Which Smoothing Setting Per Driver Type — REW Guide

Smoothing in REW is a visualization tool that averages your frequency response curve to reveal trends. The right amount depends on which driver you are measuring — too little and you chase noise, too much and you miss real problems. This guide gives you the exact setting for each driver type and explains why.

Recommended smoothing by driver type

Smoothing in REW averages the response curve to better visualize trends. The right setting depends on the driver being measured.

Driver	Smoothing	Reason
Subwoofer	1/12 octave	Cabin modes create narrow peaks/dips you need to see
Midbass / Woofer	1/6 octave	Trade-off between detail and readability
Midrange	1/3 octave	Human perception is ~1/3 octave in the midrange
Tweeter	1/3 oct. or Psychoacoustic	The ear doesn't perceive fine detail in HF

Important rules

1. ALWAYS measure at 1/48 octave (max resolution) — apply smoothing AFTERWARDS in REW
2. Smoothing is a VISUALIZATION tool, not a correction tool — it does not change the data
3. REW's psychoacoustic smoothing models real human perception (ideal for final evaluation)
4. For automatic EQ, REW uses the raw data — the displayed smoothing does not affect the calculation

Pitfalls to avoid

• Smoothing HIDES cancellations (narrow, deep dips) — never boost a dip without checking at 1/48
• A narrow -20 dB dip at 1/48 that disappears at 1/3 = acoustic cancellation → do NOT try to correct it with EQ (impossible, and dangerous for the speaker)
• Narrow peaks in HF (> 5 kHz) are often inaudible — don't waste EQ bands correcting them
• If a peak/dip is visible at 1/3 octave, it is significant and audible → correct it
• If a peak/dip is only visible at 1/48 octave, it is probably inaudible → ignore it

Conclusion

Always measure at maximum resolution (1/48 octave) and apply smoothing after capture for visualization. Use the table above as your reference: 1/12 for subs, 1/6 for midbass, 1/3 for mids and tweeters. And remember — if a dip only appears at 1/48 and vanishes at 1/3, it is an acoustic cancellation that EQ cannot fix.

Sound Architect

Sound Architect recommends the correct smoothing at each measurement step automatically.

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