Quote Originally Posted by mikesiskav View Post
Another thread here got me interested in doing some output tests on my Sierra-2s in my room. I have 5 Sierra-2s but I just tested the front right channel along with my 2 JL F112 subs. All running off my XMC-1 with Dirac and XPA-5 amp. I measured it with Room EQ Wizard and my Umik-1 microphone. Here's the results:



I didn't see any compression until the 95dB sweep (orange line). That was at -8dB on my preamp. You can see a little compression above 10khz and a little more around 150-400hz. I have a wide suckout in my room at the 150-400hz area so that's partially to blame. My subs are 5dB hot and I'm glad to see no compression at all and extension down to 15hz. When you start seeing compression, it means you're getting pretty close to the max output of the speaker, at least at those frequencies. But this is just with a single speaker. If you're watching a movie or listening to music, you're going to have multiple speakers playing simultaneously, which will increase the volume.

Since I have neighbors on the other side of the wall, I never listen louder than -13dB (purple line). Most of the time, it's more like -18dB (pink line). It's nice to see I still have some headroom available.

Edit: Forget to mention, the mic was placed on a tripod by my couch about 9ft away from the speaker.
Thanks Mike -- as I mentioned in the other post - these are ridiculously impressive in-room response measurements, and your even using a 5dB scale.

Interesting that you are seeing a slight bit of compression at the higher tweeter frequencies. I would actually expect the opposite from the tweeter, with signs of compression starting in the lower ranges of the tweeter.

Keep in mind, microphone elements also compress - in fact, mics have a much more difficult time at higher frequencies compared to mids and lows. What mic did you use for this? Still, this is quite good considering the levels you are reaching at your mic distance with only a single speaker.