(my apologies for this 'mishap" - as Derak calls it! ---Otmar)

Due, presumably, to a cut and paste mishap, my answer didn't appear in 
the response summary for this thread, although answer (3) appeared 
twice, the second time with my name attached to it.  To avoid repeating 
the other information provided, I will modify my answer slightly, and 
add more detail.

Most Y-splitters are intended to divide an output, such as splitting 
the headphone output of a computer into two signals to drive two sets 
of headphones.  Putting two headphones in parallel like this cuts the 
resistance in half, and can cause a problem.  But it rarely does, in my 
experience, with modern light-weight headphones connected to computers 
or consumer AV devices.

If the same Y-splitter is used to connect two microphones into one 
microphone input, other problems can arise.  This kind of splitter 
connects the output of the microphones to each other, as well as to the 
computer.  As mentioned, electricity is metaphorically blind, and so 
the output from one microphone will try to flow through the other 
microphone (turning it into a speaker, for some microphone designs). 
If one student is speaking, while the other is silent, the signal 
strength is divided, but the sound may be OK.  If both are speaking, 
the microphones are fighting each other, and distortion or interference 
is possible.  The success rate depends on the specific microphones 
used.  It sounds like this has worked for several other people on this 
list.

I prefer to use a different kind of Y-adapter for microphones.  This 
adapter accepts two mono microphone jacks as input, and passes them to 
the computer as a stereo signal, without mixing or combining the 
microphones electrically.  One microphone comes into the computer as 
the left channel of the stereo signal, and the other as the right 
channel.  This allows discreet adjustment or editing of the sound from 
each student, such as boosting the volume level from a student who 
speaks more softly than the other.  For anyone listening to the audio, 
having one student on the left channel, and one on the right, helps the 
listener keep track of who is talking at a given instant, and gives a 
sense of space to the recording.

Derek


Derek Roff
Language Learning Center
Ortega Hall 129, MSC03-2100
University of New Mexico
Albuquerque, NM 87131-0001
505/277-7368, fax 505/277-3885
Internet: [log in to unmask]



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