Line-level or usb measurement mic's

1

hi,

browsing measurement mic’s that can be used without the need for a good pre-amp,
i.e. line straight in to the QA402.

  • an option would be USB-mic, capture to wav, send to QA soft via api
  • another would be if there were a really flat response mems mic and tie it straight to the I2S input header on the QA402

thoughts?
david

2

I have one of these usb mics that come with a downloadable calibration file. They may be cheaper elsewhere:

3

hi! curious how do you use that with the QA software ?

4

I use the mic with REW software for speaker measurements- have not had a need to use it with the QA software & am not sure how it would be used, to be honest)- but it is a decent usb mic that has a calibration file…

5

For speakers (all acoustic transducers) REW is much more developed and capable than the QA software. QA would be a good choice for a production environment but for broader applications, development, room acoustics etc. REW or ARTA are quite popular. I don’t think there is a practical way to use the USB mike with QA since you need the stimulus in a known time relationship with the sound pickup.

6

thanks, never used REW or ARTA as I’m mainly focusing in production test.

have experience using Clio and Listen Inc for freq response & gain limits as well as rub&buzz + air-leak testing. are there any open source tools that can do this well?

7

Hello, guys!

It seems I found the way how to use QA403 and USB microphone UMIK-2 in REW, but I am not sure this way is correct or not ( unfortunately I have not time to do many tests of it.)

If this method is wrong, tell about it.

  1. Install ASIO driver for QA403.
    Configuration file is:

fullScaleInputLevelDBV = +18.0
fullScaleOutputLevelDBV = -2.0
bufferSizeSamples = 512

( About ASIO driver for QA403 read here: ASIO401/CONFIGURATION.md at master · dechamps/ASIO401 · GitHub )

  1. Install O Deus ASIO Link Pro Tool, reboot computer.
  2. In ASIO Link Pro Tool set:
    sample rate(example 48000), buffer size, ASIO channels ( example 2 IN and 2 OUT), and choose QA403 ASIO driver ( Initialise ASIO - Pick driver - choose ASIO401)
  3. ASIO Link Pro Tool will create 4 virtual audio channels. Go to Windows Settings (System-Sound), there are will be Speakers 01, Speakers 02, Speakers 03, Speakers 04.
  4. Choose Speakers 01 ( this is “L+” output on front panel of QA403).
    Go to settings of Speakers 01 and set there 48000
  5. Press button START ASIO in ASIO Link Pro Tool - it will “run” QA403 ( you will see that “RUN” LED has green color now)
  6. In Routing window of ASIO Link Pro need delete red connection lines from ASIO DRIVER IN to ASIO DRIVER OUT MIX
  7. Open REW. In Preferences choose JAVA, input is UMIK-2, output is SPEAKERS 01, sample rate 48kHz.
  8. Setup is ready, do measurements.
  9. After measurement press Stop ASIO button in ASIO Link Pro control panel

I read that unregistered version of ASIO Link Pro can specially make noise sometimes - keep it in your mind.

I compared it with my old M-audio Fast Track Pro sound card - it has not the difference (small difference in SPL not matter because may be I just little moved speaker when plug-unplugged cables in AUX)

SPL
SPL1456×1992 225 KB

8

ASIO_Link_pro_tool_control_panel
ASIO_Link_pro_tool_control_panel1306×601 234 KB

9

REW_preferences
REW_preferences1432×972 132 KB