frequency for a nice beep sound

Discussion in 'General Electronics Chat' started by bug13, Oct 5, 2015.

  1. bug13

    Thread Starter Well-Known Member

    Feb 13, 2012
    1,208
    38
    Hi guys

    I need to generate a beep sound as a feedback for user when they pressed a button, are there some frequencies that produce a nice beep sound? I am using a piezo.

    Thanks guys!
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,023
    3,236
    Have a look at these.
     
  3. bug13

    Thread Starter Well-Known Member

    Feb 13, 2012
    1,208
    38
    I have checked the top 5 links, they are all some kind of audio files. But I don't have the ability to play an audio file. I think I can combine different frequency in one tone. And I can't adjust volume neither.
     
  4. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
    2,040
    287
    400-700 Hz seems to be nice. If you want a little more bite, you can use a sawtooth wave instead of a sine wave.
     
    bug13 likes this.
  5. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,059
    3,823
    A sine wave is like a ringing bell and it can be annoying. A triangle wave is more pleasant and less piercing. A square wave sounds more like a saxophone. 440Hz is a middle C and pleasant as well. Higher frequency will make it more attention grabbing (up to 3k Hz).
     
    bug13 likes this.
  6. atferrari

    AAC Fanatic!

    Jan 6, 2004
    2,648
    764
    My (very limited) experience says that what matters for being reasonably pleasant is shape -ASDR- harmonic content and then fundamental frequency, all this managed to a discrete volume.
     
    bug13 likes this.
  7. OBW0549

    Well-Known Member

    Mar 2, 2015
    1,320
    889
    I think you have to experiment to find out what sounds best, as this is going to vary greatly depending on environment and usage.
     
    bug13 and Roderick Young like this.
  8. Sinus23

    Member

    Sep 7, 2013
    163
    411
    Just a small correction. But I agree middle C is pleasant. 440Hz was(is?) the tone on your landline phone before you make a call and is an A on the 4th octave on a piano.
    https://en.wikipedia.org/wiki/A440_(pitch_standard)
     
    bug13 and Roderick Young like this.
  9. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,059
    3,823
    Good, I knew there was something special about 440Hz, (pitch standard), I just didn't remember which note it was and I didn't have the motiviation to look. Thank you for being both musically interested and technically astute enough to make the correction.
     
    bug13 and Sinus23 like this.
  10. Sinus23

    Member

    Sep 7, 2013
    163
    411
    No problem your post actually made me think for a split second that I had tuned my guitar in the wrong key all my teenage years ;)
     
  11. d0ughb0y

    New Member

    Aug 18, 2015
    5
    2
    you are probably using a passive buzzer. I suggest that you use an active buzzer (search ebay for active buzzer), so all you need to do is set the pin high to turn it on, and low to turn it off. I use this in my project and I have coded some routines to make different number of beeps and beep length to signify success, error, etc. I use timer interrupts on arduino and IntervalTimer on teensy (arm MK20 mcu) so it does not affect main program loop execution. Early on I mistakenly purchased the passive buzzer and I had code to output the square wave to generate the beep. I can tell you that you can never make the sound as crisp as one from an active buzzer.
     
    bug13 likes this.
  12. InspectorGadget

    Active Member

    Nov 5, 2010
    211
    42
    Piezos have a resonant frequency. I usually drive them at their resonant frequency with a square wave if I want to get any significant volume level. Off resonance they're a lot fainter.

    I also drive them push-pull with two MCU outputs if I really want more volume.

    Whether I use one or two MCU outputs I always drive both sides to ground when I'm done playing a sound to relieve stress on the piezo element.

    I've never tried driving piezos with a DAC output, but in my significant experience with using gadgets, annunciators (beeps) that I've heard sound a whole lot better with an exponential (bell-like) decay in the volume.
     
    bug13 likes this.
  13. AnalogKid

    Distinguished Member

    Aug 1, 2013
    4,542
    1,251
    Just a small correction, US and British dial tones are a combination of 440 Hz and 350 Hz.

    Also, back in the days of *real* videotape, the reference level audio tone recorded at the start of every recording was 400 Hz at zero level (+8dBm). Occasionally we came across something with 1 kHz, and even more rare was 800 Hz. Those frequencies were closer to the center of the audio bandwidth, but 400 Hz was far more pleasant.

    ak
     
    Sinus23 and bug13 like this.
Loading...