Converting 4-wire Speaker/Mic pair into 3-wire Speaker/Mic..

Archived from groups: rec.audio.tech (More info?)

I have a headset that comes with 3 conductors (speaker, mic and ground).
I want to use it to connect to a PC that has separate speaker and mic
jacks (both mono). Should I connect the headset ground to the PC's:

1. Speaker ground; or
2. Mic ground; or
3. Both speaker and mic ground?

Archived from groups: rec.audio.tech (More info?)

jsmith44@attbi.com (John Smith) writes:

> I have a headset that comes with 3 conductors (speaker, mic and ground).
> I want to use it to connect to a PC that has separate speaker and mic
> jacks (both mono). Should I connect the headset ground to the PC's:
>
> 1. Speaker ground; or
> 2. Mic ground; or
> 3. Both speaker and mic ground?

Connect the ground wire from your headset to both speaker and mic
connector ground connections. That works well.

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/

Archived from groups: rec.audio.tech (More info?)

"Rob Beech" <Mail@robbeech.com> wrote in message
news:lX7cd.288$_Y.114@newsfe3-win.ntli.net...
>
> "John Smith" <jsmith44@attbi.com> wrote in message
> news:8ad2cfd4.0410121438.4b6da1ed@posting.google.com...
> > I have a headset that comes with 3 conductors (speaker, mic and
ground).
> > I want to use it to connect to a PC that has separate speaker and
mic
> > jacks (both mono). Should I connect the headset ground to the
PC's:
> >
> > 1. Speaker ground; or
> > 2. Mic ground; or
> > 3. Both speaker and mic ground?
>
> Its not uncommon to have the same ground for a speaker and a mic in
a
> headset. But they both do need it. (it effectivly completes the
circuit)
> they both need the ground. So you would need to alter your plugs
around
> accordingly.
>
> If you look at a stereo jack on a normal pair of headphones. you
have 3
> connectors. one for left one for right and a ground. Its the same
principle.

I would think that would be a very tricky business. The high current
of the speaker signal would appear on the same ground line as the low
voltage mike signal. The resistance of the ground line would cause a
significant voltage drop that would add (or subtract) from the mike
signal.

I don't know anything about the subject, but that's the first thing
that would occur to me.

Norm Strong