The MultEQ "upgrade" is only for the 5805s.There is no plan for a 4806 upgrade any time soon. That is the info from Denon as of this morning.Yep, there is a lot of confusion on this one
Don't be terribly surprised that Denon may not have a clue that the MultEQ upgrade is coming for the 4806. My source is Chris at Audyssey.
Any time, any unit, when THX is activated all crossovers are set to 80hz, that's just part of THX and THX speaker systems. dc
This is not true with the 4806. We near field measured a Klipsch KL-650-THX with EQ off in DD mode. The speaker is down 3dB at 56 Hz rather than the typical 80 Hz spec. When THX post processing was engaged, the speaker's response did not change to 3dB down at 80 Hz. I have not tested to see if it changes if "LFE THX" rather than "LFE+Main" is selected in the sub configuration menu.
Now that introduces another "problem" we have discovered. If you have a speaker that MultEQ identifies as Large, and you choose "LFE+Main" in the subwoofer configuration menu, you will find that the front and center show a "crossover" value. This in not really a crossover. Quoting my friend who did the measuring: "The EQ filter rolls off the response of the main speaker, but it's not phase coherent with the signal output by the subwoofer. It may LOOK like a crossover, but it doesn't PERFORM like a crossover. The roll-off of the main speaker (due to the EQ filter) and the roll-off of the subwoofer (due to an arbitrary low-pass filter) will not integrate properly. The sub and the main speakers will be duplicating the low frequencies. If you choose to go this way, you're basically remixing the soundtrack in a crude way to match your system. " Presuming we want a faithful, accurate reproduction of the mix, this is not a configuration to go with. This was all confirmed by electrical measurement rather than acoustic.
If you want the speaker to have a 60Hz crossover that will properly integrate with the sub, there is a way to do it. I'll be back with that.