changeset 64:6b02de926277

FC-handset-spec section 1.7.1: mention Pirelli DP-L10
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 15 Jun 2021 19:28:52 +0000
parents 4389cd2b9d02
children 153b517ccc7a
files FC-handset-spec
diffstat 1 files changed, 9 insertions(+), 6 deletions(-) [+]
line wrap: on
line diff
--- a/FC-handset-spec	Sun Jun 13 09:19:03 2021 +0000
+++ b/FC-handset-spec	Tue Jun 15 19:28:52 2021 +0000
@@ -481,10 +481,12 @@
 
 Most current mainstream phones (in fact, all that I am familiar with) have
 physically separate speaker transducers for the earpiece function (hold up to
-ear to talk) and the loudspeaker+ringer function.  The earpiece speaker is a 32
-ohm load, and the loudspeaker is an 8 ohm load.  In a Calypso+Iota design, an
-external amplifier chip is needed to drive the 8 ohm loudspeaker, whereas the
-little 32 ohm earpiece speaker can be driven directly by Iota EAR output.
+ear to talk) and the loudspeaker+ringer function.  The not-so-current and not-
+so-mainstream Pirelli DP-L10 also features the same arrangement.  The earpiece
+speaker is a 32 ohm load, and the loudspeaker is an 8 ohm load.  In a
+Calypso+Iota design, an external amplifier chip is needed to drive the 8 ohm
+loudspeaker, whereas the little 32 ohm earpiece speaker can be driven directly
+by Iota EAR output.
 
 However, a very different design was implemented by TI on their D-Sample and
 Leonardo boards.  They have only one speaker, one of 8 ohm kind, that is
@@ -507,8 +509,9 @@
 architecture, using physically separate earpiece and loudspeaker transducers.
 This architecture feels more native to me, and it will allow for independent
 tuning of the two audio paths.  In my defense, all current mainstream phones
-seem to use the same architecture - the other approach with a single loudspeaker
-in the earpiece physical position seems very uncommon.
+seem to use the same architecture, and so does the Pirelli phone that serves as
+my personal reference - the other approach with a single loudspeaker in the
+earpiece physical position seems very uncommon.
 
 1.7.2. Loudspeaker implementation