From dwatson@oceaninlay.com Wed Jun 13 09:27:11 2012
Subject:RE: IEMs

Lou,

You are right on all counts. It's interesting that Shure only gives the P4HW
"9 V Alkaline battery", "up to eight hours, volume dependant" in their
owner's manual specs. At least that rating must be extremely conservative
when Tony states, "I've done 12 full nite gigs on ONE BATTERY".

Tony, are you using lithium-ion batteries? :-)

I've also been told that Westone's UM1 and UM2, maybe their entire line, are
compatible with personal ear molds.

Donn

-----Original Message-----
From: CloneWheel@yahoogroups.com [mailto:CloneWheel@yahoogroups.com] On
Behalf Of Lou C
Sent: Wednesday, June 13, 2012 10:30 AM
To: CloneWheel@yahoogroups.com
Subject: Re: [CWSG] IEMs

Not necessarily anything wrong with his electronics, except possibly a poor
design with regards to battery life.  The Shure PSM200 receiver (P2R, mono
audio) claims a 4-hour life using Alkaline batteries.  If rechargeable NiCd
batteries were used, the life would be much less, maybe a little as 1 hour. 
To compare the capacities of 2 AAs vs. 1 9V, the PSM900 receiver (P9R,
stereo) claims a battery life up to 7 hours on 2 AA batteries.

Tony's application is NOT a receiver but rather an earphone buffer
amplifier, where battery drain is only for the earphone loudness and is a
fraction of that needed for an FR receiver.  It takes a lot more current to
run the receiver circuitry.

Lou