[PaulieWallie]

Hi all,
 
I'm new around here, but have done a few earphone DIY projects. 
 
I recently picked up a pair of old Bose IE Triports that had a torn wire right at the 1/8" jack that was not fixable. So instead I intended just to use the headphones. I wired them up to a regular pair of headphone wires but the sound was not nearly as refined as it was when I was able to wiggle the wires around to contact their appropriate leads before I took the thing apart. 
 
I never thought that the "driver" or "amp" or whatever it is at the 1/8" jack actually made that much of a difference. I decided to take the thing apart, but because it was overmolded, it was not a pretty dissection and the PCB board is basically destroyed. I was able to make a schematic of the circuit, but have no idea what it does. 
 
Can anyone help me understand what this circuit does and relate its importance to me? Also, the capacitors in the circuit were unmarked on the PCB (seen highlighted in orange below). I thankfully kept all four of them so in recreating the circuit, will hopefully not lose their function. 
 
Here is the circuit diagram and a picture of the parts. http://i.imgur.com/IGLUVl.jpg
 
Thanks!

 

[Tangster]

I think it's a band pass filter.

 

[PaulieWallie]

Hey thanks! So it would filter out certain frequencies if I'm understanding correctly?

Sent from my SCH-I535 using Tapatalk 2

 

[rcjroy]

I know this is an old thread but did you ever find the values of the two capacitors? or markings on them at the least? I too have an old bose ie that I've found but have long discarded the connector/filter