When you open the original PDF test reports of our ECM8000 microphones, the Audio Precision (APx555) logo immediately catches your eye. If you are an audio engineer or experienced measurement technician yourself, you will rightly ask: Why would anyone measure a basic electret capsule with nearly 30 dB(A) self-noise on the world's most expensive and precise audio analyzer—and even let customers pick individual serial number curves before buying, when REW or Akulap mathematically compensates the frequency response via the calibration file anyway?
The honest answer is: Because our APx555 is already powered on every day on our lab bench—and because uncompromising measurement engineering is what we love.
What pre-purchase curve selection brings you (and what it doesn't):
- Mathematical Compensation vs. Physics: As soon as you load our supplied
.calfile into REW, Akulap, or WinAudioMLS, any on-axis frequency response deviation is mathematically compensated. For standard room acoustics measurements, our regularly calibrated ECM8000 is completely sufficient. - No "Russian Roulette" with Capsule Quality: Anyone looking at our real CSV curves in the selector immediately sees how widely modern production batches vary. By selecting your curve upfront, you 100% rule out "Monday morning lemons" (e.g., severe low-end roll-off) before buying.
- Use Without a Correction File: If you use the measurement microphone on a digital mixing console, hardware DSP, or live PA system without calibration file import, a factory-linear "Golden Sample" (±1.0 dB) is worth its weight in gold.
What does our APx555 do when it isn't bored by an ECM8000?
An ECM8000 has an acoustic self-noise of nearly 30 dB(A)—our APx555 operates electrically at an extreme -150 dB THD+N and 1 MHz bandwidth. It shows its true strength in the development of our own Class-1 microphones, ultra-low-noise 6.5 dB(A) preamplifiers, and ultra-low-THD measurements on high-end DACs and amplifiers.