[ardour-users] monitor questions

Christopher Boggs c.boggs at gmail.com
Wed Dec 20 07:00:16 PST 2006

On a generic sound card, you have levels for playback of inputs, as well as
a capture level for whatever input you have selected (usually one at a time
for most cheapo sound cards)

If you're mic was plugged into the soundcard, then you could achieve
"hardware" monitoring or as close as you can get to it by leaving the
capture level where it is (on the recording section of qamix, alsmixer, etc)
as the send to ardour, but then turning up the playback level of the input
you're using (such as Mic or Line In on the Playback section of the mixer)

That essentially does what Mark mentioned, it routes the signal coming on
that input directly to the hardware outputs.

Hope I helped, or at least didn't confuse it worse :)

-----Original Message-----
From: ardour-users-bounces at lists.ardour.org
[mailto:ardour-users-bounces at lists.ardour.org] On Behalf Of Mark Knecht
Sent: Wednesday, December 20, 2006 8:37 AM
To: Atte André Jensen
Cc: ardour-users at lists.ardour.org
Subject: Re: [ardour-users] monitor questions

On 12/20/06, Atte André Jensen <atte.jensen at gmail.com> wrote:
> Hi
> I'd like to have the sound of the track being recorded mixed with the
> sound of playing tracks. Basically my setup is a microphone connected
> directly to the computer with headphones connected. It would be nice to
> be able to set the monitor level independently from the level going to
> disc + possibly apply a tiny bit of reverb.
> So I read http://ardour.org/manual/recording/monitoring and have a few
> questions:
> 1) I'm currently running jack with a latency of 23ms. Is that too much
> for software monitoring and what's the optimal latency (besides "as
> little as possible"). Also how is software monitoring setup in ardour?
> 2) I guess hardware monitoring could be accomplished by simply
> connecting the input of the mic to the output of the sound card in the
> connections window in qjackctl, right? But by doing this the only way I
> have of controlling the level of the recorded signal coming to
> headphones is by adjusting the input level of the mic. Should I have
> another (simple) application running that sits in the monitor signal
> chain to adjust volume, and if so what would be a good choice?
> --
> peace, love & harmony
> Atte

   Hi. I hope I'm understanding both what you want to do and your
setup correctly. If I'm mistaken then take the following with a grain
of salt.

   If the mic is USB and the sound card is some other hardware device
then I do not think you can do 'hardware' monitoring at least in the
sense that I think about it.

   Imagine the audio path:

1) Sound into mic.
2) Mic digitizes and puts it on the USB cable
3) USB is buffered into Jack - one delay
4) Jack mixes it, routes it and sends it toward your monitor path in
the sound card - second delay

You end up with 2 latency delays as far as I know.

   More normally 'hardware' monitoring, then way I know it, is
completely handled within the sound card. With my HDSP9652 and
hdspmixer I can route a specific hardware input directly to a specific
hardware output with no latency delays. If I hear music coming through
the card I can play my guitar and have it be exactly in time with the
music I'm hearing because the guitar I'm hearing never went into the

   In parallel I will record the guitar and then nudge it to be
aligned, if necessary, but the audio I hear just goes through the
sound card.

   Some low-end sound cards support hardware monitoring in them. You
can route a mix input to the output using some mixer or I suppose Alsa
commands from a terminal. (Tom complicated for me!) Almost all the
high-end cards are going to support this feature.

   I do not think that any audio path that goes into the computer and
through Jack is considered 'hardware' monitoring.

Hope this helps,
ardour-users mailing list
ardour-users at lists.ardour.org

More information about the Ardour-Users mailing list