What we know about the measurement:

Boston Acoustics A 25 is a passive bookshelves that cost around 180 USD each.

  • Quality of the measurement data is high.
  • Origin of the data is ASR.
  • Format of the data is generated by a Klippel NFS .
  • Sensitivity: 85.1dB (avg. 100Hz-1kHz for 2.83V measured at 1m).
  • -3dB (resp. -6db) point v.s. reference is at 82.0Hz (resp. 63.0Hz).
  • Reference level is normalised to -0.2dB computed over the frequency range [300.0Hz, 5000.0Hz].
  • Frequency deviation is 3.2dB over the same frequency range.
  • Directivity
    • Horizontal directivity is (-70.0°, 60.0°) between 1kHz and 10kHz. Angle computed for +/-6dB.
    • Vertical directivity is (-20.0°, 20.0°) between 1kHz and 10kHz. Angle computed for +/-6dB.
  • Tonality (Preference) Score
    • Tonality (Preference) Score is 3.23 and would be 5.89 with a perfect subwoofer.
      • Details: NBD: ON 0.618, LW 0.49, SP 0.386, PIR 0.415; SM: SP0.763, PIR0.426; LFQ 0.317, LFX 60Hz
    • Tonality (Preference) Score is 5.69 with an EQ and would be 8.06 with a perfect subwoofer and the same EQ.
      • Details: NBD: ON 0.436, LW 0.343, SP 0.34, PIR 0.262; SM: SP0.97, PIR0.968; LFQ 0.317, LFX 51Hz
  • Link to Original review.
Boston Acoustics A 25
AutomaticEQ (IIR)
Set preamp gain to: -3.0dB.
Type Freq Q Gain
5 96.0 0.73 2.98
3 309.0 2.01 1.01
3 668.0 2.04 1.47
3 965.0 2.9 -2.66
3 1541.0 1.58 0.88
3 2813.0 2.52 2.55
3 5677.0 1.47 -2.91
3 10713.0 2.37 -2.39
3 13537.0 1.19 -2.6
Download

These EQ optimise the Harman score and is a good start for far field listening like in your living room.

Boston Acoustics A 25 filters_auto_eq

AutomaticEQ

Boston Acoustics A 25 filters_eq_full

Target v.s. EQ

Boston Acoustics A 25
flipflop@ASR (IIR)
Set preamp gain to: -2.0dB.
Type Freq Q Gain
3 619.0 5.0 0.9
3 748.0 5.0 -2.1
3 775.0 5.0 2.6
3 937.0 3.729 -3.7
3 1356.0 5.0 -2.4
3 1541.0 5.0 2.2
3 1703.0 5.0 -2.1
3 2871.0 5.0 6.9
3 2988.0 4.932 -9.9
3 3115.0 5.0 5.8
3 3885.0 8.0 -1.0
3 4625.0 5.0 0.6
3 5232.0 5.0 -1.8
3 5711.0 5.0 -2.1
3 8083.0 5.0 0.8
3 8748.0 5.0 2.1
3 12321.0 5.0 4.2
3 12870.0 1.446 -10.7
3 13527.0 5.0 4.6
3 16700.0 3.3 -1.9
Download

These EQ is designed by ASR member flipflop.

Boston Acoustics A 25
Graphic EQ 15 bands
Set preamp gain to: -0.7dB.
Type Freq Q Gain
3 25.0 2.14 0.5
3 40.0 2.14 0.5
3 63.0 2.14 0.5
3 100.0 2.14 0.25
3 160.0 2.14 0.0
3 250.0 2.14 0.0
3 400.0 2.14 0.0
3 630.0 2.14 0.0
3 1000.0 2.14 -0.5
3 1600.0 2.14 -0.25
3 2500.0 2.14 0.0
3 4000.0 2.14 -0.25
3 6300.0 2.14 -0.5
3 10000.0 2.14 -0.75
3 16000.0 2.14 -0.75
Download

These EQ is designed for a 15 bands graphical EQ.

Boston Acoustics A 25
Graphic EQ 31 bands
Set preamp gain to: -0.8dB.
Type Freq Q Gain
3 20.0 4.32 0.0
3 25.0 4.32 0.5
3 31.0 4.32 0.5
3 40.0 4.32 0.5
3 50.0 4.32 0.5
3 63.0 4.32 0.5
3 80.0 4.32 0.5
3 100.0 4.32 0.25
3 125.0 4.32 0.0
3 160.0 4.32 0.0
3 200.0 4.32 0.0
3 250.0 4.32 0.0
3 315.0 4.32 0.0
3 400.0 4.32 0.0
3 500.0 4.32 0.0
3 630.0 4.32 0.0
3 800.0 4.32 0.0
3 1000.0 4.32 -0.5
3 1250.0 4.32 -0.25
3 1600.0 4.32 0.0
3 2000.0 4.32 0.0
3 2500.0 4.32 0.25
3 3150.0 4.32 0.25
3 4000.0 4.32 -0.25
3 5000.0 4.32 -0.25
3 6300.0 4.32 -0.25
3 8000.0 4.32 0.0
3 10000.0 4.32 -0.5
3 12000.0 4.32 -0.75
3 16000.0 4.32 -0.5
3 20000.0 4.32 0.0
Download

These EQ is designed for a 31 bands graphical EQ.

Boston Acoustics A 25: comparison between EQs
Boston Acoustics A 25

Comparison betweens various EQs

Boston Acoustics A 25

Improvements made by EQ

Frequency Frequency with EQ
Frequency Frequency with EQ
Frequency Frequency with EQ
Frequency Frequency with EQ
Frequency Frequency with EQ
Frequency Frequency with EQ
Frequency Frequency with EQ
Frequency Frequency with EQ
Frequency Frequency with EQ
Frequency Frequency with EQ
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