What we know about the measurement:

Sehlin Helium DIY is a passive bookshelves that cost around 140 USD for a pair.

  • Quality of the measurement data is high.
  • Origin of the data is ASR.
  • Format of the data is generated by a Klippel NFS .
  • Sensitivity: 78.9dB (avg. 100Hz-1kHz for 2.83V measured at 1m).
  • -3dB (resp. -6db) point v.s. reference is at 79.1Hz (resp. 67.4Hz).
  • Reference level is normalised to 0.2dB computed over the frequency range [300.0Hz, 5000.0Hz].
  • Frequency deviation is 5.5dB over the same frequency range.
  • Directivity
    • Horizontal directivity is (-30.0°, 60.0°) between 1kHz and 10kHz. Angle computed for +/-6dB.
    • Vertical directivity is (-30.0°, 20.0°) between 1kHz and 10kHz. Angle computed for +/-6dB.
  • Tonality (Preference) Score
    • Tonality (Preference) Score is 3.12 and would be 6.0 with a perfect subwoofer.
      • Details: NBD: ON 0.599, LW 0.597, SP 0.644, PIR 0.619; SM: SP0.831, PIR0.716; LFQ 0.39, LFX 67Hz
    • Tonality (Preference) Score is 5.03 with an EQ and would be 7.69 with a perfect subwoofer and the same EQ.
      • Details: NBD: ON 0.502, LW 0.413, SP 0.382, PIR 0.303; SM: SP0.943, PIR0.934; LFQ 0.39, LFX 60Hz
  • Link to Original review.
Sehlin Helium DIY
AutomaticEQ (IIR)
Set preamp gain to: -2.9dB.
Type Freq Q Gain
5 89.0 0.97 2.97
3 280.0 0.53 -2.96
3 418.0 1.32 2.9
3 933.0 2.69 2.98
3 1541.0 2.88 -1.9
3 3216.0 1.72 -2.87
3 5677.0 2.74 2.8
3 9064.0 1.84 -2.37
3 14473.0 0.74 0.63
Download

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

Sehlin Helium DIY filters_auto_eq

AutomaticEQ

Sehlin Helium DIY filters_eq_full

Target v.s. EQ

Sehlin Helium DIY
flipflop@ASR (IIR)
Set preamp gain to: -5.7dB.
Type Freq Q Gain
3 421.0 5.0 3.0
3 459.0 15.0 -0.6
3 529.0 1.056 -3.2
3 666.0 1.0 4.5
3 810.0 5.0 -16.7
3 829.0 5.0 18.0
3 981.0 5.0 1.9
3 1234.0 1.0 -1.3
3 1332.0 5.0 18.0
3 1355.0 5.0 -17.2
3 1865.0 25.0 -1.8
3 2077.0 5.0 1.2
3 2387.0 5.0 -0.9
3 2935.0 5.0 -1.4
3 3900.0 3.0 -0.5
3 5010.0 10.0 1.5
3 5850.0 4.0 2.6
3 7000.0 2.5 1.7
3 10500.0 2.8 0.4
3 14300.0 1.6 2.7
Download

These EQ is designed by ASR member flipflop.

Sehlin Helium DIY
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 0.0
3 160.0 2.14 -0.5
3 250.0 2.14 -0.5
3 400.0 2.14 0.0
3 630.0 2.14 0.0
3 1000.0 2.14 0.25
3 1600.0 2.14 -0.25
3 2500.0 2.14 -0.25
3 4000.0 2.14 -0.25
3 6300.0 2.14 0.25
3 10000.0 2.14 -0.25
3 16000.0 2.14 0.25
Download

These EQ is designed for a 15 bands graphical EQ.

Sehlin Helium DIY
Graphic EQ 31 bands
Set preamp gain to: -0.7dB.
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 0.25
3 100.0 4.32 0.0
3 125.0 4.32 -0.25
3 160.0 4.32 -0.5
3 200.0 4.32 -0.5
3 250.0 4.32 -0.5
3 315.0 4.32 -0.25
3 400.0 4.32 0.0
3 500.0 4.32 -0.25
3 630.0 4.32 0.0
3 800.0 4.32 0.0
3 1000.0 4.32 0.25
3 1250.0 4.32 0.0
3 1600.0 4.32 -0.25
3 2000.0 4.32 -0.25
3 2500.0 4.32 -0.25
3 3150.0 4.32 -0.5
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 -0.25
3 10000.0 4.32 -0.25
3 12000.0 4.32 0.0
3 16000.0 4.32 0.25
3 20000.0 4.32 0.0
Download

These EQ is designed for a 31 bands graphical EQ.

Sehlin Helium DIY: comparison between EQs
Sehlin Helium DIY

Comparison betweens various EQs

Sehlin Helium DIY

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
;