Maker Pro
Maker Pro

earphones and music

anshulj

Aug 31, 2011
3
Joined
Aug 31, 2011
Messages
3
i am very curious about working of a music player and earphones...what passes within the earphones?? is it varing current?? can i amplify it and connect a large resistance and convert it to varying voltage and see it on a CRO???

and i want to make a headphone that plays only bass...no vocals...what should i do??
plz help me...as early as possible.. thnx in advance..:)
and i know that a music file passes through some kind of encoder ic...
i am more interested in knowing about earphones...
 

davenn

Moderator
Sep 5, 2009
14,254
Joined
Sep 5, 2009
Messages
14,254
i am very curious about working of a music player and earphones...what passes within the earphones?? is it varing current?? can i amplify it and connect a large resistance and convert it to varying voltage and see it on a CRO???

and i want to make a headphone that plays only bass...no vocals...what should i do??
plz help me...as early as possible.. thnx in advance..:)
and i know that a music file passes through some kind of encoder ic...
i am more interested in knowing about earphones...

Hi
Welcome to the forums :)

its a varying voltage the louder the voltage the higher the volume
you wouldnt need to amplify it to see it on a CRO as they are very sensitive and you would easily display the output from a MP3 player etc

the only real ways to get rid of the vocals would be to buy a instrumental version of the sound track.
It could probably be done with some really serious hi tech filtering but well outside the scope of a hobbiest to be able to do

cheers
Dave
 
Last edited:

davelectronic

Dec 13, 2010
1,087
Joined
Dec 13, 2010
Messages
1,087
Headphones

Hi anshulj.
Head phones are just miniature speakers, they have a permanent magnet and moving coil and a diaphragm, the coil is pulsed by the music you play by voltage being driven through the small coils, you can amplify any audio signal, but be careful of your ears and hearing, you dont need a full size amp, you can build one from drawings ( schematic ) or by a kit first.

I listen to my local radio stations through a stereo tuner amplified by some spare pc speakers i had laying around, a wall wart, or plug in dc power supply to run the speakers, some RCA leads and a stereo jack plug to RCA adapter to listen to it. I dont own a CRO but will get one soon, yes you could amplify the head phones out put, or what goes in them should i say and see this as a wave form on a CRO. Dave. :)
 

torea

Sep 1, 2011
12
Joined
Sep 1, 2011
Messages
12
If you wanted to try to make your own vocal-less take of a stereo recording, you can invert the phase of one of the tracks. This would probably be easier to do with a computer program like Audacity or Reaper (both free!) than with electronics (although I haven't tried with electronics). Typically, vocals are centered in the middle of the stereo track, so by flipping the phase of one side it'll cancel the other, (hopefully) without canceling much else. This is how some of those karaoke machines work, if they take a normal MP3 and claim to "cancel" the vocals. Doesn't always sound right though =/

Unfortunately, the bass is also usually centered, so you might do more harm than good. Maybe just EQ the music, scooping out between maybe 500Hz-1.2kHz?


EDIT: here's a video from YouTube explaining the phase reversal method -
 
Last edited:

anshulj

Aug 31, 2011
3
Joined
Aug 31, 2011
Messages
3
one positive thing i got to know here was, tht earphones work on varying voltage and not on current...does this voltage depend upon beats?? and what is its range??
Ps- thnx 4r d replies..:)
 

davenn

Moderator
Sep 5, 2009
14,254
Joined
Sep 5, 2009
Messages
14,254
Hi anshulj.
Head phones are just miniature speakers, they have a permanent magnet and moving coil and a diaphragm, the coil is pulsed by the music you play by voltage being driven through the small coils, you can amplify any audio signal, but be careful of your ears and hearing, you dont need a full size amp, you can build one from drawings ( schematic ) or by a kit first.

I listen to my local radio stations through a stereo tuner amplified by some spare pc speakers i had laying around, a wall wart, or plug in dc power supply to run the speakers, some RCA leads and a stereo jack plug to RCA adapter to listen to it. I dont own a CRO but will get one soon, yes you could amplify the head phones out put, or what goes in them should i say and see this as a wave form on a CRO. Dave. :)

read my comment posted before your one Dave :)

he doesnt need to amplify the headphone signal for it to be seen on a CRO there's already plenty of signal available for that :)

cheers
Dave
 

davenn

Moderator
Sep 5, 2009
14,254
Joined
Sep 5, 2009
Messages
14,254
one positive thing i got to know here was, tht earphones work on varying voltage and not on current...does this voltage depend upon beats?? and what is its range??
Ps- thnx 4r d replies..:)

no not so much on the beats on their own, but on the loudness of the music the louder you have it turned up, the more voltage that is produced. Also the content of the music
imagine for a fixed volume control setting (say 1/2 way) a quiet piano piece of music compared to a blaring rock guitarist. the screaming guitar is gonna be a lot louder!! :)
anything from 0V to + and - a couple of volts or so. you would be able to measure that with your CRO to get peak to peak voltages

cheers
Dave
 

conductor3

Jun 7, 2011
84
Joined
Jun 7, 2011
Messages
84
one positive thing i got to know here was, tht earphones work on varying voltage and not on current...does this voltage depend upon beats?? and what is its range??
Ps- thnx 4r d replies..:)

it depends one the pulses coming through the wires to the speaker
 
Last edited:

conductor3

Jun 7, 2011
84
Joined
Jun 7, 2011
Messages
84
here is a project for you just build this pulse generator then turn the pot the tone should change any one els that can correct this diagrm could be helpfull
 

Attachments

  • untitled.GIF
    untitled.GIF
    12.7 KB · Views: 112

anshulj

Aug 31, 2011
3
Joined
Aug 31, 2011
Messages
3
it wud b nice if sum1 tels me the range f voltage recieved by an earphone when music is played.:)
thnx 4r al ur replies..:)
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
It all depends on the type of earphone/headphone and the volume that you're playing them at.

Have a read of this.

Use a rule of thumb that for a particular level of sound pressure (volume) that you need approx 1/1000 of the power into headphones as you do into speakers.

Let's assume that you have an average power of 10W into speakers (and that is surprisingly loud and requires an amplifier capable of probably 200WRMS) then your average power into headphones may be 10mW.

If your headphones are 32 ohm, then the average voltage is going to be something like sqrt(32 * .01) = 0.57V

So how does about half a volt sound?
 

davenn

Moderator
Sep 5, 2009
14,254
Joined
Sep 5, 2009
Messages
14,254
it wud b nice if sum1 tels me the range f voltage recieved by an earphone when music is played.:)
thnx 4r al ur replies..:)

I did .... read my previous post

Dave
 
Top