Piezo versus Dynamic

I was working on packaging a keyer and realized that my favorite, telephone ringer type of piezo wouldn't fit. These piezos use a 44 mm disc and are housed in a plastic case with mounting ears.  They can either be mounted behind a panel or put outside the case.  But I couldn't squeeze them in.

Then I decided to try a small dynamic speaker like this:

source: https://www.mouser.com/ProductDetail/DB-Unlimited/SM231508-1?qs=t9M3m0YJX4Ng139DBuQXjw%3D%3D

It's less than an inch in diameter but sounds fairly good, better than a piezo.  However that decent sound comes with a cost: higher power.  The keyer driving a piezo uses about 0.7 mA but the dynamic speaker uses 12.8 mA.  So a 12 mA difference at 5 volts, that's 64 mW versus 4.5 mW.  So battery life will be shorter.

Another thing:  I don't like to hook a low resistance directly to a PIC pin, so a series cap will also be used - it's also a little louder with the series cap (470 uF).

People have been suggesting that I use dynamic speakers for years but I've resisted, now I'll give it a try :)

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm