What we know about the measurement:

Polk Audio XT20 is a passive bookshelves that cost around 300 USD for a pair.

  • Quality of the measurement data is high.
  • Origin of the data is ErinsAudioCorner.
  • Format of the data is generated by a Klippel NFS .
  • Sensitivity: 85.7dB (avg. 100Hz-1kHz for 2.83V estimated at 1m)
  • -3dB (resp. -6db) point v.s. reference is at 64.5Hz (resp. 52.7Hz).
  • Reference level is normalised to 0.2dB computed over the frequency range [300.0Hz, 5000.0Hz].
  • Frequency deviation is 2.9dB over the same frequency range.
  • Directivity
    • Horizontal directivity is (-60.0°, 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 4.14 and would be 6.5 with a perfect subwoofer.
      • Details: NBD: ON 0.427, LW 0.397, SP 0.37, PIR 0.364; SM: SP0.831, PIR0.421; LFQ 0.544, LFX 51Hz
    • Tonality (Preference) Score is 6.41 with an EQ and would be 8.35 with a perfect subwoofer and the same EQ.
      • Details: NBD: ON 0.308, LW 0.285, SP 0.307, PIR 0.26; SM: SP0.971, PIR0.957; LFQ 0.595, LFX 41Hz
  • Link to original Review: eac review. .
Polk Audio XT20
AutomaticEQ (IIR)
Set preamp gain to: -2.5dB.
Type Freq Q Gain
3 52.0 0.27 2.98
3 105.0 1.19 -3.51
3 714.0 1.42 2.91
3 820.0 2.99 -4.46
3 1202.0 2.96 -0.5
3 8694.0 3.0 1.9
3 11882.0 0.45 -4.63
Download

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

Polk Audio XT20 filters_auto_eq

AutomaticEQ

Polk Audio XT20 filters_eq_full

Target v.s. EQ

Polk Audio XT20
Graphic EQ 15 bands
Set preamp gain to: -0.3dB.
Type Freq Q Gain
3 25.0 2.14 0.25
3 40.0 2.14 0.25
3 63.0 2.14 0.25
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 -0.25
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 -0.5
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.

Polk Audio XT20
Graphic EQ 31 bands
Set preamp gain to: -0.4dB.
Type Freq Q Gain
3 20.0 4.32 0.0
3 25.0 4.32 0.25
3 31.0 4.32 0.25
3 40.0 4.32 0.25
3 50.0 4.32 0.25
3 63.0 4.32 0.25
3 80.0 4.32 0.0
3 100.0 4.32 -0.25
3 125.0 4.32 -0.25
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 0.25
3 630.0 4.32 0.0
3 800.0 4.32 -0.5
3 1000.0 4.32 -0.25
3 1250.0 4.32 -0.25
3 1600.0 4.32 0.0
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 -0.5
3 8000.0 4.32 -0.5
3 10000.0 4.32 -0.75
3 12000.0 4.32 -0.75
3 16000.0 4.32 -0.75
3 20000.0 4.32 0.0
Download

These EQ is designed for a 31 bands graphical EQ.

Polk Audio XT20: comparison between EQs
Polk Audio XT20

Comparison betweens various EQs

Polk Audio XT20

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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