Hi,
I am trying to generate voice by using PIC's PWM module. Which means that the max Vpk-pk of the voice is 5V. However, I anticipate that it will mostly be around 4V. I connect the output of PWM to a 2nd order RC lowpass filter with a Fc of 2kHz and then to a speaker similar to **broken link removed**. However my speaker is only 8 Ohm and 0.25 Watt. Using the PWM, I generate a sine wave of 400 Hz but the sound that comes out from the speaker is quite soft. When I increase the frequency, the sound comes out abit louder but it is still quite soft.
My initial idea is to connect the output of the lowpass filter to the amplifier stage of this circuit (only the U1A). The supply for the opamp will be 9V. The output of the U1A will connect to the speaker.
Having said that, is there any other better way to make the sound louder..? What should be the specs of the speaker..?
Thanks..
I am trying to generate voice by using PIC's PWM module. Which means that the max Vpk-pk of the voice is 5V. However, I anticipate that it will mostly be around 4V. I connect the output of PWM to a 2nd order RC lowpass filter with a Fc of 2kHz and then to a speaker similar to **broken link removed**. However my speaker is only 8 Ohm and 0.25 Watt. Using the PWM, I generate a sine wave of 400 Hz but the sound that comes out from the speaker is quite soft. When I increase the frequency, the sound comes out abit louder but it is still quite soft.
My initial idea is to connect the output of the lowpass filter to the amplifier stage of this circuit (only the U1A). The supply for the opamp will be 9V. The output of the U1A will connect to the speaker.
Having said that, is there any other better way to make the sound louder..? What should be the specs of the speaker..?
Thanks..