HiFiMAN Bolt EQ settings
Parametric EQ correction for the HiFiMAN Bolt, derived from measurements by Super Review. It moves the measured frequency response toward a neutral target.
How the Bolt sounds before EQ
Measured against a neutral target, the Bolt comes out bass-heavy. The low end dominates the tuning and can mask the mids.
The sub-bass region, rumble and the weight under kick drums, sits about 6.4 dB forward of neutral, so kick drums carry extra weight and rumble. The bass region, punch and bass lines, sits about 3.9 dB forward of neutral, so bass lines carry extra weight. The mids region, vocals and most instruments, sits about 2.9 dB behind neutral, so vocals sit behind the instruments. The presence region, vocal clarity and attack, sits about 2.7 dB forward of neutral, so consonants and attack can turn sharp.
The largest deviation runs to about 6.4 dB, which is impossible to miss. This model benefits clearly from correction.
These figures are read from the correction itself: whatever the EQ lifts, the headphone lacked, and whatever it cuts, the headphone had too much of. The target is the community's neutral reference, and how far above 10 kHz you can trust any measurement varies by rig. More bass-heavy models.
The correction curve
The solid line is the full measured correction (all 10 filters). The dashed line is what Atrium applies: the same shape at 65 percent strength, capped at 6 dB per band, so the headphone keeps its own character instead of being forced flat.
What the EQ fixes
The biggest moves in this correction, and what they do:
- The filter at 4.93 kHz cuts the sibilance range by 12.0 dB with a narrow band (Q 4.01).
- The filter at 2.88 kHz cuts the clarity region by 7.2 dB with a medium-width band (Q 1.65).
- The filter at 105 Hz cuts the bass punch region by 6.8 dB with a shelf.
The preamp of -3.9 dB offsets the boosts so nothing clips at full volume.
Parametric EQ settings
Preamp: -3.9 dB (prevents clipping from the boosts below)
| # | Type | Frequency | Gain | Q |
|---|---|---|---|---|
| 1 | Low shelf | 105 Hz | -6.8 dB | 0.70 |
| 2 | Peaking | 2.38 kHz | +5.4 dB | 0.21 |
| 3 | Peaking | 213 Hz | -3.6 dB | 1.06 |
| 4 | Peaking | 4.93 kHz | -12.0 dB | 4.01 |
| 5 | Peaking | 2.88 kHz | -7.2 dB | 1.65 |
| 6 | High shelf | 1 kHz | -0.6 dB | 0.70 |
| 7 | Peaking | 69 Hz | +1.8 dB | 1.92 |
| 8 | Peaking | 130 Hz | -1.0 dB | 2.39 |
| 9 | Peaking | 6.29 kHz | +1.4 dB | 6.00 |
| 10 | Peaking | 1.37 kHz | -0.4 dB | 2.94 |
This is the full measured correction in AutoEq format. It pastes straight into Equalizer APO or Peace on Windows, and into most parametric EQ apps.
How to use these settings
Manually: enter the preamp and each filter into any parametric EQ. On Windows that is usually Equalizer APO with the Peace interface. On a Mac, eqMac or SoundSource. Set the type, frequency, gain and Q exactly as listed.
With Atrium: pick your Bolt in the app and it applies a tuned version of this correction: 65 percent strength with a 6 dB per-band cap, which fixes the rough spots without erasing what the headphone does well. Atrium also measures how you hear with a short listening test and layers your personal hearing profile on top. Two people with the same headphones do not hear the same sound. Headphone corrections are part of Signature Edition; the app itself is free.
Bolt vs other HiFiMAN models
Bass and treble are each model's average distance from the neutral target in that range. Positive means more than neutral, negative means less.
| Model | Signature | Bass vs neutral | Treble vs neutral |
|---|---|---|---|
| Bolt (this page) | bass-heavy | +5.2 dB | +0.3 dB |
| Sundara | bass-light | -2.7 dB | +0.4 dB |
| Edition XS | bright | -1.9 dB | +1.1 dB |
| Ananda Nano | bright | -1.9 dB | +1.3 dB |
| Ananda | bass-light | -2.4 dB | +0.7 dB |
Headphones that sound similar
Closest matches across all 4,332 measured models, by distance between their deviation curves. Useful if you like how the Bolt is tuned and want alternatives.