Tír Na HiFi

sbgk wrote:

Aleg wrote:

sbgk wrote:he was right though, 3.81 onwards are a bit easier to listen to

No, he was not right, he just has a different opinion because of his personal preferences.

Gordon you work in IT, and know about architecture of systems.

What would you say is the function of a software player in the complete playback chain from digital file to speakers?
What is its purpose in reproducing music?

I'm very much interested in your answer on this!

Cheers

Aleg

the software player is trying to copy data from source to device while producing the lowest electrical noise possible. To do that the aim is to have the data in L1 cache just as the cpu needs it otherwise costly stalls occur which can cause 10s of cycles to occur as the data is fetched from ram. There are various prefetching mechanisms, hardware dcu prefetch seems to produce most detail, but is also harsh to listen to, other mechanisms produce a softer sound. Hardware prefetch does produce more electrical noise and I believe this causes the harshness, I also read the hw prefetch only kicks in for the second cache line, when I prefetch the first cacheline the sound is softer. So I wouldn't be surprised if the perfect player produces a detailed soft sound.

uploaded 3.83 which has the first cacheline fetch as well as hw prefetch.

Gordon

Thank you for answering my question.
The effect of electrical noise on SQ might not be determined by other means than listening? Therefore being subjective and system dependent or would there be an objective messurement possible?

BTW, the 3.83 sounds very nice again. Only slightly less detail in low bass compared to 3.14 (which might be noise? ;-))
A very pleasurable release.

Thank you

Cheers

Aleg

Aleg wrote: Gordon

Thank you for answering my question.
The effect of electrical noise on SQ might not be determined by other means than listening? Therefore being subjective and system dependent or would there be an objective messurement possible?

Measuring noise while processing dynamic signals such as music, is a very difficult thing to do - how do you differentiate what is the signal from what is noise? One very simple approach could be done using a multitone signal as the source but there are no dynamic shifts involved - it's a static tone so is it going to expose the noise inducing conditions?

Another approach is to subtract the input signal from the output signal & what you have leftover is all the non-signal stuff but this is fraught with issues.

jkeny wrote:

Aleg wrote: Gordon

Thank you for answering my question.
The effect of electrical noise on SQ might not be determined by other means than listening? Therefore being subjective and system dependent or would there be an objective messurement possible?

Measuring noise while processing dynamic signals such as music, is a very difficult thing to do - how do you differentiate what is the signal from what is noise? One very simple approach could be done using a multitone signal as the source but there are no dynamic shifts involved - it's a static tone so is it going to expose the noise inducing conditions?

Another approach is to subtract the input signal from the output signal & what you have leftover is all the non-signal stuff but this is fraught with issues.

Might noise not be in a different frequency range than the regular music signal or digital signal?
So more easily to detect in the frequency domain?

Aleg wrote: Might noise not be in a different frequency range than the regular music signal or digital signal?
So more easily to detect in the frequency domain?

Well noise, by definition, is a broadband signal occurring at all frequencies.
If it occurs in specific isolated frequencies it is known as distortion
Audio test results usually show distortion in the audio band , not outside the audio band.
I have seen some test results on DACs showing a modulation of their noise floor which is claimed is audible - see ESS video for instance (used to be on Youtube but I can't find it now)

Found it http://www.youtube.com/watch?feature=pl ... CkyrDIGzOE
It's an interesting presentation but skip to 33 mins in for the relevant bit about noise modulation

jkeny wrote:

Aleg wrote: Might noise not be in a different frequency range than the regular music signal or digital signal?
So more easily to detect in the frequency domain?

Well noise, by definition, is a broadband signal occurring at all frequencies.
If it occurs in specific isolated frequencies it is known as distortion
Audio test results usually show distortion in the audio band , not outside the audio band.
I have seen some test results on DACs showing a modulation of their noise floor which is claimed is audible - see ESS video for instance (used to be on Youtube but I can't find it now)

Found it http://www.youtube.com/watch?feature=pl ... CkyrDIGzOE
It's an interesting presentation but skip to 33 mins in for the relevant bit about noise modulation

John

Very interesting presentation, managed to complete it to the end.
Thank you for that reference.

Cheers

Aleg

Aleg wrote:Hardware prefetching is implemented by your processor and will be different depending on which processor you use. Most recent Intel processors have several different hardware prefetchers. The Core™ i7 processor and Xeon® 5500 series processors, for example, have some prefetchers that bring data into the L1 cache and some that bring data into the L2. There are also different algorithms – some monitor data access patterns for a particular cache and then try to predict what addresses will be needed in the future. Others use simpler algorithms, such as fetching 2 adjacent cache lines. The pattern matching and detection algorithms used by the set of hardware prefetchers on the Core i7 and Xeon 5500 is improved from our last generation, and we continue to optimize these algorithms with each new processor architecture.
Aleg

That's got me interested in more exploration Aleg and may help explain some of the unusual behaviour I have seen in recent years which never made sense to me.
If there are algorithms working on data load to cache based on files submitted then it might explain or not!! why I have seen my audio PC improve playback and eventually stop breaking into white noise the more I listen.

Starting back in the JPlay days I found some times when I loaded a new version of JPlay I would get the PC breaking into white noise after half of a track, try again and I might get to a full track and eventually after several hours or by the next day it would have settled down and behave normally.

Might go some way towards explaining all this weirdness with MQN changes where tracks would not play or break up on certain versions....food for thought for those who might have proper knowledge on the subject and help me move away from the "ghost in the machine" theory :-))

That is interesting, Pearse & something to store in the back of the mind.
It does logically raise the concern about just how much affect an application can have on the sound when little control can be exercised over these various background tasks?
MQN has proven that there is a great deal that can be achieved at the application level - it just makes me wonder how much more might be possible if this control could be achieved?

jkeny wrote:...
It does logically raise the concern about just how much affect an application can have on the sound when little control can be exercised over these various background tasks?
....

software player isn't supposed to negate the noise/jitter injected by background tasks.

if people don't deal with them, hehe, good luck... buy a better DAC, and hope that your luck will change

if you have a choice bwtween a and b, you always choose the better one. audio cannot get that much worse even with all the junks exist in windows

3.83 seems leanless. sounds like 'water'.

not forward sounding. seems like a good layback presentation.

texture ok. bass ok.

this version is worth a try.

UPDATE1
listening a bit more after dinner...

the sound is very liquid also very solid also very shinny. texture enough. vocal seems like one of the best.

stage is bigger than usually. especially width.

even PC speakers can produce $$$ sound? hehe



UPDATE2
testing bass....
not enough vibration for rock! energy is superb!



UPDATE3
seems like very good density sound for piano.

this 3.83 is my new favorite


UPDATE4
weight for piano notes is slightly over.

jesuscheung wrote:

jkeny wrote:...
It does logically raise the concern about just how much affect an application can have on the sound when little control can be exercised over these various background tasks?
....

software player isn't supposed to negate the noise/jitter injected by background tasks.

if people don't deal with them, hehe, good luck... buy a better DAC, and hope that your luck will change

if you have a choice bwtween a and b, you always choose the better one. audio cannot get that much worse even with all the junks exist in windows

I'm not sure what point you're making, JC?
My point was that the MQN application audibly improves playback despite the limitations of the general purpose Windows OS - how much better could it sound if using an OS designed with audio in mind? Maybe it wouldn't sound any better but it makes me wonder.

Anyway, this is probably OT ?