Every room I measured had the same problem: a 9 dB peak at 8 kHz. Conference rooms, concert halls, recording studios, gymnasium — all of them, apparently, had an identical 8 kHz resonance. I had been treating rooms for this issue for three months, recommending absorptive treatment in the high-frequency range, before a colleague pointed out the statistical improbability.

'Every room you measure has the same peak?' she asked, with the diplomatic tone of someone about to deliver bad news. 'At exactly the same frequency? With exactly the same magnitude?' When she said it like that, the hypothesis that forty different rooms shared an identical acoustic defect seemed less plausible.

I sent my measurement microphone to the manufacturer for calibration. The report came back: a 9.2 dB resonance at 7.8 kHz, caused by a damaged diaphragm. The capsule had a microscopic dent — probably from being knocked against a mic stand — that created a mechanical resonance. Every 'room problem' I had been measuring for three months was actually a microphone problem.

I had recommended acoustic treatment to six clients. Two of them had actually installed absorptive panels. The panels did, admittedly, make the rooms sound marginally different. But the 8 kHz 'problem' was still there in my measurements, because it was living inside my microphone, not their rooms.

The Moral: If every measurement shows the same anomaly, the anomaly is probably in your measurement chain. SonaVyx's microphone calibration import with per-frequency correction curves would have revealed the mic's deviation — always calibrate before you blame the room.