# How to Average Measurements



## Jay Compton (Sep 8, 2016)

I want to take 3 measurements from the LP and near the LP, after I get these measurements how do I average them to Eq?Right now my measurements have all come from the LP, so I have eq'ed from that and it sounds good from the LP. Now if you move from the LP I have too much bass I want to correct this to be more even through out the room???


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## JohnM (Apr 11, 2006)

You can average measurements on the All SPL graph.


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## Wayne A. Pflughaupt (Apr 13, 2006)

If you’re sitting near the dead center of a square or rectangular room, then other locations, which will be closer to boundaries than the LP, will exhibit “hotter” bass. It’s just physics - EQ won’t fix it. If you EQ based on an average, then you'll have reduced bass at the main LP as well as the other locations.

Regards, 
Wayne


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## turboman (Mar 18, 2013)

Wayne A. Pflughaupt said:


> If you’re sitting near the dead center of a square or rectangular room, then other locations, which will be closer to boundaries than the LP, will exhibit “hotter” bass. It’s just physics - EQ won’t fix it. If you EQ based on an average, then you'll have reduced bass at the main LP as well as the other locations.
> Regards,
> Wayne


Hello Wayne,
I am also interested in this topic. I have also read you your article: "Minimal EQ, Target Levels, and a Hard-Knee House Curve".
Based on this , I wondered if all individual peaks occurring in all Listening Positions LP's should be corrected, or only peaks that are common to all LP's.

I was thinking about following procedure (for subwoofer EQ with miniDSP no Audyssey, LP's for a 2-seater couch):
Either:
Determine the filters individually for each LP, determine the filters that are common to all LP's, and make average of those filters? 
Or:
Make average of the LP measurements (with or without timing reference?) and EQ the average?

Or what procedure would you propose?
Thanks for your help.


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## Jay Compton (Sep 8, 2016)

Wayne A. Pflughaupt said:


> If you’re sitting near the dead center of a square or rectangular room, then other locations, which will be closer to boundaries than the LP, will exhibit “hotter” bass. It’s just physics - EQ won’t fix it. If you EQ based on an average, then you'll have reduced bass at the main LP as well as the other locations.
> 
> Regards,
> Wayne


Hi Wayne,
My room is 13.5 x 16 I sit about 11-12 feet back from the front wall. When I took all my measurements they were from the LP only. Listening from the LP everything sounds great but, if I stand up or move to say the side of the LP and I am standing then the bass is much hotter. Can I even this out some way?


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## Wayne A. Pflughaupt (Apr 13, 2006)

turboman said:


> Hello Wayne,
> I am also interested in this topic. I have also read you your article: "Minimal EQ, Target Levels, and a Hard-Knee House Curve".
> Based on this , I wondered if all individual peaks occurring in all Listening Positions LP's should be corrected, or only peaks that are common to all LP's.
> 
> ...


Hey turboman,
Most people just EQ for the main listening position. That’s the one you’d be sitting in for music listening. For movies, bass is mostly about “boom,” so less-than-perfect response isn’t readily noticeable. 

That said, if response in all the seats was similar, you could certainly get good results by averaging.

Regards, 
Wayne


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## Wayne A. Pflughaupt (Apr 13, 2006)

Jay Compton said:


> Can I even this out some way?


There’s nothing that can be done about it. EQ certainly can’t fix it. Bass traps might be an option; you might check with some manufacturers and (even better) users to see what they think. However, my understanding is that it takes lots of traps to deal with low frequency issues, and big ones at that. So I’m sticking with “nothing that can be done about it." It’s a common issue with rectangular and square rooms, especially smaller ones like yours. I avoid those rooms like the plague for serious listening.

Regards, 
Wayne


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## Jay Compton (Sep 8, 2016)

Ok Wayne,
Thanks buddy I guess I will just have to enjoy it from the LP and be happy!!!


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## AudiocRaver (Jun 6, 2012)

Wayne P's advice is solid...

Also agree: focus on the LP and getting good sound there, and forget he rest of the room. NO ONE, and I repeat NO ONE will ever care a fraction as much about the sound as you do. And if they do, you will give them your seat anyway.


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## Jay Compton (Sep 8, 2016)

AudiocRaver said:


> Wayne P's advice is solid...
> 
> Also agree: focus on the LP and getting good sound there, and forget he rest of the room. NO ONE, and I repeat NO ONE will ever care a fraction as much about the sound as you do. And if they do, you will give them your seat anyway.


Agreed!!!


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## Slybond (Feb 15, 2017)

Is there a way to include phase in the averaging? It appears to only account for magnitude


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## AudiocRaver (Jun 6, 2012)

Slybond said:


> Is there a way to include phase in the averaging? It appears to only account for magnitude


It cannot be done in the form you are thinking of.

In a sense, phase is already part of the magnitude averaging, because phase determines how the magnitudes combine (180 degrees gives complete cancellation, 0 degrees gives 3 to 6 db gain). IOW, magnitude A at phase A' combined with magnitude B at phase B' gives magnitude C at phase C'.

Averaging the phase angles either before or after the fact gives a meaningless result.:wink2:


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## JohnM (Apr 11, 2006)

If your measurements are appropriately time aligned you can pairwise average them using the trace arithmetic features, that is a vector average (magnitude and phase rather than magnitude only).


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## Slybond (Feb 15, 2017)

Thanks for the replies

I was just hoping to get a waterfall plot of the room average (and average reverb time), I have been able to do them using Easera, was just curious if REW could.


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## JohnM (Apr 11, 2006)

The vector average produces an impulse response from which a waterfall can be generated. You need a binary power of measurements to do the pairwise averaging down to an overall averaged result though.


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## turboman (Mar 18, 2013)

JohnM said:


> The vector average produces an impulse response from which a waterfall can be generated. You need a binary power of measurements to do the pairwise averaging down to an overall averaged result though.


Hallo John
What do you mean by binary power of measurements? What settings to choose to get this binary power?
Thanks for the info.


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## JohnM (Apr 11, 2006)

That means 2 measurements, or 4, or 8, or 16. The trace arithmetic has an (A+B)/2 task for averaging a pair of measurements. If you only have 2 that's straightforward. If you have 4 you would average A and B (let's call the result AB), then average C and D, then average the two results AB and CD to get the overall average. Same process for 8 or 16, averaging down pairs of measurements then averaging the results and so on.


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## Jay Compton (Sep 8, 2016)

JohnM said:


> You can average measurements on the All SPL graph.


Hi John,
I tried this with two measurements and it pretty much split them down the middle, is this right?

Jay


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## JohnM (Apr 11, 2006)

That is typically what you would expect from an average, particularly the magnitude averaging produced by e Average SPL button. If there are significant phase differences between the measurements then the trace arithmetic vector average can show pronounced dips where the measurements are out of phase with each other, in that case there will be regions in the average which are below either of the measurements that were used to produce it.


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