Following are the formulae used in calculating scores for our Secrets Benchmark reviews of subwoofers. Amplifier Formula: Auto-On 0.25 Low Level Inputs 0.25 Low Level Outputs 0.25 High Level Inputs 0.25 High Level Outputs 0.25 Low Pass Filter 0.25 Low Pass Filter Defeat/Bypass 0.25 0/180 Phase Switch 0.25 Score can only include one phase option. 0-180 Variable Phase 0.50 Score can only include one phase option. Overdrive Protection 0.25 Boundary Gain Compensation Controls 0.75 Single Band PEQ 0.75 Score can only include one PEQ option. Multi-band PEQ (external or on-board) 1.25 Score can only include one PEQ option. PEQ with Auto EQ 1.50 Score can only include one PEQ option. Digital Signal Processing (DSP) Chip 0.50 Cannot also include servo. Servo Feedback System 1.00 Cannot also include DSP.   Anechoic Frequency Response Formula: 35-100 Hz +/- 3 dB = 2.00 points 30-100 Hz +/- 3 dB = 2.75 points 25-100 Hz +/- 3 dB = 3.75 points 20-100 Hz +/- 3 dB = 4.25 points 15-100 Hz +/- 3 dB = 4.50 points <15-100 Hz +/- 3 dB = 4.75 points   If FR is +/- 1.5 dB, then multiply score by 1.05 If FR is +/- 5.0 dB (or larger), then multiply score by 0.95   Deep Bass Compression Formula: Deep bass output compression is measured at/above the quasi-anechoic F3 at the highest sweep level, relative to the highest uncompressed sweep. The highest sweep level is defined as any of the following: When the subwoofer starts to exhibit uniform compression across the pass band, in which case the previous sweep curve shall be considered the highest sweep level. When obviously audible distress occurs at the attempted sweep level, in which case the previous sweep curve shall be considered the highest sweep level. When the attempted sweep level drops below the previous curve at any point, in which case the previous sweep curve shall be considered the highest sweep level. When compression reaches 10 dB at the attempted sweep level. If compression exceeds 10 dB at the attempted sweep level, the previous sweep curve shall be considered the highest sweep level.   Deep Bass Compression Scores: 0 dB = 5.0 points 1-2 dB = 4.5 points 3 dB = 4.0 points 4 dB = 3.5 points 5 dB = 3.0 points 6 dB = 2.5 points 7 dB = 2.0 points 8 dB = 1.5 points 9 dB = 1.0 point 10 dB = 0.5 points >10 dB = 0 points   CEA 2010 Distortion Output Limits Formula: Each test frequency is already weighted. The score for each test bandwidth is a simple average of the point values. If the sound pressure is a fraction, then round up if >0.5 dB. Example 99.5 dB rounds down to 99 dB, and 99.6 dB rounds up to 100 dB. At 40, 50, 63, 80 Hz: 115-118 dB = 5.0 points 111-114 dB = 4.5 points 107-110 dB = 4.0 points 103-106 dB = 3.5 points 99-102 dB = 3.0 points 95-98 dB = 2.5 points 91-94 dB = 2.0 points 87-90 dB = 1.5 points 83-86 dB = 1.0 point <83 dB = 0 points At 32 Hz: 109-110 dB = 5.0 points 107-108 dB = 4.5 points 105-106 dB = 4.0 points 104-105 dB = 3.5 points 102-103 dB = 3.0 points 100-101 dB = 2.5 points 98-99 dB = 2.0 points 96-97 dB = 1.5 points 94-95 dB = 1.0 point <94 dB = 0 points At 25 Hz: 107-108 dB = 5.0 points 105-106 dB = 4.5 points 104-105 dB = 4.0 points 102-103 dB = 3.5 points 100-101 dB = 3.0 points 98-99 dB = 2.5 points 96-97 dB = 2.0 points 94-95 dB = 1.5 points 93-94 dB = 1.0 point <93 dB = 0 points At 22 Hz: 104-105 dB = 5.0 points 102-103 dB = 4.5 points 100-101 dB = 4.0 points 98-99 dB = 3.5 points 96-97 dB = 3.0 points 94-95 dB = 2.5 points 92-93 dB = 2.0 points 91-92 dB = 1.5 points 90 -91dB = 1.0 point < 90 dB = 0 points At 20 Hz: 100-101 dB = 5.0 points 98-99 dB = 4.5 points 96-97 dB = 4.0 points 94-95 dB = 3.5 points 92-93 dB = 3.0 points 90-91 dB = 2.5 points 88-89 dB = 2.0 points 86-87 dB = 1.5 points 84-85 dB = 1.0 point <84 dB = 0 points At 18 Hz: 98-99 dB = 5.0 points 96-97 dB = 4.5 points 94-95 dB = 4.0 points 92-93 dB = 3.5 points 90-91 dB = 3.0 points 88-89 dB = 2.5 points 86-87 dB = 2.0 points 84-85 dB = 1.5 points 82-83 dB = 1.0 point <82 dB = 0 points At 16 Hz: 94-95 dB = 5.0 points 92-93 dB = 4.5 points 90-91 dB = 4.0 points 88-89 dB = 3.5 points 86-87 dB = 3.0 points 84-85 dB = 2.5 points 82-83 dB = 2.0 points 80-81 dB = 1.5 points 78-79 = 1.0 point <78 dB = 0 points At 14 Hz: 90-91 dB = 5.0 points 88-89 dB = 4.5 points 86-87 dB = 4.0 points 84-85 dB = 3.5 points 82-83 dB = 3.0 points 80-81 dB = 2.5 points 78-79 dB = 2.0 points 76-77 dB = 1.5 points 74-75 = 1.0 point <75 dB = 0 points   Bandwidth Linearity Formula: % values are obtained from the review body. 84-85% = 1.0 points 86-87% = 1.5 points 88-89% = 2.0 points 90-91% = 2.5 points 92-93% = 3.5 points 94-95% = 4.0 points 96-97% = 4.5 points 98-99% = 5.0 points   Group Delay Formula: If the subwoofer holds GD below 1 cycle down to: 40 Hz = 1.0 point 35 Hz = 2.0 points 30 Hz = 3.0 points 25 Hz = 3.5 points 20 Hz = 4.0 points 15 Hz = 5.0 points   System Ringing and Stored Energy Release Formula (score cannot exceed 5.0 in any case): Ring Time: 40-60 ms = 5.0 points 60-80 ms = 4.5 points 80-100 ms = 4.0 points 100-120 ms = 3.5 points 120-140 ms = 3.0 points 140-160 ms = 2.5 points 160-180 ms = 2.0 points 180-200 ms = 1.5 points 200-220 ms = 1.0 point If system resonance is centered at/below: 30 Hz then multiply score by 1.10 25 Hz then multiply score by 1.20 20 Hz then multiply score by 1.30 16 Hz then multiply score by 1.40   In-Room Frequency Response Formula: Due to room acoustics and modes, in-room FR will vary widely. Therefore the in-room FR score is based on useable extension limits as measured at the listening position. The usable extension limit is the F3 value as compared to the upper bass regions. 30 Hz = 3.0 points 25 Hz = 3.5 points 20 Hz = 4.0 points 16 Hz = 4.5 points <16 Hz = 5.0 points   HT Performance Formula: Score is an average of four HT evaluation criteria - see review body for individual scores.   Music Performance Formula: Score is an average of five music evaluation criteria - see report body for individual scores.   Parts I-III Total Weighted Score Formula: Weighting Scheme: Part I x 0.25 Part II x 0.25 Part III x 2.25 Part IV x 1.25 Final Score: Total Score With Price Considered Formula: Outstanding performance value: Weighted Score x 1.10 Good performance value: Weighted Score x 1.05 Average performance value: Weighted Score x 1.00 Pricey for the performance: Weighted Score x 0.95 Extremely expensive for the performance: Weighted Score x 0.9

 

- Ed Mullen -