David Wright <deb...@lionunicorn.co.uk> writes: > On Thu 03 Aug 2017 at 15:43:15 (+0200), Rodolfo Medina wrote: >> Rodolfo Medina <rodolfo.med...@gmail.com> writes: >> >> > Jeremy Nicoll <jn.ml.dbn...@letterboxes.org> writes: >> > >> >> On Thu, 3 Aug 2017, at 13:23, Rodolfo Medina wrote: >> >> >> >>> 3) mic2 is stereo. >> >> >> >> Not necessarily. It might be a mono signal that's been duplicated across >> >> two outputs. >> >> Is there, as far as you know, a mono microphone model that we can be sure it >> does not do so? I.e., its sound is heared on only one channel? > > Most mono microphones will be fitted with a plug that has a tip and > barrel, but no ring (between the two). The effects you observe could > be no more than chance vagarities in the mechanical construction of > plug and socket. > >> >> It's only 2-channel if it can record two separate sounds at the >> >> same time. >> >> >> >> You can get microphones which, in a single unit, record more than one >> >> channel at once. Their labelling or artwork on them normally makes it >> >> clear that they have L and R (or more than that) inputs. >> >> >> >> What makes and models are your mics? >> > >> > >> > I can't tell, because they're old and I don't keep their specs. One of >> > them was given to me about 15 years ago, the other I don't even remember >> > how I have it. But I've got another teo: they are, each of them, part of >> > a headphone. They also let hear the recorded sound from both channels. >> > They are: >> > >> > http://www.trust.com/it/product/11916-primo-chat-headset >> > >> > and >> > >> > http://www.trust.com/it/product/20685-mauro-headset >> >> >> Just now I received a reply from Trust assistence and they say the mic >> (Primo) is mono. >> >> Anyway, about my example above, can we conclude that mic1 is mono and that >> the mic input of my PC is stereo...? > > If you want to know whether the input is stereo, plug in a cable which > has a stereo 3.5mm plug going to two phono plugs. (These computer↔monitor > sound cables were everywhere at one time.) Touch just the pin of each > phono plug in turn and see if you get mains hum separately on the > left and right channels of the computer.
I used a cable thath has, at one end, a 3.5mm stereo male plug; and, at the other end, a couple of twin phono RCA males. I plugged the 3.5mm into the mic input of the PC. Then I did: $ sox -t alsa default output.wav Then I touched alternatively one and the other of the two phone plugs and saw that the output of sox alternatively filled up the left or right channel. > If you're keen to use these microphones and you have the budget and > attitude of a school pupil, buy two mono 3.5mm sockets and a twin > phono socket unit. Solder the connections yourself using the phone > socket pair to anchor the 3.5mm ones and give it stability. Then > connect this device to the computer with the aforementioned cable > and plug in the mikes. Not very clear to me... But I'm not good at soldering... Many thanks, Rodolfo
