Acoustic room optimization

[BenWatts]

Hi everyone,

I feel particularly silly for not understanding, but I’m exhausted from not getting it and I’m reaching my limit here.

I’m diving into acoustic measurement for my room, but I’m running into some technical misunderstandings despite having the supposed relevant equipment. Here’s my current setup:

- iMac with a 2.1 Focal system
- REW
- Zoom H5 (used as a USB audio interface, powered by the Mac)
- 5m XLR cable (connecting the iMac to the central listening point)
- ECM8000 microphone

My issues:

1. Calibration
I’ve selected the Zoom H5 as the audio input in my iMac’s preferences and set it to audio interface mode. However, when calibrating at -18 dBFS in REW, I can’t reach the required sound level. How do I adjust the gain on the H5 or in REW to get a usable signal?

2. ASIO Driver
In REW, the list of audio drivers doesn’t offer ASIO. Is this a problem? How do you handle this?

3. The Measurement Principle Itself (yes, I’m embarrassed to ask these questions).
I don’t understand why the calibration sound needs to come from the iMac’s speakers (located in a corner of my living room) when I want to measure my main hi-fi system (listening point in the center of the room). I don’t get the principle at all. In my mind, it was about sending a test signal (e.g., a specific frequency from Qobuz) through my system to measure the response.

My goal is to optimize the acoustics of my room for a system that feels too intrusive and oppressive to me. After watching YouTube videos, I still don’t understand the procedure.

Thanks in advance for your help.