Connect the DAC
Use a current Chrome or Edge browser over HTTPS. Press Connect DAC, select the hardware, and let AEQDB™ read its profile. Your HID data stays inside the browser.
AEQDB™ GUIDE / 01
How to build an IEM EQ you can actually use.
AEQDB™ is hardware-native: it compares a measured earphone with a target, then fits the difference to the actual ten filters, fixed Q, gain range and digital-filter options your compatible DAC can store. The final decision stays with your ears.
Choose your IEM
Pick a brand and model from the measured catalogue. The white line is the selected IEM response, normalized at 1 kHz so comparisons are meaningful.
Choose a target
Start with a public Harman In-Ear curve, or choose a source-referenced sound style such as PEQdB Ultra or HiFiEndgame, or use Favourite earphone to move your IEM toward another measured model. The blue dashed line is the target.
Generate, then listen
Press Generate EQ. AEQDB™ uses the DAC’s fixed ten bands, 0.75 Q and ±6 dB range. Orange shows the estimated post-EQ response. Above 10 kHz is deliberately weighted less because coupler measurements are less repeatable there.
Fine-tune safely
Drag a fader or type a gain. Each band has a filter menu: PK for focused correction, LS/HS for shelves, HP/LP for roll-off. Start with small changes; a target is a reference, not an instruction.
Compare, preview or save
After an EQ has a real gain change, Hear original temporarily sends a neutral 10-band EQ to the DAC. It then becomes Hear adjusted EQ, so you can switch back without changing the digital filter. Preview on DAC restores the current EQ temporarily. Save EQ + filter writes to compatible DAC flash only after you decide.
TARGETS AND FILTERS
What the controls mean
Starting point
Harman in-ear targets are listening-preference research curves, not proof that one sound fits everyone. AEQDB™ includes the public 2016, 2017 variants and 2019 in-ear curves.
Filter format
PEQ means parametric EQ: a collection of frequency, gain, Q and filter-type settings. It is not itself a target curve. AEQDB™ converts a target difference into this hardware format.
Leave room
When EQ boosts a band, reduce playback gain by the recommended preamp amount. This helps avoid digital clipping before the signal reaches the DAC.
DAC DIGITAL FILTER
Five ways the DAC reconstructs audio.
This Filter menu is separate from the ten PEQ bands. It changes the DAC’s digital reconstruction filter; it does not change your saved target curve. Choose one, preview it, then use Save EQ + filter to write it to the DAC.
Fast · low latency
A fast filter with low latency. A good default when you want direct timing and a crisp transient feel.
Fast · phase compensated
A fast filter with a different phase response. Try it when comparing image placement and leading-edge definition.
Slow · low latency
A slower roll-off with low latency. Often preferred when you want a gentler sense of high-frequency edge.
Slow · phase compensated
A slower roll-off with the alternate phase behaviour. Compare it with Slow-LL using familiar recordings.
Non-oversampling
An alternative reconstruction method. It is a listening preference, not an upgrade; audition it with your own music.
HOW TO CHOOSE A DIGITAL FILTER
Use it as a final seasoning, not a repair tool.
A digital filter controls how the DAC reconstructs the samples in a music file into an analogue waveform. It mainly changes behaviour close to the top of the audible range, timing around transients and ultrasonic filtering. It does not add bass, increase detail, widen the soundstage or correct an IEM’s frequency response. Use PEQ for tonal correction; use the digital filter only after the EQ is already where you want it.
Use FAST-LL first
FAST-LL is the sensible default. Keep it selected while creating or comparing PEQ, so the digital filter does not confuse your EQ decision.
Change one thing
Use two or three familiar tracks. Keep the same volume, switch only one filter at a time, and listen for cymbal edges, vocal consonants and the first attack of drums or strings.
There is no universal winner
Try SLOW-LL if you prefer a gentler top-end presentation. Try FAST-PC or SLOW-PC only as a direct comparison. Choose the one that sounds most natural to you, not the one with the most impressive name.
A different mode
NOS is an alternate processing mode, not a “warmth” setting. Its result depends on the DAC, sample rate and recording. Treat it as an optional flavour and compare it at the same listening level.
Write your final choice
Preview changes are temporary. When you have chosen a filter and checked the PEQ, press Save EQ + filter. AEQDB™ then writes both settings to compatible DAC flash.
PEQ BAND FILTER
What each band filter does.
Peak
A focused bell-shaped boost or cut around one frequency. Use it for most automatic corrections and small tonal refinements.
Low shelf / High shelf
LS raises or lowers the range below its frequency; HS does the same above it. Use shelves for broad bass or treble taste changes.
High pass / Low pass
HP rolls off bass below its frequency; LP rolls off treble above it. These are deliberate roll-off tools, not normal tone controls.