How to PEQ: From graph to filter

[May Kasahara]

I would like to set the following filter (purple) with the PEQ function.



However, I can't get it to work. I have tried a lot with the filter functions HS/LS/PK as well as dB and Q, but I can't do it.

Is there a procedure how to get from a graph to the corresponding filter settings or does only experience and trial and error help here?

Goal: Start at approx. 6 kHz and down to -1 dB at 20 kHz.

 

[Wiimer]

I would like to set the following filter (purple) with the PEQ function.

View attachment 17949

However, I can't get it to work. I have tried a lot with the filter functions HS/LS/PK as well as dB and Q, but I can't do it.

Is there a procedure how to get from a graph to the corresponding filter settings or does only experience and trial and error help here?

Goal: Start at approx. 6 kHz and down to -1 dB at 20 kHz.

The band value that can be set in PEQ is up to 22 kHz, so I think it would be difficult to reproduce that perfectly.

 

[May Kasahara]

Up to 22 kHz would also be perfectly fine for me.

 

[harkpabst]

This exact filter behaviour is currently not possible to achieve, because PEQ does not support low pass filters.

A low shelf filter might be able to recreate a similar response between 6 kHz and 20 kHz, but would be lacking the falling slope above. That alone is probably not much of a problem, but unfortunately the WiiM Home app does not display the influence of the chosen Q factor correctly. The default Q for shelving filters is 0.25, but the visual representation looks more like Q = 0.7. To make matters worse, there are different definitions for Q and we don't really know what definition is used here.

A low Q negative gain peak filter could also be used, but the visual representation (which is believed to be correct) indicates an asymmetric response towards the upper frequency limit of 22 kHz, so the result is probably not as described.

Your best bet might be the low shelf filter, but you had to perform acoustical measurements to confirm the actual response.

 

[canard]

This exact filter behaviour is currently not possible to achieve, because PEQ does not support low pass filters.

A low shelf filter might be able to recreate a similar response between 6 kHz and 20 kHz, but would be lacking the falling slope above. That alone is probably not much of a problem, but unfortunately the WiiM Home app does not display the influence of the chosen Q factor correctly. The default Q for shelving filters is 0.25, but the visual representation looks more like Q = 0.7. To make matters worse, there are different definitions for Q and we don't really know what definition is used here.

A low Q negative gain peak filter could also be used, but the visual representation (which is believed to be correct) indicates an asymmetric response towards the upper frequency limit of 22 kHz, so the result is probably not as described.

Your best bet might be the low shelf filter, but you had to perform acoustical measurements to confirm the actual response.

(solution easy not in """acoustic""".... but just ana or digital input/output of the wiim via chirp or white noise etc .
approach via digital very useful and fast to check adapt the gain after peq _rc for those who have suitable sound cards.... MT is very effective and simple for this kind of exercises...
in a few clicks ;-) )

(ps for may kasahara , it remains a filtering really painful in real life (see value at 8k 10k 12k ..16k).... see a little difficult to measure in acoustics as the impact is weak..you have an interest in having class 1 microphone with very serious calibration... bk mesureaments microphone? ;-)) )

 

[harkpabst]

I was assuming that @May Kasahara has limited ways of measuring the output of his unnamed WiiM device. If anything, it's easier for most people to perform acoustic measurements than electric measurements.

Having said that, the influence of a 1 dB drip at 20 kHz will be marginal, if detectible at all by an adult person.

 

[canard]

I was assuming that @May Kasahara has limited ways of measuring the output of his unnamed WiiM device. If anything, it's easier for most people to perform acoustic measurements than electric measurements.

Having said that, the influence of a 1 dB drip at 20 kHz will be marginal, if detectible at all by an adult person.

Often, acquisition cards for microphones accept line level inputs ;-)
( -0.2db 10k....0.5db 16k... ;-)) )

 

[May Kasahara]

I was assuming that @May Kasahara has limited ways of measuring the output of his unnamed WiiM device. If anything, it's easier for most people to perform acoustic measurements than electric measurements.

That is absolutely correct. And just for the record, the unnamed WiiM device is an Ultra (see thread-tags).

Having said that, the influence of a 1 dB drip at 20 kHz will be marginal, if detectible at all by an adult person.

This is also absolutely correct, like so much of what we measure but cannot actually hear.

I think that's enough of an answer for me. For my specific use case, I was just careful to adjust all the factors that I can influence in a comparison so that I was comparing apples with apples as far as possible.

I wasn't aware that WiiM's PEQ implementation was so mediocre (e.g. no low-pass filter option and no correct display of Q results for low-shelf filters)

 

[harkpabst]

I wasn't aware that WiiM's PEQ implementation was so mediocre (e.g. no low-pass filter option and no correct display of Q results for low-shelf filters)

You are right in pointing out this criticism, but I'm not aware of any network pre-ceiver remotely in this price range offering a better PEQ implementation.

Q settings actually work for shelving filters, but you have to perform your own measurements to visualise the effect. You can help promoting an improvement by hitting the upvote arrow for this feature request:

Thread 'PEQ: Graph should reflect Q value for shelf filters'

May 22, 2024

The PEQ feature in WiiM's products has developed very well over time and definitely turned into an extremely powerful tool. One great feature is the support of fully flexible filter Q values, not only for peak filters, but also for high shelf and low shelf filters.

Unfortunately, the effects of different Q values are currently displayed for peak filters, only.

For example, here are the graphs for a 200 Hz +10 dB PK filter with either Q=1.5 or Q=0.15. The difference is obvious and understood very intuitively.





In contrast, the graphs for a 200 Hz +10 dB LS...

• harkpabst
• Replies: 21
• Forum: General WiiM Home App & Device Feature Requests

• 

It doesn't hurt if you also send feedback to WiiM through the WiiM Home app (More > Send us feedback), directly asking for a change.