headphone adapters

[ddtwelve]

hi ive got the oxford bike mike 2 wired intercom and i need to wire in my sat nav as my intercom is a wired system ive used one adapter but one input was ok but the other was all feedback, does anyone know where i can get a two input(sat nav+bike mic) to one output to headphone  adapter as in ear earphones are starting to kill my ears 

[Dead Eye]

Do you mean 2 females to 1 male or 2 females to 1 female? You can get the first pretty cheaply on eBay (http://www.ebay.co.uk/itm/3-5mm-Stereo-A...4173b017ed)

The female to female are rare but you can use something like this; http://www.ebay.co.uk/itm/GENUINE-BRAND-...2a1e4cf050

I have one myself which I use for multiple inputs which then output to the single Line-In on the back of my PC

[simonm]

http://superuser.com/questions/154997/ca...one-output

Worth a read. Joining the outputs of two amplifiers is not generally recommended but it will work as Deadeye has evidenced ;-)

[Dead Eye]

Well the source signals aren't coming from anything particularly powerful (and they aren't connected to an amp) so all should be fine

My reason for using this sort of thing is that I have two monitors connected to my PC (via DVI). I then have a second PC (a server) connected via HDMI to one monitor and previously had an Xbox 360 connected via HDMI to the other. The monitors then have a 3.5mm stereo output for the HDMI audio as they don't have built in speakers. So, I've routed these two down to the Line-In to allow the audio to piped out of my PC sound system (a 5.1 setup). I've also occasionally plugged in my guitar (sans amp) which is good fun

Ok... that got out of hand

[simonm]

Well the source signals aren't coming from anything particularly powerful (and they aren't connected to an amp) so all should be fine

My reason for using this sort of thing is that I have two monitors connected to my PC (via DVI). I then have a second PC (a server) connected via HDMI to one monitor and previously had an Xbox 360 connected via HDMI to the other. The monitors then have a 3.5mm stereo output for the HDMI audio as they don't have built in speakers. So, I've routed these two down to the Line-In to allow the audio to piped out of my PC sound system (a 5.1 setup). I've also occasionally plugged in my guitar (sans amp) which is good fun

Ok... that got out of hand

It's a waste of a 5.1 amp to put stereo from an Xbox through it.. I'd try and use an optical out or coaxial to get proper 5.1 through it.

I just bought a onkyo which does dts-hd and has a 7 port hdmi switch too.

Back to the issue at hand, amplifier signals.  It doesn't matter that it isn't a powerful amp, the issue still stands, backfeeding voltage in to the low power satnav or whatever is just as dangerous as it's the relative powers that are important.  I'm sure it will be fine but if it isn't it could be expensive to fix :-P