# Filters - non parametric EQ - with REW



## ghstudio (Jul 27, 2007)

I'm trying to learn how REW assigns filters, works with EQ's and to see if it will do what I want. It is interesting to see how the different supported equalizers would be set up and how the resultant curve looks....which is surprisingly different depending on the EQ. 

I am using a 31 band EQ, not a parametric EQ....and it seems that REW only suggests parametric eq settings.

Is there any way to show the fixed 31 eq band settings on the graphs (to help me manually adjust the EQ)?

Is there any way to get recommended settings for a 31 band EQ (non parametric)?

Is there any way to get REW to suggest gain settings for filters in addition to the cut suggestions?

Is there any way to get recommended EQ settings full range instead of limiting the under 500hz?


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

REW is designed to generate recommendations for parametric filters. It won’t work automatically for higher frequencies because it’s the lower frequencies that are the most affected by the room. Unfortunately REW will not recommend boosted filters, but it’s easy enough to generate your own.



> Is there any way to show the fixed 31 eq band settings on the graphs (to help me manually adjust the EQ)?


Under the “Equaliser” tag at the top left of the screen, chose the “Generic” option. Choose “PK” as type, and set the bandwidth to 4.3 Q (which is 1/3 octave). Then you can enter in the frequency field the numeric frequency centers your EQ has – 40 Hz, 50 Hz, 63 Hz, etc. Changing the gain, you will see on-screen the effect of 1/3-octave filters. I think you’ll find out pretty quickly how limited 1/3-octave EQs are for bass.

Regards,
Wayne


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## weverb (Aug 15, 2008)

You could also use the RTA feature of REW and adjust the graphic eq on the fly. With the RTA function, you see the changes right away without having to go through the filter steps.


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## ghstudio (Jul 27, 2007)

weverb said:


> You could also use the RTA feature of REW and adjust the graphic eq on the fly. With the RTA function, you see the changes right away without having to go through the filter steps.


I am just learning REW....yes, the spectrum, mode RTA 1/3 octave appears to do exactly what I want. I've been iterating by changing settings and then doing another measurement....but with spectrum, I can just generate pink noise and set the result to give a flat response curve. Right?


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## brucek (Apr 11, 2006)

Read this post on the settings for Spectrum and REW. Note the periodic (PN) noise.

brucek


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## arack (Feb 21, 2013)

I understand that the REW 20-band Parametric Equalizer works much better to align the room, but I have already connected a 31-band Graphic Equalizer to my studio system.
Do you have plans to put new 31-band fixed bandwidth EQs that work with Match Response to Target?

I am using Generic but as it does not have 31 bands the analysis does not get so accurate ... I currently have two analysis presets. One of 20-1,6K and the other of 250-20K. Both with 4.32 bandwidth and the frequencies contained in my Graphical EQ.

I have to do two tests to complete the Match and even then, I have different results in the 250 and 1.6K regions.

People who align their own Homestudio with a 31-band EQ would go crazy with this REW match option.

Thank you very much.

Big fan of REW


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## kewlbug (Jan 5, 2022)

arack said:


> I understand that the REW 20-band Parametric Equalizer works much better to align the room, but I have already connected a 31-band Graphic Equalizer to my studio system.
> Do you have plans to put new 31-band fixed bandwidth EQs that work with Match Response to Target?
> 
> I am using Generic but as it does not have 31 bands the analysis does not get so accurate ... I currently have two analysis presets. One of 20-1,6K and the other of 250-20K. Both with 4.32 bandwidth and the frequencies contained in my Graphical EQ.
> ...





Is this still not a thing? 31 band GEQ are still very prevalent especially in car audio. Even better would be the ability to create custom EQs or limit options for a filter. example Filter 1 20-100hz Filter 2 63-315hz with 1/3 stepped choices. This is what my cars head unit has. Also my yamaha receiver is limited similarly


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

Seems unrealistic to expect that John can build in support for ever equalizer that exists in the world. Even with the 1/3-octave EQs mentioned in Post #6, they don’t all have the same Q characteristics, as some cut a wider path than others, as you would have (for instance) with a constant Q model vs. one that’s variable Q. As always, the best way to use REW with an equalizer that the platform doesn’t support is via the RTA feature.

Regards,
Wayne


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## kewlbug (Jan 5, 2022)

Wayne A. Pflughaupt said:


> Seems unrealistic to expect that John can build in support for ever equalizer that exists in the world. Even with the 1/3-octave EQs mentioned in Post #6, they don’t all have the same Q characteristics, as some cut a wider path than others, as you would have (for instance) with a constant Q model vs. one that’s variable Q. As always, the best way to use REW with an equalizer that the platform doesn’t support is via the RTA feature.
> 
> Regards,
> Wayne


I totally get what you're saying. I wouldn't expect a setup for everything in the world, But if generic could just be expanded to 31 filters or at least a button to add more, That would satisfy a Large portion of those in need. I of course will be using RTA, but auto EQ will at least give me a starting point. 

My Yamaha receiver is a different subject. I am just imagining a tool to "Create your own" set. where you go in, enter all of your constraints, fixed or unlimited and let REW do its magic. I have a process to tune already.. I just thought it was a cool idea.


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## focusedphil (Apr 14, 2013)

I'd like to vote to have at least the generic EQ have 31 slots. It would make this much easier to use for people who have these common EQ's, even if they are not as good as the other options.

I know this has been asked for a lot in the past - kind of surprised that it's not been added by this point.

Remember, people still love Kraft Process Cheese slices even though there is much better cheese available.


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