Re: [solved] Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Thu, 17 Aug 2017, at 08:57, Rodolfo Medina wrote:
>> Jeremy Nicoll  writes:
>
>> > You do realise that merging files, adjusting balance etc are all possible
>> > with sox?
>> >
>> > One reason I do that sort of thing with sox is that by keeping note of the
>> > commands I used to do each stage, I automatically document how I
>> > manipulated a set of audio files.  Documenting anything done via a GUI as
>> > in Audacity is a great deal more difficult.
>> >
>> > It's worth documenting what you do so that if necessary you can exactly 
>> > repeat the process at a later date.
>> 
>> 
>> Thanks...  In fact, what you suggest is exactly what I wanted to do but
>> didn't manage to...  In fact, suppose I have two files: piano.wav and
>> voice.wav, created by sox in recording piano and voice respectively,
>> simultaneously.  piano.wav is a stereo file, with the two channels, left and
>> right, inside it; whereas voice.wav is a monophonic file.  When I put them
>> together to create the final, say, result.wav, I must properly allign them.
>> Now, Audacity makes this job easy thanks to the graphical possibility of
>> seeing the waving forms and magnifying them.  Instead, with sox, I tried to
>> use the `delay' option with no success.  Maybe can you suggest a better and
>> proper way to do that...?
>
> I've never tried that.  The sox mail list is a good place to ask for sox
> help.
>
> One thing I'd suggest (since sox is potentially complicated) is that instead
> of trying to use sox with one command that does everything, you try to do it
> in stages.  That way you can check that what you get at the end of each stage
> is what you expect.  Sox has effects that will tell you about what is in a
> file.
>
> I think first I'd check simply that I could create a file containing all
> three channels, eg by:
>
>  sox -V2 --no-clobber -M piano.wav voice.wav threech.wav  
>
> The -V2 sets a fairly high level of verbosity; you might need -V3
>  
> The --no-clobber prevents sox from overwriting a file.  It's easy to get a
> command wrong and accidentally destroy an original file; personally I work on
> copies of files AND use --no-clobber.
>
> -M tells sox to merge the files.  You should end up with a 3 channel file,
> with the piano audio on channels 1 and 2 and voice on 3.
>
>
> If that works (and ironically, Audacity might be an easy way to make sure) I
> think I'd next try to make a file with the voice channel offset from the
> others, perhaps by (guessing again!):
>
>  sox -V2 --no-clobber threech.wav delay 0 0 2t voicedelayed.wav 
>
> For an experiment, it's worth making the delay substantial, for example the
> two second value (2t) here.  It'll be easy to tell if that worked.  Later you
> can try different values to get the audio aligned where you need it to be.
>
> (Also note that there's an effect named 'silence' that can be used to chop
> unwanted 'silent' or at least quieter than the wanted sound audio out of a
> track, so a different approach that might help would be to make sure that
> none of the tracks have much silence at the start, before you merge them.)
>
> Note that so far, none of the three channels have had their relative volumes
> changed.
>
> To do that, and create a stereo file from the three, you'd need to use the
> remix effect.


I did:

 $ sox -M piano.wav voice.wav voicedelayed.wav delay 0.3 0.3 0

to delay piano of 0.3 seconds (`delay' at the end of the command line), and

 $ sox voicedelayed.wav final_result.wav remix -m 1p-5,3p-5 2p+5,3p-5

to decrease the volume of the left channel of piano of 5db, increase the volume
of the right channel of piano of 5db and decrease voice's volume of 5db.  It
seems to be working fine.  Thanks.  Then I'll be using sox instead of Audacity
to manipulate recorded tracks...


>> One more thing: I remember, Jeremy, your suggestion of purchasing a
>> multi-channel audio interface, to be preferred to a mixer, and will do in
>> future.  But do you think that the solution I'm adopting for now: different
>> files on different single-channel audio cards and then merging them - dou
>> you think this is a good solution as well...?  What difference between this
>> cheap one and more or less expensive multi channel interface...?
>
> Your current solution is the cheapest I can think of, and no doubt you'll
> learn quite a lot doing this.


The reason why I'm starting with that cheap solution is not only its cheapness
but that I first want to learn with it, and also because it suits my basic
needs for now.

Thanks,

Regards,

Rodolfo

Re: [solved] Re: Live recording

[Jeremy Nicoll]

On Thu, 17 Aug 2017, at 08:57, Rodolfo Medina wrote:
> Jeremy Nicoll  writes:

> > You do realise that merging files, adjusting balance etc are all possible
> > with sox?
> >
> > One reason I do that sort of thing with sox is that by keeping note of the
> > commands I used to do each stage, I automatically document how I manipulated
> > a set of audio files.  Documenting anything done via a GUI as in Audacity is
> > a great deal more difficult.
> >
> > It's worth documenting what you do so that if necessary you can exactly 
> > repeat the process at a later date.
> 
> 
> Thanks...  In fact, what you suggest is exactly what I wanted to do but
> didn't
> manage to...  In fact, suppose I have two files: piano.wav and voice.wav,
> created by sox in recording piano and voice respectively, simultaneously.
> piano.wav is a stereo file, with the two channels, left and right, inside
> it;
> whereas voice.wav is a monophonic file.  When I put them together to
> create the
> final, say, result.wav, I must properly allign them.  Now, Audacity makes
> this
> job easy thanks to the graphical possibility of seeing the waving forms
> and
> magnifying them.  Instead, with sox, I tried to use the `delay' option
> with no
> success.  Maybe can you suggest a better and proper way to do that...?

I've never tried that.  The sox mail list is a good place to ask for sox
help.

One thing I'd suggest (since sox is potentially complicated) is that
instead
of trying to use sox with one command that does everything, you try to
do 
it in stages.  That way you can check that what you get at the end of
each
stage is what you expect.   Sox has effects that will tell you about
what is in 
a file.

 I think first I'd check simply that I could create a file containing
 all three 
channels, eg by: 

 sox -V2 --no-clobber -M piano.wav voice.wav threech.wav  

The -V2 sets a fairly high level of verbosity; you might need -V3
 
The --no-clobber prevents sox from overwriting a file.  It's easy to get
a command
wrong and accidentally destroy an original file; personally I work on
copies of files
AND use --no-clobber.

-M tells sox to merge the files.  You should end up with a 3 channel
file, with the piano
audio on channels 1 and 2 and voice on 3.


If that works (and ironically, Audacity might be an easy way to make
sure) I think 
I'd next try to make a file with the voice channel offset from the
others, perhaps 
by  (guessing again!):

 sox -V2 --no-clobber threech.wav delay 0 0 2t voicedelayed.wav 

For an experiment, it's worth making the delay substantial, for example
the two 
second value (2t) here.  It'll be easy to tell if that worked.  Later
you can try different
values to get the audio aligned where you need it to be.

(Also note that there's an effect named 'silence' that can be used to
chop unwanted
'silent' or at least quieter than the wanted sound audio out of a track,
so a different 
approach that might help would be to make sure that none of the tracks
have much 
silence at the start, before you merge them.) 

Note that so far, none of the three channels have had their relative
volumes changed.

To do that, and create a stereo file from the three, you'd need to use
the  remix  effect.



 
> One more thing: I remember, Jeremy, your suggestion of purchasing a
> multi-channel audio interface, to be preferred to a mixer, and will do in
> future.  But do you think that the solution I'm adopting for now:
> different
> files on different single-channel audio cards and then merging them - dou
> you
> think this is a good solution as well...?  What difference between this
> cheap
> one and more or less expensive multi channel interface...?

Your current solution is the cheapest I can think of, and no doubt
you'll learn quite a
lot doing this.  I'm afraid I've no idea about what's currently
available in cheap audio 
interfaces.  Reading buyer reviews in eg Amazon is a good way of finding
out what can 
and cannot be done with equipment though.

More expensive interfaces will be sold on the assumption that people
using them are
using higher quality equipment, eg decent microphones.  As price and
quality of mics
increase you expect to get things like: mics that add little (or barely
audible) noise to a 
recording; mics that are more accurate, mics that can better cope with
both quiet and 
loud sounds...

Such mics though typically need 'phantom power'.  They'd probably be on
'balanced' 
audio cables (so 2 wires plus earth/screen per mic), and possibly XLR
connectors...  
There comes a point where the box you plug the mics into needs to be
designed for 
that.

Then, the signal that comes from a mic is (especially with very
sensitive mics) very 
small.  It needs to be amplified - which is what microphone
pre-amplifiers do.  Cheap
mic pre-amps tend to add noise or ruin the sound from a decent mic... 

After that, the amplified sound from each mic needs to be converted from
an analogue
signal to digital.  Better 

Re: [solved] Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Thu, 17 Aug 2017, at 01:37, Rodolfo Medina wrote:
>
>> Thanks...  But for my present needs, it seems that sox and audacity are
>> sufficient: with sox I record tracks from multiple audio cards into
>> different files; then with Audacity I merge those tracks into one final
>> file, and have the possibility of adjusting at pleasure the balancing
>> between left and right channel for each track and also adjust the relative
>> volumes.  In my litte basic experiments, I don't note any minimum effect due
>> to time drifting or so, about which I read...
>
> You do realise that merging files, adjusting balance etc are all possible
> with sox?
>
> One reason I do that sort of thing with sox is that by keeping note of the
> commands I used to do each stage, I automatically document how I manipulated
> a set of audio files.  Documenting anything done via a GUI as in Audacity is
> a great deal more difficult.
>
> It's worth documenting what you do so that if necessary you can exactly 
> repeat the process at a later date.


Thanks...  In fact, what you suggest is exactly what I wanted to do but didn't
manage to...  In fact, suppose I have two files: piano.wav and voice.wav,
created by sox in recording piano and voice respectively, simultaneously.
piano.wav is a stereo file, with the two channels, left and right, inside it;
whereas voice.wav is a monophonic file.  When I put them together to create the
final, say, result.wav, I must properly allign them.  Now, Audacity makes this
job easy thanks to the graphical possibility of seeing the waving forms and
magnifying them.  Instead, with sox, I tried to use the `delay' option with no
success.  Maybe can you suggest a better and proper way to do that...?

One more thing: I remember, Jeremy, your suggestion of purchasing a
multi-channel audio interface, to be preferred to a mixer, and will do in
future.  But do you think that the solution I'm adopting for now: different
files on different single-channel audio cards and then merging them - dou you
think this is a good solution as well...?  What difference between this cheap
one and more or less expensive multi channel interface...?

Thanks,

Rodolfo

Re: [solved] Re: Live recording

[Jeremy Nicoll]

On Thu, 17 Aug 2017, at 01:37, Rodolfo Medina wrote:

> Thanks...  But for my present needs, it seems that sox and audacity are
> sufficient: with sox I record tracks from multiple audio cards into
> different
> files; then with Audacity I merge those tracks into one final file, and
> have
> the possibility of adjusting at pleasure the balancing between left and
> right
> channel for each track and also adjust the relative volumes.  In my litte
> basic
> experiments, I don't note any minimum effect due to time drifting or so,
> about
> which I read...

You do realise that merging files, adjusting balance etc are all
possible with 
sox?  

One reason I do that sort of thing with sox is that by keeping note of
the 
commands I used to do each stage, I automatically document how I 
manipulated a set of audio files.  Documenting anything done via a GUI
as
in Audacity is a great deal more difficult.

It's worth documenting what you do so that if necessary you can exactly 
repeat the process at a later date.


-- 
Jeremy Nicoll - my opinions are my own.

Re: [solved] Re: Live recording

[Rodolfo Medina]

Zenaan Harkness  writes:

> If you ever need more flexibility, or more control over latency, or a
> need to adjust individual track offsets ("latency") after the fact,
> post-recording mix down sessions, many types of automation whilst
> recording, and many other high end audio tasks - jackd/Ardour may be
> just the solution you will then be looking for :)
>
> jackd may be built Ardour these days - if so, that would likely make
> config even easier.
>
> [...]
>
> Summary: the best of
> the best is available with jackd and Ardour, for absolutely any
> tricky situation.


Thanks...  But for my present needs, it seems that sox and audacity are
sufficient: with sox I record tracks from multiple audio cards into different
files; then with Audacity I merge those tracks into one final file, and have
the possibility of adjusting at pleasure the balancing between left and right
channel for each track and also adjust the relative volumes.  In my litte basic
experiments, I don't note any minimum effect due to time drifting or so, about
which I read...

Rodolfo

Re: [solved] Re: Live recording

[Zenaan Harkness]

On Wed, Aug 16, 2017 at 11:16:06AM -0400, Ric Moore wrote:
> On 08/16/2017 09:40 AM, Zenaan Harkness wrote:
> please excuse my amateur wording here. Summary: the best of
> > the best is available with jackd and Ardour, for absolutely any
> > tricky situation.
> 
> Doesn't jack require an rt kernel to enable all of it's features?? Ric

That sounds right - I certainly installed the ...-rt kernel, but I
think it just depends on your latency requirements - again from
memory, I tyhink jackd will happily run at "pulse audio" levels of
latency with a simple setting, and thereby audio will be buffered
long enough to not need an -rt kernel.

Re: [solved] Re: Live recording

[Ric Moore]

On 08/16/2017 09:40 AM, Zenaan Harkness wrote:
please excuse my amateur wording here. Summary: the best of

the best is available with jackd and Ardour, for absolutely any
tricky situation.


Doesn't jack require an rt kernel to enable all of it's features?? Ric


--
My father, Victor Moore (Vic) used to say:
"There are two Great Sins in the world...
..the Sin of Ignorance, and the Sin of Stupidity.
Only the former may be overcome." R.I.P. Dad.
http://linuxcounter.net/user/44256.html

Re: [solved] Re: Live recording

[Zenaan Harkness]

On Wed, Aug 16, 2017 at 01:42:18PM +0200, Rodolfo Medina wrote:
> Zenaan Harkness  writes:
> 
> > On Wed, Aug 16, 2017 at 03:03:46AM +0200, Rodolfo Medina wrote:
> >> Apparently, Audacity doesn't let you record simultaneously from two or more
> >> sources...  you have to choose one source.
> >
> > Ardour should only take half a day to start using - it absolutely
> > rocks - high end DAW FTW :D
> 
> 
> Thanks...  As far as I see, Ardour and Jack are powerful tools...  On the 
> other
> hand, with the above recording procedure, i.e. several simultaneous sessions 
> of
> sox, no drifting or latency effects did I appreciate at all...  So it is maybe
> worth for me to continue that way till the moment such problems will arise...

Indeed - if it aint broke as they say :)

Glad to hear you have achieved your desired recording result.

If you ever need more flexibility, or more control over latency, or a
need to adjust individual track offsets ("latency") after the fact,
post-recording mix down sessions, many types of automation whilst
recording, and many other high end audio tasks - jackd/Ardour may be
just the solution you will then be looking for :)

jackd may be built Ardour these days - if so, that would likely make
config even easier.

One little nugget in the back of my mind from a few years ago when I
was last multi-tracking, is a jackd plugin with high quality "audio
anti aliasing" (not sure the proper term sorry) in real time, to mix
input sources which are delivering different sample rates, AND
different skew rates, with respect to each other - basically a full
software "time lock" function WITH high end sample rate anti
aliasing. I didn't need it, but it looked like it would allow
seamless "real time latency/skew correction" of basic mobo line-in
tracks, with tracks coming from hardware with proper time sync
codes... please excuse my amateur wording here. Summary: the best of
the best is available with jackd and Ardour, for absolutely any
tricky situation.

Have fun :)

Re: [solved] Re: Live recording

[Rodolfo Medina]

Zenaan Harkness  writes:

> On Wed, Aug 16, 2017 at 03:03:46AM +0200, Rodolfo Medina wrote:
>> Rodolfo Medina  writes:
>> 
>> > deloptes  writes:
>> >
>> >>> 
>> >>> For human voice, I bought a USB audio card and plugged a third
>> >>> microphone into it.  So now I have:
>> >>> 
>> >>>  mic1 for piano basses; |__ plugged together into the
>> >>>  mic2 for piano highs;  |   above Y cable
>> >>>  mic3 for voice -> -> -> -> plugged into the USB dongle.
>> >>> 
>> >>> Then I do:
>> >>> 
>> >>>  $ sox -t alsa default piano.wav
>> >>> 
>> >>> and, at the same time, on another xterm session,
>> >>> 
>> >>>  $ sox -t alsa wh:2,0 voice.wav
>> >>> 
>> >>> where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get
>> >>> two audio files: piano.wav and voice.wav.  The first one is stereo and
>> >>> the second is mono.  In the end I merge the two together with Audacity.
>> >>> By default, Audacity puts the mono file just in the middle between left
>> >>> and right channel; but, if you like, you can have it weight more left or
>> >>> more right, in the percentage you want.  I must say that the result is
>> >>> acceptable, and more...
>> >>> 
>> >> Why not do all that directly in Audacity? I am sure it works and it will
>> >> take care of the timing automatically
>> >
>> >
>> > Thanks, I'll have a try.
>> 
>> 
>> Apparently, Audacity doesn't let you record simultaneously from two or more
>> sources...  you have to choose one source.
>
> Ardour should only take half a day to start using - it absolutely
> rocks - high end DAW FTW :D


Thanks...  As far as I see, Ardour and Jack are powerful tools...  On the other
hand, with the above recording procedure, i.e. several simultaneous sessions of
sox, no drifting or latency effects did I appreciate at all...  So it is maybe
worth for me to continue that way till the moment such problems will arise...

Rodolfo

Re: [solved] Re: Live recording

[Zenaan Harkness]

On Wed, Aug 16, 2017 at 03:03:46AM +0200, Rodolfo Medina wrote:
> Rodolfo Medina  writes:
> 
> > deloptes  writes:
> >
> >>> 
> >>> For human voice, I bought a USB audio card and plugged a third microphone
> >>> into it.  So now I have:
> >>> 
> >>>  mic1 for piano basses; |__ plugged together into the
> >>>  mic2 for piano highs;  |   above Y cable
> >>>  mic3 for voice -> -> -> -> plugged into the USB dongle.
> >>> 
> >>> Then I do:
> >>> 
> >>>  $ sox -t alsa default piano.wav
> >>> 
> >>> and, at the same time, on another xterm session,
> >>> 
> >>>  $ sox -t alsa wh:2,0 voice.wav
> >>> 
> >>> where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get
> >>> two audio files: piano.wav and voice.wav.  The first one is stereo and the
> >>> second is mono.  In the end I merge the two together with Audacity.  By
> >>> default, Audacity puts the mono file just in the middle between left and
> >>> right channel; but, if you like, you can have it weight more left or more
> >>> right, in the percentage you want.  I must say that the result is
> >>> acceptable, and more...
> >>> 
> >> Why not do all that directly in Audacity? I am sure it works and it will
> >> take care of the timing automatically
> >
> >
> > Thanks, I'll have a try.
> 
> 
> Apparently, Audacity doesn't let you record simultaneously from two or more
> sources...  you have to choose one source.

Ardour should only take half a day to start using - it absolutely
rocks - high end DAW FTW :D

Re: [solved] Re: Live recording

[Rodolfo Medina]

Rodolfo Medina  writes:

> deloptes  writes:
>
>>> 
>>> For human voice, I bought a USB audio card and plugged a third microphone
>>> into it.  So now I have:
>>> 
>>>  mic1 for piano basses; |__ plugged together into the
>>>  mic2 for piano highs;  |   above Y cable
>>>  mic3 for voice -> -> -> -> plugged into the USB dongle.
>>> 
>>> Then I do:
>>> 
>>>  $ sox -t alsa default piano.wav
>>> 
>>> and, at the same time, on another xterm session,
>>> 
>>>  $ sox -t alsa wh:2,0 voice.wav
>>> 
>>> where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get
>>> two audio files: piano.wav and voice.wav.  The first one is stereo and the
>>> second is mono.  In the end I merge the two together with Audacity.  By
>>> default, Audacity puts the mono file just in the middle between left and
>>> right channel; but, if you like, you can have it weight more left or more
>>> right, in the percentage you want.  I must say that the result is
>>> acceptable, and more...
>>> 
>> Why not do all that directly in Audacity? I am sure it works and it will
>> take care of the timing automatically
>
>
> Thanks, I'll have a try.


Apparently, Audacity doesn't let you record simultaneously from two or more
sources...  you have to choose one source.

Rodolfo

Re: [solved] Re: Live recording

[deloptes]

> 
> 
> Thanks, I'll have a try.  But can we say that all this allows us to do
> without
> mixer or multi-channel audio interface...?  In fact, I suppose I could
> even add some other USB cards if I wanted to add more instruments, say a
> violin...
> 
> Cheers,
> 
> Rodolfo

there are always some physical limitations, so it depends on your computer,
if it is usb3, how the usb are implemented etc.

you can always try

regards

Re: [solved] Re: Live recording

[Rodolfo Medina]

deloptes  writes:

>> 
>> For human voice, I bought a USB audio card and plugged a third microphone
>> into
>> it.  So now I have:
>> 
>>  mic1 for piano basses; |__ plugged together into the
>>  mic2 for piano highs;  |   above Y cable
>>  mic3 for voice -> -> -> -> plugged into the USB dongle.
>> 
>> Then I do:
>> 
>>  $ sox -t alsa default piano.wav
>> 
>> and, at the same time, on another xterm session,
>> 
>>  $ sox -t alsa wh:2,0 voice.wav
>> 
>> where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get
>> two
>> audio files: piano.wav and voice.wav.  The first one is stereo and the
>> second
>> is mono.  In the end I merge the two together with Audacity.  By default,
>> Audacity puts the mono file just in the middle between left and right
>> channel; but, if you like, you can have it weight more left or more right,
>> in the
>> percentage you want.  I must say that the result is acceptable, and
>> more...
>> 
> Why not do all that directly in Audacity? I am sure it works and it will
> take care of the timing automatically


Thanks, I'll have a try.  But can we say that all this allows us to do without
mixer or multi-channel audio interface...?  In fact, I suppose I could even add
some other USB cards if I wanted to add more instruments, say a violin...

Cheers,

Rodolfo

Re: [solved] Re: Live recording

[deloptes]

> 
> For human voice, I bought a USB audio card and plugged a third microphone
> into
> it.  So now I have:
> 
>  mic1 for piano basses; |__ plugged together into the
>  mic2 for piano highs;  |   above Y cable
>  mic3 for voice -> -> -> -> plugged into the USB dongle.
> 
> Then I do:
> 
>  $ sox -t alsa default piano.wav
> 
> and, at the same time, on another xterm session,
> 
>  $ sox -t alsa wh:2,0 voice.wav
> 
> where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get
> two
> audio files: piano.wav and voice.wav.  The first one is stereo and the
> second
> is mono.  In the end I merge the two together with Audacity.  By default,
> Audacity puts the mono file just in the middle between left and right
> channel; but, if you like, you can have it weight more left or more right,
> in the
> percentage you want.  I must say that the result is acceptable, and
> more...
> 
Why not do all that directly in Audacity? I am sure it works and it will
take care of the timing automatically

regards

Re: [solved] Re: Live recording

[Rodolfo Medina]

Rodolfo Medina  writes:

> Rodolfo Medina  writes:
>
>> According to:
>>
>>  http://www.upubuntu.com/2013/05/how-to-record-your-voice-from.html
>>
>> I record live sound via microphone just doing:
>>
>>  $ sox -t alsa default output.wav
>>
>> Now I was wondering about the stereo o non-stereo character of such a home
>> made recording...  I tried to use two microphones together, plugging them
>> together into the PC with a small common connection doubber.  Can we say the
>> result is stereo...?  I would doubt...  and how to have - if possible - a
>> stereo effect with the above basic recording instruments?
>
>
>
>
> Thanks to all.  The problem seems to be solved with such a cable:
>
>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm

Well, actually better this one:

 http://hosatech.com/product/ymm-261/

> as suggested by deloptes and other listers.  The cable consists in two female
> 3.5mm terminations, each of them mono, and a male 3.5mm stereo.  One mic at
> one female end, the other one at the other female end, and the male end
> plugged into the microphone input of my netbook.  All this seems to produce a
> perfect stereo effect: the two channels sound to be very well separated.
>
> I'll be using the above simple connection system to live piano recording: mic
> 1 on the basses (left), mic 2 on the high (right).
>
> My next step is trying to add human voice, say in the middle.  I'll see if
> this is possible by slightly complicating the above solution, without preamp
> or mixer or multi-channel audio interface.  I'll be posting here if the
> attempt succeeds.


For human voice, I bought a USB audio card and plugged a third microphone into
it.  So now I have:

 mic1 for piano basses; |__ plugged together into the
 mic2 for piano highs;  |   above Y cable
 mic3 for voice -> -> -> -> plugged into the USB dongle.

Then I do:

 $ sox -t alsa default piano.wav

and, at the same time, on another xterm session,

 $ sox -t alsa wh:2,0 voice.wav

where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get two
audio files: piano.wav and voice.wav.  The first one is stereo and the second
is mono.  In the end I merge the two together with Audacity.  By default,
Audacity puts the mono file just in the middle between left and right channel;
but, if you like, you can have it weight more left or more right, in the
percentage you want.  I must say that the result is acceptable, and more...

Thanks,

Rodolfo

Re: [solved] Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Sun, 6 Aug 2017, at 17:18, Rodolfo Medina wrote:
>
>> To add a third microphone for human voice (the former two are for piano),
>> I plan to use a second PC as suggested by Fungi4All.  This way I'll
>> continue to do without mixer or audio interface, till the moment I'll want 
>> to do things more professionally.  Now, they're just home made records...
>
> The single best reason for using a multi-channel (ie not just a stereo) audio
> interface is simplicity.  All the channels will be in-sync with each other
> and all the audio signals can be captured on a single computer.


...within different files...?

Thanks,

Rodolfo

Re: [solved] Re: Live recording

[Jeremy Nicoll]

On Sun, 6 Aug 2017, at 17:18, Rodolfo Medina wrote:

> To add a third microphone for human voice (the former two are for piano),
> I plan to use a second PC as suggested by Fungi4All.  This way I'll
> continue to do without mixer or audio interface, till the moment I'll want 
> to do things more professionally.  Now, they're just home made records...

The single best reason for using a multi-channel (ie not just a stereo)
audio 
interface is simplicity.  All the channels will be in-sync with each
other and 
all the audio signals can be captured on a single computer.

-- 
Jeremy Nicoll - my opinions are my own.

Re: [solved] Re: Live recording

[Rodolfo Medina]

David Christensen  writes:

> On 08/06/17 09:18, Rodolfo Medina wrote:
>> The cable that made me possible to live record stereo from two mics, without
>> mixer nor preamp nor external audio card nor audio interface, is a 3.5mm
>> twin-mono-female and a 3.5mm single-stereo-male: the two mics plugged into
>> the two mono females and the stereo male plugged into the `mic' input of my
>> PC.  This cable was solded for me by the owner of the electricity shop near
>> my house.
>
> That is called a stereo break-out cable:
>
> http://hosatech.com/product/ymm-261/
>
>
>> To add a third microphone for human voice (the former two are for piano), I
>> plan to use a second PC as suggested by Fungi4All.  This way I'll continue
>> to do without mixer or audio interface, till the moment I'll want to do
>> things more professionally.  Now, they're just home made records...
>
> As I understand it, professional digital audio recording gear includes clock
> in and clock out connectors.  All the devices are linked together with
> cables, one device serves as the master clock, and all the other devices are
> slaves.
>
>
> Without hardware clock synchronization, the clocks for the various recording
> devices will drift ("clock skew") and the recordings will lose time
> alignment.  One work-around is to record audible synchronizing marks near the
> beginning of a take and near the end -- e.g. strike two sticks together, clap
> your hands, use a "clicker" device, etc..  Then during editing/ mix-down, use
> digital audio workstation software with time-stretch/ time-compression/
> time-alignment features to adjust the individual recordings until all the
> synchronizing marks line up exactly.


It seems that Audacity can do that...

Rodolfo

Re: [solved] Re: Live recording

[David Christensen]

On 08/06/17 09:18, Rodolfo Medina wrote:

The cable that made me possible to live record stereo from two mics, without
mixer nor preamp nor external audio card nor audio interface, is a 3.5mm
twin-mono-female and a 3.5mm single-stereo-male: the two mics plugged into the
two mono females and the stereo male plugged into the `mic' input of my PC.
This cable was solded for me by the owner of the electricity shop near my
house.


That is called a stereo break-out cable:

http://hosatech.com/product/ymm-261/



To add a third microphone for human voice (the former two are for piano), I
plan to use a second PC as suggested by Fungi4All.  This way I'll continue to
do without mixer or audio interface, till the moment I'll want to do things
more professionally.  Now, they're just home made records...


As I understand it, professional digital audio recording gear includes 
clock in and clock out connectors.  All the devices are linked together 
with cables, one device serves as the master clock, and all the other 
devices are slaves.



Without hardware clock synchronization, the clocks for the various 
recording devices will drift ("clock skew") and the recordings will lose 
time alignment.  One work-around is to record audible synchronizing 
marks near the beginning of a take and near the end -- e.g. strike two 
sticks together, clap your hands, use a "clicker" device, etc..  Then 
during editing/ mix-down, use digital audio workstation software with 
time-stretch/ time-compression/ time-alignment features to adjust the 
individual recordings until all the synchronizing marks line up exactly.



David

Re: [solved] Re: Live recording

[Rodolfo Medina]

Richard Hector  writes:

> On 05/08/17 03:56, Rodolfo Medina wrote:
>> Thanks to all.  The problem seems to be solved with such a cable:
>> 
>>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
>
> Except that it's hard to tell what size those connectors are. Unless
> there's something in the description that I can't read that says they're
> 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
> think 3.5mm plugs are usually more rounded on the end, while the larger
> ones often have that point. Also, it looks like the case comes apart,
> and I think the only ones I've seen with such skinny bodies are moulded
> plastic. If that's 3.5mm, I think it would be very hard to assemble by
> hand, which the body designs suggest.


The cable that made me possible to live record stereo from two mics, without
mixer nor preamp nor external audio card nor audio interface, is a 3.5mm
twin-mono-female and a 3.5mm single-stereo-male: the two mics plugged into the
two mono females and the stereo male plugged into the `mic' input of my PC.
This cable was solded for me by the owner of the electricity shop near my
house.

To add a third microphone for human voice (the former two are for piano), I
plan to use a second PC as suggested by Fungi4All.  This way I'll continue to
do without mixer or audio interface, till the moment I'll want to do things
more professionally.  Now, they're just home made records...

Rodolfo

Re: [solved] Re: Live recording

[Joe]

On Sun, 6 Aug 2017 15:37:15 +1200
Richard Hector  wrote:

> On 06/08/17 13:18, Eike Lantzsch wrote:
> > On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:  
> >> On 05/08/17 03:56, Rodolfo Medina wrote:  
> >>> Thanks to all.  The problem seems to be solved with such a cable:
> >>>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm  
> >> Except that it's hard to tell what size those connectors are.
> >> Unless there's something in the description that I can't read that
> >> says they're 3.5mm, they look to me more like 6.25mm. I'm not sure
> >> what it is - I think 3.5mm plugs are usually more rounded on the
> >> end, while the larger ones often have that point. Also, it looks
> >> like the case comes apart, and I think the only ones I've seen
> >> with such skinny bodies are moulded plastic. If that's 3.5mm, I
> >> think it would be very hard to assemble by hand, which the body
> >> designs suggest.
> >>
> >> Richard  
> > 3.5mm and 2.5mm plugs can be soldered all right but  
> 
> Yes - I was trying to suggest that the plugs in the picture, if it's a
> 3.5mm plug, look a bit small in the body to be user-assembled - yet
> they clearly come apart. The ones I've soldered have bigger bodies
> relative to the actual connector. The really thin ones tend to be
> moulded.
> 
> I'm not sure if I'm making myself clear ... it would help if the site
> actually specified what they're selling :-)
> 

Yes, but I think the real issue in making one is that the plug is a
right-angle one, and right-angled plugs are usually pigs to fit. But
they are certainly 1/4" in the picture, the proportions are different
for the miniature versions.

No problem getting 2.5mm and 3.5mm mono or stereo rewireable plugs:
https://www.maplin.co.uk/p/35mm-metal-stereo-plug-fj99h
https://www.maplin.co.uk/p/25mm-plastic-stereo-plug-fj85g

though as another poster said, they need fairly lightweight cable.

-- 
Joe

Re: [solved] Re: Live recording

[Richard Hector]

On 06/08/17 13:18, Eike Lantzsch wrote:
> On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:
>> On 05/08/17 03:56, Rodolfo Medina wrote:
>>> Thanks to all.  The problem seems to be solved with such a cable:
>>>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
>> Except that it's hard to tell what size those connectors are. Unless
>> there's something in the description that I can't read that says they're
>> 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
>> think 3.5mm plugs are usually more rounded on the end, while the larger
>> ones often have that point. Also, it looks like the case comes apart,
>> and I think the only ones I've seen with such skinny bodies are moulded
>> plastic. If that's 3.5mm, I think it would be very hard to assemble by
>> hand, which the body designs suggest.
>>
>> Richard
> 3.5mm and 2.5mm plugs can be soldered all right but

Yes - I was trying to suggest that the plugs in the picture, if it's a
3.5mm plug, look a bit small in the body to be user-assembled - yet they
clearly come apart. The ones I've soldered have bigger bodies relative
to the actual connector. The really thin ones tend to be moulded.

I'm not sure if I'm making myself clear ... it would help if the site
actually specified what they're selling :-)

Richard

Re: [solved] Re: Live recording

[Doug]

On 08/05/2017 08:11 PM, Eike Lantzsch wrote:

On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:

On 05/08/17 03:56, Rodolfo Medina wrote:

Thanks to all.  The problem seems to be solved with such a cable:
  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm

That's 1/4" ~ 6.35mm
Stereo on one end and 2 x mono on the other end
but both 6.35mm


Except that it's hard to tell what size those connectors are. Unless
there's something in the description that I can't read that says they're
3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
think 3.5mm plugs are usually more rounded on the end, while the larger
ones often have that point. Also, it looks like the case comes apart,
and I think the only ones I've seen with such skinny bodies are moulded
plastic. If that's 3.5mm, I think it would be very hard to assemble by
hand, which the body designs suggest.

Richard


I have put together a number of 3.5mm connectors, which you used to be 
able to
get in Radio Shack. I confess that they were not stereo. Also put 
together the
power connectors for 5V and 12V. It's a little hairy, and you need a 
soldering
iron with a fine tip, a good light, and probably magnifying 
lenses--which I have.


--doug

Re: [solved] Re: Live recording

[Eike Lantzsch]

On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:
> On 05/08/17 03:56, Rodolfo Medina wrote:
> > Thanks to all.  The problem seems to be solved with such a cable:
> >  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
> 
> Except that it's hard to tell what size those connectors are. Unless
> there's something in the description that I can't read that says they're
> 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
> think 3.5mm plugs are usually more rounded on the end, while the larger
> ones often have that point. Also, it looks like the case comes apart,
> and I think the only ones I've seen with such skinny bodies are moulded
> plastic. If that's 3.5mm, I think it would be very hard to assemble by
> hand, which the body designs suggest.
> 
> Richard

here's a good write-up of phone connectors of all kind
https://en.wikipedia.org/wiki/Phone_connector_(audio)

Re: [solved] Re: Live recording

[Eike Lantzsch]

On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:
> On 05/08/17 03:56, Rodolfo Medina wrote:
> > Thanks to all.  The problem seems to be solved with such a cable:
> >  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
> 
> Except that it's hard to tell what size those connectors are. Unless
> there's something in the description that I can't read that says they're
> 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
> think 3.5mm plugs are usually more rounded on the end, while the larger
> ones often have that point. Also, it looks like the case comes apart,
> and I think the only ones I've seen with such skinny bodies are moulded
> plastic. If that's 3.5mm, I think it would be very hard to assemble by
> hand, which the body designs suggest.
> 
> Richard

3.5mm and 2.5mm plugs can be soldered all right but the problem mostly is to 
purchase the really fine cable with two inner conductors, both shielded.
Common "Stereo Shielded Cable" is commonly too fat and its use always results 
in ugly and unwieldy kludges.
Sometimes I resorted to reusing the cables of old earphone sets, which I had 
otherwise no use for anymore.

Cheers
Eike

Re: [solved] Re: Live recording

[Eike Lantzsch]

On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:
> On 05/08/17 03:56, Rodolfo Medina wrote:
> > Thanks to all.  The problem seems to be solved with such a cable:
> >  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
> 
That's 1/4" ~ 6.35mm
Stereo on one end and 2 x mono on the other end
but both 6.35mm

> Except that it's hard to tell what size those connectors are. Unless
> there's something in the description that I can't read that says they're
> 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
> think 3.5mm plugs are usually more rounded on the end, while the larger
> ones often have that point. Also, it looks like the case comes apart,
> and I think the only ones I've seen with such skinny bodies are moulded
> plastic. If that's 3.5mm, I think it would be very hard to assemble by
> hand, which the body designs suggest.
> 
> Richard

Re: [solved] Re: Live recording

[Richard Hector]

On 05/08/17 03:56, Rodolfo Medina wrote:
> Thanks to all.  The problem seems to be solved with such a cable:
> 
>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm

Except that it's hard to tell what size those connectors are. Unless
there's something in the description that I can't read that says they're
3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
think 3.5mm plugs are usually more rounded on the end, while the larger
ones often have that point. Also, it looks like the case comes apart,
and I think the only ones I've seen with such skinny bodies are moulded
plastic. If that's 3.5mm, I think it would be very hard to assemble by
hand, which the body designs suggest.

Richard

[solved] Re: Live recording

[Rodolfo Medina]

Rodolfo Medina  writes:

> According to:
>
>  http://www.upubuntu.com/2013/05/how-to-record-your-voice-from.html
>
> I record live sound via microphone just doing:
>
>  $ sox -t alsa default output.wav
>
> Now I was wondering about the stereo o non-stereo character of such a home
> made recording...  I tried to use two microphones together, plugging them
> together into the PC with a small common connection doubber.  Can we say the
> result is stereo...?  I would doubt...  and how to have - if possible - a
> stereo effect with the above basic recording instruments?


deloptes  writes:

> First of all you need to get basic knowledge of signal and audio processing
>
> One good way to understand things 8especially about electricity is water and
> pipes.
>
> Now your mic is a one bucket full of water and you have to pipes (left and
> right) ... where does the water flow?
>
> Rodolfo Medina wrote:
>
>> 1) the mic input on my PC is stereo.  In fact, it is a laptop, nay a
>> netbook, doesn't have a line in and it is reasonable that its mic input is
>> also a line in;
>> 
>
> there is no stereo mic - keep in mind - one bucket full of water - not two


Doug  writes:

> You can't get something for nothing. If you want stereo, you will have to
> have two mics or a mic with two separate microphone elements aimed in two
> (left and right) directions. Such a device will have a plug with three
> connections on it: left, right, and ground. Your PC will not be able to
> handle such a microphone! You would need a stereo preamplifier to plug that
> mic into, and then you would plug the stereo output of the preamp into the
> LINE IN jack of the PC.
>
> I would hope that this information will settle the question!



Thanks to all.  The problem seems to be solved with such a cable:

 https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm

as suggested by deloptes and other listers.  The cable consists in two female
3.5mm terminations, each of them mono, and a male 3.5mm stereo.  One mic at one
female end, the other one at the other female end, and the male end plugged
into the microphone input of my netbook.  All this seems to produce a perfect
stereo effect: the two channels sound to be very well separated.

I'll be using the above simple connection system to live piano recording: mic 1
on the basses (left), mic 2 on the high (right).

My next step is trying to add human voice, say in the middle.  I'll see if this
is possible by slightly complicating the above solution, without preamp or
mixer or multi-channel audio interface.  I'll be posting here if the attempt
succeeds.

Thanks again,

Rodolfo
<