How to make speaker louder.

I am using the speaker found on http://www.jameco.com/1/1/1925-gc0201m-32-speaker-round-32ohm-8-inch-dx-169-inch-h-micro.html. It is hooked up to an arduino UNO R3s pwm pin with a series resistor of 50ohms. The loudness is not getting anywhere near the specified 78dB even when I send 5V directly to the speaker. Anyone know how I can increase the loudness?

Oh and the max power rating is .2W. Using the equation P=V^2/R gives .2=V^2/32 => V=2.5V. 2.5V across the speaker is not loud at all.

The loudness is probably only possible to reach within the speakers frequency limits. For this speaker 700Hz to 8000Hz.

For the lower frequencies a box (or similar) is needed to stop air from going between front- and backside of the speaker.

I recommend u build a simple AMPLIFIER circuit like this one:

if u r too elite then search for a better amp circuit on YouTube and if u r too novice then find a simpler one.

Good luck

Same chip, different circuit -

Duane B

rcarduino.blogspot.com