I played around with the Yamaha EQ settings. There are 3 choices.
1. Through - Bypass mode - no EQ, does not allow you to adjust anything.
2. Auto EQ - 3 options - Flat, Front, or Natural- does not allow you to adjust anything except for the 3 choices of Flat, Front, or Natural.
3. Manual - Parametric EQ - by default it is set to no EQ - frequency response is flat. This allows you to manually adjust all the speakers and subwoofers.
Yamaha PEQ
Number of Bands: 7
Default Bands:
#1: 62.50 Hz
#2: 125.0 Hz
#3: 396.9 Hz
#4: 1.00 kHz
#5: 2.52 kHz
#6: 6.35 kHz
#7: 16.0 kHz
Frequencies: 15.6 Hz, 19.7, 24.8, 31.3, 39.4, 49.6, 62.5, 78.7, 99.2, 125 Hz, 157.5 Hz, 198.4 Hz, 250 Hz, 315.0 Hz, 396.9 Hz, 500.0 Hz, 630.0 Hz, 793.7 Hz, 1.0 kHz, 1.26 kHz, 1.59 kHz, 2.0 kHz, 2.52 kHz, 3.17 kHz, 4.0 kHz, 5.04 kHz, 6.35 kHz, 8.0 kHz, 10.1 kHz, 12.7 kHz, 16.0 kHz
Q: 0.5, 0.63, 0.794, 1.0, 1.26, 1.587, 2.0, 2.52, 3.175, 4.0, 5.04, 6.35, 8.0, 10.08
Gain (0.5 dB increments) : -20.0 to +6.0 dB
PEQ Data Copy: Copies the Parametric EQ values acquired with "AUTO SETUP" to the "MANUAL" fields for fine adjustment
3 Auto Setup EQ options: Flat, Front, Natural
PEQ Data Clear: Restore default settings for all speakers - all speakers set to no EQ.
Take Home message:
You can apply the YPAO auto EQ if you want. Then, use “PEQ Data Copy” to copy the Auto EQ to manual PEQ. For example, Gene copied the NATURAL YPAO to the Manual PEQ. Then adjusted the manual EQ to fine-tune.
If you don’t want to mess with frequencies above 125Hz, then set the Gain for Frequencies above 125Hz to 0.0dB (flat, no EQ).
As for me, I left all the speakers manual PEQ to default 0.0dB (flat, no EQ) and adjusted only the 2 subwoofers PEQ from 24.8Hz-99.2Hz.