My Home Studio - Construction and Design

Measuring my Starting Point

With the major fixed elements of the room in place, it is time to see what I have, sound-wise. I did two things: recorded a short sample of acoustic guitar in the room, and took some measurements with the ETF software. This is a bare room, with 6 hard surfaces, so I was expecting it to sound bad, and I wasn't disappointed.

Sound Samples

Sample 1. A Neumann TLM103 18 inches away from the guitar, sitting near the middle of the room

Sample 2. Recorded with A Behringer ECM8000 omni measurement mic about 7 feet away.

OK, it sounds really bad... Nowhere to go but up from here.

ETF Measurements

I took ETF measurements in several places in the room. Here's the impulse response measured from the center of the room. I'm still struggling to interpret these graphs, but I suspect this first graph tells me all I really need to know. There are lots of strong reflections and many smaller ones, which is evident in the recording tests. The first large peak is the initial impulse, with successive peaks being reflections off various surfaces in the room.

ETF can also graph the room modes. The following graph shows different time slices. A true room mode will show up in all time slices. There's a strong mode at 84 Hz, one at 42, and so on. I'm not sure what to make of the strange pattern around 164 Hz, but this pattern was there consistently present thru repeated tests.

The reverb time is lower than I expected. The sound of the room seems to be dominated by strong reflections, but the RT60 is in the 600-700 range over most of the frequency range, except for the low end.

Finally, ETF plots the frequency response of the room. I  seem to have a rolloff towards the high end.