The MAC Mini Thread

[Natural Sound]

I'm real interested in building a music server for my lossless music files. I'm seriously considering a MAC Mini for the job. If anyone has information that can get me started please post it here. I'd be interested in hearing about hardware, software, modifications, compatible DAC's and the best lossless formats. And of course, how it integrates into your Bottlehead gear.

[Doc B.]

For software Amarra is great. I'm using an older Intel Core Duo Mini that has has a processor upgrade to something like 2GHz. It's limited to 2GB of RAM, which is not really enough for the best performance, as Amarra and Itunes running together really gobble it up. A later Mini that can handle more RAM would probably be more suitable. I don't use lossless compression because the difference in quality compared to AIFF or WAV is very obvious in my setup.  External drives are cheap enough that I feel I can justify storage in the larger file size.

[ramicio]

How does lossless compression change the quality when the name implies that literally there is no loss?  If there is a difference that's not placebo, it sounds like a faulty software decoder, to me.

[Pfenning]

OK, not trying to hijack your thread, but I have questions too. Is the music server for convenience only? I can't see how it could change the current sound quality of my cd's? Plus, the thought of adding all my cd's to another computer is not appealing to me. Do I have to buy my favorite albums again from one of the online sellers offering higher quality recordings? How close are those higher quality recordings to vinyl? I'll be watching this thread close. Thanks.

Pfenning

[BNAL]

I have all my music saved as flac, and use a squeezebox. I do not let the player decode the flac files. I do the decoding on my computer first. This seems to make a noticeable improvement in sound quality. If I were to guess I would think that it has to do with the additional processing required by the computer to convert a lossless file that is effecting sound quality.

[tdogzthmn]

If your running OSX for software I strongly recommend you look at using BitPerfect which is found on the Mac App Store.  It's only $4.99 and made a considerable improvement with my DAC performance, especially with the new version 1.0 which has been noticeably better and has a bunch of ways to tweak how you send the audio signal through the computer.  

For me, its a must try.    

[ramicio]

It doesn't matter if something has to be decoded, or where it is decoded.  If the decoder is written properly, you get the same exact PCM data out of the decoder.  The only decoders that can vary in quality from decoder to decoder are those decoding lossy files, and the same thing goes for the lossy encoders.  CPU cycles having to decode a lossless file, and then affecting something in the analog domain, especially when most people are using external DACs, is something that doesn't make any sense.  Yes, there are things in the analog domain that are tough to explain, but a digital signal is a digital signal is a digital signal.  If you believe a CPU and other things inside of a computer can affect the digital data, while even being bit-identical to the CD, then you really should just stick to a CD player and manually loading CDs, because your brain is affecting how things sound to you, not your ears.  The key here is proper decoding.  I wouldn't mind helping people get their lossless stuff to decode properly if they can admit that the philosophy of lossless means you get the same exact data in the end, and that there could possibly be something wrong with their setup.

A music server is for convenience.  What I consider as a music server is a device that doesn't even play the music, but just something with a hard drive that serves it up to a network via WiFi or Ethernet.  Why you would use a Mac Mini for this, I don't know.  I would just get a SAN box and fill it with hard drives and maybe use some RAID on it.

[corndog71]

I thought AIFF and WAV were lossless.  I use apple lossless in itunes and they sound as good as the CD as far as I can tell.  Of course higher resolution files will sound better than CD's limited 16 bit format.  But apple lossless is clearly superior to any compressed songs.  Good vinyl on a good table still kicks ass though.

I've read that the Mac Mini makes a great music server.  And if you have an ipod touch, ipad, or iphone you can get a remote app that allows you full control of your music library.

There's a company that sells slightly modified (warranty intact) mac minis as music servers.  
www.mach2music.com  They can also upgrade a currently owned 2010-2011 mac mini.  I want to get one but the price is a bit over my typical allowance for such things.  I'll probably do it in steps.

I would also disagree that a digital signal is a digital signal and that's it.  Stereophile debunked that over a decade ago.

[porcupunctis]

I think what Doc was saying about lossless compression was that he chooses not to allow any compression when creating lossless files.  You can, for example, utilize some file compression without loss.  FLAC, for example, allows you to choose some compression if you want it.  When playing the computer/decoder will have to uncompress the file, but there is enough information there to restore it to its original form.

Lossy compression takes compression to the point that perfect restoration is no longer possible.  Some parts are intentionally left out to get the smallest file size.

Also, my understanding about the Mac Minis is that they are loved for their quiet operation.  I use a standard PC tower and the fan was so loud that I ended up moving it to another room. 

[ramicio]

AIFF and WAV are uncompressed.  When people say lossless they imply compression (why would a raw file imply any loss?).  How did stereophile debunk that a digital signal is a digital signal?  I'd like to hear this magic explanation (and a $64 million question).  Over a decade ago was a MUCH different time when it comes to DACs, and now they are totally impervious to jitter unless it is longer than half a clock cycle (which is highly unlikely, and you're then back to searching for things that are broken and faulty), even though people still complain about nano- and picosecond jitter.  The DACs reclock the signals now, and since the paths the signal travel at light speed now become microscopic, you have jitter that approaches down to relativistic times.  If your ears can pick of variations in the attosecond ranges, you likely have other super powers and should be worried about such things as instituting world peace or something useful to humankind.

The argument that CPU cycles decompressing a lossless file is also utter nonsense.  These people writing magazine articles must be geniuses to hold degrees in so many fields (not).  They don't have honesty at heart, they have sponsors to cater to.  FLAC, as an example, can be decoded on a Pentium II, so CPU power of today shouldn't even report any load over the usual background CPU usage fluctuations.  It takes much more power to compress it than it does to decompress it.  It's literally just like a ZIP or RAR file.  What you put in, you will always get the same thing out.

Yeah, vinyl sounds good, but that's also a matter of taste.  The noise floor is above a CD's, and any high frequency response is just noise, as well.  It's better if you can't find a CD of the music you're seeking that hasn't been loudness-warred, or if you like noise, pops, and clicks.  You may prefer the sound, but remember, as far as specifications go, it is technically inferior to Redbook CD.  Not to mention degradation from each play.  It's something like 11 or 12 bits can represent the dynamic range of vinyl.  So in 16 bits, you have 4 or 5 bits of noise.  I'd imagine those laser turntables might blow away CDs, though.

[ramicio]

I think what Doc was saying about lossless compression was that he chooses not to allow any compression when creating lossless files.  You can, for example, utilize some file compression without loss.  FLAC, for example, allows you to choose some compression if you want it.  When playing the computer/decoder will have to uncompress the file, but there is enough information there to restore it to its original form.

Lossy compression takes compression to the point that perfect restoration is no longer possible.  Some parts are intentionally left out to get the smallest file size.

FLAC compresses the file, period.  There is no way to have an uncompressed FLAC file.  The levels you can select are for a balance between encoding power and decoding power.  Level 0 is a fast encode, and takes more power to decode, and level 8 is a slow encode, and takes little power to decode.  The file size differences are negligible.  Uncompressed files are not lossless, because there is no compression.  Compression does not imply loss.  With ANYTHING lossless, you get exactly what you put in.  There is nothing thrown away, even though it is compressed.  It is based on redundant patterns and unused least significant bits.  It does not throw away any audible information.

Lossy compression works on removing things it thinks you will not hear.

I think people are generally mixing up lossless (which implies compression) files, and raw/uncompressed files.

[Chris]

Sorry to clarify, you are saying that raw uncompressed files and something like apple lossless (i also use), have the potential to sound the same using the SAME playback equipment?

[grufti]

Yes, lossless means that the bits received by the digital to analog conversion process will be the exact same bits that were in the uncompressed file. Lossless refers to the algorithm [the math] used to go from original to compressed to original ... no loss, same bits. The advantage is smaller file ... the cost is more processing, but even stoneage cpu's chuckle about the workload involved in going back and forth.

Sorry to clarify, you are saying that raw uncompressed files and something like apple lossless (i also use), have the potential to sound the same using the playback equipment?

[ramicio]

Sorry to clarify, you are saying that raw uncompressed files and something like apple lossless (i also use), have the potential to sound the same using the playback equipment?

Correct, they should sound the same because they are the same exact data being passed onto the sound card, unless there is a flaw in the decoder.  I'm not ruling out the possibility that people hear an honest difference, I'm just saying that it means something in the playing software chain MUST be broken for this to happen.

[Grainger49]

How does lossless compression change the quality when the name implies that literally there is no loss?  If there is a difference that's not placebo, it sounds like a faulty software decoder, to me.

I have to admit, "Lossless Compression" is an oxymoron.  But the marketing guys get to call it whatever they want.  Obviously if the data is compressed something is lost.  128 is not equal to 64, even a fifth grader knows that, I hope!

Still the marketing guys are to blame, not the engineers.

For the OP, I have a buddy who is running a music server on a Mac Mini.  I will email him and point him to this thread.  I have heard the system and it sounds good.  Not the best I have ever heard, that is reserved to some over $100,000 systems I have heard, but I relaxed and listened to his system for hours.

Edit: I contacted him we will see if I can lure him here. 

Now I have the analogy of Winzip I see that there can be compression without data loss.  I'm not stupid just ignorant of some computer related functions.