Step 1: Import the House Curve into REW
In REW: Preferences → House Curve tab → Browse → select the target curve .txt file.
This file can come from:
- • The House Curve Builder in this app (.txt export)
- • A standard target curve (Harman, etc.)
- • A custom file created manually
The house curve applies globally to all measurements in REW.
Step 2: Select the driver measurement
In REW, select the driver measurement to equalize (e.g. "Tweeter L MMM").
Open the EQ window: click "EQ" in the toolbar.
Step 3: Configure the equalizer
Equaliser: select "Generic" (compatible with Helix DSP and most DSPs)
This mode generates standard PEQ (Parametric EQ) filters with frequency, gain and Q — directly transferable into DSP PC-Tool.
Step 4: Target and levels
- • Target type: "Full range speaker" (even for a band-limited driver — crossovers are handled separately)
- • Target Level: adjust so the target line sits at the right level relative to the measurement
- • Target = house curve + level offset → REW computes the difference and generates the EQ filters
Step 5: Crossovers in REW
In EQ Filters → Crossover types, set the ELECTRICAL crossovers that match the target ACOUSTIC slopes.
Important: these are NOT the same as the DSP crossovers (see the "Electrical vs Acoustical" section). Here you tell REW the driver's target passband so it doesn't try to correct the natural out-of-band attenuation.
Step 6: Filter frequency range
EQ filter frequency range:
- • Low limit: 1 octave below the driver's HPF
- • High limit: 1 octave above the driver's LPF
Example tweeter HPF 3500 Hz (value from the driver datasheet), no LPF:
→ Range = 1750 Hz to 20000 Hz
This prevents REW from wasting EQ bands correcting the crossover's natural attenuation.
Step 7: Filter parameters
- • Individual max boost: 6 dB (limit aggressive corrections)
- • Overall max boost: 5 dB (global safety margin)
- • Flatness target: 1 dB (acceptable tolerance — below this, too many filters for an imperceptible gain)
- • Number of filters: 10-15 per driver (the Helix DSP has 30 bands per channel, keep some in reserve)
Step 8: Generate and export
- 1. Click "Match response to target" — REW generates the filters automatically
- 2. Verify visually: the "predicted" curve should follow the target closely
- 3. Export: "Export filter settings as text" → .txt file
- 4. In Helix DSP PC-Tool: channel Output EQ → "Load import file" → select the .txt
- 5. Re-measure to verify the real result vs the REW prediction
Repeat for EVERY driver in the system (tweeter L, tweeter R, mid L, mid R, etc.)
Conclusion
With these 8 steps mastered, you can generate accurate EQ corrections for every driver in your system. The key is measuring well (MMM technique), setting appropriate filter limits, and always re-measuring to verify. Sound Architect automates the target curve creation and guides you through each measurement — the REW Auto-EQ step becomes just one part of a complete calibration workflow.
Sound Architect
Sound Architect generates your target house curve and guides you through this entire workflow automatically.
Related Guides
Which Smoothing Setting Per Driver Type — REW Guide
Different drivers need different smoothing settings in REW. Using the wrong one leads to over-correction or missed problems. Here is the definitive guide.
Electrical vs Acoustical Crossovers: What Every DSP User Must Know
Your DSP crossover settings and your measured acoustic response will almost never match. Understanding why is the key to proper crossover tuning.