The **OFFICIAL** DENON AVR-4520CI thread - Page 19

have you tested the same scenes with Audyssey DSX disabled? One of the things that DSX does is something called "surround envelopment processing"; users in the Audyssey thread have done some testing and it appears that part of this processing involves decorrelating the surrounds (to make them more diffuse) and also dropping the level of the surrounds slightly. This (in theory) makes the front soundstage with the wide/height speakers more enveloping, and the stuff going on behind you less distracting, so you can be more "immersed" in the movie.... thus, the results you are experiencing could be a result of that.

It's interesting that you ended up adjusting each surround +3dB manually to restore your desired balance, because this is the exact amount by which DSX drops the level of each surround. If you have a calibration disc with test tones and an SPL meter, you can verify this by playing a tone to one of your surround speakers and measuring the SPL with DSX on vs. off.

As always, your preference rules the day, so if you prefer a slightly less front-heavy presentation, the approach you took to tweak the surround volumes is perfectly legit

Same goes for the sub -- many folks prefer the bass a bit "hot", so if you like it roll with it.

In my experience, having changed through multiple Denon AVR's with Audyssey from different generations, I also get changes in channel levels (absolute, not relative) with different models. It could be something as simple as the different mic, or some tweaks in the background to the digital gain structure at the DSP level. For example, changing recently from a 2310ci to a 2113ci resulted in channel levels that were about 3dB higher across the board. However, when I measured with an SPL meter the absolute output hadn't changed.

As long as the *relative* levels are good and the system sounds balanced, I wouldn't sweat it.

In terms of your musings on EQ (cutting peaks vs. raising valleys), as Chris notes the EQ is independent of the channel level trims. The channel trims are set via the Audyssey "chirps" which measure the speaker's output without EQ. When Audyssey applies its EQ, Chris (Audyssey CTO/founder) has explained that there is a "normalization" process by which the relative levels are maintained to account for whatever EQ cuts or bumps were made. For example, if the sub volume is set to a specific level with the test tones during calibration, but there is a massive modal hump at 80Hz that Audyssey needs to cut by 10-12dB, the resultant average level of the sub may be reduced from where the channel level would have set it. To correct for this, the overall sub level is "normalized" with the other speakers to make sure the average level is still balanced.

However, this "normalization" process is part of the Audyssey block and is still independent of the channel trims -- otherwise your system balance would be thrown off if you disabled Audyssey EQ.