What we know about the measurement:

Yamaha NS-A638 is a passive bookshelves

  • Quality of the measurement data is unknown.
  • Origin of the data is Yamaha.
  • Format of the data is .
  • Sensitivity: 88.4dB (avg. 100Hz-1kHz for 2.83V measured at 1m).
  • -3dB (resp. -6db) point v.s. reference is at 195.8Hz (resp. 90.4Hz).
  • Reference level is normalised to 1.1dB computed over the frequency range [300.0Hz, 5000.0Hz].
  • Frequency deviation is 5.8dB over the same frequency range.
  • Tonality (Preference) Score
    • Tonality (Preference) Score is 1.54 and would be 4.83 with a perfect subwoofer.
      • Details: NBD: ON 0.82, LW 0.684, SP 0.498, PIR 0.582; SM: SP0.814, PIR0.404; LFQ 1.605, LFX 84Hz
    • Tonality (Preference) Score is 4.65 with an EQ and would be 7.02 with a perfect subwoofer and the same EQ.
      • Details: NBD: ON 0.608, LW 0.49, SP 0.46, PIR 0.42; SM: SP0.949, PIR0.911; LFQ 1.391, LFX 51Hz
  • Link to Original review.
Yamaha NS-A638
AutomaticEQ (IIR)
Set preamp gain to: -4.7dB.
Type Freq Q Gain
3 52.0 0.85 2.98
3 197.0 0.25 2.96
3 219.0 2.95 -1.06
3 820.0 0.69 -3.16
3 2579.0 2.59 2.99
3 2964.0 2.95 -3.55
3 4818.0 1.82 -5.62
Download

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

Yamaha NS-A638 filters_auto_eq

AutomaticEQ

Yamaha NS-A638 filters_eq_full

Target v.s. EQ

Yamaha NS-A638
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 0.5
3 160.0 2.14 0.5
3 250.0 2.14 0.25
3 400.0 2.14 0.5
3 630.0 2.14 0.25
3 1000.0 2.14 -0.25
3 1600.0 2.14 0.0
3 2500.0 2.14 0.25
3 4000.0 2.14 -0.5
3 6300.0 2.14 0.0
3 10000.0 2.14 0.5
3 16000.0 2.14 0.25
Download

These EQ is designed for a 15 bands graphical EQ.

Yamaha NS-A638
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 0.5
3 125.0 4.32 0.5
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 0.5
3 400.0 4.32 0.5
3 500.0 4.32 0.25
3 630.0 4.32 0.5
3 800.0 4.32 0.0
3 1000.0 4.32 0.0
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 -0.25
3 4000.0 4.32 -0.5
3 5000.0 4.32 -0.25
3 6300.0 4.32 0.0
3 8000.0 4.32 0.25
3 10000.0 4.32 0.25
3 12000.0 4.32 0.5
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.

Yamaha NS-A638: comparison between EQs
Yamaha NS-A638

Comparison betweens various EQs

Yamaha NS-A638

Improvements made by EQ

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