# Does the auto EQ really work?



## Glimmie (Apr 26, 2012)

In working with REW for two years now, I find the auto EQ feature is not very good. I get far better results by manually running sweeps and tweaking my MiniDSP EQ's based on the REW results. A lot of trial and error but the auto EQ just doesn't even come close.

And I often get strange auto EQ settings with zero gain, IOW, they do nothing with zero gain. Is this a bug?

Am I missing something or is this like most labor savings applications? In that they can't compete with a precision time consuming manual tweak?

Also the auto EQ feature seems to be limited to 10khz? Why? 
_
REW 5, UMIK-USB, USB to SPDIF DAC feeding MiniDSP hardware, all digital REW path._


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## AudiocRaver (Jun 6, 2012)

Glimmie said:


> In working with REW for two years now, I find the auto EQ feature is not very good. I get far better results by manually running sweeps and tweaking my MiniDSP EQ's based on the REW results. A lot of trial and error but the auto EQ just doesn't even come close.


REW can give very good results via its filter values, but it usually takes playing with the EQ control parameters a bit to get there. It is not intended to be a hands-off, "let it figure everything out for you" program, but is a powerful tool with a lot of options.

However, I personally tend to agree with you that manual EQ can give satisfying results just as easily.



> And I often get strange auto EQ settings with zero gain, IOW, they do nothing with zero gain. Is this a bug?


I have not seen this. We'll see what John (the author) has to say.



> Am I missing something or is this like most labor savings applications? In that they can't compete with a precision time consuming manual tweak?


Your statement might be a little strong and over-generalized. Any such application must make certain assumptions. If they are not the same as the assumptions of the user, frustration is a likely outcome.



> Also the auto EQ feature seems to be limited to 10khz? Why?


It is pretty tough to do anything constructive with EQ above 10 kHz, other than roll off highs that are too hot. 10 kHz is actually a good practical limit for any auto EQ.


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## Glyptoron (Apr 20, 2006)

Glimmie said:


> Also the auto EQ feature seems to be limited to 10khz? Why?[/I]


Hello,

The EQ match range goes from 10 Hz to 20 KHz.

@+


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## subterFUSE (May 10, 2014)

Glimmie said:


> And I often get strange auto EQ settings with zero gain, IOW, they do nothing with zero gain. Is this a bug?



I was getting this just a couple of days ago.

When I ran auto EQ it would suggest filters with 0.0 gain.


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## Glimmie (Apr 26, 2012)

Glyptoron said:


> Hello,
> 
> The EQ match range goes from 10 Hz to 20 KHz.
> 
> @+


What version are you using?

Mine stops at 10khz. You can put 20k in but it will default back to 10k.


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## Lumen (May 17, 2014)

I would imagine that the filters default to zero gain. So there's not really any "programming" to do. Just leave any non-zero filters alone.


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## Glyptoron (Apr 20, 2006)

The last one, Sir ! id est V5.11.
Beyond 10 kHz, as it is rightly pointed out, live field wavelength is so short that it hardly matters. A few centimeters outside the measurement axis and the measurement will be distorted. Moreover, now the limit is 20 KHz but my 63 year old ears barely hear 12 KHz with headphones!


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## Glimmie (Apr 26, 2012)

BlueRockinLou said:


> I would imagine that the filters default to zero gain. So there's not really any "programming" to do. Just leave any non-zero filters alone.


Right, we should just ignore these entries in the list. However it does point to a bug in the software, hopefully harmless.


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## Phillips (Aug 12, 2011)

I understand it is limited due anyone putting boost to that range where damage could occur.


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## IslandHydro (Mar 13, 2014)

I tend to agree, auto filters just didn't seem to do anywhere near as well as I could do with manual filters. It could be I'm not properly configuring the objective curve but I gave up and did mine manually throughout, with great results I might add.


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## subterFUSE (May 10, 2014)

Glimmie said:


> Right, we should just ignore these entries in the list. However it does point to a bug in the software, hopefully harmless.



I was trying to EQ a large peak downward and REW only suggested 2 filters, both of which had 0.0 gain.

It didn't make any sense.


Sent from my iPad using Tapatalk


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## JohnM (Apr 11, 2006)

There could be a bug of course, but problems with the EQ are usually down to the settings being used. Best to use the latest version of REW, which is 5.11.

The optimiser makes an initial approximate assignment of filters then adjusts their gains, bandwidths and centre frequencies to best match the selected target curve whilst meeting the gain constraints selected. That might mean that one of the initial filters selected doesn't make a useful contribution when others have been adjusted so its gain could be set to zero to remove its contribution. There is an equaliser preference setting "Drop filters if gain is small" which will automatically remove any filters whose gain is less than half the flatness setting.

If the EQ does seem to be going wrong post the file and the target/EQ settings being used and I'll be happy to check whether it is behaving as expected.


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## Babs (Nov 6, 2014)

Good afternoon gentlemen.. I think maybe this is a first post for me. I'm one of 'those' car-audio guys  learning REW, but I'm certain I'll be using it for home theater as well hopefully sooner than later. 

On the subject of Auto-EQ, is there a good singular thread that explains in in the forum, or maybe a vid etc for the EQ section of REW specifically? 

I made a feeble attempt at it last night measuring a front 2-way system (mid and tweeter), doing A (left) and B (right) pairs from averaged sweeps to attempt to have REW recommend EQ trims which it did. Results were iffy at best and not sure how to apply the trims (left/right/both?) so I'm thinking it's something I did incorrectly I imagine.

I will say my current tune was very successful using the steps in Kyle Ragsdale's youtube videos, after getting timing and phase correct, doing individual driver EQ's, then driver pairs and left / right groups, via a Helix DSP. I guess this method is not uncommon, by a moving-mic and pink noise averaging (I'm sorry if there's a simple term for such method.. I don't know the lingo). 

As a tool, I'll say REW is truly a beast I hope to master with knowledge. With a UMM-6 or IMM-6 (I have both), I've gotten through the basics of measuring and RTA sections, but looking into learning that next step in what REW can do in the EQ tool.


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