audiolaz

Guide · Microphones

UMIK-1 room correction: from the calibration file to the filter

To correct a room with a UMIK-1, plug it in, load its 90° calibration file (the one tied to its serial number), and put it at your listening seat at ear height, pointing at the ceiling, on a stand. audiolaz Room reads the file, recognises the microphone, measures three positions and builds a correction filter for the whole range, fully up to 18 kHz. The same goes for the UMIK-2 and the Dayton iMM-6C.

Updated by Alexandre Besson, who makes audiolaz. audiolaz Room is in beta.

Steps

From the box to the filter.

  1. Download the calibration files from the maker’s site with your microphone’s serial number (miniDSP for the UMIK, Dayton Audio for the iMM-6C).
  2. Plug the microphone in: into the phone (the iMM-6C is USB-C; a UMIK through a USB adapter) or into the computer that runs audiolaz Room.
  3. In the app, add the 90° file. The app recognises the microphone from it.
  4. Put the microphone on a stand at your seat, at ear height, capsule pointing at the ceiling.
  5. Measure: three short sweeps, the seat, 50 cm to the left, 50 cm to the right. The app refuses a measurement that is too quiet or clipped.

0° or 90°

Point it up, use the 90° file.

A measurement microphone is not equally sensitive in every direction in the treble. The 0° file corrects it when it points straight at one speaker; the 90° file when it points up, so that both speakers and the room’s reflections reach it from the side. For a stereo pair measured at the seat, 90° pointing up is the usual choice, and the one audiolaz Room expects.

What it adds

Treble, deep bass, time.

  • Accurate treble: the whole range, fully up to 18 kHz and fading out by 19 kHz, where an iPhone is approximate above 4 kHz.
  • Lower bass, measured more reliably.
  • Left and right aligned in time at the seat.
  • Bass optimisation: the two speakers’ bass put back in phase at the seat; the result says what it gains there.
  • Boosts can reach 3 dB instead of 2 with a phone.

With Room Plus, a calibrated microphone also opens the wider image preset. See what an iPhone measures for comparison.

Mistakes

The usual suspects.

  • The wrong file: the 0° file, or another microphone’s. The serial number on the file must match the one on the microphone.
  • Input level: too quiet and noise creeps in; too loud and it clips. Raise the playback volume rather than shouting at the microphone; the app says which.
  • Hand-held: hands and body reflect sound and move; use a stand.
  • A different seat: measure where you listen, at ear height, not on the sofa’s armrest.

Questions

Short answers.

  • Is the Dayton iMM-6C enough?

    Yes: it is a calibrated microphone like the UMIK, with its own file, and it plugs straight into a USB-C phone.

  • UMIK-1 or UMIK-2?

    Both work the same way in audiolaz Room. The UMIK-2 handles louder levels; for room correction at listening levels, the UMIK-1 does the job.

  • Can I use it with REW as well?

    Yes, the same microphone and files work in REW; the two do not interfere.

  • Where do the measurements go?

    They stay on the computer that runs audiolaz Room.

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