In this instructable I'll share with you how to salvage landline phone's handset into a headset for tablets or mobile phones.
In short words:
cut the headset's wire, you will see 5 colored wires, connect one of the speakers wire of the headset to that of the handset, do the same for the mic and that's it.
details are in the following steps..
Warning: it is a stupid idea!
Step 1: Components
I got the handset from an old landline phone, though any handset can work as long as you know the wiring (speaker and mic wires, will be explained later).
Step 2: Cutting Headset Wire
Cut the wire the same way indicated in the pictures (two cuts, one before the buttons and one after them).
in this step you will need to know the coloring code of the wire, as there will be 5 wires connected to the left speaker,right speaker and the mic... see the pictures..
the left speaker has three wires:
red: for the speaker itself (won't be used)
green: for the mic
non colored: common
the green and common wires will be later connected to the handset mic wire.
right speaker wires will be connected to handset speaker wire
to make sure of the coloring code, the second cut (the one after the buttons) tells you what wire goes to the speaker, thus the remaining one will be for the mic, (the common is known, as it's usually not colored..)
Step 3: Cutting Handset Wire
Yellow and black wires: for the microphone.
Green and red: for the speaker.
Headset wire can be either connected to the handset cable, or directly to the speaker and mic wires inside the handset (what I did), however, it would be even better if you connect it to a female handset connector keeping everything neat and reusable!
Step 4: Soldering
Now before you solder everything together, make sure the insulation that covers the wires is removed (this is very important).
connect the handset speaker wire to the right speaker wire of the headset.
connect the handset microphone wire to that of the headset.