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Gary
07-07-2005, 04:59 PM
I put one of these in last week, and man does it sound like crap. Has anyone else used the iPort? What were your results?

tomciara
07-10-2005, 03:27 AM
Would it not depend on the quality of the rip that the client used?? See if they'll rip their CDs at a higher quality setting.

Gary
07-10-2005, 09:24 AM
Would it not depend on the quality of the rip that the client used?? See if they'll rip their CDs at a higher quality setting.

Most of their music was from the iTunes music store.

nholmes
07-10-2005, 10:25 AM
I know there is supposed to be an option for higher quality downloads. Not sure of exactly what it is but I have seen mention of the option in a few places.

Gary
07-10-2005, 10:50 AM
After further review I don't think this is a iPort issue. I hooked my iPod up to my system (B&K receiver/Kef XQ1) and it sounds bad as well.

Maybe I'm just spoiled.

nholmes
07-10-2005, 11:00 AM
What bit rate are your Mp3/AACs encoded at? I used to use a minimum of 160 and now use EAC/LAME to rip at 192 based VBR. Still not as good as the original but very close without taking up the full space of a raw rip.

Gary
07-10-2005, 11:08 AM
I don't know what bit rate music from the iTunes store uses, but you have no control over it.

I rip all my CDs at 192, but most of my music on my iPod is from the music store.

avophile
07-10-2005, 02:45 PM
The MPEG-4 AAC spec supports a variety of bit rates as well as CBR and VBR. From a deeply hidden recess of the Apple Music store:


Purchased songs are encoded using MPEG-4 Advanced Audio Coding (AAC) format, a high-quality format that rivals CD quality.

Songs purchased and downloaded from the Music Store are AAC Protected files and have a bitrate of 128 kilobits per second (kbit/s).

The purchased song should sound as good as or better than a 160 kbit/s MP3 file. Because the bit rate is lower, though, the AAC file takes less disk space than the MP3 file.

I imagine the specific AAC spec the Music Store uses is hidden so as to not upset consumers looking for the highest kbit/s. This is similar to the dilemma facing display manufacturers providing accurate information on ANSI lumens and contrast ratios.

Advantages and disadvantages of AAC from chapter three of How to Do Everything with Your iPod & iPod Mini, by Guy Hart-Davis (McGraw-Hill/Osborne, ISBN 0072254521, 2004):


For music lovers, AAC offers higher music quality than MP3 at the same file sizes, or similar music quality at smaller file sizes. Apple reckons that 128 Kbps AAC files sound as good as 160 Kbps MP3 files—so you can either save a fair amount of space and enjoy the same quality or enjoy even higher quality at the same bitrate...

The main advantage of AAC for the music industry is that the format supports digital rights management (DRM). This means that AAC files can be created in a protected format with custom limitations built in. For example, the song files you can buy from the iTunes Music Store are authorized to be played on up to three different computers at the same time. If you try to play a song on a computer that’s not authorized, the song won’t play...

For consumers, the largest potential disadvantage of AAC is the extent to which DRM can limit their use of the files. At the time of writing, Apple has delivered a relatively flexible implementation of DRM in the music sold by the iTunes Music Store. However, if Apple and the record companies tighten the licensing terms of the files in the future, consumers may have cause for concern. In this sense, AAC could act as a Trojan horse to wean customers off MP3 and onto AAC, then gradually lock them in to a format that the music industry can control.

Book excerpt from:
http://www.devhardware.com/c/a/Software/Bringing-Yourself-Up-to-Speed-with-AAC-MP3-and-Digital-Audio/3/

Storage space becomes increasingly trivial as an issue. DRM will be a back and forth issue as the political economic tug of war plays itself out (a threat/opportunity for us). The most important technical issue influencing your choice of bit rates when ripping CDs is that playing back files encoded at higher rates makes the hard drive have to spin up more frequently leading to heat issues and earlier failure.