This is a review and detailed measurements of the Audyssey Room Equalization. Audyssey is standard technology in a number of Audio/Video Receivers such as the Denon AVR-X3600H I recently reviewed . The standard version in the AVR is mostly all or nothing so I downloaded the Marantz/Denon Android App that for $20 lets you customize some critical aspects of it as you will see later.My setup is my main music system which I would show you a picture of but it got so torn up with cables going everywhere to wire up the AVR which I am ashamed to show you. So see this picture from measurements of the Lyngdorf RoomPerfect EQ I put the AVR on the center amp you see on the floor and wired it to the two Salon 2 speakers. The sub is no longer there so I did not have it connected or tested.I first ran the Audyssey EQ using the software built into the Denon AVR. The process was straightforward requiring a pair of measurements for each seat and a couple in the back. The chirp signal was run at surprisingly soft level. Maybe the microphone is sensitive.I got a kick out of a few pieces of cardboard/plastic that you put together to act like a tripod. It reminded me of the 25 cent wooden gliders we would build when I was a child! This is in sharp contrast to the professional setup/tripod that comes with the likes of Anthem ARC. Or Minidsp DIRAC.I had a tripod that I was going to use but it had a larger screw terminal than the one that came with the mic. So I used my hand to hold the mic while the measurements ran, being thankful that they ran rather quickly.When finished, I could tell the improvement in room modes being reduced which was good. I noticed that Dynamic EQ was on by default. I turned it off and the sound became a lot less pleasant (I used the "Reference" mode). So was time to go into the app to adjust things.I bought the app for my Samsung S8+ phone. It installed and instantly recognized the Denon AVR which was great. The AVR by the way was hardwired using Ethernet. I went into the wizard on the phone and it proceed to play the chirp signal on the left speaker. Once done though, it waited a few seconds and then complained that it could not communicate with the AVR ("Communication error (2)"). I was surprised there were very few hits on google search for this.I decided to upgrade the AVR firmware which restarted it. Sadly, that didn't fix anything. So I decided to kill the App on my phone and restarted it. This time it worked! I ran through the wizard which was similar to the one in the AVR. Once there though, I immediately turned off the "BBC dip" which is an ill thought of feature of Audyssey where by default it puts a dip in mid frequencies. All the work good speaker designers do to produce a flat on-axis response gets destroyed by this decision.Next, I wanted to fix another ill which is the target response. Audyssey uses a flat target curve for low frequencies which is a mistake. Equalization usually brings down the peaks created by the room modes. This fixes the problem but then overall bass feels too low compared to no EQ, resulting in many people not liking automatic EQ. The right "target curve" is one that has emphasis for bass and some dipping for highs. There is quick target curve with the high frequency attenuation but none with bass boost which is major miss. I had to create this manually which was a major pain to do by hand on a touch screen. Still, I managed to get there with a quick and dirty one:Sorry for spelling mistake.Audyssey App then did its thing and reported this as before an after:As you will see shortly, the before measurements are pretty accurate. The after curve though seems like a miracle with every up and down completely eliminated, sans that one dip in low frequencies. This is a simulated lies of course. Audysssey does not remeasure the room to tell you what the after EQ results look like. This is some kind of simulated results which is basically the target curve and not much more. Since measurements are made at multiple points, repeating them is very hard anyway so even if it wanted to remeasure, it could not replicate the same conditions.Anyway, I told it to upload the data to the AVR which took a bit.The sound out of my system was now reference quality, pinning me down to my seat listening to track after track from my "audiophile" playlist. Room modes were gone and the deep, floor shaking bass that I expect from my Salon 2 speakers were back with the new target curve. Detail was to die for. Bass was clean. On and on.I do wish that I could have multiple target curves to compare. Sadly there is no way to have multiple profiles in the AVR for different target curves. Every change to the target curve requires download into the AVR and waiting for it to restart. My Dirac EQ lets me do that and switch between them in a second or two. AVRs are built cheap and don't have the necessary memory for multiple filter coefficients.Given the fact that the app lies to us as far as the response after the measurement, we need to do our own homework to see what has been done. For this, I measured the room using my own microphone and Room EQ Wizard . I used a USB to S/PDIF converter to push audio into the Denon AVR and switched Audyssey on and off. Here are the results with 1/12 octave filtering so we can see what is going on in the important low frequency domain:I have noted in my speaker reviews how I filter out a room mode at 102 Hz and you can see the reason clearly here. The black curve is without EQ and we see a very high amplitude peak there. It is about 8 to 10 dB higher than average level! Audyssey EQ has correctly identified that peak and pulled it down to the custom target curve I had created (red graph).The dips are reduced in bass frequencies which usually is hard with just a filter. Dips are created due to partial cancellation of the direct and reflected sounds. Changing the signal electronically modifies both direct sound and reflected one so the net sum is zero. In practice, you can try to boost them a few dB and see what happens (this stressed the amplifier and speaker by the way). Alternatively EQ systems bring the entire level down and as such, what used to be a deep dip, is no longer so. Once all the correction is done, they slightly boost things back up. I am assuming that is what is going on.Stepping back for a second, we can see the red graph looks nothing like the one the App had told us was "after" results. Even if we filter the curvers a ton, we still don't get to what it said was happening:I have overlaid the target curve on top of the before and after measurement. We see that it has generally followed that curve. The big dip at the end is probably due to my measurement mic running without calibration.I came into this review expecting Audyssey to not perform. That was my experience and that of formal blind testing of it years back. The out of box results of this "XT32" version was better than I remembered. Still, using the App is mandatory to properly incorporate a target curve with more bass and removal of "BBC dip." Once there, I had no issues with its performance and I think it comes very close to advanced solutions like Dirac and Anthem ARC.-----------As always, questions, comments, recommendations, etc. are welcome.I just bought a $600 lift to help me elevate big and heavy speakers onto my measurement rig. Needless to say, nothing makes more more depressed than spending my own money. So I hope you help replenish my piggy bank byusing