Onkyo TX-SR806 THX Ultra2 Plus 7.1 A/V Receiver


Audyssey MultEQ / Bass Management

Onkyo has fully embraced the Audyssey automated setup and room compensation system as seen by its inclusion, in one flavor or another, in almost all their current models.

Enough has been said about MultEQ at this point, that we don't need to rehash the basics, except as it relates to its implementation in the 806.

As expected, it got speaker distance of the main channels perfect, except for the subwoofer which it interpreted as being 2.5 feet from me (instead of the actual 7.5 that it is).  It's not uncommon for such systems to turn out not-real values there, as a result of the way a room loads with bass, and in such cases it may well be best to leave it where Audyssey sets it (though the 805 hit my sub's distance bang on).  Also as expected, although relative level of one channel to another was perfect, master calibrating level was a couple dB off.  This is due to the necessarily inexpensive mic favoring spectral consistency at a cost of absolute level accuracy.

Disconcerting is Onkyo's continued omission of the choice for Audyssey's target curve.  Integral to the Audyssey MultEQ system is a choice of final curve it filters to:  the Audyssey curve, a Flat curve, or a Front curve.  The Flat curve, as its name implies, is a classic, "Let's make the system response as text-book neutral as we can," and is best for rooms which have already received a modicum of attention to their acoustics.  The Audyssey curve, which may be considered the default, is a shaped target which seeks to mitigate some of the inherent high frequency reverb of typical home spaces, not unlike what THX's Re-EQ's purpose is, but on a much more sophisticated level. The concept of the Front curve is to filter the front speakers as little as possible and make the rest of the system conform to them.  Yet integral as it is to the Audyssey system, Onkyo does not give you this choice of target curve.  Since it is inherent to the Audyssey system, "cost" is not an excuse for its omission.  Onkyo's answer to this is that while the 806 implements Audyssey with its default Audyssey curve, when in any THX Cinema mode, it implements the Flat curve.  This passes in my book because I tend to use THX processing most of the time in my acoustically treated room, but for those with good acoustics who eschew THX processing, you are out of luck here.

Switching gears to "Manual" (or if you simply override Audyssey's choices), crossover frequency can be set from 40 Hz to 100 Hz (10 Hz increments), and then 120 Hz, 150 Hz, and 200 Hz.

The crossover frequency can be set independently for each pair of speakers, the soundtrack's bass can be sent to both the main speakers and a subwoofer ("Double Bass" they call it), and the LFE channel can be low-passed at a different frequency from the rest of the bass being sent to the subwoofer . . . all of which we vehemently maintain are bad ideas, and we back that up in our essay on the subject: Miscellaneous Ramblings on Subwoofer Crossover Frequencies. It is no fault to the product's performance, but it questions Onkyo's marketing decision to give the people what they think they want even though it may mean they hang themselves with it (unaware as they may be).

In practice, this multiple crossover frequency thing is really not all that big of a deal, but if we are going to go through all this care to get the best D/A performance, the cleanest amplification, the tightest room acoustics, and then top it off with intelligent FIR based EQ, why undermine it all on a technicality?

Ultimately, I have no hesitation recommending the use of the Audyssey system to any 806 buyer, provided you, as THX recommends, do a double check of whatever is in your power to second guess, namely speaker settings, especially the subwoofer level.

The 806 has a new Audyssey feature:  Dynamic EQ.  This is, in every practical sense, the same idea as THX's Loudness Plus, but whereas this last is only "engageable" for THX playback modes, Dynamic EQ may be applied to everything else (though not the THX modes IF THX Loudness Plus is already enabled).   The goals of the two are one in the same, differing only in the underlying math.  Comparing the two is extremly difficult as one cannot "separate" THX Loudness PLus from the fundamental THX processes.  Anecdotally though, its not hard to identify Dymanic EQ as being the more "live" of the two.  It tends to add what I'd call "sparkle" to the sound, THX Loudness Plus being more "true" I feel.  If I had to pick a preference it would probably be THX's take, though if it were not available, I'd be just as happy with Dynamic EQ.  Moving forward I dont think I can live without at least one of them.