Hardware digital effects have come a long way—which you know if you’ve tried new technology like the Kemper Profiling Amp, Fractal Axe-FX, or Line 6 Helix. Lately, I’ve been particularly fond of the Helix’s ability to do multiband processing that lets you split the guitar into four bands (low, low mid, high mid, and high), and then distort each band individually. For rhythm guitar and power chords, this gives a big, clean, focused sound compared to having all the frequencies go into a single amp. Here’s how to do multiband amps with the Helix.
Split the Bands. Set both signal paths to the same input, and then drag a block downward from each signal path to create a second, parallel line for their respective paths. This creates four parallel signal paths.
Each path starts with a 10-band graphic EQ block. For the low frequency band, I turned the 62.5Hz, 125Hz, and 250Hz bands up full, and set 500Hz at around -10dB. At the next higher band, I set the 250Hz and 500Hz bands up full, with 1kHz down about -4dB. The next band had 500Hz down about -8.5dB, and 1kHz and 2kHz up all the way. For the highest band, I turned 2kHz, 4kHz, 8kHz, and 16kHz up full, with 1kHz at about -8dB. The bands overlap somewhat, because I felt that gave the best sound, but where to split the bands varies with your guitar of choice, and the preset’s purpose.
Amp Up. Next come the four Amp+Cabs. I tend to use the same Amp+Cab in each chain, but you can also mix and match. To compensate for multiband operation, you’ll probably want to turn up the Drive, because there isn’t as much signal going into each amp. But turn down the Master, because the output from four amps adds up. However, note that turning down Drive for the highest-frequency path can give a sweet, less harsh sound, and pulling down all the Drives somewhat can produce some beautiful clean tones.
Analyze. The next stage is for diagnostic purposes—a Gain block in each signal chain turned to zero gain. Enabling the Gain block mutes the sound, so bypassing a Gain block allows tweaking a particular path without hearing the others. After creating your preset, you can delete these. The last block is for Pan. I usually leave the high and low bands centered, with the middle bands spread a bit to give a cool stereo effect.
And there’s more! Remember that amps and cabs take a lot of processing power. Still, with the hardware Helix, you’ll usually be able to add some more effects. This is where it gets really interesting. For example, insert chorus, delay, or auto filter in only the middle two bands. But the proof is in the playing. Create a preset with only one Amp+Cab, and then create a multiband preset using the same Amp+Cab, and prepare to be blown away when you compare the two.