Anthem ARC Room EQ Interview with Dr. Peter Schuck and Nick Platsis Part 2

Anthem's D2v 3D processor comes standard with ARC

Audioholics: With ARC, once there is a dip above a few hundred Hz, how does ARC know whether it's the loudspeaker response (and therefore able to be equalized) vs. it being a characteristic of acoustical interference and therefore should be left alone?  If it's the latter, for example, wouldn't adding a boost to the dip  add a resonance to the loudspeaker and that resonance would then radiate everywhere?
 
Nick Platsis: ARC sets its curve according to interference common in all mic positions.  It wants to EQ as little as possible, the point being to address acoustical interference as opposed to EQ'ing the speaker.  It's not very often that a midrange frequency needs a 6 dB boost and ARC was never meant to serve as a crutch for inadequate speaker design, with the expectation being that the speaker has certain minimum performance including smooth anechoic response both on and off axis.

 
Audioholics: Are there any speaker technologies that ARC is not designed to correct.  For example, 360 degree speakers (like Mirage) electrostatic, magneplanar, or exotic speakers (like a plasma arc).  I assume that dipole and bipole are not a problem since that's a supported speaker type in the Anthem menu?
 
Nick Platsis: We experimented with various directivities and ARC continues to work well with all of them.  It may also bear mentioning that a few years ago Paradigm/Anthem and Martin-Logan became sister companies.  Note that with dipoles, including planars, the amount of room gain can be lower depending on whether the speaker also uses a regular woofer.  We haven't tried plasma arc due to ozone issues, but the expectation is that the room correction would work just the same.  The reason that the prepros have a dipole setting, and this was in place before EQ came about, is unrelated and meant to prevent over-delaying surround channels in terms of the time alignment menu, since most of the sound from a dipole or bipole surround speaker bounces off the front and back walls before reaching the listener.

Detail of the calibrated ARC USB Microphone

Audioholics: Is there any reason why ARC doesn't auto-level and phase match single or multiple subwoofers (assuming a maximum dual configuration where a sub would be one connected to each outputs with no Y connector)?  Would there be any advantage or disadvantage to having a future version of ARC—rather than the enthusiast user—auto-level and phase-match multiple subwoofers automatically?
 
Nick Platsis: There are many reasons.  We experimented with independent sub channels and connecting a mic into the unit instead of computer, but it kept coming back to leaving these things as they are.  It may not be apparent to the enthusiast community but the majority of our receivers and prepros are dealer-installed and "multiple subs" most often means using four of them.

 
Audioholics: If a user has multiple subs that are either different models or from different manufacturers, would ARC do an adequate job correcting the multiple subs and any acoustic differences they would present such a setup?
 
Nick Platsis: It shouldn't matter as long as system design principles that existed before EQ came along are still observed, which means using the more capable subs at the front of the room, and the ones at the back to fill in the valleys.  Initial setup using Quick Measure is the same - start with rear sub level turned down and increase it until response on the live graph is smoothest, then run full measurement.

Audioholics: To wrap things up, is there anything specific about ARC you would like to tell our readers?

Nick Platsis: Although graphs provide the results, listen with the ears not the eyes.  ARC was designed to benefit all systems and was blind-tested with good speakers in a good room, good speakers in a bad room, bad speakers in a good room and bad speakers in a bad room.  Listener preferences were consistent - sound was better with the correction turned on in all of the above.

Many thanks to the Nick and Peter for taking the time to answer our questions about their excellent ARC room correction system.  Fellow Anthem enthusiasts, please share your experiences with ARC in our forum.