Originally Posted by kbgl
In my measurements, I found that I needed the gating at about 1.5 ms to 2 ms. After doing a little quick math, this makes sense because my first reflection off the floor would be roughly 2 ms behind the direct signal. This is with the drivers about 30" to 39" above the floor, and measuring from between 3 to 5 feet away.
The gating marker on the spl trace shows up at about 500 hz to 800 hz range. I assume that any frequencies above the marker should be accurate, and any below could be partly contaminated by the reflections.
Yes, the gated response will depend on the room. You can drag the gated line to see how it changes the response, you will notice the upper frequencies, 1K Hz and above do not really change that much but the lower frequencies do.
My measurements are done in my HT room which has treatements, I also put 4" thick panels on the floor and behind the speaker Im measuring. I can get gating out about 4 ms or more.
You are correct about the marker, everything below includes room interaction and everything above is just the speaker.
HOLM is pretty good with room noise too, someone on DIYaudio.com did a a measurement while playing music the FR response didnt change much at all. The music just should up in the THD as noise. This means we do not need to worry about dead silence in the room.