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More => Old Versions => JRiver Media Center 19 for Windows => Topic started by: SteveR on July 19, 2013, 09:20:58 pm

Title: Audio improvements
Post by: SteveR on July 19, 2013, 09:20:58 pm
I skipped MC18 as they were no audiophile benefits allegedly and none I could hear. Are they any in 19?
Title: Re: Audio improvements
Post by: JimH on July 19, 2013, 10:10:20 pm
You missed a lot.
Title: Re: Audio improvements
Post by: astromo on July 19, 2013, 10:30:58 pm
I skipped MC18 as they were no audiophile benefits allegedly and none I could hear. Are they any in 19?
You missed a lot.

Dunno mate. Probably depends on the specifics of your setup:
http://yabb.jriver.com/interact/index.php?topic=81980.0 (http://yabb.jriver.com/interact/index.php?topic=81980.0)
Title: Re: Audio improvements
Post by: Matt on July 19, 2013, 10:34:30 pm
You could read more here:
http://yabb.jriver.com/interact/index.php?topic=81891.0

But if you didn't like MC18, you probably won't like MC19 either.  Sorry.
Title: Re: Audio improvements
Post by: SteveR on July 20, 2013, 05:57:40 am
 I didn't say anything about not liking MC18!!! I think MC17 is fantastic, and that followed 14 and 15 versions that I also bought: OK not your biggest fanboi perhaps, but certainly a disciple....

I understood that there were no fundamental changes in 17->18 that improved the accuracy of the bit stream from a laptop into an external DAC (async USB ASIO mode), and this was advice I got from these very forums when I posed the question at the release of MC18.

So, all I'd like to know (having read the MC19 link to the significant features) is there any improvements to the accuracy of the audio stream? I can figure out the other improvements and make a value judgement, and probably will upgrade for the improvements in UI etc. I've read through this thread and cannot find the answer. No, I'm not stupid, I just don't have a background in software design so a less patronising response would be really welcome.

Thanks.
Title: Re: Audio improvements
Post by: JimH on July 20, 2013, 07:07:23 am
I understood that there were no fundamental changes in 17->18 that improved the accuracy of the bit stream from a laptop into an external DAC (async USB ASIO mode), and this was advice I got from these very forums when I posed the question at the release of MC18.
This will probably be locked again, but it isn't possible to improve the accuracy of an already perfect bit stream.  Really. 

I am not trying to be patronizing, and I realize that some audiophiles believe otherwise, but ones and zeroes really are ones and zeroes.

MC18 is still a better product for audiophile use.  MC19 will be too.
Title: Re: Audio improvements
Post by: Matt on July 20, 2013, 07:52:56 am
http://wiki.jriver.com/index.php/Bit-perfect_Audio
Title: Re: Audio improvements
Post by: SteveR on July 20, 2013, 04:06:39 pm
This will probably be locked again, but it isn't possible to improve the accuracy of an already perfect bit stream.  Really. 

I am not trying to be patronizing, and I realize that some audiophiles believe otherwise, but ones and zeroes really are ones and zeroes.

MC18 is still a better product for audiophile use.  MC19 will be too.

Thanks Jim, a lot more helpful - I really wasn't trying to troll another cable debate believe me.

I don't want to argue about 1s and 0s either. I get the bit perfect bit too, and thanks for the link Matt - I missed that last time round. Most of my info source is from the well tempered computer site, which pretty much says the same thing. I'm more concerned about the control over the soundcard, since occasionally spotify will play whilst MC17 is also playing - in other words does MC19 control the windows environment "better"?

Thanks for your patience.
Title: Re: Audio improvements
Post by: kstuart on July 20, 2013, 11:25:47 pm
The term "bit perfect" is a marketing term, and doesn't really refer to anything in real world audio.

There is currently no such thing as "digital audio", in the sense that speakers are still analog devices driven by analog power amplifiers.

So, audio is produced by voltages, not bits.

Personal computers have a huge number of different voltages in a huge number of circuits.

MC18 is an excellent tool in the quest to improve playback in such a challenging environment.
Title: Re: Audio improvements
Post by: 6233638 on July 20, 2013, 11:37:43 pm
The term "bit perfect" is a marketing term, and doesn't really refer to anything in real world audio.
There is currently no such thing as "digital audio", in the sense that speakers are still analog devices driven by analog power amplifiers.
So, audio is produced by voltages, not bits.
Personal computers have a huge number of different voltages in a huge number of circuits.
MC18 is an excellent tool in the quest to improve playback in such a challenging environment.
The signal between your computer and the DAC is digital though, and anything that happens once the signal reaches the DAC is no longer up to the computer.

"Bit-perfect" means that the decoded bits in the file, is exactly what the computer is sending to the DAC.
Once you are sending a bit-perfect signal from the computer to the DAC, there is no further room for improvement unless you are wanting to process the audio to make it sound better in your setup. (e.g. room correction, headphone virtualization etc.)
Title: Re: Audio improvements
Post by: kstuart on July 21, 2013, 01:08:44 am
A number wrote: " "Bit-perfect" means that the decoded bits in the file, is exactly what the computer is sending to the DAC.  Once you are sending a bit-perfect signal from the computer to the DAC, there is no further room for improvement..."

But audio does not work that way.   The bits also have to be processed in time.   Any test that shows you whether the DAC receives the same bits as in the file, merely records the bits.   The process of recording and playback is not in real-time, so you do not detect any problems in timing.

Timing is everything in audio.


Title: Re: Audio improvements
Post by: JimH on July 21, 2013, 06:33:11 am
You're talking about two different things.

1.  Delivery of digital data to the DAC

2.  Conversion of the data to analog.

Bit perfect means that #1 works correctly.  Nothing has changed the original data before it has been received.  Timing here isn't a factor, other than to make sure the right sequence of 1's and 0's is reliably delivered.  The data flowsirregularly and is buffered by the DAC.  Timing of the PC, etc. just doesn't have any other role.

Your DAC may be great at #2 or bad at it.  Timing here matters, but is not affected by the source of the data (the PC in this case).

So, bit perfect is not marketing speak.  It's real, as 6233638 says.

Timing is a DAC issue if the DAC is outside the PC.

And, if the DAC is onboard, timing is still usually not an issue.  Even cheap or old computers are surprisingly good at timing.  Their clocks are many orders of magnitude higher than we can hear.

I'll let this thread go a little longer and then lock it.
Title: Re: Audio improvements
Post by: kstuart on July 21, 2013, 11:28:56 am
"Timing here isn't a factor, other than to make sure the right sequence of 1's and 0's is reliably delivered.  The data flows irregularly and is buffered by the DAC.  Timing of the PC, etc. just doesn't have any other role."

There is not enough space here for pages of DAC design information, and it would just duplicate what is elsewhere on the web.

Suffice to say, that the two people I know who disagree with the quote above, are both DAC manufacturers.


Title: Re: Audio improvements
Post by: 6233638 on July 21, 2013, 12:20:59 pm
"Timing here isn't a factor, other than to make sure the right sequence of 1's and 0's is reliably delivered.  The data flows irregularly and is buffered by the DAC.  Timing of the PC, etc. just doesn't have any other role."

There is not enough space here for pages of DAC design information, and it would just duplicate what is elsewhere on the web.

Suffice to say, that the two people I know who disagree with the quote above, are both DAC manufacturers.
Could you post something in the sound hardware/DAC section about this? I'm interested in hearing what these manufacturers are saying.

That said, I don't see how it's up to the player to control "timing" of the USB signal from the computer at all - surely the OS/Driver controls that, and it's the player's job to keep that buffer full.
I don't see how timing matters at all when you are sending it to a modern DAC design that is - for all intents and purposes - jitter immune.
Title: Re: Audio improvements
Post by: JimH on July 21, 2013, 01:29:30 pm
An outboard DAC has a clock of its own, and that's the only clock that matters.  The PC's clock can't affect it.
Title: Re: Audio improvements
Post by: dean70 on July 21, 2013, 04:51:44 pm
Doing my own testing has shown enabling HPET timer in the OS which increases the Performance Counter resolution from 3.5mhz to 14.3mhz has shown a positive effect in the high freqency smoothness in MC. There is a utility WinTimerTest which shows the relationship between Performance Counter and Clock Tick & they sync up much closer with HPET enabled.

Comparing to 2 other "niche" lighweight players has shown they were mostly immune to the HPET timer changes, but it did bring MC to the same level of high freqency smoothness as the others.

This was done with A/B testing using headphones through Realtek onboard audio. It also has had a positive effect on my AMD HTPC system (which the BIOS doesnt have the option to disable HPET, so could not repeat all the tests).

The only downside is that it makes the PC more laggy for general use, so I would only recommend this setting on a dedicated HTPC.
Title: Re: Audio improvements
Post by: rayooo on July 21, 2013, 06:02:09 pm
I must say thanks for this! new information for a change!  I'm so very tired of these bits ain't bits discussions these days over and over and over...with same old stories over and over....  thanks JimH for not locking this...yet :)  I would have! :)  but now my interest is piqued. :)  Thank you Dean70 :)

I've noticed in most new motherboards the option for enable HPET in Bios, it seems to be enabled by default.
I've never experimented with enabling it in Win(7) apparently there is a CMD Line statement to enable it, disable it, correct?

The following statement is my own conjecture, just to get your comments:
With an on-board "sound card", utilizing motherboard and OS resources, it could be expected to benefit from higher accuracy clocks/timing/etc..which seems to be what you are seeing...  interesting....

However, running an external DAC, via an Asynchronous USB interface (thus by definition immune to upstream timing instabilities) would not benefit as did the motherboard-embedded audio system. ???

Doing my own testing has shown enabling HPET timer in the OS which increases the Performance Counter resolution from 3.5mhz to 14.3mhz has shown a positive effect in the high freqency smoothness in MC. There is a utility WinTimerTest which shows the relationship between Performance Counter and Clock Tick & they sync up much closer with HPET enabled.

Comparing to 2 other "niche" lighweight players has shown they were mostly immune to the HPET timer changes, but it did bring MC to the same level of high freqency smoothness as the others.

This was done with A/B testing using headphones through Realtek onboard audio. It also has had a positive effect on my AMD HTPC system (which the BIOS doesnt have the option to disable HPET, so could not repeat all the tests).

The only downside is that it makes the PC more laggy for general use, so I would only recommend this setting on a dedicated HTPC.