Levels
Two settings decide whether the HX One sounds like the demo or sounds broken. Neither of them is a tone control, and both are buried in a menu.
Almost every "it sounds thin", "it sounds quiet", "it sounds harsh" or "it sounds fizzy" report comes down to two settings, and neither is a tone control. One is what you told the box your instrument is. The other is what you told it your speakers are. Get both right and the preset that sounded broken sounds like the demo. The HX One is also the only box in the family whose manual says what these settings mean in numbers, which makes it the clearest place to learn what Instrument and Line actually are.
HX One Owner's ManualFirst, tell it what you plugged the outputs into
These are not under Global Settings like the rest of the family. Hold the EFFECT knob for a second for the Settings View, then page to page 3 — Out Level. Instrument is −10 dB, for the input of another pedal or an amp; Line is +4 dB, for outboard gear.
- The instrument input on a guitar or bass amp
- Instrument
- The guitar input of a stompbox or another multi-effect
- Instrument
- The instrument-level effects return of an amp — four-cable method, or post effects
- Instrument
- The inputs of a studio rack effect, or a mixer
- Line
Then tell it what you plugged in
Same screen, In Level. Instrument suits electric guitar and bass; Line suits anything already at line level.
- A guitar or bass with passive pickups
- Instrument
- A guitar or bass with really loud active pickups
- Instrument or Line — trust your ears
- A keyboard, synth, or drum machine
- Line
Distortion that appears on loud notes and disappears on quiet ones is clipping, not the effect model. Turn the input down before you reach for a tone control.
Impedance is per preset here, on page 2
The Settings View carries an Input Z parameter, stored per preset rather than globally. Line 6 suggest experimenting with it: it changes the tone and feel of your instrument, and it can be set to suit the particular effect model that preset is running.
The loop's position is a level decision too
I/O Config on the same screen decides whether the Send and Return jacks act as an insert, and Insert Position places the HX One's own effect before or after that loop. If you set I/O Config to Insert, the Bypass Type has to be DSP rather than True — on True bypass the signal stops being fed through the Send and Return jacks when the pedal is bypassed, which looks exactly like a dead loop.
There is no Global EQ on this one
The bigger Helix boxes carry a Global EQ for compensating on the day. The HX One does not — if a room needs fixing, it has to happen in the preset or on whatever it is plugged into.
Watch the block levels too
One more level worth knowing about: every block has its own Level parameter, and Line 6's advice is to leave it at 0.0 dB on most of them. Nudging three or four in a row is a common way to clip the output while every individual setting still looks reasonable.
Levels are half of it. The other half is the cab block — on into anything full-range, off into anything that ends in a real guitar speaker. Get both right and almost nothing else can make it sound broken.