REM or Free-Field Speaker Calibration Issues or Inaccuracies

Product(s): Measure · Primus · Unity
Applies to version: All current versions
Audience: External – Customers
Difficulty: Intermediate
Estimated resolution time: 10–20 minutes
Last updated: 2026-06-27
Article type: Troubleshooting guide

Quick summary

Free-field loudspeaker calibration or REM probe calibration is failing, returning inaccurate results, or noise equalization is not working as expected. This guide walks you through the correct calibration sequence to restore accurate measurements.

⚙️ Before you begin

Make sure the room is quiet - background noise directly affects calibration accuracy.
You will need the local calibration password: primusFFcal.
Do not move the speaker or patient chair during calibration.

Step 1: Perform free-field loudspeaker calibration

Has free-field loudspeaker calibration been completed recently and with the correct speaker selected?

✅ Yes → Proceed to Step 2.
❌ No → Take these steps:

In Primus/Measure, go to Tools → Sound Field Calibration. Enter the local password primusFFcal when prompted.
Confirm the correct Free Field Speaker is selected - it must match the speaker physically connected to the board.
Position the speaker exactly 1 metre from the patient's head (or microphone position).
Ensure the room is quiet, then run the calibration.
If the patient or speaker position has changed since the last calibration, recalibrate now.

→ Check if the issue is resolved. If yes - you're done ✓. If no - continue to Step 2.

Step 2: Perform REM probe calibration

Has REM probe calibration been performed in the current session?

✅ Yes → Proceed to Step 3.
❌ No → Take these steps:

Ensure the test environment is quiet.
Hold the probe tubes as close to the speaker as possible during calibration.
Run the REM probe calibration from within the software.

→ Check if the issue is resolved. If yes - you're done ✓. If no - continue to Step 3.

Step 3: Reset REM noise equalization

Have you tried disabling and re-enabling REM noise equalization?

✅ Yes → Proceed to the escalation path below.
❌ No → Take these steps:

In the software, locate the REM noise equalization setting.
Disable it and wait a few seconds.
Re-enable it.

→ Check if the issue is resolved. If yes - you're done ✓. If no - proceed to the escalation path below.

🔺 Escalation path

If none of the above steps resolved the issue, contact Auditdata Support.

Please have ready:

Product name and version number
Device model and serial number
Firmware version
Description of the calibration error or inaccuracy (e.g., values too low, calibration fails at a specific frequency)
Your account name and contact details
Which steps above you already tried
Screenshots of calibration results if available

✅ Expected outcome

After completing these steps, free-field calibration should complete without errors and REM measurements should be accurate. The noise equalization setting should be active and stable.

📝 Additional notes

Free-field calibration must be repeated any time the speaker is moved, the room layout changes, or after a software reinstallation.
REM probe calibration should be performed at the start of each session or whenever probe tubes are replaced.
Background noise - even from ventilation or nearby equipment - can cause calibration inaccuracies. Calibrate in the quietest conditions possible.
Related articles: Free field Calibration with REM Headset too low · PRIMUS - High-Frequency Transducer Not Responding · No Sound from Loudspeakers

Need more help? Visit the Auditdata Help Centre or contact our support team.