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
PK 52.0 0.85 2.98
PK 197.0 0.25 2.96
PK 219.0 2.95 -1.06
PK 820.0 0.69 -3.16
PK 2579.0 2.59 2.99
PK 2964.0 2.95 -3.55
PK 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
PK 25.0 2.14 0.5
PK 40.0 2.14 0.5
PK 63.0 2.14 0.5
PK 100.0 2.14 0.5
PK 160.0 2.14 0.5
PK 250.0 2.14 0.25
PK 400.0 2.14 0.5
PK 630.0 2.14 0.25
PK 1000.0 2.14 -0.25
PK 1600.0 2.14 0.0
PK 2500.0 2.14 0.25
PK 4000.0 2.14 -0.5
PK 6300.0 2.14 0.0
PK 10000.0 2.14 0.5
PK 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
PK 20.0 4.32 0.0
PK 25.0 4.32 0.5
PK 31.0 4.32 0.5
PK 40.0 4.32 0.5
PK 50.0 4.32 0.5
PK 63.0 4.32 0.5
PK 80.0 4.32 0.5
PK 100.0 4.32 0.5
PK 125.0 4.32 0.5
PK 160.0 4.32 0.5
PK 200.0 4.32 0.5
PK 250.0 4.32 0.5
PK 315.0 4.32 0.5
PK 400.0 4.32 0.5
PK 500.0 4.32 0.25
PK 630.0 4.32 0.5
PK 800.0 4.32 0.0
PK 1000.0 4.32 0.0
PK 1250.0 4.32 0.0
PK 1600.0 4.32 0.25
PK 2000.0 4.32 0.25
PK 2500.0 4.32 0.25
PK 3150.0 4.32 -0.25
PK 4000.0 4.32 -0.5
PK 5000.0 4.32 -0.25
PK 6300.0 4.32 0.0
PK 8000.0 4.32 0.25
PK 10000.0 4.32 0.25
PK 12000.0 4.32 0.5
PK 16000.0 4.32 0.25
PK 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
Frequency Frequency with EQ
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