project help

[audioguru]

Your circuit has a microphone. I don't know what produces the sounds. A tiny speaker will not produce low frequencies.

 

[fkuk]

what frequencys do you concider low?

 

[audioguru]

what frequencys do you concider low?

We can hear down to 20Hz. We can feel lower frequencies.
Cheap speakers cutoff at about 100Hz. Pretty good woofers cutoff at 50Hz.
The subwoofer in my car and my home stereo speakers cutoff at 30Hz.

 

[fkuk]

so basically this will not show 100hz very well then

 

[fkuk]

hopefully i have the parts by next thursday

 

[fkuk]

project help *UPDATED*

you know this circuit on the first page
i finaly got it to work with the lm3619

what i did was take out Q3 and its capacitor and the wire going to Q3 was sent to pin 5 of the lm3916

the only other change i had to do was change the Vref by having two 1K resistors in series from pins 7 and 8 to ground and adding pin eight to the middle of the two resistors

it works really great now at good sound levels

the only thing i have now is that 4 leds at the start are on constantly and i want to know how to turn them off and react to sound?

do i add a bigger resistors to pin 5 to ground?
or something else

 

[audioguru]

Your attachment does not work.

Pin 5 of the LM391x must]/b] have a resistor to ground (1M or less) and must have capacitor coupling from the DC output of Q2.
The four LEDs are lighted due to the DC voltage at the output of Q2. A coupling capacitor from the output of Q2 to the input pin 5 of the LM391x will block the DC but allow the signal level to light the LEDs.

 

[fkuk]

what value capacitor

 

[fkuk]

dont worry i have got it now

i have stuck a 4.7 uF capacitor betwwen pin 5 and transistor and then put pin 8 to ground then added a 1k reistor to ground from pin 6 and 7

now i am happy with the results

i cant thank you enough over the past month or so guiding me in the correct direction and i hope i was not too ignoying