IPB

Welcome Guest ( Log In | Register )

4 Pages V   1 2 3 > »   
Reply to this topicStart new topic
If the output is digital does the player make any difference to the so
db579
post Jul 31 2012, 00:21
Post #1





Group: Members
Posts: 30
Joined: 16-August 11
Member No.: 93077



I'm wondering whether if you had two media playing pieces of hardware outputting digital music would the quality of the device make any difference? For example say you had a cheap-to-mid range android phone or mp3 player playing a flac file and outputting over HDMI to a receiver, and a higher spec digital media player like say the Olive 06HD playing the same flac file output over HDMI to a receiver would you hear/should there theoretically even be any difference in audio quality?

Thanks
Go to the top of the page
+Quote Post
xnor
post Jul 31 2012, 01:05
Post #2





Group: Developer
Posts: 379
Joined: 29-April 11
From: Austria
Member No.: 90198



I'd say that if you stay in the digital domain and don't do any digital signal processing and jitter doesn't matter then the quality of the device doesn't matter either.
Go to the top of the page
+Quote Post
db579
post Jul 31 2012, 01:13
Post #3





Group: Members
Posts: 30
Joined: 16-August 11
Member No.: 93077



Wouldn't jitter occur in the DAC process if at all rather than the output? I assume I'm wrong but why? Would this affect the audible sound?
Go to the top of the page
+Quote Post
xnor
post Jul 31 2012, 01:18
Post #4





Group: Developer
Posts: 379
Joined: 29-April 11
From: Austria
Member No.: 90198



I think with HDMI it's entirely in the 'hands' of the receiver.
Go to the top of the page
+Quote Post
db579
post Jul 31 2012, 01:50
Post #5





Group: Members
Posts: 30
Joined: 16-August 11
Member No.: 93077



Same thing for digital optical?
Go to the top of the page
+Quote Post
hlloyge
post Jul 31 2012, 07:33
Post #6





Group: Members
Posts: 689
Joined: 10-January 06
From: Zagreb
Member No.: 27018



I think it's the same with all modern devices and all modern digital connections, coax, optical, hdmi. Receiving device does buffering and re-clocking the incoming signal, so jitter is practically non-existent.
Go to the top of the page
+Quote Post
probedb
post Jul 31 2012, 08:15
Post #7





Group: Members
Posts: 1121
Joined: 6-September 04
Member No.: 16817



Plus from reading around here, if you can actually hear jitter something is very seriously wrong with the device.
Go to the top of the page
+Quote Post
db579
post Jul 31 2012, 13:56
Post #8





Group: Members
Posts: 30
Joined: 16-August 11
Member No.: 93077



So with that in mind if you wanted portable audiophile sound quality, all you'd need is any flac or wav player (quality not particularly important) with a digital out, good headphones and a good portable DAC? Does such a DAC exist? How do they compare to AV receivers?
Go to the top of the page
+Quote Post
Nessuno
post Jul 31 2012, 14:09
Post #9





Group: Members
Posts: 422
Joined: 16-December 10
From: Palermo
Member No.: 86562



QUOTE (db579 @ Jul 31 2012, 14:56) *
if you wanted portable audiophile sound quality, all you'd need is any flac or wav player

No need for lossless codec, actually, if SQ is the target. High bitrate (i.e. transparent) lossy will suffice (and this could sometimes require lower hardware specs for the player).

This post has been edited by Nessuno: Jul 31 2012, 14:12


--------------------
... I live by long distance.
Go to the top of the page
+Quote Post
Kohlrabi
post Jul 31 2012, 14:14
Post #10





Group: Super Moderator
Posts: 953
Joined: 12-March 05
From: Kiel, Germany
Member No.: 20561



QUOTE (db579 @ Jul 31 2012, 14:56) *
So with that in mind if you wanted portable audiophile sound quality, all you'd need is any flac or wav player (quality not particularly important) with a digital out, good headphones and a good portable DAC? Does such a DAC exist? How do they compare to AV receivers?
"Audiophile" audio quality is more a question of skewed perception than hardware. I found most of the things you mention pretty irrelevant for portable audio. Well encoded lossy audio on hardware like the Sansa Clip+ with good headphones is good enough from my experience. Why would you need digital out in a portable device?

This post has been edited by Kohlrabi: Jul 31 2012, 14:14


--------------------
Audiophiles live in constant fear of jitter.
Go to the top of the page
+Quote Post
skamp
post Jul 31 2012, 14:21
Post #11





Group: Developer
Posts: 1343
Joined: 4-May 04
From: France
Member No.: 13875



QUOTE (db579 @ Jul 31 2012, 14:56) *
So with that in mind if you wanted portable audiophile sound quality


Just get a Sansa Clip+ or an iPod (and Rockbox it).


--------------------
caudec.net
Go to the top of the page
+Quote Post
greynol
post Jul 31 2012, 15:30
Post #12





Group: Super Moderator
Posts: 10000
Joined: 1-April 04
From: San Francisco
Member No.: 13167



QUOTE (db579 @ Jul 31 2012, 05:56) *
a good portable DAC? Does such a DAC exist?
Yes, and it can be found in the portable media player.

QUOTE
How do they compare to AV receivers?
Short of any objective listening tests proving otherwise, they are every bit as good.

I don't see how adding rockbox to an iPod changes its intrinsic sound quality. While someone may be inclined to talk about the snazzy eq or some other feature, the topic is about hardware; and since the topic is about hardware, it will be moved to the appropriate forum.

This post has been edited by greynol: Jul 31 2012, 15:36


--------------------
Your eyes cannot hear.
Go to the top of the page
+Quote Post
db579
post Jul 31 2012, 15:36
Post #13





Group: Members
Posts: 30
Joined: 16-August 11
Member No.: 93077



I'm asking more out of theoretical interest than anything else. I'm just wondering whether it is possible to get the same sound quality out of an entirely portable system (assuming you are sat in the same conditions obviously) as a top end separates system (I'm talking about exact sound output as well as just 'what you can hear').

Since I am assuming that no portable player in production at the moment has a DAC built in that is as good as top of the range separates DACs (happy to be corrected if this is wrong?) I was wondering whether something like this exists. Sort of like a top end separates system but portable? (I understand why in 99.9% of cases this would be pointless and you wouldn't hear a difference I'm just curious)

Thanks guys

edit. Apologies if this was the wrong forum

This post has been edited by db579: Jul 31 2012, 15:37
Go to the top of the page
+Quote Post
xnor
post Jul 31 2012, 15:39
Post #14





Group: Developer
Posts: 379
Joined: 29-April 11
From: Austria
Member No.: 90198



I think that portable players can easily sound better than the headphone out on your receiver. Many receivers have resistors in series with the headphone jack raising the output impedance up to several hundred ohms. This will cause audible frequency response deviations up to several dB.
The best DAC won't matter if the output impedance causes, lets say, a narrow +5 dB peak around 100 Hz.

This post has been edited by xnor: Jul 31 2012, 15:41
Go to the top of the page
+Quote Post
greynol
post Jul 31 2012, 15:43
Post #15





Group: Super Moderator
Posts: 10000
Joined: 1-April 04
From: San Francisco
Member No.: 13167



The answer is yes, it is possible to get the same quality out of a portable player. To determine whether any particular device achieves the same quality as any particular non-portable device will require an objective listening test. How else can someone assess how something actually sounds (as opposed to how it measures)?

This post has been edited by greynol: Jul 31 2012, 15:45


--------------------
Your eyes cannot hear.
Go to the top of the page
+Quote Post
db579
post Jul 31 2012, 15:48
Post #16





Group: Members
Posts: 30
Joined: 16-August 11
Member No.: 93077



Interesting responses and not what I expected, thanks. Has anyone done any such tests here/does anyone have a measured data on this?
Go to the top of the page
+Quote Post
skamp
post Jul 31 2012, 16:46
Post #17





Group: Developer
Posts: 1343
Joined: 4-May 04
From: France
Member No.: 13875



The O2/ODAC is a portable DAC + headphone amp that rivals top of the line components in measurements, and is claimed by its designer to be audibly transparent in double blind tests. According to fellow HA member DanBa, you can use it with a Samsung Galaxy S III (or a laptop or any other portable source that works with regular USB Audio devices). I guess that meets you criteria of portability and top notch quality.

Whether you could tell the difference between such a rig and a simple Clip+ or iPod or other portable players that measure less but still pretty well, only you can answer that.

Disclaimer: I love both my O2/ODAC and my iPod Classic. I don't know that I could tell the difference between the two, but then again I use them in different situations and with different headphones.

This post has been edited by skamp: Jul 31 2012, 16:50


--------------------
caudec.net
Go to the top of the page
+Quote Post
xnor
post Jul 31 2012, 16:54
Post #18





Group: Developer
Posts: 379
Joined: 29-April 11
From: Austria
Member No.: 90198



QUOTE (greynol @ Jul 31 2012, 16:43) *
To determine whether any particular device achieves the same quality as any particular non-portable device will require an objective listening test. How else can someone assess how something actually sounds (as opposed to how it measures)?

High output impedance causing a bass 'boost' will sound bassier like the measurements show. wink.gif If the differences were fractions of a dB then I'd also say a listening test is required to see whether there's an audible difference or not, but not if the difference are as big as several dBs.

db579: Here are some portable players tested with sensitive, low-impedance (therefore even more susceptible to high output impedance) IEMs. It's german but you should be able to read the graphs nonetheless. Even some portable players show a relatively high output impedance compared to 16 or 32 ohm headphones.

This post has been edited by xnor: Jul 31 2012, 16:55
Go to the top of the page
+Quote Post
db579
post Jul 31 2012, 18:01
Post #19





Group: Members
Posts: 30
Joined: 16-August 11
Member No.: 93077



Thanks guys, really appreciate the detailed and helpful responses on here! Fortunately I speak german so will have a proper read through this!

Skamp - Am I right in thinking the O2+ODAC requires a power socket so can't really be used on the move?

xnor - He seems to suggest that the response of the DACs he tests is better when given an optical digital input than when given a USB digital input. This thread had given me the impression that shouldn't be the case?

This post has been edited by db579: Jul 31 2012, 18:15
Go to the top of the page
+Quote Post
DVDdoug
post Jul 31 2012, 19:12
Post #20





Group: Members
Posts: 2440
Joined: 24-August 07
From: Silicon Valley
Member No.: 46454



QUOTE
xnor - He seems to suggest that the response of the DACs he tests is better when given an optical digital input than when given a USB digital input. This thread had given me the impression that shouldn't be the case?
It shouldn't make a difference unless different digital data is coming-in the different inputs, or unless "something else" is different. If the "numbers" are the same, it shouldn't matter how the numbers get into the DAC.

Digital audio data is numbers... This message is coming to you as digital data... It doesn't matter if the data is sent over wires, or fiber-optics, or the distance the message travels, or whatever... As long as the data doesn't get corrupted somehow, you are reading exactly the letters I typed. If there are any "typos", it's probably not a problem with the digital transmission... biggrin.gif Digital data storage & transmission is super-reliable. If we can send data around the world without corruption, you can safely send data across the room to your DAC...

Yes, you might run into a case where the driver is sending different data (such as a different sample rate) over the different digital interfaces.
Go to the top of the page
+Quote Post
xnor
post Jul 31 2012, 20:07
Post #21





Group: Developer
Posts: 379
Joined: 29-April 11
From: Austria
Member No.: 90198



QUOTE (DVDdoug @ Jul 31 2012, 20:12) *
It doesn't matter if the data is sent over wires, or fiber-optics, or the distance the message travels, or whatever... As long as the data doesn't get corrupted somehow, you are reading exactly the letters I typed. If there are any "typos", it's probably not a problem with the digital transmission... biggrin.gif Digital data storage & transmission is super-reliable. If we can send data around the world without corruption, you can safely send data across the room to your DAC...


But it does matter. Very few USB devices are isolated whereas S/PDIF typically is. Actually, many devices are also powered by the USB port so that noise in the computer's PSU also affects the device. Yeah, if 'properly implemented' such devices should reject that noise and you shouldn't hear any difference.

Another problem with USB DACs is DPC latency. I've heard many people report problems with 'streaming' audio over USB, like random glitches due to latency spikes. Again, if the drivers for you computer's hardware are 'properly implemented' you shouldn't have any problems.

The default transfer mode for streaming audio over USB is isochronous, which means that for example every millisecond your computer has to send audio data. Data loss is possible. One DPC latency spike and you might experience a glitch because the data won't arrive in time.

I don't know if the same is true for HDMI. Old receivers had horrible jitter problems but I guess this problem was fixed one or two years ago.

This post has been edited by xnor: Jul 31 2012, 20:11
Go to the top of the page
+Quote Post
greynol
post Jul 31 2012, 20:08
Post #22





Group: Super Moderator
Posts: 10000
Joined: 1-April 04
From: San Francisco
Member No.: 13167



Identical numbers are fine and dandy, but they don't account for the possibility that the connection might introduce noise such as (but not limited to) a ground loop.


--------------------
Your eyes cannot hear.
Go to the top of the page
+Quote Post
mzil
post Jul 31 2012, 20:41
Post #23





Group: Members
Posts: 422
Joined: 5-August 07
Member No.: 45913



QUOTE (DVDdoug @ Jul 31 2012, 14:12) *
...Digital audio data is numbers... This message is coming to you as digital data... It doesn't matter if the data is sent over wires, or fiber-optics, or the distance the message travels, or whatever...

But what does matter is if you are sending the original, raw digital file vs. some manipulated version of it.

When using a USB cord I can perfectly replicate a digital file from one location to another in just seconds, true, however when sending a signal over HDMI, from say my DVD or Blu-ray player (or Toslink for audio, I suspect) I'm not sending the original raw data file found on the optical disc (or storage drive) but rather a streaming version of that file in "real time" (a one minute song takes one minute to transfer), and the conversion from the original, raw file to the streaming version may vary device to device, so to answer the OP's question, I think the technically correct answer is:

"Yes, the original source device, when playing the exact same digital file, may have a slightly different output from another device streaming a digital version of the same song over HDMI."

I make no claims there would be an audible difference in real world use, however in reading reviews of DVD players and Blu-ray players using HDMI out, there seems to be machine measurable differences in, for example, (video) dynamic range. This tells me that HDMI outs, at least when it comes to video playback devices, aren't "all the same and bit for bit replications of the stored file".

This post has been edited by mzil: Jul 31 2012, 20:50
Go to the top of the page
+Quote Post
db579
post Jul 31 2012, 21:14
Post #24





Group: Members
Posts: 30
Joined: 16-August 11
Member No.: 93077



QUOTE (xnor @ Jul 31 2012, 20:07) *
Very few USB devices are isolated whereas S/PDIF typically is. Actually, many devices are also powered by the USB port so that noise in the computer's PSU also affects the device.


So I think I've read some new android phones, the galaxy nexus for example, can output audio over mhl via the micro usb port at the same time as being charged by it. Any way of knowing how well isolated this might be or how good the sound quality would be short of buying them all and trying it?
Go to the top of the page
+Quote Post
yourlord
post Jul 31 2012, 22:33
Post #25





Group: Members
Posts: 172
Joined: 1-March 11
Member No.: 88621



All things being equal, the delivered data should be identical regardless of whether it was sent over a USB cable, fiber, or via radio waves in the atmosphere so long as it's sent via a reliable link or protocol.

If you are powering a DAC/amp using the USB port, then other factors can come into play such as noise on the power from the USB port. But, that's not an issue of the data being delivered incorrectly. The noise on the power rail could affect the analog output stages past the DAC, but it won't do anything to the data being fed to the DAC..

2 separate devices, one feeding a known data set at a sufficient bit-rate for real-time presentation to the other, should perform according to the specs of the receiving device.. Always.

There is no "streaming version of a file". There is only data. It can be packetized and delivered as needed, but it's still the same data at transmitter and receiver. Any data differences seen in video or audio delivered via HDMI would have to come down to differences in the decoders on the source devices since HDMI normally carries uncompressed audio and video. What is delivered to the receiver is exactly what the decoder produced at the source.

When you "stream" audio from an internet radio station they are simply encoding a pcm data stream and then sending you the resulting data as it becomes available. The delivered encoded data will always be identical to the source if delivered over a reliable link (TCP). Different decoders may produce different results from the same encoded data due to differences/bugs in implementations, but that stream delivered to a million devices that all use the exact same decoder will all get the exact same resulting decompressed data.

Obviously once the digital data has been transformed to analog, all bets are off and all kinds of things can then happen to the data. I'm just trying to drive home that data delivered via a reliable link will not contain errors. Encoders can screw up, decoders can screw up, but the data transmitted across a $3 HDMI cable, $5000 HDMI cable, or a $2 USB cable will all be bit identical.
Go to the top of the page
+Quote Post

4 Pages V   1 2 3 > » 
Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 16th April 2014 - 17:52