codifus wrote:
> I recently upgraded the software in my music server and found that
> rather than improve my system, it was degraded.
> I upgraded to iTunes 7.6.2 and a newer quicktime so that I could
> download 256 kbps AACs from the itunes store.
>
> Every so often I would hear a glitch in the stream but dismissed it as
> some sort of bug that I need to work on finding at some point.
>
> The other day, though, I decided to run Densen Demagic CD to clear my
> system of any residual magnetism in the audio path. I have the Demagic
> CD ripped losslessy to my itunes library and played that. I hit the
> play button and left the room as it sounds quite annoying. during its
> playback I noticed some distortion that I never heard before. I
> investigated further and found that the distortion was there even at
> low volumes.
>
> Did I damage the preamp section of my amplifier? To find out I took
> the original Demagic CD and played it in my DVD player. It sounded
> fine, just as it always had.
>
> It turns out that the itunes upgrade degraded my music server. It is
> not so much the fault of itunes, more of the ever same issue where
> bigger software needs bigger, or faster, hardware.
>
> My upgraded iTunes server is runnning on a lowly Macintosh G3 at 350
> Mhz and I found that the system requirements of iTunes 7.6.1 specify a
> G3 with 500 Mhz or greater.
>
> The degradation is not very apparent with regular music but became
> dramatically so when playing a test tone at near peak amplitude.
>
> Time to upgrade the hardware.
> Just a word to the wise.
>
> CD
So I upgraded my Macintosh to a G4/733. My music server is solid again.
I didn't realize how much everything was affected. Now my MP3 and AACs
sound whole lot better than before and there's no distortion anywhere.
My lossless files go loud, are very dynamic, and clean. It's weird this
relation****p between itunes and the air****t express. I figured that
Itunes was bascially acting as a truck and simply trans****ting the data
to the air****t. The itunes upgrade (on my barely adequete hardware,
admittedly) shouldn't have had such a detrimental effect on my system,
but it did.
Also, my speaker was repaired and returned to me. I set everything up
and listened to the system again.
Found a problem:imaging was shot. This was strange, though. Usually the
imaging problem is due to the speakers being out of phase, but these
weren't, or didn't seem to be.
I investigated further and ran these tests:
Played the demagic CD. Sometimes it clears up imaging. No good. Imaging
was still terrible.
I played sources in mono. With your eyes closed you should hear the
sound coming from midway between the speakers. No dice. Even mono
sources sounded "everywhere and nowhere"
Listening some more I started to notice this:
Bass was definitely in phase. Out of phase bass is usually weak and
undefined. Not here.
Mostly the upper regions is where the imaging seemed to suffer. If,
however, a strong treble signal would play, like the cymbals of a drum
set, their image would center properly.
Maybe the midrange was the only driver out of phase. So I took apart the
repaired speaker and reversed the connections to the mid-range only.
BAM! Monophonic sources were dead center now.
Apparently the technician who repaired the crossover must have reversed
the connections to the mid-range driver. It was inevitable since both of
the wires for the mid-range were orange and indistinguishable.
Anyway my system's back and unfortunately I do envision some more cooked
crossovers in my future. The G4 upgrade really brought my music server
back to its earlier glory. I will be enjoying the music too much, and
especially too long:)
CD
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