I have kept you all under the radar thus far, but I have just completed my fall 2007 subwoofer test session. These are the subwoofers (and one speaker) I tested today. Results and pictures will follow.
Anthony Gallo TR-1
Audio Pro Level 110
BK XLS300/
PR
BK Extreme
Gradient Evidence MKII
DIY CSS SDX15 sealed 100L
DIY CSS 2xSDX15 sealed 140L
DIY TC Sounds LMS-5400 18" sealed 100L
DIY TC Sounds LMS-5400 18" + 2x18"
PR 200L
DIY Servo v2 (see. round 3)
JL Audio Fathom f113
SVS PB12-NSD
SVS PB13-Ultra (all four settings)
Velodyne SPL-1200 MKII
Yamaha YST-SW1500
Pictures!
Here are the results for the CEA-2010 standard I also used last time (round 4). I would recommend everyone to read
this document regarding the standard. The CEA-2010 standard defines a new way for measuring and determining the clean maximum output level for a subwoofer. The signal used is a 6.5 cycle long sine burst which allows a safe measurement of the maximum output level. The max SPL is limited by the stepped distortion threshold (allows less distortion for higher harmonics) or the limitations/limiters of the subwoofer itself, which ever is reached first. The standard defines the max SPL normalized to 1 meter distance (half-space) and peak value of the sine burst, but I use the more familiar 2 meter distance and the RMS value of the sine burst. That way these figures are more comparable to the results measured by using the more common sine wave sweep/tone method.
The amplifier for all the DIY subwoofers (except the "DIY Servo v2") measured during round 5 was a Crown CE4000. The rated output at 4 ohms bridged is 3600 watts. With "DIY CSS 2xSDX15 sealed 140L" I used two of these amplifiers.
The
"Gradient Evidence MK2" is a Finnish main speaker that I own (naturally a pair of them). I wanted to measure its bass performance because I haven't seen this kind of measurements done on speakers, even though their role in achieving well balanced sound system is absolutely critical. It is a 3-way speaker using a 6.5" coaxial driver and an 8" woofer in a ~35-40 liter ported enclosure. I used only one speaker during the measurements, but later on added 6 dB for the second speaker (assuming full coupling).
Below are the results for the newest (fall 2007/round 5) and the one prior to that (spring 2007/round 4) measurement session organized in "Low-bass Avg." (average of the 40-63 Hz values) column order.
Below are the results for the newest (fall 2007/round 5) and the one prior to that (spring 2007/round 4) measurement session organized in "Ultra low-bass Avg." (average of the 20-31.5 Hz values) column order.
Below are the results for the newest (fall 2007/round 5) and the one prior to that (spring 2007/round 4) measurement session organized in average of the 20-80 Hz order. I had to estimate the 20 Hz and 25 Hz values for the HSU MBM-12 and the Gradient Evidence MK2. I subtracted 9 dB from the 31.5 Hz and 18 dB from the 25 Hz values.
*** Notice that the TC Sounds 2xTC-2000 15" sealed 140L had a bad second driver (surround came off due to a manuf. defect) during the CEA-2010 test so it's results at 40 Hz and down are NOT what they should be. The real numbers at the low end should be slightly higher than the numbers for the CSS 2xSDX15 sealed 140L.
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