Jump to content


Photo
- - - - -

TRIVIA question of the day


  • Please log in to reply
4 replies to this topic

#1 klipshcom

klipshcom

    Member

  • Members
  • PipPip
  • 32 posts
  • Offline

Posted 11 July 2013 - 11:42 PM

Hi guys....,

Is there is such a thing as a digital db meter that that i could plug directly into a headphone speaker jack? I do not want the external mic at all. I am trying to determine the level of sound of a beep (just a simple beep) that is being produced from the HP jack if the beep gets too quite for me to hear the digital meter would still pick it up, either a spike on a graph or a higher number on the display which of course also would also show an even higher reading or spike for the stronger signal "beeps" sounds funny but.....This is a very real question....Any Ideas??

This is a great forum with lots of knowlege....figured id try it here first

Thanks in Advance guys



#2 tube fanatic

tube fanatic

    tube amp designer

  • Members
  • PipPipPipPip
  • 1,016 posts
  • Offline

Posted 12 July 2013 - 10:34 AM

Not sure exactly what you're trying to accomplish. If the only audio from the jack is the beep, you could use almost anything capable of measuring a low level AC signal. But, if you're simultaneously playing music, the level of the beep could be easily masked; if you raise its level sufficiently to be monitored over the music, it would certainly be loud enough to be heard. More specifics would be helpful.

#3 klipshcom

klipshcom

    Member

  • Members
  • PipPip
  • 32 posts
  • Offline

Posted 12 July 2013 - 08:40 PM

I have a metal detector. I thought perhaps a visible graph or number display as to the intensity of the beep might be helpful... the signal beep that i can hear diminishes the further down the object is. The standard type DB meters can filter out or lock out the ambiant noise and should i see a small spike from the graph.... even though I cant hear it, the machine can.....

Just an experiment



#4 tube fanatic

tube fanatic

    tube amp designer

  • Members
  • PipPipPipPip
  • 1,016 posts
  • Offline

Posted 14 July 2013 - 02:15 AM

Your ears are likely the most sensitive indicators that you could use. The issue is that the beep may be below the noise floor of the audio amplifier in the detector. So, while the detector may respond to the weak signal from the object, you still won't be able to pick it up either with your ears or with any kind of indicating device. One possible way around it is to construct an audio filter with very steep skirts centered on the frequency of the beep. By having an extremely narrow passband, the beep should theoretically be audible at lower levels than without the filter. Probably not worth the trouble imo.



#5 William F. Gil McDermott

William F. Gil McDermott

    Klipsch Fanatic

  • Members
  • PipPipPipPipPipPip
  • 6,014 posts
  • Offline

Posted 21 August 2013 - 03:30 PM

If you are just interested in a beep, and there is no other signal, and it is on some media.

Then I try using MS Media Player and switch the display to bars display. This is a simple real time display of several dozen bands.

Unfortunately, there are no labels for frequency or level. But it is a start.

I've fooled with the recording program Audacity which has a real time level display. So if you have another computer you could feed the headphone out to a line input on the computer running Audacity. Maybe that will show the beep.

WMcD