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Assistance in creating REW EQ filters, please

ricof

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Hi all,

I have spent the best part of the day measuring my room and I am getting more and more confused with what I am expecting. I have taken measurements in an empty room (apart from my desk, photo below) and added in the limited acoustic treatment I have and tested each time.

This is where I have got to, filters generated at 1/6th smoothing, 55Hz cutoff, 24db slope. My room is 2.5 x 3.5 x 2.5 (w x l x h) and the speakers are on the 2.5m wall. MLP is approx 130cm from front wall (as per '38%' rule) and speakers are 50cm from side walls, 40cm from front wall and 110cm from the floor.

no eq vs eq.jpg


Here is my room (ignore mic position, not being used for measuring there).

IMG_5638.jpeg


I would really appreciate some assistance in generating some optimal EQ filters. I have attached the complete REW folder. The principal measurement I am using is 13 and the filter applied above is 23. There are some near field (1cm) measurements of the bass/mid drivers too.

REW file here: REW

Many thanks in advance
 

thorvat

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Hi all,

I have spent the best part of the day measuring my room and I am getting more and more confused with what I am expecting. I have taken measurements in an empty room (apart from my desk, photo below) and added in the limited acoustic treatment I have and tested each time.

This is where I have got to, filters generated at 1/6th smoothing, 55Hz cutoff, 24db slope. My room is 2.5 x 3.5 x 2.5 (w x l x h) and the speakers are on the 2.5m wall. MLP is approx 130cm from front wall (as per '38%' rule) and speakers are 50cm from side walls, 40cm from front wall and 110cm from the floor.

View attachment 173646

Here is my room (ignore mic position, not being used for measuring there).

View attachment 173647

I would really appreciate some assistance in generating some optimal EQ filters. I have attached the complete REW folder. The principal measurement I am using is 13 and the filter applied above is 23. There are some near field (1cm) measurements of the bass/mid drivers too.

REW file here: REW

Many thanks in advance

I don't see a need to correct anything beside that peak at 95Hz. I would suggest you check your measurements with MMM (moving mic method), but as it currently looks in your current REW measurements you should be good with this simple correction:

Capture.JPG



As you are listening nearfield you should not force much of a tilt with EQ unless you personally prefere LF dominance in the sound.
 
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ricof

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I don't see a need to correct anything beside that peak at 95Hz. I would suggest you check your measurements with MMM (moving mic method), but as it currently looks in your current REW measurements you should be good with this simple correction:

View attachment 173650


As you are listening nearfield you should not force much of a tilt with EQ unless you personally prefere LF dominance in the sound.

Thank you for your reply - my other concern was the mismatch in L & R channels (your image shows the R channel). In some freq's there appears to be a substantial db differential - around 100Hz, 400Hz and 3kHz for example:

left vs right channels.jpg
 

thorvat

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Thank you for your reply - my other concern was the mismatch in L & R channels (your image shows the R channel). In some freq's there appears to be a substantial db differential - around 100Hz, 400Hz and 3kHz for example:

View attachment 173653

There indeed seems to be some channel imbalance. It is best observed when you apply 1/1 smoothing, here it is shown with your measurements #14 and #15:

Capture.JPG


It can be because of slight differences in measurements, but it can also be caused by inter-individual difference between left and right speaker, channel imbalance in the amp, volume pot imbalance etc.

For a start I would suggest you repeat the measurement with MMM over your sitting surface area with 25-30cm in height centered around your ear height.

But, as it looks now, this should sound pretty balance as it is. Which speakers are those? :)

What I can also suggest is that you try to move speakers wider apart so they sit closer to the corners. This should widen your soundstage and enhance speaker's LF response. This may result in a little more excitement of that room mode at 95 Hz but you are anyhow going to correct it.
 
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ricof

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There indeed seems to be some channel imbalance. It is best observed when you apply 1/1 smoothing, here it is shown with your measurements #14 and #15:

View attachment 173654

It can be because of slight differences in measurements, but it can also be caused by inter-individual difference between left and right speaker, channel imbalance in the amp, volume pot imbalance etc.

For a start I would suggest you repeat the measurement with MMM over your sitting surface area with 25-30cm in height centered around your ear height.

But, as it looks now, this should sound pretty balance as it is. Which speakers are those? :)

What I can also suggest is that you try to move speakers wider apart so they sit closer to the corners. This should widen your soundstage and enhance speaker's LF response. This may result in a little more excitement of that room mode at 95 Hz but you are anyhow going to correct it.

Thank you once again for the reply. I'm using Neat Acoustic Motive 3 speakers - they are a small British manufacturer.

I actually did think about pushing the speakers into the corners to try and leverage some better LF response. The plots from L & R seem to align a little better too - I think in their previous positions the offset window reveal was playing with the response.

speakers in corners.jpg


Averaged and with some auto generated EQ in 1/6th and psy (because everything looks better!)

speakers corner EQ.jpg


speakers corner EQ psy.jpg



For today, my eyes and ears need to rest! Back to it tomorrow
 

thorvat

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Thank you once again for the reply. I'm using Neat Acoustic Motive 3 speakers - they are a small British manufacturer.

I actually did think about pushing the speakers into the corners to try and leverage some better LF response. The plots from L & R seem to align a little better too - I think in their previous positions the offset window reveal was playing with the response.

View attachment 173658

Averaged and with some auto generated EQ in 1/6th and psy (because everything looks better!)

View attachment 173662

View attachment 173663


For today, my eyes and ears need to rest! Back to it tomorrow

Those speakers seem to have very decent response and certainly are looking very nice.

Should you choose to do measurements with moving mic method in this video you will learn how to do it:

I would also suggest to skip auto EQ feature and to create filters mannually. I suggest you leave the range above 900Hz as it is (uncorrected) and concentrate on the range below 900Hz. Thread lightly in the 400-900Hz range, don't correct narrow dips and be sure to reduce all significant peaks, especially below 250Hz.
 
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ricof

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Those speakers seem to have very decent response and certainly are looking very nice.

Should you choose to do measurements with moving mic method in this video you will learn how to do it:

I would also suggest to skip auto EQ feature and to create filters mannually. I suggest you leave the range above 900Hz as it is (uncorrected) and concentrate on the range below 900Hz. Thread lightly in the 400-900Hz range, don't correct narrow dips and be sure to reduce all significant peaks, especially below 250Hz.
Thank you, I appreciate the link to the video. Is there any reason to avoid the auto EQ? For some reason, my room/system give me some fatigue after a while so taming the HF is definitely needed.

Switching back and forth between the filters I currently have with LAConvolver, I can't understand why anyone would NOT want to measure their rooms and apply EQ. The difference is night and day.
 

thorvat

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Thank you, I appreciate the link to the video. Is there any reason to avoid the auto EQ? For some reason, my room/system give me some fatigue after a while so taming the HF is definitely needed.

Auto EQ will try to tame the HF the wrong way using numerous filters in an effort to linearize the response curve, which is fundamentally wrong in the range above app 900Hz as pseudo-anechoic measurements are needed to do that instead of measurements taken from LP, because above app 900Hz you are correcting the speaker and not the room.

If you want to adjust ratio between LF and HF manual shelving filters should be used instead.
 
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ricof

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Hi @thorvat I have been playing around with the MMM and I can see it's benefits already.

Average of 4no readings for each channel, no filtering yet:

MMM l and r.jpg


What do you advise for manual filtering?

Thanks
 

thorvat

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Hi @thorvat I have been playing around with the MMM and I can see it's benefits already.

Average of 4no readings for each channel, no filtering yet:

View attachment 173912

What do you advise for manual filtering?

Thanks

This looks pretty good as a start! If you attach REW file with this measurement I'll be happy to suggest filters.

Please also include MMM measurement with pink noise where both speakers are playing at the same time.
 
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ricof

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This looks pretty good as a start! If you attach REW file with this measurement I'll be happy to suggest filters.

Please also include MMM measurement with pink noise where both speakers are playing at the same time.
I will take some more measurements - in the case you suggest with pink noise playing on both channels where should I point the microphone?
 

thorvat

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I will take some more measurements - in the case you suggest with pink noise playing on both channels where should I point the microphone?

With moving microphone method you are (quite surprisingly, right? :) ) moving mic around your listening position, as shown in the video I linked above.

In the case of both channels playing you are trying to see if there are bass cancelations due to phase mismatch between channels, so you can as well have mic pointed at the midpoint between the speakers while moving it around. As you will be looking only at LF part of the response it is not really critical where you will be pointing mic while moving it around.
 
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ricof

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With moving microphone method you are (quite surprisingly, right? :) ) moving mic around your listening position, as shown in the video I linked above.

In the case of both channels playing you are trying to see if there are bass cancelations due to phase mismatch between channels, so you can as well have mic pointed at the midpoint between the speakers while moving it around. As you will be looking only at LF part of the response it is not really critical where you will be pointing mic while moving it around.
Yes - I am moving the mic around my listening position but it's pointed towards either the L or R speaker depending on which I am measuring (just like in the video). I hope that is correct?

I've done a fresh set of measurements: each channel with mic pointed towards speaker and mic pointed towards mid point and both channels pointed towards mid point, link MMM v3

Some quick comparisons:

MMM towards speakers L and R.jpg


MMM midpoint L and R.jpg

MMM both channels mid point.jpg


Many thanks again!
 

thorvat

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Yes - I am moving the mic around my listening position but it's pointed towards either the L or R speaker depending on which I am measuring (just like in the video). I hope that is correct?

I've done a fresh set of measurements: each channel with mic pointed towards speaker and mic pointed towards mid point and both channels pointed towards mid point, link MMM v3

Some quick comparisons:

View attachment 174081

View attachment 174082
View attachment 174083

Many thanks again!


Yes, correct.

I added some simple filters in the attached REW file, they should do the job nicely, so please apply them and re-measure the same way you did before. Here's the predicted response:

Capture.JPG
 

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  • MMM tests v3 22nd dec 2021.zip
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ricof

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Yes, correct.

I added some simple filters in the attached REW file, they should do the job nicely, so please apply them and re-measure the same way you did before. Here's the predicted response:

View attachment 174120

Thank you for taking the time to do that, sorry for the delay - I have had a fever. Should I be generating different filters for each channel? I feel like that might be a stupid question but i'll ask anyway!

Edit: what would you do about the peaks at 4k and 10k?
 
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Backflash

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Thank you for taking the time to do that, sorry for the delay - I have had a fever. Should I be generating different filters for each channel? I feel like that might be a stupid question but i'll ask anyway!
Yes, but I do a sanity check for myself. I do L+R, L, R then same but with MMM/RTA method from listening position and cross check it with no EQ data. If separate is close enough to L+R I keep the EQ, it has variations in my case, yours could be identical.
If you are using EQ APO, it's really easy to separate channels, open included filters file with an arrow up button, press plus Control- Channel and select a channel for specific correction.
 

thorvat

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Thank you for taking the time to do that, sorry for the delay - I have had a fever. Should I be generating different filters for each channel? I feel like that might be a stupid question but i'll ask anyway!

Edit: what would you do about the peaks at 4k and 10k?

Yes, different filters for each channel. This is for left channel:

Left.JPG


And this one is for right channel:

Right.JPG


Dont' worry about the response above 900Hz as you can't correct it based on the measurements taken this way. You would need to make pseudoanechoic measurements to correct speaker response but I wouldn't worry about that.

If you're interested how to do that, I believe @napilopez wrote a nice post describing how to do that so you may try searching for it.

I hope you'll get better soon, enjoy your music!
 
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ricof

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@thorvat thank you for the well wishes, hope you had a good holiday. See below a comparison between predicted and measured:

L predicted v measured.jpg


R predicted v measured.jpg


Would you be thinking about tweaking the filters based on that response?

Also, what do you think is going on at about 600Hz in the comparison below? Are the responses out of phase?

measured with EQ L and R.jpg
 
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