Allen & Heath Xone:23C — hidden technical detail and quirks

The brand new Allen & Heath Xone:23C has been presented in countless preview videos and smaller reviews, all mentioning the main features of this great device. I have just obtained mine. There are some important details to know about, which are not mentioned in the documentation and in the reviews I have found so far. I want to share these non-obvious technical details with you, particularly regarding the USB sound hardware that is built into the Xone:23C.

The Xone:23C is a true 3+3 channel mixer

The Xone:23 (without the C) is a 2+2 channel mixer, with two main channels, whereas each main channel can be fed from two analogue sources that have an independent gain control. Still, Chris Brackley from DJ TechTools found that the Xone:23 has too few input options with only two true stereo line inputs, because the other two stereo inputs are made for low voltage (phono) input devices and cannot be switched to line level without hacking the device. The Xone:23C adds two USB audio stereo channels to the mix which can be fed via USB, rendering the Xone:23C to effectively be a 3+3 channel mixer. However, the Internet resources available so far and especially the manual do not explain explicitly how to toggle between USB and line/phono sound. The most obvious observation is that there is no switch to toggle.

The circuit diagram at the end of the manual explains the behavior. I have taken a screenshot from the relevant part and labeled a few components:


The USB audio is processed and converted (to an analogue signal) by the USB sound card block shown in the diagram. This block has two stereo outputs (send 1+2 and send 3+4). I have marked these two stereo channels with blue arrows. This is where your USB audio starts its way into the mixer after being converted to an analogue signal.

The important thing now are the summing amplifiers which I have labeled with green circles (what looks like an M or W actually is a capital Greek sigma, a symbol commonly used for summation). The circuit diagram tells us that each main channel mixes the stereo signals from phono, from line, and from USB, in equal parts. Phono and line have their distinct hardware gain controls on the mixer for controlling the mix ratio. Such a control is missing for the USB audio stream. But it is not needed: the volume of the USB audio can easily be controlled digitally, in the source (your computer).

One of the first things I tried when I got the mixer was to attach a line device and USB audio at the same time to the same main channel. Indeed, both audio sources are mixed into each other, and the loudness of the line signal and the USB signal can be set independently. Hence, the Xone:23C is a true 3+3 channel mixer. No need to toggle between line/phono and USB.

Keep the digital master output low enough!

Obviously, I choose to mix externally with the Xone:23C, using the ASIO drivers for transporting the audio signal from within Traktor to the USB sound card in the mixer. For tracks that are mastered quite loudly, the default master output volume of Traktor is too high, already clamping the signal, and going into the reds on the VU-meter on the mixer. Add some EQ effects or some HPF/LPF with resonance, and your signal becomes horribly distorted. I found that with a Traktor master output volume set to somewhere between -5 dB and -10 dB, the Xone:23C meters stay around 0 dB most of the time for normal parts of most tracks I listened to, whereas the signal increases to at most +6 dB for especially loud parts in a song, or when some effects are added.

If you are using any music player for playing audio on the mixer not through ASIO, but through the normal audio driver of your operating system, I found that a master volume of about 60 % to 70 % is sufficiently low enough for not clamping the signal. If this is set to 100 %, as it usually is, you are already in the reds. Bad.

USB audio from the mixer to the computer.

The USB sound card in the Xone:23C provides two output stereo channels (from the computer into the mixer) and to input stereo channels (from the mixer into the computer). The usage of the output channels is obvious: get sound into the mixer. Each of the two input channels plays a special role, this information is rather hidden in the manual. The mixer has an analogue stereo RCA record output, for capturing the main mix into an analogue recording device. USB input channels 1 and 2 are the same, just digitally. Hence, you can easily use your computer to record the master output of the Xone:23C, with no additional hardware and through the same USB cable that is connecting the mixer to your computer anyway. This is great.

The mixer also has an analogue effects unit stereo output. USB input channels 3 and 4 are the same, just digitally. Hence, you can use software for capturing this input (e.g. in Ableton), generate a corresponding effect output, and feed this one back into the FX input of the Xone:23C. The latter, however, requires additional hardware (another sound device that generates an analogue signal), because there is no digital FX input into the mixer.

Recording only works through ASIO so far

There seems to be one caveat with the USB recording function, at least on Windows. The Xone:23C presents a Line-In WDM recording device, for recording the master mix. However, I was not able to access this device with another software simultaneously playing back through ASIO. Playback and recording only seem to work simultaneously through the ASIO interface.

Audacity (and many other popular open source tools) does not support ASIO (ASIO is a proprietary interface and GPL-licensed software must legally not be binary-distributed with ASIO support built-in). On the other hand, Audacity could record through the Xone:23C Line-In WDM device. However, as stated above, this cannot be accessed if e.g. Traktor at the same time feeds the Xone:23C with audio data through ASIO. In other words, Audacity can not be used for recording the master mix through the Xone:23C WDM Line-In device, while having Traktor playback through the Xone:23C ASIO interface. Opening the WDM device in this scenario results in an error, saying that the device cannot be accessed. What works, indeed, is recording via the Xone:23C ASIO driver through e.g. Traktor or other commercial software.

Recording the master mix from within Traktor, however, is not totally straight-forward. One needs to define an external input source for a normal track deck (e.g. deck A). This input source must be the channels 1+2 from the Xone:23C ASIO input. As long as you do not switch deck A to be of type “live deck”, this input effectively is a no-op input (it does not end up in the output again). Now, you can switch to external recording mode, and choose deck A as input source. Don’t worry, deck A still behaves as a normal track deck, it is just mis-used for this workaround.

Issues with playback on one of my platforms

I have tested the Xone:23C’s internal ASIO sound hardware with two laptops. Both have Windows 7 Professional installed. One is 64 bit architecture and operating system, the other is 32 bit architecture and operating system. I have installed the ASIO drivers from here, specifically the 32 bit version for the 32 bit OS/laptop, and the 64 bit version for the 64 bit OS/laptop. On the 64 bit system, the audio chain (playback software -> ASIO driver -> USB audio interface) behaves as expected. On the 32 bit system I have observed infrequent crackling sounds in the output.

The 32 bit system is a fresh and clean Windows operating system install, and the driver is the “Xone:23C Windows 32bit Driver V2.9.65”. I tried different setups, all without success. Important examples that I tried:

  • Foobar audio player to Xone:23C audio WDM device with small and large buffer sizes
  • Traktor 2.6.8 output to Xone:23C ASIO driver, with small and large buffer sizes
  • Traktor 2.6.8 output to ASIO4ALL driver, with small and large buffer sizes

In all cases, the crackling appears and seems to be independent of the buffer size. The crackling is not very prominent, it appears roughly every 10 seconds, and is rather quiet. I tried different USB ports, re-installing the driver, and a couple of other things, but could not get rid of the cracks. The same Xone:23C attached to the 64 bit machine works perfectly. My 32 bit laptop has an Intel P8800 CPU, i.e. it is definitely not too weak, and playback from Foobar right to the WDM device does not require much CPU power at all. It could be a problem with the 32 bit driver (I have submitted a support ticket to A&H), but it could also be a certain quirk of this specific platform, where one of the drivers (e.g. ACPI or USB) is leading to high latencies. I have to further investigate. It would be great if you could report whether you got the Xone:23C USB audio properly working on a 32 bit Windows system.

  • Ben Perham

    Brilliantly in depth and informing. Answered a few worries I had. Thanks.

  • j

    Thanks for the tips! Really cool

  • sebastian

    Hi, can you explain how you can record your mix with cross dj that comes along with the 23c? It does not work when in external mixer mode. Should i use the recording ports on the mixer, and how should i connect it if i use another external soundcard for example?

    I would use traktor if it wasnt for the buildin dvs for cross dj..
    Would appriciate some help..

    • Please excuse the late response, Sebastian. Your 23C provides two record outputs, where you can record whatever the mixer sends to main out: one analog (RCA output), the other is digital (USB/ASIO). I guess you know how to deal with the RCA record output. Remember, the 23C has a built-in ADC, i.e. it digitally records the main output, and provides this data via ASIO through USB. In order to use that you should connect the 23C to your computer via USB and properly set up the ASIO drivers for your operating system. Then you run an ASIO-capable software (e.g. Traktor), choose the correct two channels (should be called in1 and in2) and start recording.

  • q

    the simplest case… is it possible to send two seperate signals from my computer to the mixer where i have one signal on deck1 and the second on deck2? i was trying to do it only with the usb interface but it didnt work … so the second approach was with rca + usb where rca was set for channel 3-4 and xone usb iterface was set for 1-2 ( im using mixxx and Ubuntu ) basically i cant figure out how to control independently the 2 sources on my mixer (23c) … is it a issue with my driver on Ubuntu or a hardware limitation

    • It is of course possible, but you *need* to use the ASIO interface over USB. ASIO is a proprietary protocol developed mainly for Windows. The Xone 23C drivers for ASIO are officially available for Windows and Mac. Over this ASIO interface, your mixer provides four mono channels which you can *independently* feed. Channels 1+2 end up on the left side of your mixer as stereo signal (stereo channel A), and channels 3+4 end up on the right side of your mixer (stereo channel B). I have never tried to get the ASIO interface running under Linux, but I can imagine that it is either impossible or a hassle. Note that Linux driver support is not to be expected, see for instance where an A&H support employee says (as of May 2014) “Windows and OSX along with the constant OS shifts present many
      challenges and I don’t see us adding Linux drivers to Xone any time
      soon.”. If that is something that interests you, you should definitely submit a feature request to A&H.

  • Hey! I really like your review on the details of the 23c. Hopefully you would be able to help me understand the device a little further. I currently use a xone22 (a friends) and I am looking to purchase the 23c. I use DVS as well as vinyl. I currently use traktor scratch but I am fine using any other software, such as mix vibes if it might change my situation. I want to be able to use control vinyl along with real vinyl, is there any way to do this? Will rewiring the mixer for DVS remove ALL of the line/phono inputs? My names mario, I’m a programmer, photographer, and DJ too! If you’d prefer, email me at thank you for all your help!!!

    • Hey Mario. In order to answer your questions, you probably just need to understand what “Rewiring” the 23C actually means. The 23C has two stereo ASIO channels which you can listen to on the computer (“input”, from the computer’s point of view). By default, one of these two stereo channels contains the mixer’s master out, and the other one transports the mixer’s FX send. In this configuration, you can use your computer to easily record your mix or to generate effects based on FX send. What you need for DVS is very different: the computer needs to be able to “listen” to the two vinyl signals. “Rewiring” your mixer means to change the meaning of the two stereo ASIO channels: after rewiring, your computer has direct access to the digitized vinyl signal. What disadvantages does this bring? Your computer does not have direct access to the FX send and master out anymore. This is everything. So, “Will rewiring the mixer for DVS remove ALL of the line/phono inputs?” — not at all.

      • Wow! That makes so much more sense. Thank you for explanation, it was exactly what I needed. I was correct in assuming rewiring (for DVS) on the 23c would limit functionality, just wasn’t sure how! Much obliged

      • Thank you for this info and this amazing review!!!! I just rewired my mixer then spent the last 2 hours trying to get my software to record, like it was before without putting it together. Out of desperation, I remembered this article and started looking in the comments and now I have the answer! My decision is to grab this Tascam recorder. Been meaning to do so any way. peace from Akron, Ohio!

  • Justin Pearce

    Not sure if this is weird.. I’m getting L-fader and R-fader on the two usb outputs from the mixer. That is, when I try to record in ableton I’m getting two stereo premixer channels rather than master output and FX like you’ve written. Is there some way to change this in the mixer or is this a software problem? Cheers!

    edit: this happens when using asio4all as well as just the 23:c driver..

  • Josh C.

    Hello, I recently bought the xone:23c mixer and happened to stumble upon this blog. i am very interested in using the mixer as a controller for Ableton instead of mix vibes. Can the crossfader on the mixer be used to crossfade in ableton, or do you have to connect a midi device to the mixer in order to do this? The manual states this….

    “To configure the computer and mixer for both track replay and FX you need to
    aggregate the mixer’s soundcard with the built-in soundcard on the computer. On a
    Mac this is done in the Audio MIDI utility (see page 12) – on a PC you will need to
    download and install the utility ASIO4ALL (
    Using a 3.5mm to RCA stereo jack lead, connect the headphone socket on the
    computer to the FX return on the mixer. Download install the free demo of Ableton
    Live ( – and configure it for FX send/return – input to Ableton from
    the mixer soundcard 3 – 4 and output to the computers headphone.
    You can now play tracks into the mixer from your chosen DAW and use the effects in
    Ableton via the mixers FX send/return.”

    Does this mean you can use the mixer as a controller for ableton live or only use the filters from the mixer as effects in ableton live? I am a bit confused coming from a pure analog DJ background.

    any insight would be appreciated.




    I was wondering how it worked with using the preview player in Traktor. Can you pre-listen to a track while the two channels are doing something else?

  • Oscar González Arrioja

    Hello, is there a way to use traktor effects with regular cd players setup? i read in the user guide it is possible to do it with ableton, but Im not sure if it can be done with traktor as well

  • iGio

    sorry i don’t understand, but if i use the mixer in dvs mode, can i change the control vinyl in real vinyl while i play the music? simply, can i use timecode and real vinyl,together?

  • Jonathan King

    Hi Jan-Philip. So, just to be really clear here, with regards to recording via the USB connection WHEN you have the DVS wiring enabled internally, I don’t believe this works, as per your comment to “Mario” a year ago.

    I have a Xone23C, I’m using the supplied Mixvibes Cross LE software and I have wired the 2 cables internally, so the DVS vinyl works. Cross LE happily works with the DVS Vinyl AND I can play normal vinyl – all good.

    Now that I’ve done this, the software does NOT records the Master Mix over it’s USB connection, which I believe is what you were saying about how the ASIO channels for FX send and MASTER out, get re purposed.

    Therefore if I want to record my mixes, I think I have to use the RECORD RCA connections on the back of the mixer and send them to a compatible recording device. Using something like an external Tascam DR40 or something else which turns analogue inputs into a digital recording.

    Is this correct?

  • Leonard DSouza

    I need your help on this….while my Xone23c is connected to the computer for mix / Cue purpose, on the other end I need the sound output to pass through another souncard to my main speakers.

    Plz advice.