# MCACC mis-setting sub distance?



## Todd Anderson (Jul 24, 2009)

When I run the speaker distance program on MCACC it always calculates my subs as being farther away than the are. It correctly sets my 7 channels... Just not the sub. 

Right now my sub is roughly 10 ft 11 in away from the microphone and the system is saying it's 14 ft 2".

What gives, here? Should I enter the correct value? It does LFE have characteristics that require the AVR to think the sub is farther away than it really is?

Thanks guys!


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## Todd Anderson (Jul 24, 2009)

Hmm... I may have found an answer on the net... What do you all make if these comments? (I'm on my iPhone so I can italicizes the quotes... So bare with me here)

First, this one:
MCACC does not measure distance, per se. It merely translates its measurements into distance units for the benefit of users. It actually measures time delay. Additional time delay is inherent in LFE and subwoofer signals, so MCACC almost always reports the "distance" as greater than it actually is. This is how it should be and changing the distance based on tape measurements will degrade the sound, not enhance it. 

Second, this one:
The manual specifically states that the subwoofer distance calculated by MCACC may not be the ACTUAL distance and that this is normal. MCACC tries to correct certain subwoofer anomolys and does this by varying the actual distance. If you are happy with the way your sub sounds after MCACC you should NOT change the subwoofer distance...

• The subwoofer distance setting may be farther than the actual distance from the listening position. This setting should be accurate (taking
delay and room characteristics into account) and generally does not need to be changed
• Since the distance measurements have been set according to the sound characteristics of your speakers, there are cases where (for optimal
surround sound) the actual distance may differ from the speaker distance setting.





These look like fairly legit responses. ?


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## chashint (Jan 12, 2011)

Pioneer is big on phase correction and adjusts distance as part of that correction.
Depending on the AVR you have there are many things that you can see and tweak with the MCAAC.
Give it a chance to do its thing and listen to it for a week or so to really see how you like it.


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## tonyvdb (Sep 5, 2007)

It is very common to see a distance setting on a sub to be greater than actual measurements. Its not only MCACC that does this. The distance setting is also accounting for phase and delay.


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## Todd Anderson (Jul 24, 2009)

Thanks guys. We just watched half of Return of the King. No complaints, sub-wise. Everything sounded in sync. I guess I'll let it keep it's sub measurements! ;-)


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