Connecting 2 1W speakers
Points 1 &amp; 2 are the soldering points for the speaker voice coil. Do not solder connecting wires on 1 &amp; 2 as the voice coil wires may get disturbed and cause damage to the speaker.
Points A &amp; B are the copper pads where the wires are to be soldered.
Soldering slender wires will avoid overheating and damage to the speaker. 
The wires are to be held in the headphone jack lug holes and soldered.
Wire colours are only to identify 'left channel', 'right channel' and 'common'.
Wire as shown below.




Since you are using 8Ω 1W speakers, take care to ensure that the headphones are not plugged into a high power amplifier output which may cause hearing damage. 

A power input of 10mW to the headphones may be adequate for comfortable listening. Standard headphone impedances are 32Ω and 300Ω.