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Mark Jenkins
2004-09-30, 15:23
I have played around extensively with the Squeezebox to see how to wring the best sound quality out of it. 



When I first bought it I was so stunned by how the easy access to my music (1000+ CDs) improved my musical enjoyment despite its sound quality falling well short of my NZD 15,000 CD Player.  Therefore I went about finding out how to get the best of both worlds.



The Squeezevox does not create any miracles with its sound quality, but it is creditable at its price and easily beats CD Players at the same price.  Through its analogue outs you will get very good detail but the sound will have a degree of aggression and hard edge to it that may be the reason you describe it as tinny or lacking bass.  In fact it does not lack bass, except perhaps if you are running long lengths or poor quality interconnect cable between it and your preamp/amp/receiver, or if your amp is proving to be a difficult load for the SB to drive.  But there is a brightness and hardness to the sound that will cause you to perceive higher frequencies more than low frequencies.  One simple way to alleviate this is use a device like a Musical Fidelity X10D between the SB and your amp.  This will smoothen and warm up the sound as well as improve the drive to the amp so that more bass is perceived.  There are similar devices on the market to the X10D.  A further band-aid style solution is to use a warm cable such as those sold by firms like Cardas.



Those simple solutions are band-aids.  Once the analogue signal is poor then there is nothing you can do to recover sound quality, you can only play with its character.



The best course of action is to work with the digital stream.  I perceive that the comments that follow will take you into a more costly area than you may feel comfortable with, but it relates to the comments in other posts about audiophiles such as myself using a squeezebox in preference to very costly CD Transports. 



I use EAC to rip my CDs at full resolution and store them first as wav files.  I then use FLAC to get greater efficiency of disk storage space without losing sound quality.  This is far superior to using mp3 or any other lossy compression, and there is no way that any mp3 through the SB will ever sound as good as a very basic CD transport.  But the SB will deliver mp3's fairly well.  I believe that using EAC I probably end up with better resolution than using a very expensive CD transport.  An expensive CD transport is hampered by the fact that it must read the CD in real-time and so any error encountered must be dealt with using error correction, where as using EAC it can take its time to get the best read it can before using error correction.




If I take the digital stream out of the SB via the RCA socket and feed it into a good DAC - in my case a USD2,500 Northstar M192 - the sound is not as good as from a decent CD transport, but is better than using say a DVD player as a CD transport.  Clearly the sound suffers from jitter, even though I am using a wired connection not a wireless connection between PC and SB.  As an aside, wired will have much lower jitter than wireless, simply because of how the two media work.  In simple terms, the jitter error in the stream is the only real issue you have to now deal with.  Jitter is variation in the delay between when the data sample should be processed and when it arrives.  Reclocking it to totally remove jitter is difficult but a lot can be achieved and, unlike analogue, the damage done to the digital signal by jitter is theoretically fully recoverable.  Without the jitter removed, the sound of the SB is the reverse of the sound from its analogue outs - it is warm and fuzzy, losing all of the brightness and hardness of the analogue outs but too softened and losing resolution.  This is actually a bit odd as jitter more commonly results in aggressive sound, but it is not unheard of for it to result in a soft and fuzzy sound either.



To deal with the jitter, I experimented with a variety of devices.  Sure enough, depending on the device used to remove jitter, I could change the quality of the digital signal coming out of the SB right up to the quality of CD transports costing sevarl thousand dollars.  At the cheapest end of the spectrum I got very good results using a Behringer Ultramatch SCR2000, which I believe you can get from Pro Audio stores in the US for around USD100.  The Behringer tightened things up and removed the softness and fuzz.  However I got a lot more natural sound by spending a lot more on a Meridian 518 and I use that instead of the Behringer.  So the Meridian goes between the SB and the Northstar DAC.  With this configuration, I have sold my CD Player and no longer own one!



So what I am saying is you can get whatever quality you like out of the SB, it all depends on what you want to spend.  From my experience, if you are thinking of spending x dollars on a CD Player, then spending x dollars on a SB plus other stuff described above, the SB will match the standalone CD player.  The added cost of a PC and storage is another matter, and its justification is about the sheer convenience of instant and flexible access to your music.



Mark Jenkins







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>Subject: Discuss Digest, Vol 11, Issue 66



>Date: Thu, 30 Sep 2004 06:10:14 -0700 (PDT)



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>Today's Topics:



>



>    1. EAC Cue sheets and WAV Cdimage,



>        glitches between tracks when two squeezebxes are sync'd



>        (Andrew Lucas)



>    2. Remote Stream Control (bubba)



>    3. Remote Stream Control (PAUL WILLIAMSON)



>    4. Remote Stream Control (kdf)



>    5. One album won't play (Philip Bouscarle)



>    6. SB Sound quality (Danny Rego)



>    7. SV: [slim] SB Sound quality (Tore Johnsson)



>    8. SB Sound quality (Danny Rego)



>    9. SV: [slim] SB Sound quality (Tore Johnsson)



>   10. SB Sound quality (Craig, James (IT))



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jacobdp
2004-09-30, 16:05
On Thursday, 30 Sep 2004 22:23:21 +0000, Mar Jenkins
<themarkjenkins (AT) hotmail (DOT) com> wrote:
>If I take the digital stream out of the SB via the RCA socket and
feed it into a
>good DAC - in my case a USD2,500 Northstar M192 - the sound is not as good
>as from a decent CD transport, but is better than using say a DVD player as a
>CD transport. Clearly the sound suffers from jitter, even though I am using a
>wired connection not a wireless connection between PC and SB. As an aside,
>wired will have much lower jitter than wireless, simply because of how the two
>media work.

I would think that it wouldn't make any difference. Remember, there's
a substantial buffer in the Squeezebox itself - 2 Mb, or almost a
second and a half of uncompressed PCM. Variations in how the signal is
transmitted shouldn't have any effect unless the buffer itself runs
dry, causing a very noticable dropout. Of course, unless your wireless
signal is strong enough to support sustained lossless streaming, then
wired is preferable.

Bits are bits; the method of delivery shouldn't have any impact on
what goes out the back of the Squeezebox... Have you actually done a
test of wired vs. wireless?

>In simple terms, the jitter error in the stream is the only real issue
>you have to now deal with. Jitter is variation in the delay between
when the data
>sample should be processed and when it arrives. Reclocking it to
totally remove
>jitter is difficult but a lot can be achieved and, unlike analogue,
the damage done
>to the digital signal by jitter is theoretically fully recoverable.
Without the jitter
>removed, the sound of the SB is the reverse of the sound from its an! alogue
>outs - it is warm and fuzzy, losing all of the brightness and hardness of the
>analogue outs but too softened and losing resolution. This is
actually a bit odd
>as jitter more commonly results in aggressive sound, but it is not
unheard of for
>it to result in a soft and fuzzy sound either.

Are you sure you disabled the digital volume control in the Player Settings?

- Jacob

Danny Rego
2004-10-01, 10:32
Thanks for the info!!!

I think should clarify what my setup is, and perhaps this can/will narrow the discussion!?

I am using a SqueezeBox on a WIRED network. It is connected to my DENON receiver (excellent sounding unit) using a TOSLINK (digital) cable. I don't know how, but when I swap the TOSLINK from the Squeezebox to/from my Pioneer CD player, I seem to hear a difference.

When doing my audible test, I have a CD in the CD player....and on my squeezebox, I have the same CD ripped to these three formats (as I'm trying to figure out what format to encode/store in that doesn't kill my server, and cause hiccups in the stream, as my server is also a home-made tivo, and gets quite busy sometimes). The three formats I have the CD ripped to are WMA (192kb), MP3 (192kb), and WMA lossless.

In theory, the lossless format should have the same sound quality as my cd player, but it doesn't seem to. It could be my imagination, which is why I asked about it here...just to get the experts' opinions/knowledge.

Danny Rego



----- Original Message -----
From: Mark Jenkins
To: discuss (AT) lists (DOT) slimdevices.com
Sent: Thursday, September 30, 2004 6:23 PM
Subject: [slim] SB Sound Quality


I have played around extensively with the Squeezebox to see how to wring the best sound quality out of it.

When I first bought it I was so stunned by how the easy access to my music (1000+ CDs) improved my musical enjoyment despite its sound quality falling well short of my NZD 15,000 CD Player. Therefore I went about finding out how to get the best of both worlds.

The Squeezevox does not create any miracles with its sound quality, but it is creditable at its price and easily beats CD Players at the same price. Through its analogue outs you will get very good detail but the sound will have a degree of aggression and hard edge to it that may be the reason you describe it as tinny or lacking bass. In fact it does not lack bass, except perhaps if you are running long lengths or poor quality interconnect cable between it and your preamp/amp/receiver, or if your amp is proving to be a difficult load for the SB to drive. But there is a brightness and hardness to the sound that will cause you to perceive higher frequencies more than low frequencies. One simple way to alleviate this is use a device like a Musical Fidelity X10D between the SB and your amp. This will smoothen and warm up the sound as well as improve the drive to the amp so that more bass is perceived. There are similar devices on the m! arket to the X10D. A further band-aid style solution is to use a warm cable such as those sold by firms like Cardas.

Those simple solutions are band-aids. Once the analogue signal is poor then there is nothing you can do to recover sound quality, you can only play with its character.

The best course of action is to work with the digital stream. I perceive that the comments that follow will take you into a more costly area than you may feel comfortable with, but it relates to the comments in other posts about audiophiles such as myself using a squeezebox in preference to very costly CD Transports.

I use EAC to rip my CDs at full resolution and store them first as wav files. I then use FLAC to get greater efficiency of disk storage space without losing sound quality. This is far superior to using mp3 or any other lossy compression, and there is no way that any mp3 through the SB will ever sound as good as a very basic CD transport. But the SB will deliver mp3's fairly well. I believe that using EAC I probably end up with better resolution than using a very expensive CD transport. An expensive CD transport is hampered by the fact that it must read the CD in real-time and so any error encountered must be dealt with using error correction, where as using EAC it can take its time to get the best read it can before using error correction.


If I take the digital stream out of the SB via the RCA socket and feed it into a good DAC - in my case a USD2,500 Northstar M192 - the sound is not as good as from a decent CD transport, but is better than using say a DVD player as a CD transport. Clearly the sound suffers from jitter, even though I am using a wired connection not a wireless connection between PC and SB. As an aside, wired will have much lower jitter than wireless, simply because of how the two media work. In simple terms, the jitter error in the stream is the only real issue you have to now deal with. Jitter is variation in the delay between when the data sample should be processed and when it arrives. Reclocking it to totally remove jitter is difficult but a lot can be achieved and, unlike analogue, the damage done to the digital signal by jitter is theoretically fully recoverable. Without the jitter removed, the sound of the SB is the reverse of the sound from its an! alogue outs - it is warm and fuzzy, losing all of the brightness and hardness of the analogue outs but too softened and losing resolution. This is actually a bit odd as jitter more commonly results in aggressive sound, but it is not unheard of for it to result in a soft and fuzzy sound either.

To deal with the jitter, I experimented with a variety of devices. Sure enough, depending on the device used to remove jitter, I could change the quality of the digital signal coming out of the SB right up to the quality of CD transports costing sevarl thousand dollars. At the cheapest end of the spectrum I got very good results using a Behringer Ultramatch SCR2000, which I believe you can get from Pro Audio stores in the US for around USD100. The Behringer tightened things up and removed the softness and fuzz. However I got a lot more natural sound by spending a lot more on a Meridian 518 and I use that instead of the Behringer. So the Meridian goes between the SB and the Northstar DAC. With this configuration, I have sold my CD Player and no longer own one!

So what I am saying is you can get whatever quality you like out of the SB, it all depends on what you want to spend. From my experience, if you are thinking of spending x dollars on a CD Player, then spending x dollars on a SB plus other stuff described above, the SB will match the standalone CD player. The added cost of a PC and storage is another matter, and its justification is about the sheer convenience of instant and flexible access to your music.

Mark Jenkins

>From: discuss-request (AT) lists (DOT) slimdevices.com
>Reply-To: discuss (AT) lists (DOT) slimdevices.com
>To: discuss (AT) lists (DOT) slimdevices.com
>Subject: Discuss Digest, Vol 11, Issue 66
>Date: Thu, 30 Sep 2004 06:10:14 -0700 (PDT)
>
>Send Discuss mailing list submissions to
> discuss (AT) lists (DOT) slimdevices.com
>
>To subscribe or unsubscribe via the World Wide Web, visit
> http://lists.slimdevices.com/lists/listinfo/discuss
>or, via email, send a message with subject or body 'help' to
> discuss-request (AT) lists (DOT) slimdevices.com
>
>You can reach the person managing the list at
> discuss-owner (AT) lists (DOT) slimdevices.com
>
>When replying, please edit your Subject line so it is more specific
>than "Re: Contents of Discuss digest..."
>Today's Topics:
>
> 1. EAC Cue sheets and WAV Cdimage,
> glitches between tracks when two squeezebxes are sync'd
> (Andrew Lucas)
> 2. Remote Stream Control (bubba)
> 3. Remote Stream Control (PAUL WILLIAMSON)
> 4. Remote Stream Control (kdf)
> 5. One album won't play (Philip Bouscarle)
> 6. SB Sound quality (Danny Rego)
> 7. SV: [slim] SB Sound quality (Tore Johnsson)
> 8. SB Sound quality (Danny Rego)
> 9. SV: [slim] SB Sound quality (Tore Johnsson)
> 10. SB Sound quality (Craig, James (IT))
><< message5.txt >>
><< message7.txt >>
><< message9.txt >>
><< message11.txt >>
><< message13.txt >>
><< message15.txt >>
><< message19.txt >>
><< message23.txt >>
><< message27.txt >>
><< message31.txt >>
>

Nick Silberstein
2004-10-01, 12:43
Danny Rego wrote:
> I am using a SqueezeBox on a WIRED network. It is connected to my DENON
> receiver (excellent sounding unit) using a TOSLINK (digital) cable. I
> don't know how, but when I swap the TOSLINK from the Squeezebox to/from
> my Pioneer CD player, I seem to hear a difference.
[snip]
> In theory, the lossless format should have the same sound quality as my
> cd player, but it doesn't seem to. It could be my imagination, which is
> why I asked about it here...just to get the experts' opinions/knowledge.

This sort of question really belongs in the FAQ. ;)

Q. My $250 squeezebox doesn't seem to have the same quality as the
[insert audio transport here] that I paid [insert GDP of Switzerland
here] for. I haven't confirmed that I can actually hear a difference by
doing a single or double blind test with a helper. Am I hearing things?

Choose A or B below.

A.

i. Confirm that your config is set up best for lossless digital output.
Search the archives for this info. Set the volume to fixed, make sure
the audio isn't being transcoded into mp3 due to bandwidth constraints,
etc. Try swapping the inputs that the sources are connected to.

ii. Still hear a difference? The scientific approach would be to do a
double-blind test with two helpers, ensuring that the volume levels are
identical at your listening position. You can help ensure this with a
sound level meter, available from Radio Shack for under $100, for example:

http://www.tnt-audio.com/clinica/spl-meter_e.html

A sample way to conduct the test:

The first helper should connect the Squeezebox and the product you're
comparing it with in such a way that an observer can not tell which
product is connected to which input, while you and the other helper are
not present. The first helper can now leave. The second helper, who
should be ignorant of which source is connected to each input, should
play back a sample of your favorite audio, say 20 times, with gaps of
5-10 seconds of silence between samples, without telling you which input
is selected. If your audio setup has tell-tale feedback when it changes
inputs, and most do in the form of a click or hum, have the helper
switch to an unused input, then to the desired input (ie, A->C->A or
A->C->B, with the Squeezebox and the other source being A or B).

Face-away from the helper at all times. Selection of the input source
should be random, ie, AABAAAABBBABABABABBB. Take notes during or after
each sample playback, describing what you like or don't like about the
sound quality, and your decision of which source is currently playing.
Label each note with the # of the sample you're listening to.

Have the helper keep track of his input changes, so at the end of the
session, you can match your notes to the selected input source. When
the session is over, look at the connections to confirm which input
source was connected to which input on the receiver.

Just for fun, you may want to try the above test, while you have all the
equipment and helpers, with various bitrates of lossy audio compared
with losslessly compressed audio.

After concluding the tests, decide whether any difference that was
audible is worth spending money to alter.

B.

Alternatively, the 'humanistic'/psychoacoustic approach would be to
purchase an add-on DAC for [GDP of Canada], connect it to the Squeezebox
and receiver with cables extruded from a pure gold ingot (milled, not
cast, of course -- heating the gold will permamently color the sound).
The add-on DAC will, in the process of converting digital bits to a
continuous analog voltage, gently fan the outgoing electrons with
miniature banana leaves, calming them and ensuring that they are neither
too warm or too cold. It will also get them a glass of water if they
are thirsty. The end result will be acceptable sound, sadly still with
hints of jitter, wow, flutter and zowee. Still, you'll know you did
what you could to correct the problem without going overboard like some
of those ridiculous audiophiles.

....that is, unless you haven't bought a custom power conditioner to
fluff up the power as it enters your Squeezebox and other audio gear?
That would explain a distinctly muddy, compressed sound much like a cat
being sat on by a very large man.

*cough*

Sorry, it's been a long week. TGIF! :-)

Nick


--
Nick Silberstein
Senior Developer
Flying Machine Development, Inc.

kdf
2004-10-01, 14:52
Quoting Nick Silberstein <nick (AT) flyingmachine (DOT) com>:


> This sort of question really belongs in the FAQ. ;)
>
> Q. My $250 squeezebox doesn't seem to have the same quality as the
> [insert audio transport here] that I paid [insert GDP of Switzerland
> here] for. I haven't confirmed that I can actually hear a difference by
> doing a single or double blind test with a helper. Am I hearing things?
>
> Choose A or B below.
>
better yet...

A) yup..thanks for your patronage ;)

Darren White
2004-10-01, 18:17
> What ripping tool are you using? If you are not using a secure ripping tool
> then you are getting errors in the ripped output. You should be using EAC
> in SECURE MODE to ensure that your rips are bit for bit accurate.

I would like to emphasize that point. You should be using a Secure
Ripping Tool(tm) in SECURE MODE. I ripped 300 or 400 CD's to
256CBRMP3. Only now have I realized I did *NOT* have the secure
mode enabled. As a result, I have a growing collection of skipping,
distorted tracks that were ripped with errors. Most CD's are fine, but
the scratched ones came out bad.. Double check that you are ripping
in secure mode. And keeping a flac/wav copy is nice too, as you can
re-convert anytime.. mp3/aac/atrac/wma/ogg/whatever from files as
perfect as the originals..

Darren White
InterStar Inc.
530-224-6866 x 103