FLAC replay through a Squeezebox

Posted by: jfritzen on 13 August 2009

Hi (for the first time),

I'm a bit at my wits end: I have a Squeezebox Classic v3 attached via coax to a SuperNAIT DAC, feeding it with FLACs ripped from CD.

Compared to

- CD5 + Hi-Line or
- PowerPC Mac Mini (1.4MHz, M-Audio Transit soundcard, squeezeslave player, SN DAC, same FLACs)

the Squeezebox sounds less open and relaxed, almost lossy like MP3. I used to blame the SN DAC for this (sorry SuperNAIT!) until I tried out my aged Mac Mini.

One should expect a performance comparable to that of the Mac Mini, given the same music data and the same DAC. As an experiment I configured SqueezeCenter to transcode FLAC to WAV and sent WAV to both players. Result: I could not hear a difference between Mac Mini and Squeezebox anymore and both sounded fine.

So currently my explanation is (don't laugh):

Decoding FLAC is too demanding on Squeezeboxes CPU and in order to keep pace with the music it discards unimportant data, producing a lossy output. WAV on the other hand means minimal decoding for the CPU, so this works fine.

Sounds weird, but would you say that this makes sense somehow? Did you observe similar effects?

Setting up digital audio seems not to be as straight-forward as one might think.


Kind regards,
Jochen
Posted on: 24 August 2009 by js
I can hear the difference between a FLAC and WAV file on any good system I've tried it on so this discussion isn't of great import to me regarding ultimate goodness unless I find out those differences are minimized by changing the compression level to 0.

That's a pretty silly rant. Every system has compromises. It's up to an individual to chose his own. Mains, humidity etc. have nothing to do with this. If (I haven't tried) this is better, it will be relatively better under any of these circumstances. It's only becomes inconsequential when you're on the wrong side of a discussion, the system isn't informative enough or the difference actually isn't there (wrong to assume given these posts) but barometric pressure isn't part of the mix. LOL
Posted on: 24 August 2009 by pcstockton
quote:
Originally posted by js:


That's a pretty silly rant.


If you can hear the difference between FLAC and WAV, I cannot believe you, as a very intelligent reasonable person, wouldn't chalk it up to placebo or self-fulfilling prophecy.

i KNOW for a fact that the exact same hot dog is the same if had at the ballpark vs at home. But i "feel" that the one at the ballpark tastes better.

I dont take the leap to believe that there is a difference in the dogs. It is merely a difference in perception.

This is the only way I can imagine you preferring one over another.

I dont mean to "rant" above but seriously.... If your threshold of hearing is ultra-supernatural, how do you filter out all of the microscopic factors and listen to the music?

If you can hear something like the levels of compression on a FLAC file, why wouldn't the fly buzzing outside the window affect your hearing.

I am being completely serious. So if I play a track for you on your super duper all revealing kit, will you be able to say "thats a FLAC level 5", "oh that one is a WAV", "That one was converted to FLAC then back to WAV, its obvious."

How about ALAC, can you tell if its been in the mix? What if the original digital files had been converted to FLAC and back to WAV prior to pressing the CD? Could you hear that as well?

I guess my 102/180 isn't good enough to reveal the differences. THANK GOD!!!!!! You just saved me thousands on upgrades I surely don't want.

-Rant ended.

PS - I agree with you on one account in that "this discussion isn't of great import"
Posted on: 24 August 2009 by Graham Russell
All my comments about audible differences were in context of Sonos on PC. There are playback issues with the hardware in the box.

I have discussed this with a Sonos rep.
Posted on: 24 August 2009 by js
PC, you can test me any time. Smile I think you're missing the point about the processing part but that's fine. I'm not insistent that you change your beliefs. That shoe is on your foot. I also don't mean to disparage FLAC as I think it pretty good but for me it's not the same...so far and I can only comment on my experience. I'm also not trying to be a snob about it. I happily use 320 bitrate on my portable. Something you called virtually worthless. Hey, we're not going to agree every time. I have to admit, I love your passion but sometimes it's a bit over the top. This thread was started by a poster looking for a solution to a problem subsequently confirmed by others yet it's now just another what you can or can't hear thread. Very unproductive for the OP and others looking for help.
Posted on: 24 August 2009 by Graham Russell
quote:
Originally posted by Graham Russell:
All my comments about audible differences were in context of Sonos on PC. There are playback issues with the hardware in the box.

I have discussed this with a Sonos rep.


Just spotted typo in my reply. Should read:
All my comments about audible differences were in context of Sonos not PC
Posted on: 24 August 2009 by pcstockton
quote:
Originally posted by js:
I love your passion but sometimes it's a bit over the top. This thread was started by a poster looking for a solution to a problem subsequently confirmed by others yet it's now just another what you can or can't hear thread. Very unproductive for the OP and others looking for help.


Sorry for the hijack Jochen!!! My original point, for what its worth, is that I sincerely doubt the level of compression has anything to do with the problems the OP is having with their Squeezebox's sound quality.

I suspect the problem is more complex than that. Or really simple....

If I had to put money on it, I would guess that the Squeezebox is not very good at decoding the FLAC regardless of level of compression.

Jochen, how are you playing the FLACs on the mini? Also, what is the source of the files for the Squeezebox?

I am very interested in learning more about the experience.

Unfortunately, and what leads to my "ranting", is the words "think", "tend" and "often"...

Jochen stated "I did not do a strict blind listening test. My impression was that in most cases, when the music sounded more open and relaxed, it was either WAV or sometimes FLAC level 0, almost never level 5. On the other hand, when the music lacked openness it was often FLAC level 5 and sometimes level 0 or even WAV. There might be a trend, but it is not statistically valid."

If there is a really noticeable difference, why can you not pick them out EVERY time?

Otherwise, why wouldn't one employ Occam's razor and assume there is a human brain involved in these "tests" and that is probably the answer.

Anyway...... Once again, I apologize for ranting or diverting the topic. For what it is worth i was NOT the ope who started talking about sound quality between FLACs. That would have been yourself as well as the OP.

Lastly, I said 320 kbps were unlistenable, not worthless. Winker And I think I said that about 256ers as pertains to iTunes downloads. All of my mp3s (the 8GBs worth on my iPhone) are in V0 or 320 as well.

Ironically, I get shit from friends who claim they cannot hear the difference between a FLAC and a 320/V0. I can hear that difference every single time. I had a buddy "quiz" me. I nailed 20 for 20. Albeit I had a 50-50 chance everytime of being right.
Posted on: 24 August 2009 by js
We're just lucky I guess. Big Grin
Posted on: 24 August 2009 by jfritzen
Going on camping tour for week, away from Naim and Computer. You may hijack the thread for a while :-)

Thanks so far, Jochen