- sound level must be high enough, ie the voice level should be comparable to someone speaking in the room, also avoid any clipping on the recording
- notice that we have no responsibility due to too high levels : start with low levels
- record without filter, compression or any process or EQ (unless you do a measurement with correction EQ).
- the recommended mic is MiniDSP Umik, at a resonnable price under 100€, connected in usb so you need no preamp. This mic is delivered with an individual calibration file at 0 and 90° : https://www.minidsp.com/products/acoustic-measurement/umik-1 or http://www.audiophonics.fr/fr/micros-de-mesure/minidsp-umik1-micro-mesure-usb-omnidirectionnel-p-8269.html or https://www.amazon.com/miniDSP-UMIK-1-Measurement-Calibrated-Microphone/dp/B00N4Q25R8
- keep the mic vertically , pointing to ceiling, with the hand low on mic. Note that you have to send the corresponding calibration file (ie the one for 90°)
- for left, right, front and rear position, better change slightly mic height
- while sweeps, distance between positions is about 30cm for a studio or listening room and about 1m for a theater or large mixing room
- with pink noise, the volume scanned by the mic is about 1mx1mx0.5m (Lxlxh) for a listening room or a studio up to 3mx3mx1m for a large room (preferably use a mic boom)
- avoid any obstacle between loudspeakers and mic when moving mic
- don’t move mic less than 30cm of obstacles (seat, table, console,…)
- while moving mic, take care to constantly vary distance between mic and your body
- the way to move mic is not very important but allways move slowly to avoid wind noises, ie 30cm/second
- the whole stereo sequence is about 2mn 30 seconds
- synchronisation is automatically done by software : no need to precisely cut the record by keep less than 15sec before voice start and keep the whole record up to the end (sequence can be cut anywhere after end of sounds, but not too long to avoid excessive upload time ).