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Subject: Re: High kbps/Low kbps power consumption
From: Neon John (johngd_at_bellsouth.net)
Date: 2003-06-06


On Thu, 05 Jun 2003 16:11:57 -0700, Jon Drukman <jsd_at_cluttered.com> wrote:

>At 02:37 PM 6/5/2003, Neon John wrote:
>>No, not a bug. Just an effect of running the thing at the edge of its
>>performance envelope.

<snippity>

>no offense, but that's a load of rich creamery butter. my JBR is happily
>playing 320K mp3's right now with only 30% battery life left. not a skip
>to be heard in 80 minutes (so far) of playing.

Now consider a unit with perhaps a slightly slower CPU clock, perhaps tired
batteries with a slightly higher internal impedance than your, perhaps a hard
drive that is a little less tolerant of voltage dips, perhaps highly
fragmented, perhaps even a different brand drive with lower performance specs
and/or higher power consumption - all in the range of normal tolerance buildup
(Mine and my friend's FM recorder, bought a couple of days apart from the same
shelf space have different brand drives.) That it may work for one unit and
not for another is practically the definition of being on the edge of the
performance envelope.

The test for this is to change one thing at a time and test. Try a little
lower sample rate. Different batteries. Defrag the drive. Hook a DC power
supply to the battery terminals and vary the voltage. See what happens. If
any of these steps reduce the problem then it is fairly obvious that it is an
edge-of-the-envelope problem. If not, then we look elsewhere. Since it only
happens when his batteries are partially depleted (slightly lower voltage),
I'm betting on an edge phenomena.

>i hope you are not transcoding the 192K files to 128K files but rather
>generating the 128's from the original wav or cd.

Of course I'm transcoding. And I'm completely happy with the results. Maybe
it's an age thing or something but having grown up with 8 tracks and then
cassettes in the car and being perfectly happy with them IN THAT ENVIRONMENT,
I'm more than satisfied with 128k (which sounds better than the best cassette)
on my PORTABLE player. This is my PORTABLE player, used while doing things
and in my car. It is not my main system - I have a computer dedicated to
playback on my home system. Practical concerns such as how many songs I can
get on the thing and how long the battery lasts is vastly more important to me
than theoretical artifacts potentially introduced by transcoding, none of
which are audible through headphones or in the car with normal levels of
ambient background sound.

To pull this away from audiophile theology, let's remember that the original
question was why his Archos was acting up while operating near the max bit
rate. I'm simply explaining why that could happen, how to find out the cause
and the operational benefits to using a lower sample rate ON THIS PORTABLE
DEVICE. Can I hear the difference on my home system using my electrostatic
headphones? Of course. Does it matter on my Archos? For me it doesn't.

John

---
John De Armond
johngdDONTYOUDARE_at_bellsouth.net
http://bellsouthpwp.net/j/o/johngd/
Cleveland, Occupied TN



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