Rockbox.org home
release
dev builds
extras
themes manual
wiki
device status forums
mailing lists
IRC bugs
patches
dev guide



Rockbox mail archive

Subject: RE: Battery life as related to output volume
From: Fred Maxwell (rockbox_at_anti-spam.org)
Date: 2004-03-14


Jörg wrote:

> Headphones need only little power to punch your eardrums, the difference
> is not significant. I measured 77 mA with zero volume, 80 mA at full blast
> (you would not want to have wear that), with a low-impedance headphone
> (sortof the worst case).

While impedance is a key factor, the other key to power consumption by
headphones is their efficiency. If you have one headphone that's rated
92db/mw and another that's rated 101db/mw, the 92db/mw will take eight times
the power to reach the same volume level. For every 3db decrease in
efficiency, the power doubles. If you want to increase battery life, pay
close attention to the efficiency of the headphones that you use.

Also, with the undersized capacitors in the outputs of many of the Archos
units, it's best to select a high-impedance headphone for optimal bass
response.

Regards,
  Fred Maxwell

_______________________________________________
http://cool.haxx.se/mailman/listinfo/rockbox



Page was last modified "Jan 10 2012" The Rockbox Crew
aaa