Faq

Frequently Asked Questions

If you've got a question that's not answered here, please post in the forums! Also see the Troubleshooting page.

How do I monitor one track in the headphones with the other playing out the main output?

This requires either a multi-channel sound card or multiple sound cards. Note that nearly all built-in sound cards have only one output pair, so you will need to add a second sound card with one or more additional output pairs. See below and the sound card information page for more information.

How do I record my Mixxx session?

Mixxx 1.6.0 and up support recording mixes to WAV and AIFF files. Versions 1.9.0 and up also support recording to MP3 and Ogg Vorbis formats. To choose the format, click "Options", then "Preferences", then "Recording" and set the options as you like. To start recording your mix, click "Options" and select "Record Mix". You will then be prompted to enter a file name, and after that, Mixxx will start recording about 5 seconds after you start playing a track. (So to get the beginning, play something, stop the deck, wait 5 seconds, then begin mixing.) When you're done recording, go back to "Options "and toggle "Record Mix" again, or just exit Mixxx.

What's the best hardware DJ controller to use with Mixxx?

"Best" is a matter of preference. It depends on what exactly you want to do with a controller. Do you want to control everything, or use one as a bunch of extra buttons in conjunction with turntables? Mixxx 1.7 and up has the ability to provide comprehensive support for any MIDI controller due to its scripting engine, and it ships with mappings for a number of popular controllers, a complete list of which can be found on the Hardware Compatibility page. Community-contributed mappings for more controllers can be found on the forums.

Does Mixxx support multiple soundcards?

Yes, as of v1.6.0. This means you can have the headphone output coming out of one sound card and have the master output going out another.

But please note that due to natural differences in clock crystals even between two cards of the exact same model, it's not possible to have multiple cards work synchronously. As a result, you will likely hear pops or skips when using more than one card. Mixxx v1.9.2 and up will lock to the clock of the card used for the Master output so at least these pops aren't heard on the dance floor, but it's always recommended to instead use a single sound card with multiple stereo outputs, such as on a true surround (5.1 channel) sound card: you can use the "front" output as your master output, and plug your headphones into the "rear" output for cueing.

:!: Be aware that sound cards are usually marketed with the number of monaural channels they have, and you need two mono channels for one stereo signal, so you would need at least a four-output card to have Master and Headphones outputs on the same card. (And if you're using vinyl control with two decks, that means you need a card with at least four inputs too.)

Is it possible to use Mixxx with an external mixer?

Yes. There are two ways to do it depending on what you want to achieve:

• Direct deck outputs: Direct deck outputs is a feature of Mixxx 1.9.0 onwards. Set the outputs in Options->Preferences->Sound Hardware and you're done. If you are on 1.8.x or below, the trick is to force Mixxx's master output to play back the left/top track, and the headphone output to playback the right/bottom track. (Each track will come out a separate output, suitable for plugging right into an external DJ mixer.) The way one does this is by sliding Mixxx's crossfader all the way to the left, and turning on the headphone cue for the right channel. This forces the first track to play out the master out, and the second track to play out the headphone out. (Since both outputs are now going straight into an external mixer, you'd use the headphone cue on the mixer as well as it's crossfader.) Using an external mixer is also described briefly in the Threadbox tutorial.
• Software mixing as an additional sound source: If you want to mix on-screen but need to integrate with an external mixer (such as when playing CDs and/or records as well, or in a radio studio) you can plug the headphone output into one channel of the mixer, and the main output into another. Then bring the channel fader of the headphone one all the way down on the mixer and set it to play in your headphones all the time (thereby adding Mixxx's headphone bus to the mixer's.) Then use the other fader (with Mixxx's main output) when you want to bring Mixxx's output into/out of the main mix.

What's vinyl control all about? How do I use it?

See the Vinyl Control page.

Does Mixxx modify the files or structure of my library?

No, Mixxx does not write to or move any files in your library. It's safe to use Mixxx with your iTunes library - Mixxx will not change anything in your library.

As of Mixxx 1.9.0, there is an option to write metadata changes back to the file tags (e.g. ID3, Xiph/Ogg, APE) but this is disabled by default. You can enable it from the Mixxx Library Preferences.

What platforms are officially supported by Mixxx?

As of release 1.6.0, the official Mixxx binary releases attempt to support the following operating systems equally:

• Windows - XP (Home/Pro) and Vista (all versions)
• Linux - Ubuntu (Hardy Heron)
• Mac - Intel Macs (OSX 10.4+)

We also support the following platforms through binary releases on a best effort basis, not all beta releases will be built for these platforms and full releases often lag behind the release cycle by a month or so:

• Linux - Generic i386 binary
• Mac - PPC Macs

Many Linux distributions (e.g. Debian) bundle their own copy of Mixxx rather than relying on our official releases, check with your distribution for more details.

Of course as an open source project, source is always available to build for whatever platform you work on, either a Linux distribution which doesn't provide Mixxx packages or something more exotic. Historically Mixxx has been known to compile on FreeBSD.

We are always happy to hear from people building Mixxx on other platforms, whether you are doing a one-time build for yourself or maintaining a Mixxx package for a distribution please get in touch.

What music file formats can Mixxx play?

As of release 1.8.x, Mixxx supports the following file formats:

• MP3
• OGG
• FLAC
• WAV, AIFF
• AAC/M4A (with plugin)
• WavPack (WV) (with plugin)

If your music isn't currently in one of these formats (or you don't have a suitable plugin installed,) it won't show up in the Mixxx library. You'll need to use a program like Sox or Audacity to convert it.

What happens if a file's sample rate is different from the sound card rate?

Mixxx performs sample rate conversion on the fly.

Note that the quality of the re-sampling depends on the setting of the pitch behaviour. Having key lock disabled ("vinyl emulation" in 1.8.x and below) will use linear interpolation, which doesn't sound very good (you will notice graininess and increased noise, especially obvious on high, long notes). When you enable key lock ("pitch-independent time-stretch" in 1.8.x and below,) Mixxx will use a vocoder-based algorithm from the SoundTouch library, which sounds a lot better (but is not recommended when scratching.)

How can I move my music to another folder or hard drive without loosing information like bpm or cue points?

Unfortunately, as of today (mixxx 1.10) this does not work automagically but needs some manual fiddling with the music configuration files. Here is one way of doing it:

1. Backup your mixxx configuration files (under Linux, this is .mixxx/ in the home folder)

2. Move your music folder to the new folder or new hard drive

3. Install SQLite Manager, which is a firefox extensions that lets you manipulate the mixxx database: https://addons.mozilla.org/de/firefox/addon/sqlite-manager/

4. Open the SQLite Manager from within firefox. Within SQLite Manager open the file mixxxdb.sqlite that can be found in your mixxx configuration folder

5. Go on Execute SQL and enter: `update track_locations set directory = replace (directory, '/old/path/DJ/Music/', '/new/path/DJ/Music/');

   update track_locations set location = replace (location, '/old/path/DJ/Music/', '/new/path/DJ/Music/');` where the old and new paths point to your corresponding music folders.

6. Then hit Run SQL. The above statements will replace all instances of /old/path/DJ/Music/ to /new/path/DJ/Music/ in the field of location and directory of track_locations table.

7. Start mixxx and under settings change your music folder to the new one. If you want you can do a rescan to check that the music files do not turn up twice suddenly (if you are on linux, do especially check music files which where in symbolically linked directory). Check if bpm and other meta infomation like cue points are still stored with the files.