regardless of bitrate, all flac, or wav ripped from CD, etc) will always be 44,100?

Correct. This is what is called Redbook.
All standards by Sony/Philips for the optical disk are published with a different color.
Redbook says it is 2 channel audio with a 16 bit word and a 44.1 kHz sample rate.
If there is something different on an audio CD, it simply won't play.

Although rare, there are recordings with a lower bit rate than 44.1, so the option < 44.1 might be useful one day.

Personally, I wonder why you want to double each sample rate as depicted in your opening post.
I suggest to play everything at its native rate.
If the Dacmagic is an upsampling DAC, try the upsampling to 24/192 in JRiver.
Maybe it does something sound quality wise.

[mwillems]

Although rare, there are recordings with a lower bit rate than 44.1, so the option < 44.1 might be useful one day.

I've encountered a number of audio files that had sampling rates below 44.1, but they are pretty rare. The two main categories I've seen were music and sound files from older PC games (when games had to fit on floppy disks), and some older recordings of over-the-air radio theater broadcasts on various webarchive services (the shows were originally broadcast with limited audio bandwidth).  

I remember the first time I tried to use JRiver to play back some audio files from the mid-90's PC game Space Hulk (trying to place a tune running through my head), and was told my DAC couldn't play that sample rate!  When I looked at the file's sample rate I was amazed to see it was only 18 or 21KHz or something like that.  So I had to set JRiver to upsample everything <44.1 to 44.1.

Can't imagine too many people find themselves sifting through old floppy disks to listen to 8-bit music from 20 years ago, but it happened to me  

[arthur071169]

No longer confused!
Incidentally, I took the device home last night. I was testing it without speakers (!) on my bench at work to see how JRiver played with it.  Quite nicely it seems.
So knowing how to configure JRiver I took it home, and installed same and started listening to music.
I thought to test it at the same input>output  and it sounded great.
Then I tried 44.1 > 88.2 and it sounded slightly better (but the difference was barely noticeable.  I may have been convincing myself.)
Then I tried it at 192.
!!!!!
All of a sudden the stereo image of the vocal, and the instruments were almost living in my music room.  The stereo positioning was most certainly improved.  To make sure I was not 'convincing myself' once again, I went back to 88.2
The sound was great, but the positioning of instruments, and the vocal (front and center in this particular song) were sort of there but not as well defined.
Back to 192 and 'POP', everything was almost 'holographic' or 3d in its positioning in and around my speakers.
I am now sold 100% that the benefits of upsampling make sense, at least with my equipment and the appropriate source material which in my case is everything FLAC'd from original CD's. 
I have some darn fine floor standers with positional tweeters, and previoulsy I struggled to make the stereo image work.
Last night I sat down and could not decide what to try next, such was my excitement.

A VERY happy customer (Cambridge Audio DacMagic 100).
I will be registering JRiver just prior to my trial expiring.

Thanks for the assist guys.
Arthur.