Rockbox mail archive
Subject: Re: High kbps/Low kbps power consumption
From: Eugenio Perea (eugenio_at_perea.com)
So you encode every CD twice? One for keeps at 192 and another for the
Archos at 128?
Eugenio Perea L.
Neon John wrote:
> On Thu, 5 Jun 2003 13:08:28 -0400 (EDT), <stevem_at_gator.net> wrote:
>>As a followup to my previous email, I've noticed that my Jukebox recorder
>>20 has trouble with 320kbps-formatted MP3 music files when the battery
>>level gets down to around 55 percent or less. Is this a known issue with
>>the Jukebox? I didn't see much about it in the bug reporting list.
>>I loaded the daily build ajz from June 4th, but I'm still having this
>>problem. I can hear the hard drive being accessed, then, afer a while, the
>>music will cut in again. It drops out intermittently.
> No, not a bug. Just an effect of running the thing at the edge of its
> performance envelope. Contemplate how much data the thing has to move to
> handle that bitrate and how much processing it takes and how much power that
> requires. Given that there is a fixed amount of RAM, the higher the bitrate
> the more often the drive runs. More power required. You're simply
> overwhelming the unit and with no material gain in sound quality.
>>Anyway, seeing this happen is what prompted my previous question. Is it
>>best not to play music on the recorder formatted above 128 kbps?
> I have very good ears and I can't hear the difference between the original CD
> and 192kbps even on my mid-level home system playing directly from the
> computer. I certainly can't hear the difference once the sound goes through
> the Archos' audio output circuit and then through headphones, even my
> PortaPros. It is a waste of space and processing power to put anything above
> 128kbps on the Archos, unless perhaps you're using the digital out to a high
> end system.
> I store all my rips at 192kbps on my computer. I downsample to 128kbps for
> the Archos using CDex and LAME. On this 2 gig machine the process is quite
> rapid. Since I have the disc space I simply maintain two file trees, one for
> the original rips and one for the archos.
> If you're using the thing primarily in non-optimal listening environments such
> as a noisy office, the car, jogging and such, you might try going even lower.
> There is a tradeoff between bit rate and battery life. You might find the
> lower sampling rate adequate for those environments.
> I downsample my audio books to 32kbps. there is a little distortion but it's
> acceptable, certainly better than, say, a mobile radio. My FM can suck in
> whole chapters at once, spinning the hard drive only every 15-20 minutes or
> so. That is how I get better than 14 hours' life out of a charge.
> Best thing to do is simply experiment some. Downsample to various rates and
> do some listening tests. When you find something you like, check the battery
> life. You'll be pleasantly surprised.
>>>I have an Archos recorder 20. Does playing a 320 kbps recording pull
>>>more power from the batteries than playing a 64 kbps recording?
> John De Armond
> Cleveland, Occupied TN
Page was last modified "Jan 10 2012" The Rockbox Crew