Speck Electronics XSUM-03


If you need more than simple summing, then you need the X.Sum.

The X.Sum is a 32 x 4 line mixer that can be used for external DAW summing or as a line mixer for synths, samplers, and effect returns. Any of the 16 stereo channels can be assigned to either the main stereo Mix output or the stereo Mix-B output
The In’s & Out’s

Connect the X.Sum to virtually any line level source: balanced, unbalanced, transformer, or transformer-less. The X.Sum has high headroom that will handle balanced signals up to +28dBu. All audio inputs and outputs are fully balanced and available on TRS connectors. Looking a bit closer at the rear panel, you will notice a Multi-function I/O connector. This connection increases the functionailty of the X.Sum’s inputs and outputs.

The X.Sum includes an external breakout box that adds connectors for the Mix-B outputs and “Pre” Mix-A outputs. The left/right “Pre” Mix-A outputs bypass the X.Sum’s master section so you can use your own external preamps to add character and color to your mix.


16 Stereo Line Inputs-
Stereo level control.
Pan/balance control.
Mix assign switch that routes input
channel to the main stereo mix or
Mix-B stereo mix.
Mono Switch.
Left and right balanced TRS inputs.

Master Section-
Master level control.
Stereo/mono switch
Monitor/Phone level provides
adjustment to headphone jack and
Mix-B output.
Balanced TRS stereo mix output.

Frequency Response (12 dB gain)
3Hz-54kHz (+0/-.5dB)
THD+n (Gain 12, Output +24dBu)
Noise (22Hz-22kHz)
-102dBu (Residual output noise)
-87dBu (16 channels routed, faders off)
Maximum Input Level
Maximum Output Level
Input Impedance
30K Ohms (Balanced)
15K Ohms (Unbalanced
Output Impedance
60 Ohms
Dimensions (Mixer)
WxHxD=1.75″ x 19″ x 10.75″
(44mm x 483mm x 273mm)
Dimensions (Power Supply)
WxHxD=4.6″ x 2.75″ x 7.3″
(117mm x 70mm x 185mm)
Shipping Weight (Mixer & PS)
15 Lbs (6.8kg)

Additional information

Weight 15 lbs
Dimensions 11 × 2 × 19 in