The DUAL Emotiva T2 Experiment with MEASUREMENTS!
Jul 18, 2020 14:54:49 GMT -5
AudioHTIT, pedrocols, and 1 more like this
Post by boomzilla on Jul 18, 2020 14:54:49 GMT -5
OK Loungers - for what it's worth... Here's the Baseline Measurements via REW for my single pair of Emotiva T2s in the listening room. All measurements taken with a calibrated UMIK-1 using REW software with the microphone at the listening position.
PART 2 of this Experiment shown HERE
PART 3 of this Experiment shown HERE
The room measures 23.5 x 16 feet x 9 tall for a total volume of 3,384 cubic feet. Ceiling is sheetrock. Floor is plank on a concrete slab, with an 8x10 area rug in front of the speakers. Listening couch is pulled out 2 feet from the wall behind. Speakers are placed 32" from the wall behind them on the long room wall. Room treatments include:
four 2'x4'x2" absorbers behind the speakers
two 2'x4'x4" absorbers on the side walls at the first reflection points
two 2'x4'x4" absorbers behind the listening couch
one 2'x4'x6" diffuser in the front left corner
one 2'x4'x6" diffuser on the right wall
Room configuration:
The previous factoids will not change through subsequent measurements. All graphs are Left Speaker first, then Right.
SOUND PRESSURE LEVEL: The SPL graph uses an integrating, logging sound level measurement that displays sound pressure level based on the RMS level of the input channel.
WATERFALL GRAPHS: A waterfall graph (in this context) is a tool to measure the acoustics of a room. The decay times illustrate what sound does in a room after the initial sound is played from the speakers. An ideal waterfall would look like a smooth hill. It would increase fairly uniformly across the frequency band, tapering toward the extreme low and high ends, and decay fairly reasonably back down without any frequency ringing.
DISTORTION: The Distortion graph shows the measurement's fundamental (the linear part of its response) and its harmonic distortion components up to the ninth harmonic. The Total Harmonic Distortion (THD) is the sum of these, and the level of the noise floor, which is captured before the measurement starts.
GROUP DELAY: The group delay plot shows how much each frequency is being delayed. Mathematically, it is the slope of the unwrapped phase plot, so anywhere that phase is dropping linearly corresponds to a constant group delay region (i.e. that region is delayed by a constant time). I'm not too sure that this info is particularly useful, so I may omit it on future measurements.
IMPULSE RESPONSE: The impulse response is in essence a graph of what an extremely loud, extremely short click - something like the crack of a pistol shot, would sound like in the room. The less the "tail" after the initial click, the less the room echoes.
RT60: The "RT60" is a measure of how long sound takes to decay by 60dB in the room. In a large enough room, reflections from the source would reach the mic from all directions at the same level. I'm not truly convinced of the value of this data, either, and may eliminate it on future measurements. But if I'm just not understanding it, please enlighten me. Thanks!
Now, for those of you who can further diagnose these specific graphs, feel free to enlighten us, please.
Thanks - Boomzilla
PS - If you want to reply to this thread PLEASE DON'T REQUOTE THE ORIGINAL POST - Nobody needs to see all those graphs again and again. Thanks.
PART 2 of this Experiment shown HERE
PART 3 of this Experiment shown HERE
The room measures 23.5 x 16 feet x 9 tall for a total volume of 3,384 cubic feet. Ceiling is sheetrock. Floor is plank on a concrete slab, with an 8x10 area rug in front of the speakers. Listening couch is pulled out 2 feet from the wall behind. Speakers are placed 32" from the wall behind them on the long room wall. Room treatments include:
four 2'x4'x2" absorbers behind the speakers
two 2'x4'x4" absorbers on the side walls at the first reflection points
two 2'x4'x4" absorbers behind the listening couch
one 2'x4'x6" diffuser in the front left corner
one 2'x4'x6" diffuser on the right wall
Room configuration:
The previous factoids will not change through subsequent measurements. All graphs are Left Speaker first, then Right.
SOUND PRESSURE LEVEL: The SPL graph uses an integrating, logging sound level measurement that displays sound pressure level based on the RMS level of the input channel.
WATERFALL GRAPHS: A waterfall graph (in this context) is a tool to measure the acoustics of a room. The decay times illustrate what sound does in a room after the initial sound is played from the speakers. An ideal waterfall would look like a smooth hill. It would increase fairly uniformly across the frequency band, tapering toward the extreme low and high ends, and decay fairly reasonably back down without any frequency ringing.
DISTORTION: The Distortion graph shows the measurement's fundamental (the linear part of its response) and its harmonic distortion components up to the ninth harmonic. The Total Harmonic Distortion (THD) is the sum of these, and the level of the noise floor, which is captured before the measurement starts.
GROUP DELAY: The group delay plot shows how much each frequency is being delayed. Mathematically, it is the slope of the unwrapped phase plot, so anywhere that phase is dropping linearly corresponds to a constant group delay region (i.e. that region is delayed by a constant time). I'm not too sure that this info is particularly useful, so I may omit it on future measurements.
IMPULSE RESPONSE: The impulse response is in essence a graph of what an extremely loud, extremely short click - something like the crack of a pistol shot, would sound like in the room. The less the "tail" after the initial click, the less the room echoes.
RT60: The "RT60" is a measure of how long sound takes to decay by 60dB in the room. In a large enough room, reflections from the source would reach the mic from all directions at the same level. I'm not truly convinced of the value of this data, either, and may eliminate it on future measurements. But if I'm just not understanding it, please enlighten me. Thanks!
Now, for those of you who can further diagnose these specific graphs, feel free to enlighten us, please.
Thanks - Boomzilla
PS - If you want to reply to this thread PLEASE DON'T REQUOTE THE ORIGINAL POST - Nobody needs to see all those graphs again and again. Thanks.
