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View Full Version : Comparing Flac - CD Transport



Jason
2004-05-27, 15:49
Have you checked to see that the output levels of the devices are identical?
Even with digital output not all manufacturers output the signal at the same
level, so it is possible that the reason your CD transport going to the DA
sounds better is simply because there is a slightly increase in the dB
level.

To be sure you could get a reference disc, encode some of the test tones to
FLAC and then play them and compare to the CD original. You would need a
decent sound pressure level meter to know if there are any volume
differences.

A last possible source of your troubles is simply the placebo affect. It
has been demonstrated over and over that if the user knows there is a
difference in the equipment they will transfer that into their evaluation.
It would be more helpful to you if you conducted a double blind test, with
someone else switching the inputs and you (blindfolded) see if you can
stilll easily distinguish between the two devices.

Other than the reasons I stated I can think of no reason that the devices
would sound any different.

-----Original Message-----
From: discuss-bounces (AT) lists (DOT) slimdevices.com
[mailto:discuss-bounces (AT) lists (DOT) slimdevices.com] On Behalf Of James
Sent: Thursday, May 27, 2004 3:36 PM
To: Slim Devices Discussion
Subject: [slim] Comparing Flac - CD Transport

Thanks,

I have the Slimserver set up to only stream Flac - Wav. The bitrate for the
player set for no limit.

I use an external DAC with same digital coax cable to either the Squeezebox
or transport to test.

From what you and others say it is possible to close the performance
>gap
between Flac and using a transport. That would mean that I have something
wrong in the creation of the Flac. I use EAC, then Flac on the fly. Is this
the best way?








----- Original Message -----
From: "Mark Bennett" <mark (AT) markandliz (DOT) co.uk>
To: "Slim Devices Discussion" <discuss (AT) lists (DOT) slimdevices.com>
Sent: Thursday, May 27, 2004 1:42 PM
Subject: [slim] Comparing Flac - CD Transport


>
> I've done some testing using a Benchmark DAC1 external DAC on
> a high-end system (Naim Pre/Power Amps, Kef Reference speakers)
> and comparing the use of a Squeezebox and an Audiolab 8000
> transport (was ~$2k just for a CD transport...).
>
> The details can be seen on an earlier posting:
>
http://article.gmane.org/gmane.music.equipment.slimdevices.general/8640/matc
h=external+dac
>
> The bottom line is that there is no perceivable difference
> between the squeezebox and a normal CD transport even on a
> $20k+ system.
>
> Just one thought comes to mind on this. Are you sure you're
> streaming uncompressed? In recent versions of SlimServer
> Slim "helpfully" introduced a feature where all music was
> re-encoded to 320kb MP3 for a wireless SB. I'm not quite sure
> when this was introduced, but I think it was in 5.1.5. Try
> one of the more recent nightlies and make sure the bitrate
> limit is set to "no limit" in the player settings.
>
> We could clearly tell the difference between 320kb MP3 and
> uncompressed audio. This might explain why you're hearing a
> difference.
>
> Others have suggested alternative causes, which are also
> worth checking if it isn't being re-encoded to MP3.
>
> James wrote:
> > Hello Everyone,
> >
> > I am curious to get opinions from serious audiophiles about the quality
of
> > steaming Flac - Wav files to their DA converter compared to using a CD
> > transport. I created a sample library using EAC and Flac, then stream
over
> > the wireless network. I use the coax out to my DA.
> >
> > Now, without throwing big prices and audiophile words around, I can say
I
> > have a very nice setup.
> >
> > About testing. I can easily go back and forth from Squeezebox and the CD
> > transport, so it is very easy to hear any differences there are. The
> > streaming Flac - Wav is very very good, in fact, if you haven't heard
any
> > better you would think it was outstanding. But, when you listen via the
CD
> > transport you hear 'more'. Again, without getting into fancy audiophile
> > language, the instruments have better detail. For example, with Flac, a
> > bongo in the background is noticeable and distinguishable. With the
> > transport, the bongo is closer to you, more detailed and pronounced.
Overall
> > a better presentation. I don't have special ears either, you would hear
it
> > too I am sure.
> >
> > So, I would like to hear from those who have heard the gap in
performance
> > and what can be done to close it. Perhaps there are better ways to
create
> > the Flac file from CD in the first place? Also, I wonder if anyone has
> > created a test Flac file? This way there would be a way to hear the best
it
> > can be and compare to the original CD.
> >
> > thanks,
> >
> >
> >
> >
> > ---
> > Outgoing mail is certified Virus Free.
> > Checked by AVG anti-virus system (http://www.grisoft.com).
> > Version: 6.0.689 / Virus Database: 450 - Release Date: 5/21/2004
> >
> >

James
2004-05-27, 16:09
Using test tones is a great idea, thanks.

Considering the 'placebo effect' is fine, but the differences I am hearing
are quite obvious. If I told a listener to focus on a particular background
instrument, then change sources, anyone could hear the improvement using the
transport. This is why I must go back and look at the best way to use EAC. I
am using a Fujitsu NSeries to rip the CD's. I read somewhere that results
can vary from computer to computer using the same EAC settings.








----- Original Message -----
From: "Jason" <jason (AT) pagefamily (DOT) net>
To: "'Slim Devices Discussion'" <discuss (AT) lists (DOT) slimdevices.com>
Sent: Thursday, May 27, 2004 3:49 PM
Subject: [slim] Comparing Flac - CD Transport


> Have you checked to see that the output levels of the devices are
identical?
> Even with digital output not all manufacturers output the signal at the
same
> level, so it is possible that the reason your CD transport going to the DA
> sounds better is simply because there is a slightly increase in the dB
> level.
>
> To be sure you could get a reference disc, encode some of the test tones
to
> FLAC and then play them and compare to the CD original. You would need a
> decent sound pressure level meter to know if there are any volume
> differences.
>
> A last possible source of your troubles is simply the placebo affect. It
> has been demonstrated over and over that if the user knows there is a
> difference in the equipment they will transfer that into their evaluation.
> It would be more helpful to you if you conducted a double blind test, with
> someone else switching the inputs and you (blindfolded) see if you can
> stilll easily distinguish between the two devices.
>
> Other than the reasons I stated I can think of no reason that the devices
> would sound any different.
>
> -----Original Message-----
> From: discuss-bounces (AT) lists (DOT) slimdevices.com
> [mailto:discuss-bounces (AT) lists (DOT) slimdevices.com] On Behalf Of James
> Sent: Thursday, May 27, 2004 3:36 PM
> To: Slim Devices Discussion
> Subject: [slim] Comparing Flac - CD Transport
>
> Thanks,
>
> I have the Slimserver set up to only stream Flac - Wav. The bitrate for
the
> player set for no limit.
>
> I use an external DAC with same digital coax cable to either the
Squeezebox
> or transport to test.
>
> >From what you and others say it is possible to close the performance
> >gap
> between Flac and using a transport. That would mean that I have something
> wrong in the creation of the Flac. I use EAC, then Flac on the fly. Is
this
> the best way?
>
>
>
>
>
>
>
>
> ----- Original Message -----
> From: "Mark Bennett" <mark (AT) markandliz (DOT) co.uk>
> To: "Slim Devices Discussion" <discuss (AT) lists (DOT) slimdevices.com>
> Sent: Thursday, May 27, 2004 1:42 PM
> Subject: [slim] Comparing Flac - CD Transport
>
>
> >
> > I've done some testing using a Benchmark DAC1 external DAC on
> > a high-end system (Naim Pre/Power Amps, Kef Reference speakers)
> > and comparing the use of a Squeezebox and an Audiolab 8000
> > transport (was ~$2k just for a CD transport...).
> >
> > The details can be seen on an earlier posting:
> >
>
http://article.gmane.org/gmane.music.equipment.slimdevices.general/8640/matc
> h=external+dac
> >
> > The bottom line is that there is no perceivable difference
> > between the squeezebox and a normal CD transport even on a
> > $20k+ system.
> >
> > Just one thought comes to mind on this. Are you sure you're
> > streaming uncompressed? In recent versions of SlimServer
> > Slim "helpfully" introduced a feature where all music was
> > re-encoded to 320kb MP3 for a wireless SB. I'm not quite sure
> > when this was introduced, but I think it was in 5.1.5. Try
> > one of the more recent nightlies and make sure the bitrate
> > limit is set to "no limit" in the player settings.
> >
> > We could clearly tell the difference between 320kb MP3 and
> > uncompressed audio. This might explain why you're hearing a
> > difference.
> >
> > Others have suggested alternative causes, which are also
> > worth checking if it isn't being re-encoded to MP3.
> >
> > James wrote:
> > > Hello Everyone,
> > >
> > > I am curious to get opinions from serious audiophiles about the
quality
> of
> > > steaming Flac - Wav files to their DA converter compared to using a CD
> > > transport. I created a sample library using EAC and Flac, then stream
> over
> > > the wireless network. I use the coax out to my DA.
> > >
> > > Now, without throwing big prices and audiophile words around, I can
say
> I
> > > have a very nice setup.
> > >
> > > About testing. I can easily go back and forth from Squeezebox and the
CD
> > > transport, so it is very easy to hear any differences there are. The
> > > streaming Flac - Wav is very very good, in fact, if you haven't heard
> any
> > > better you would think it was outstanding. But, when you listen via
the
> CD
> > > transport you hear 'more'. Again, without getting into fancy
audiophile
> > > language, the instruments have better detail. For example, with Flac,
a
> > > bongo in the background is noticeable and distinguishable. With the
> > > transport, the bongo is closer to you, more detailed and pronounced.
> Overall
> > > a better presentation. I don't have special ears either, you would
hear
> it
> > > too I am sure.
> > >
> > > So, I would like to hear from those who have heard the gap in
> performance
> > > and what can be done to close it. Perhaps there are better ways to
> create
> > > the Flac file from CD in the first place? Also, I wonder if anyone has
> > > created a test Flac file? This way there would be a way to hear the
best
> it
> > > can be and compare to the original CD.
> > >
> > > thanks,
> > >
> > >
> > >
> > >
> > > ---
> > > Outgoing mail is certified Virus Free.
> > > Checked by AVG anti-virus system (http://www.grisoft.com).
> > > Version: 6.0.689 / Virus Database: 450 - Release Date: 5/21/2004
> > >
> > >