Building switch between PC headphones and PC speakers. Can I combine the Grounds?

[Guineaman]

Hi there,
The speakers and the headphones both take same signal from normal 3.5mm pc out, both standard 3.5mm stereo jacks.
Do I need a 3 pole 3 throw switch to keep the grounds for each device separate or can I use a 2p2t and solder together the ground of the speakers input and headphones input together, and just use the switch to switch between the 2 left and right signals?
Thanks very much
Michael

 

[Audioguru]

Usually a headphones output has attenuation so the speaker level does not blow your head off.
Headphones usually have the grounds connected together. Frequently speakers have each wire driven from separate amplifiers (bridged) so there is no ground wire.

 

[Guineaman]

Hi,
They are powered pc speakers with an amp an aux input and they take the same signal /level type, from the pc out, as the headphones. On a standard stereo 3.5mm audio jack, theres left, right and then 0? ground? idk. Do you think I can connect the (0)s and save myself pins on the switch? Or are you saying I don't need that 3rd pin at all?
Hopefully I'm not being too vague :/
Thanks,
Michael

 

[Audioguru]

All the powered pc speakers I have seen have a 3.5mm stereo headphones jack that is already attenuated and when headphones or an aux cable is plugged in the speakers are switched off.

I do not know why your pc speakers do not have a headphones jack and I do not know if the speaker amplifiers are bridged with no ground wire going to each speaker.