3.SETUP continued …

3.15ARC-1 ANTHEM ROOM CORRECTION

ARC-1 corrects the effects of reflective surfaces and room boundaries on sound quality by measuring the response of each speaker relative to the listening area and equalizing it. ARC equalizes response without stressing the amplifier or speakers and does not downsample the source material to process it. ARC’s filters are neither graphic nor parametric – ARC is a sophisticated system that flattens response using its ability to create practically any suitable function, inherently correcting phase effects created by the room.

The default correction range is up to 5 kHz. Although the limit can be changed if needed, a higher one is generally not advised since the microphone becomes directional at upper frequencies, affecting measurement accuracy especially if the height of the speaker’s high frequency driver is not at ear level.

ARC also detects how much the room reinforces low frequencies due to its boundaries and pressurization. This room gain shows as a bump in the target response. ARC does not remove it because if flattened, bass sounds thin. Ideal anechoic speaker response, a straight line as measured in a special non-reverberant facility, is not the same as ideal in-room response which normally includes, to varying degree, this room gain.

ARC senses where each speaker’s low-frequency response declines and sets high-pass filters accordingly.

Calibration is set such that average level is the same when comparing EQ “On” vs “Off”. Note that to set levels ARC uses a midrange band that’s wider than the standard home theater setup noise, which is centered at 1 kHz and narrow so there’s no chance its level would be reduced by a crossover.

Sample response:

Calculated response after EQ

Measured response before EQ

Target response – dotted line

My subwoofer also has equalization. Should I use it?

Since rooms, correction systems, number of subwoofers, and speaker/listener positions vary, the answer varies although it is best to disable the subwoofer’s EQ before running ARC. If the resulting calculated and target curves resemble each other, there is usually no reason to use the sub’s EQ. If the curves significantly differ through a wide range, enable the sub’s EQ and run ARC again to see if it helps. If you have run ARC with the sub’s EQ enabled, ARC must be run again once the sub’s EQ is turned off.

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