Qtractor: cannot achieve hard panning

Support & discussion regarding DAWs and MIDI sequencers.

Moderators: khz, MattKingUSA

Established Member
Posts: 7
Joined: Mon Nov 26, 2018 12:49 pm
Location: Seoul, South Korea

Qtractor: cannot achieve hard panning

Postby rizzin » Mon Nov 26, 2018 1:16 pm


I have a pretty simple project in Qtractor (manually built from latest code, commit 632a657e): two tracks, both have stereo "Master" as their input/output.
Both channels have a mono audio clip each, each clip's panning is centered (0). No external audio input is not used in this case.

I cannot make the channels pan in this setup. If you look at the screenshot I took during playback, you can see that I muted the "bass" channel altogether to have a clean experiment, panned "gtr" channel to the left, and only the left channel of the Master has any sound. However my speakers/headphones have sound coming out on both sides.

I did a simple test in Audacity: created a stereo track and copied these audio clips into the left / right channels respectively, and during playback Audacity's panning controls behaved exactly as expected: at the leftmost position only the left channel's content was coming out of the left speaker and vice versa for the right panning.

This means it is not my hardware problem, but me not understanding something about Qtractor. Could someone please explain what could I be doing wrong?
You do not have the required permissions to view the files attached to this post.

User avatar
Established Member
Posts: 751
Joined: Mon Apr 19, 2010 12:20 pm

Re: Qtractor: cannot achieve hard panning

Postby rncbc » Thu Nov 29, 2018 8:33 am

You seem to have two extra Master buses, named after "Master In" and "Master Out", which I don't get their purpose in this scenario.
Make sure you have only one and the same output bus (eg. "Master") on the audio track you're trying to run; disconnect all others but Master/out_1,2 ports to your speakers system:playback_1,2 resp.

The Master output bus meters are showing the correct levels (hard-pan to the left) and if it's the only that connects to your speakers then it should be what you hear : sound on the left speaker only.


Established Member
Posts: 7
Joined: Mon Nov 26, 2018 12:49 pm
Location: Seoul, South Korea

Re: Qtractor: cannot achieve hard panning

Postby rizzin » Sat Dec 01, 2018 11:42 am

Thanks for the reply, but ultimately it turned out to be an audio card configuration issue... One of the card's output had correct alsamixer levels (headphones, thus the correct result in Audacity), another, speakers, didn't, because setting things correctly is hard when you have no idea what exactly things like PCMA-OutB correspond to.

If there are any other owners of M-Audio C400 audio card reading this in the future, it seems that:
PCM N, where N is 1 to 6 correspond to the "Software returns" of the card. According to the manual (https://verleih.fhstp.ac.at/upload/M-Au ... 382965.pdf), 1 and 2 are default playback channels.

1 / 2 - headphones / speakers 1-2
3 / 4 - speakers 3-4
5 / 6 - SPDIF L/R

Thus, correct volumes to set in alsamixer were:
PCM1-Out1 / PCM2-Out2 for the headphone output
PCM1-Out3 / PCM2-Out4 for the speakers connected to the 3-4 output

The mistake I made was also having non-zero levels in channels like PCM1-Out4, which means that left channel of the audio being played back went into the right channel of the output device. Headphones were set correctly, speakers were not.
Sorry for the trouble!

Return to “Recorders & Sequencers”

Who is online

Users browsing this forum: Google [Bot] and 4 guests