Daisy chaining headphones

[anuragaks10]

Hello folks,

I am building a set of daisy chaining headphones to transmit from one pair of headphones to another through Infrared in real-time. When I say real-time I mean that suppose I m listening to some good music which I would like to share, I simply connect this device to my music player and my headphones on the other side of the device. This device will enable me to listen the music and simultaneously transmit it to my friend who would have an identical device and a pair of headphones. So basically my design is that device and one can attach any headphones to it (as long as it is 3.5mm jack).
The circuit I am building has to be simple due to time and money constraints. We are stuck on a few things like :
(1) What kind of amplifier should we put ? and which side, transmitter or receiver ?
(2) How should we do noise filtering ? What circuit we should use for that ?
(3) Do we need modulation ? We are going to use the device to transmit music only.

We want to include a unique selling point to our device. I was thinking if we could store some music to play later or transmit to another device later. Any thoughts on this ?


Cheers,
Anu

 

[gabeNC]

Is IR a good choice? Start moving around and you lose the signal. The infamous zune player had a similar concept but used wifi to share music.

 

[anuragaks10]

yes. unfortunately this is just a project from a university course. Our initial plan was to use RF, but then lecturer told us to use IR coz of time constraints.

 

[audioguru]

I guess you forgot to research the many wireless headphones products that are mass-produced by major manufacturers and are inexpensive.
Are you simply going to copy one? Why will your unknown and more expensive one be purchased by anybody?

You don't know anything about amplifiers (maybe you also forgot about powering the amplifiers). You need one stereo transmitter (radio or IR) and power supply for it. Each set of headphones needs a receiver, amplifier and power supply. You don't understand that if you filter the audio then important frequencies in the audio which are the same frequencies as noise will be missing.

If you do not use modulation then you will be transmitting silence.

 

[anuragaks10]

ah....I apologize. Electronics is not my major, I am doing this as an elective. But thanks your advice in the most condescending tone...
I just wanted to know how to do noise filtering and modulation.

 

[audioguru]

You forgot to describe the "noise".
If it is mains hum pickup then you can use a highpass filter to reduce it but then all the low frequencies of music will also be reduced. You can use a notch filter set to your mains frequency so that the fundamental frequency will be removed (and any sound in music that is at that frequency) but harmonics of the mains frequency will still be audible.

If the noise is hiss from a poor communications link then it can be reduced with a lowpass filter but then all high frequencies of music will also be reduced so that everything sounds like a telephone or like an AM radio.

The simplest forms of modulation are AM and FM. AM has a lot of interference so FM is usually used for music.
All FM radio stations boost high audio frequencies and all FM radios reduce the high audio frequencies back down to normal which reduces hiss.

 

[Sceadwian]

anuragaks, what is the extend of your knowledge of electronics?