Audyssey Dynamic EQ, should I enable or disable it?
Here’s my take on DEQ…and don’t worry, I’m not going into all the technical verbiage.
If you are using an external EQ device like miniDSP, I agreed that DEQ “Off” is probably a better option since PEQ has been engaged to help smooth out the bass response (from 20hz - 250hz) with higher filters applied. Anything beyond that, Audyssey should be able to take care of it. Also for those who desired a custom house curve can also do it with ease using miniDSP compared to Audyssey MultEQ XT32 Pro app which is not as robust. The only reason I’ve gotten the app is due to its ability to turn off/on Mid-Range Compensation (MRC) as well as to adjust the frequency range for EQ to be applied. If your speakers are audiophile grade with clear mids and highs and you don’t wish to ruin it, then the app is a must-have.
Back to DEQ, the benefits of having DEQ enabled is to allow listeners whom preferred to listen at a lower volume level (say -30db to -25db below Reference Level) to still able to retain the same SPL for bass. This is important as humans tends to be more sensitive to low frequency (e.g. 30Hz and below) variation. This is why many complain about the “lack of bass” when listening at lower volume. For a well-calibrated HT setup, listening anywhere between -20db and -15db is a norm these days. By enabling DEQ, it helps to compensate the loss in relative SPL on bass when listen at lower volume. Jag had brought up a very good observation, DEQ tends to exaggerate the lower frequency to the extent which “muddle” the bass to a great extent when you listen at lower MV. This is something which unfortunately is true and I really hope Audyssey can improve in that aspect of the DEQ. Having say that, I still believe that sum of its parts is still greater than the whole. If you are able to tame the modal frequency range regardless whether you are using miniDSP or Audyssey’s very own SubHT EQ, you can still benefit from DEQ enabled. You can think of DEQ as a form of Audyssey “house curve” since its objective is the SAME as building a custom “house curve” using the miniDSP - i.e. to restore the SPL of the bass when listening at lower volume - some called it “Loudness Compensation” and in Audyssey’s term is called Dynamic EQ (DEQ).
My recommendation is to ensure that you get your HT setup properly calibrated, especially the subwoofers which produced the bass content. More often than not, it is not DEQ that contribute to the poor muddy or bloated bass but the room mode. This is why a miniDSP can help a long way for HT setup in a less-than-ideal room setup because of the odd room shape and layout etc. If you are blessed with a good room dimension and you follow strictly on the proper speaker/subwoofer placement (using Harman Room Mode Calculator as a basis), you can easily do away with the need to use an external EQ device like miniDSP.
For the surround being tuned “hotter” than the rest of the speakers which makes the surround sounded a bit “overwhelming”…again Audyssey theory is that humans perceive sound differently coming from the front soundstage (LCR) compared to the sides (Surrounds) and the rears (Surround Backs). I agreed that DEQ does make the Surround channels at least 1 - 2db hotter but this can be easily calibrated using test tones from say a Dolby Atmos test tones playback (Note: When you wish to tune your SPL for all your speakers to the same SPL level - e.g. 75db, PLEASE DO NOT use the the test tone emited by the AVR as it is not accurate).
I am able to listen at -25 - 20db below Reference level w/o a hint of boominess…if anything, I need to increase the MV to -15db to get the whole listening experience to a cinematic level. With DEQ turned on, there is lesser need for me to reach out to my remote controller to turn up or down the Master Volume for any content I throw at it. With DEQ disabled, you may need to re-adjust the volume level for some of the media content that is authored differently.
Beware: “DEQ and Trim Levels (doing channel level checks)”
I have went through some of my past email exchanges with former Audyssey Chief Technical Officer Chris pertaining to the DEQ and one important piece of information which I have “missed out” is the correlation between DEQ and trim level adjustments. It turns out that was told that for DEQ to be effective, one should refrain from playing with the trim levels as this will screw-up the DEQ! The reason being DEQ is based on the “finalized” calibration EQ. This is a “target” reference level at which DEQ will rely upon to make adjustments to its frequency (boost or cuts) on a scene-by-scene analysis (dynamically). If we change the trim levels, it will have an impact on the perceptivity of the audio when volume level changes. Hence if you wish to make any kind of adjustments, you should use the Channel Level under the Options for each source - e.g. increase the height/Atmos speakers by 2 - 3db. By and large, the reading from Audyssey is rather accurate which minimize the need for you to make adjustment to the channel trims. If this is the case, I can only assume that it will also apply to the Distance setting where any changes (if any) made AFTER the Audyssey calibration may screw up the phase (time domain) of the speaker and subwoofer(s).
And also another note on the “Channel level” checks, Chris also recommended the use of test tones emitted by the AVR instead of using a test dics (which I have previously recommended)…the reason was the possibility of the difference in dialnorm that a test disc was authored. What I understand is that at ‘0db’ (Reference level), the internal bandwidth limited pink noise emitted will produce a SPL of “75db” at (-30dbfs).
On the part of the Surround channels running “hotter” than the mains, this is an intentional engineering design by Audyssey as their lab studies showed human auditory perception drops drastically when there are sound effects coming from the sides and the rear. As such, the boost in Surround sounds many experienced when DEQ is engaged. If you feel it is too “loud” due to the close proximity of you and one of the side surround speakers, it is advisable to ensure that the Surround speakers are placed further behind your MLP - 110 degrees is a good starting point.
This is something worth noting…