Exploring the Creative Possibilities of the Boredbrain Music EQx5 Eurorack Module

The Boredbrain Music EQx5 Eurorack Module is a versatile and powerful five-band stereo equalizer that offers voltage-controlled adjustments to all parameters, making it a valuable tool for creative EQ processing in a eurorack setup. Its features include ±12 dB gain for each frequency band, graphic equalization, voltage control inputs, post-EQ balance and level controls, and three outputs, including a mono output that is useful for crossfading between two signals or obtaining a mix of two audio signals.

The module has five different frequency bands from high to low: 10 kHz shelf, 4 kHz peak, 1 kHz peak, 400 Hz peak, and 100 Hz shelf. These can be used to make subtle or dramatic changes to the frequency content of the source audio signal(s), such as attenuating problem frequencies and accentuating others, or strategically making space in the mix. The first order filters employed for equalization have slopes of 6 dB/oct from their respective center frequencies.

The BALANCE parameter is an equal-power crossfader that affects the gain of the Left and Right channels. When a stereo signal is connected to the module's inputs, this parameter functions like a pan control, shifting the stereo image left and right. When two mono signals are connected to the module's inputs and the OUT L+R mono output is used, this parameter functions like a volume crossfader with no perceivable level drop in the center.

The LEVEL parameter is a post-eq volume adjustment used to compensate for level changes after frequency equalization. The module implements a pseudo-loudness feature, which gradually boosts the low and high shelving filters as LEVEL is reduced to account for the equal-loudness contour.

One of the key features of the Boredbrain Music EQx5 Eurorack Module is the ability of all parameters to be controlled with external voltages, making it easy to incorporate into a modular environment. The amount of boost or cut for each band can be modulated using control voltage signals, with the full range being ±5 V (10 Vpp). The frequency band's gain knob then defines the bias point to offset the incoming control voltage. Additionally, both BALANCE and LEVEL have their own respective CV inputs, also with a full range of ± 5 V.

The module has two inputs, L and R, designed for audio signals within the audible spectrum. These inputs are AC-coupled, and will block DC signals to reduce noise. R is normalled to L, so if no plug is present, the channel will obtain a copy of L. In addition to the two discrete L and R outputs, the module has a mono output, OUT L+R, which is the sum of the two channels.

Overall, the Boredbrain Music EQx5 Eurorack Module is a powerful and creative tool for a eurorack enthusiast looking to experiment with EQ processing. Its voltage-controlled adjustments and unique features make it stand out among other graphic equalizers on the market.

Example Usage

If you are a novice looking to experiment with the Boredbrain Music EQx5 Eurorack Module, a simple application could be to use the HIGH frequency band to boost the brightness in a dull recording. Start by routing your source audio through the EQx5 module and adjust the knobs to hear the difference. You can manually turn the HIGH frequency band knob to add some sparkle and shine to the audio. For more experimental processing, try modulating the HIGH frequency band with a control voltage signal to create interesting textures and movement in the audio.

An intermediate-level usage example of the Boredbrain Music EQx5 Eurorack Module is using its CV inputs to create an envelope-controlled EQ processing on a drum loop. By patching an envelope generator's output to the EQx5's CV inputs, the frequencies can be adjusted dynamically based on the envelope's shape. For example, setting the envelope to trigger on the kick drum hits and adjusting the EQx5's LOW band to cut out the bass frequencies during the attack of the kick can create a punchier and more defined sound. Similarly, modulating the HI-MID peak frequency with the envelope can create a subtle wah effect on the drum loop. The possibilities with using the EQx5's CV inputs for creative EQ processing are endless and can add dynamic and expressive elements to any sound.

Further Thoughts

For a creative EQ processing application using the Boredbrain Music EQx5 module, try using external CV signals to modulate the frequency bands while a drum sequence is playing through the module. Set up a simple sequence with a kick on the low end and a snare on the mid-high range. Use a complex LFO to modulate the LOW, LO-MID, and MID bands, creating a pulsing effect on the kick drum while also adding movement to the snare. Additionally, you can use an envelope generator to modulate the HI-MID and HIGH bands, creating a dynamic effect that accentuates the drum transients. Finally, use the BALANCE parameter to pan the drums and the OUT L+R mono output to obtain a mix of the two signals. This approach can add a lot of interest and movement to an otherwise static drum arrangement.