Using Subs with ARC 2 Advanced Room Correction System

Just wondering if the ARC system analyzes and adjusts the response plot of your listening environment when you have a sub woofer incorporated? I am assuming that it would be different from just a straight two speaker near field system. Thanks, h

Haven't installed ARC 2 yet, and haven't re-tested since I added the sub.
I can say that with the sub the current correction is off (as it should be).
I shouldn't put words in Danny's mouth, but I get the impression the ARC 1 works fine with the sub.

T

"It is common knowledge that low frequencies (below about 100Hz) are non-directional,"


That is not a true statement. I know why people make that erroneous generalization but that doesn't make it true.

It is true that the statement they have made is commonly repeated... but it is an erroneous statement.

That is why they back pedal and attempt to explain further why placement does actually matter.







Here's what got my curiosity sparked:

If you are testing for the right and the sub is on the left ARC will build it's fuzzy logic, convolution file package and attempt to correct everything, however it has no practical way to control the actual driver discretely so what ever solution is employed will effect the entire system before the cross over.

That's the part I find fascinating... what happens to the common spectral range that is coming out of both the sub and the mains? Crossovers have a range of overlap and so there is some portion of the sound that is coming out of both the sub and the mains. It's the same sound... coming from 2 places.

I'm imagining a scenario where the speaker on the right is getting info that includes compensation for sound that is actually emanating from the left and it all gets generalized into a single "solution".



An extreme example might be if you swapped your speaker placement e.g move the left one to the right and the right to the left but didn't tell ARC. It can probably work it's magic and make compensations to make the best of that circumstance.



It seems, to me, like a compensation system could be even more effective if it treated each and every discrete driver AFTER the crossover rather than treating speaker systems as systems.



Just wondering out loud.


best regards,
mike

I have several different readings for all conditions: door opened/closed, sub on/off, and combinations of both. Just click on the current setting and away you go. 

And +1 to Mike: I have my woofer sitting on the floor next to my workstation and when it is on it is obviously shaded left.

Sure, let us know what you end up doing! Sub placement and all.

Sub placement is important, but not because low frequencies are directional. They truly are not, and it's because of the long wavelengths relative to the space between your ears. 

It's phase differences from one ear to the other that we subconsciously process to derive directional information. Consequently, frequencies with a quarter-wavelength less than the distance between your ears are difficult or impossible to identify where they're coming from. That's why the conventional cutoff between directional and non-directional frequencies is usually given as 500Hz - that's about a 24-inch wavelength, or a quarter-wavelength of 6 inches, a little less than the approximate distance from ear to ear.

At 100Hz, the wavelength is about ten feet, making it impossible to detect either a phase or amplitude difference from one ear to the other. You'd have to have a head 2 1/2 feet wide to have any hope of determining what direction the sound is coming from.

What makes sub placement critical is the dispersion of resonant peaks and nulls. This is also why mastering rooms typically have two (sometimes even 3 or 4!) subwoofers, so that they can partially cancel out each others' constructive and destructive interference. (See Floyd Toole's superb book "Sound Reproduction" for the full story.)

If you place your sub in such a way that there is a large peak at the listening position, ARC will have a hard time compensating for it. If you place your sub so that there is a large null at the listening position, ARC will be unable to do anything about it at all. You can't compensate for something that isn't there. 

What you could do is experiment with different sub locations and let ARC show you which one is the least problematic. Of course, you don't need ARC for that. You can do it by ear. And you don't even have to move the subwoofer to do it.

Rather than drag a heavy speaker around the room, set your subwoofer on a tall stool at the listening position and play music or noise while you move yourself around to different locations. When you find the spot that has the fewest noticeable peaks and nulls, that's where you want to set your sub.

Do you get many Elephants listening to your stuff Mike?

I'm trying to penetrate that demographic, your input here may be vital to my success.

Thanks for the input.

btw the guy that designed these before radar existed knew that low frequencies were directional 80 or so years ago.  They worked out where the next enemy plane was coming from miles out in the English Channel.  But that application needed to work better than human hearing.  Music production doesn't generally have a requirement to identify a Heinkel's position from 20 miles out, unless I'm really old-fashioned.

Here's how the French were listening:

FWIW ---  from the Audyssey web page:

ARC uses Audyssey MultEQ® XT32 

http://www.audyssey.com/audio-technology/multeq


MultEQ XT32 
Our newest and most accurate room correction solution with more than ten thousand individual control points allowing finer details of the room’s problems to be captured and corrected. The ultra high resolution filters are applied to all channels including the subwoofers, with the most obvious benefit being heard in the low frequency range where correction is needed the most.

Never thought I would learn this much with the question ! Now I am thinking I may need to plan on a few I beams in the floor and the pick up an elephant or two to put in the corners. If I can train them to trumpet when they hear too much low end, I will be able to really tune the room nicely! I guess I just need to make sure they are not male and female or I may really be in trouble LOL. Thanks again all! gs

I'd just like to add to those that often scoff that I believe that a practical EQing system such as this one can simplify the complex choices needed to make repeatable results in different environments.

Used as a tool toward that goal then ARC is a good system, despite many of the shortcomings that are often cited which are based on some truth, there is nothing currently on the market that comes close to ARC on bringing as much control of such a big variable as equalization of the surroundings.

So yes it doesn't take into account the exacting standards required by elephants, nor control discrete elements of a playback system but it does make a good judgement of what is happening at the listening position and calculates accordingly.

Even I can see that and I don't use it, I tend to best guess the foibles of my own particular environment from experience but I can certainly warm to the appeal it has to many by arriving at a decent ball park from an EQ point of view in a quest to find a way of producing repeatable results when mixing.