JBL 305P mkII equalization

[Pio2001]

Hi,
After reading the review of the JBL 305P mkII speaker (that I own), I decided to try and equalize them according to the measurements that were published.

The two conditions for the equalization to succeed were that the directivity indices are smooth, and that my own pair sounds exactly the same as the one measured by Amir.

We can see in the review that the first condition is met, and that these speakers are good candidates for equalization.
The second condition seems to be fulfilled according to my own measurements (see my post here with the curves : https://www.audiosciencereview.com/...pro-monitors-review.10811/page-19#post-302946 )

I thus generated a set of eq filters in the REW software that should compensate for the JBL's frequency response, as measured by Amir (on-axis and listening window curves).
Here is the equalization curve that I managed to generate. It is displayed upside down, and I have overlaid it on Amir's graph. It is the light blue curve. I am very happy with the accuracy that I got while playing manually with all the PK coefficients, just looking at Amir's picture.
I didn't set any correction above 14 kHz for the time being, as I am completely deaf above 13.5 kHz anyway.

Once applied to the speakers, it sounds... a bit weird.

I then measured the frequency response before and after the correction from the listening position. I use the moving microphone method for this purpose, drawing the cumulated RTA of a Pink periodic noise.
Unfortunately, I can't measure the windowed response of the speaker alone, as I can't apply the correction to the REW signal. I can only apply it to music played by the Foobar2000 software player, with its convolver plugin. What we see here is the room curve in addition to the speaker curve :

The left part of the curve, up to 500 Hz, can be ignored. It represents the room's response rather than the speaker's response, with a correction setup for the Neumann KH-120 monitors, that are front vented, while the JBL are rear-vented.
The right part, from 1000 Hz to 20000 Hz, is supposed to decrease gently as the frequency goes up, as expected in any room.

Oops ! My correction obviously created some problems that were not there to begin with. Let's compare this curve with the correction itself :

The part around 500 Hz is difficult to interpret. On one hand, it looks like the correction is too strong, but on the other hand, this frequency range is supposed to by higher than the treble frequencies, measured from the listening position. Let's put it aside. The real problem is obvious : from 4000 Hz and up, the correction is useless. The original curve was neutral and didn't need any correction.

Let's drop this part from the eq and keep only the useful corrections, up to 4000 Hz.

Making a "half correction" is something very difficult, because there is no reference level for the part that is not corrected. In my first try, I just naively drew a straight line from 4000 Hz upwards. But the result didn't sound good. The treble were muffled. I realized that I had not calculated any target level for the part that is above 4000 Hz.
So I went back to Amir's graph, and tried to evaluate the average level measured above 4000 Hz. I restricted my reading to the 5000 to 15000 Hz range, ignoring what's happening above. I tried to draw a straight line so that half of the curve is above, and half is below. Then I noticed that this level was exactly the same as the 150 Hz peak. That would be my reference point.
Reading now my REW correction overlaid on Amir's graph, I noticed that it was accurately following it at 150 Hz. I therefore set the shelf level of my correction above 4000 Hz exactly identical to my 150 Hz peak (I mean 150 dip, since the curve is displayed upside down).

I generated the impulse response of the new correction and loaded it in Foobar's convolver and... wow ! Now, that sounds really great !!!

Here is how it measures from the listening position :

When I say it sounds great, I'm talking about medium and high frequencies. The low frequencies need re-equalization, as the bass reflex of the JBL is on the back of the speaker, and the MiniDSP room correction (still active from 35 to 600 Hz) was setup for the Neumann.

The measurement shows yet a little problem around 1000 Hz that was not there before correction. Here is the response without eq, the final correction, and REW's prediction of the result.

We can see that the level is unduly decreasing from 1000 to 1400 Hz, while it was not the case before correction.
Comparing with the first picture with Amir's graph, we can see that the correction is supposed to be ok. Since I'm not sure what's happening here, I didn't try any other adjustment.

The forum doesn't allow audio nor binary attachments, so here are links to my correction :

44100 Hz impulse response for convolvers : JBL 305P mk2 equalization.wav
Eq filters for REW : JBL 305P mkII eq filters.req

Important :
The correction is valid for JBL 305P mkII speakers, not for regular LSR 305 speakers.
The impulse response works at 44100 Hz only. The convolver must be preceded by a 44100 Hz resampler, or have a built-in resampler. Otherwise, if a file with a sampling frequency different from 44100 Hz is played, the correction will be wrong.

 

[Pio2001]

PS : I'll write more about how it sounds later this week.
For the time being, the result seems to be as good as the Neumann KH120 themselves.

 

[Pio2001]

I have listened to the equalized JBL a bit more today.

My reference point are the Neumann KH-120 monitors. They cost 1300 euros for one pair, and are said to be very neutral. I have been listening to them for 4 years and I could not be more satisfied.
My listening room sounds a bit bright, with hard ceiling, walls and floor. The RT60 decay time from the speakers to the listening position is 0.45 s at 500 Hz. The distance to the speakers is 2.1 meters.
Both speakers were listened to with their treble trim to -1.

The question is how good can sound the JBL 305p mk2 once equalized ? Is correcting them enough to make them sound as good as a pair of Neumann ?

Well, I don't know.

First, the correction is a big improvement. Without correction, they sound beautifully bright, but human voices are harsh. With correction, they sound much more balanced, and the voices are much more realistic.

Now, if I compare them to the Neumann, the first difference is how the treble sounds. It is slightly quieter with the JBL, but its texture sounds completely different.
With the JBL, all treble sounds are pure, like a glockenspiel played with metallic hammers. On the contrary, with the Neumann, treble sounds are soft and dull, like brushed cymbals.
To put it otherwise, the JBL sound "ding" while the Neumann sound "pshh". The JBL treble sounds obviously more beautiful, but is it too beautiful to be true ? I am unable to tell which one is closer to reality !

But there is also an important difference in medium frequencies. They sound a bit recessed on the corrected JBL, while they sound very good with the Neumann. Here, I have the feeling that the Neumann are closer to reality.

In this cantata by J.S.Bach, the choir and soprano sound more realistic with the Neumann. On the JBL, the singers sound like they are too far away.
I listened to the part from 14:35 (soprano). The strings too sound better on the Neumann. And also to the part from 22:45 (choir).

The strange thing is than the frequency response from the listening position looks better with the corrected JBL than with the Neumann :

These curves were measured with the same room correction in low frequencies. I then applied an extra correction in order to have the same bass level on both speakers, but, although it changes the general balance a lot, it didn't change much the presence of the human voices.

At this point, my first vote would go to the Neumann, but I would like a comparison with a real acoustic concert in order to have a better reference.

 

[DDF]

Unfortunately, I can't measure the windowed response of the speaker alone, as I can't apply the correction to the REW signal. I can only apply it to music played by the Foobar2000 software player, with its convolver plugin. .

Equalizer APO's convolver works with all audio going through the windows mixer. I haven't tried it's convolver yet (I use PEQ/GEQ in EAPO and its fantastic), but I imagine doing the correction in EAPO vs Foobar2000 would allow you to measure the fully corrected speaker with REW. It would also correct the speaker's response with streaming services and not just local files.

 

[Thomas_A]

I have listened to the equalized JBL a bit more today.

My reference point are the Neumann KH-120 monitors. They cost 1300 euros for one pair, and are said to be very neutral. I have been listening to them for 4 years and I could not be more satisfied.
My listening room sounds a bit bright, with hard ceiling, walls and floor. The RT60 decay time from the speakers to the listening position is 0.45 s at 500 Hz. The distance to the speakers is 2.1 meters.
Both speakers were listened to with their treble trim to -1.

The question is how good can sound the JBL 305p mk2 once equalized ? Is correcting them enough to make them sound as good as a pair of Neumann ?

Well, I don't know.

First, the correction is a big improvement. Without correction, they sound beautifully bright, but human voices are harsh. With correction, they sound much more balanced, and the voices are much more realistic.

Now, if I compare them to the Neumann, the first difference is how the treble sounds. It is slightly quieter with the JBL, but its texture sounds completely different.
With the JBL, all treble sounds are pure, like a glockenspiel played with metallic hammers. On the contrary, with the Neumann, treble sounds are soft and dull, like brushed cymbals.
To put it otherwise, the JBL sound "ding" while the Neumann sound "pshh". The JBL treble sounds obviously more beautiful, but is it too beautiful to be true ? I am unable to tell which one is closer to reality !

But there is also an important difference in medium frequencies. They sound a bit recessed on the corrected JBL, while they sound very good with the Neumann. Here, I have the feeling that the Neumann are closer to reality.

In this cantata by J.S.Bach, the choir and soprano sound more realistic with the Neumann. On the JBL, the singers sound like they are too far away.
I listened to the part from 14:35 (soprano). The strings too sound better on the Neumann. And also to the part from 22:45 (choir).

The strange thing is than the frequency response from the listening position looks better with the corrected JBL than with the Neumann :

View attachment 45856

These curves were measured with the same room correction in low frequencies. I then applied an extra correction in order to have the same bass level on both speakers, but, although it changes the general balance a lot, it didn't change much the presence of the human voices.

At this point, my first vote would go to the Neumann, but I would like a comparison with a real acoustic concert in order to have a better reference.

Try toning down the 2-5 kHz range 1-2 dB on the Neumann.

 

[Krunok]

Hi,
After reading the review of the JBL 305P mkII speaker (that I own), I decided to try and equalize them according to the measurements that were published.

The two conditions for the equalization to succeed were that the directivity indices are smooth, and that my own pair sounds exactly the same as the one measured by Amir.

We can see in the review that the first condition is met, and that these speakers are good candidates for equalization.
The second condition seems to be fulfilled according to my own measurements (see my post here with the curves : https://www.audiosciencereview.com/...pro-monitors-review.10811/page-19#post-302946 )

I thus generated a set of eq filters in the REW software that should compensate for the JBL's frequency response, as measured by Amir (on-axis and listening window curves).
Here is the equalization curve that I managed to generate. It is displayed upside down, and I have overlaid it on Amir's graph. It is the light blue curve. I am very happy with the accuracy that I got while playing manually with all the PK coefficients, just looking at Amir's picture.
I didn't set any correction above 14 kHz for the time being, as I am completely deaf above 13.5 kHz anyway.

View attachment 45745

Once applied to the speakers, it sounds... a bit weird.

I then measured the frequency response before and after the correction from the listening position. I use the moving microphone method for this purpose, drawing the cumulated RTA of a Pink periodic noise.
Unfortunately, I can't measure the windowed response of the speaker alone, as I can't apply the correction to the REW signal. I can only apply it to music played by the Foobar2000 software player, with its convolver plugin. What we see here is the room curve in addition to the speaker curve :

View attachment 45738

The left part of the curve, up to 500 Hz, can be ignored. It represents the room's response rather than the speaker's response, with a correction setup for the Neumann KH-120 monitors, that are front vented, while the JBL are rear-vented.
The right part, from 1000 Hz to 20000 Hz, is supposed to decrease gently as the frequency goes up, as expected in any room.

View attachment 45739

Oops ! My correction obviously created some problems that were not there to begin with. Let's compare this curve with the correction itself :

View attachment 45740

The part around 500 Hz is difficult to interpret. On one hand, it looks like the correction is too strong, but on the other hand, this frequency range is supposed to by higher than the treble frequencies, measured from the listening position. Let's put it aside. The real problem is obvious : from 4000 Hz and up, the correction is useless. The original curve was neutral and didn't need any correction.

Let's drop this part from the eq and keep only the useful corrections, up to 4000 Hz.

Making a "half correction" is something very difficult, because there is no reference level for the part that is not corrected. In my first try, I just naively drew a straight line from 4000 Hz upwards. But the result didn't sound good. The treble were muffled. I realized that I had not calculated any target level for the part that is above 4000 Hz.
So I went back to Amir's graph, and tried to evaluate the average level measured above 4000 Hz. I restricted my reading to the 5000 to 15000 Hz range, ignoring what's happening above. I tried to draw a straight line so that half of the curve is above, and half is below. Then I noticed that this level was exactly the same as the 150 Hz peak. That would be my reference point.
Reading now my REW correction overlaid on Amir's graph, I noticed that it was accurately following it at 150 Hz. I therefore set the shelf level of my correction above 4000 Hz exactly identical to my 150 Hz peak (I mean 150 dip, since the curve is displayed upside down).

View attachment 45741

I generated the impulse response of the new correction and loaded it in Foobar's convolver and... wow ! Now, that sounds really great !!!

Here is how it measures from the listening position :

View attachment 45742

When I say it sounds great, I'm talking about medium and high frequencies. The low frequencies need re-equalization, as the bass reflex of the JBL is on the back of the speaker, and the MiniDSP room correction (still active from 35 to 600 Hz) was setup for the Neumann.

The measurement shows yet a little problem around 1000 Hz that was not there before correction. Here is the response without eq, the final correction, and REW's prediction of the result.
View attachment 45743

We can see that the level is unduly decreasing from 1000 to 1400 Hz, while it was not the case before correction.
Comparing with the first picture with Amir's graph, we can see that the correction is supposed to be ok. Since I'm not sure what's happening here, I didn't try any other adjustment.

The forum doesn't allow audio nor binary attachments, so here are links to my correction :

44100 Hz impulse response for convolvers : JBL 305P mk2 equalization.wav
Eq filters for REW : JBL 305P mkII eq filters.req

Important :
The correction is valid for JBL 305P mkII speakers, not for regular LSR 305 speakers.
The impulse response works at 44100 Hz only. The convolver must be preceded by a 44100 Hz resampler, or have a built-in resampler. Otherwise, if a file with a sampling frequency different from 44100 Hz is played, the correction will be wrong.

Nice work!

But as you are doing speaker correction I think you should leave the sub 600Hz region intact as that one is room dependent so everyone can adjust your filters with their own room EQ in sub 600Hz region to fit their own room.

You should also consider using on-axis sweeps from app 1.5m instead of MMM as that may yield better precision for the range north of 600Hz.

 

[Krunok]

The strange thing is than the frequency response from the listening position looks better with the corrected JBL than with the Neumann :

View attachment 45856

These curves were measured with the same room correction in low frequencies. I then applied an extra correction in order to have the same bass level on both speakers, but, although it changes the general balance a lot, it didn't change much the presence of the human voices.

At this point, my first vote would go to the Neumann, but I would like a comparison with a real acoustic concert in order to have a better reference.

IIRC we mostly perceive human voice from the 200-400Hz range and Neumann seem to be doing a better job there. Maybe it would be more visible if you apply some more smoothing (1/12 or 1/6 octaves) to those curves.

 

[loprent1]

Noob question, is there a way to apply a REW filter to a hardware device that could sit in-between the XLR output and 3.5mm input to a 'dumb' device like a TV?

 

[Pio2001]

Noob question, is there a way to apply a REW filter to a hardware device that could sit in-between the XLR output and 3.5mm input to a 'dumb' device like a TV?

I'm not sure I follow the direction of your signal.
Anyway, yes. The MiniDSP 2x4 is one of the cheapest (about 150 $) and most powerful (it accepts biquad filters, allowing the strongest and werdiest corrections, as long as they are minimal phase).
In REW, when you select it as an equalizer, REW lets you export 6 filters at once. However, the MiniDSP can directly accept 5+5 = 10 filters (with the "2x4 advanced" plugin), or 6+6 = 12 filters (with the alternative "2-way advanced" plugin), plus 8 manually configurable filters (in any of the two plugins), which lets you combine a maximum of 20 filters per channel.
Although the method to get the 20 of them outside of REW and then inside the device is quite clumsy, as you have to export them in four separate batches (three batches of 6, plus one batch of 2, negative corrections first, and you have to rewrite and combine the last two exports and type them manually in the MiniDSP software).

You'll need two XLR to RCA adapters, then a 2xRCA to mini jack adapter.
If your output is line level or pro level (not preamp level), ask for the MiniDSP to be configured with a 2 volts input sensitivity (not 0.7 volts).
Anyway, take care of the output level of your source so as to never overload the input of the MiniDSP. It would clip the signal and distort the sound.

Equalizer APO's convolver works with all audio going through the windows mixer.

Thanks for the tip. Unfortunately, I run REW and everything else in Linux, not Windows.

Try toning down the 2-5 kHz range 1-2 dB on the Neumann.

I have tried various experiments of this kind. In the end, the critical factor is always the overall tilt of the target curve rather than these local oscillations in the frequency response.
Toning down 1-2 dB this range will get the overall target curve a bit too low in the treble side. To do this correctly, it would be necessary to compensate, rising slightly the surrounding frequency regions, so that the overall level above 1000 Hz remains exactly the same as before in average.
At least, that's my conclusion after repeated experiments and listening tests.

And in the end, the reponse of the Neumann is dead flat on axis. In theory, correcting this deviation in the frequency response measured from the listening position would please the microphone, but not the ear. At these frequencies, the ear "hears through the room" and separates the direct sound's flat frequency response, heard as it is, from the delayed room reverberation that is responsible for these measured deviations, that are heard separately, as ambient clues about the environment in which the sound is playing.

But as you are doing speaker correction I think you should leave the sub 600Hz region intact as that one is room dependent so everyone can adjust your filters with their own room EQ in sub 600Hz region to fit their own room.

That's right. The correction below 600 Hz is optional. I included it just in case.

 

[Pio2001]

Today I have tried to complete the equalization of my JBL 305P mkII with a correct room correction below 600 Hz.

I couldn't reach a result that sounds as good as the Neumann's KH-120, however, it seems to me that it's not the speaker's fault. Equalizing the speaker is quite straightforward. All the problems lies in the room correction, that is very difficult in my case, because of the presence of a large window 80 cm behind the speakers, with a very deep null around 100 Hz, and a strong constructive interference around 200 Hz, plus several other problems until 800 Hz.

In conclusion, I think that the result sounds better on the Neumann mainly because the whole room correction for them has been fine-tuned during one year. I can't get such a balanced room correction for the JBL in one day. It would take more time to fine-tune for the comparison to be fair.

But something very interesting happened during the experiment.
During the first trials, I found the vocals to sound harsh with the JBLs. I played with Foobar's graphic equalizer in order to identify the frequency that was causing the problem. I found it to be somewhere around 2000 Hz.
First, I thought that I was used to the dip in the off-axis frequency response of the Neumann, that I have been listening to for years, and that I needed to get used to the JBL response. But nonetheless, it didn't sound right... until I realized that I had forgotten to turn on the JBL 305P equalization ! I was only listening to the room correction below 800 Hz, with the JBL 305P playing with its uncorrected frequency response above that.

And that's intersting because it shows that the 1800 Hz peak in the JBL's frequency response is clearly audible and quite annoying.

 

[LightninBoy]

Now, if I compare them to the Neumann, the first difference is how the treble sounds. It is slightly quieter with the JBL, but its texture sounds completely different.
With the JBL, all treble sounds are pure, like a glockenspiel played with metallic hammers. On the contrary, with the Neumann, treble sounds are soft and dull, like brushed cymbals.
To put it otherwise, the JBL sound "ding" while the Neumann sound "pshh". The JBL treble sounds obviously more beautiful, but is it too beautiful to be true ? I am unable to tell which one is closer to reality !

I know exactly what you are talking about. I noticed the same thing regarding the JBL 3 series treble compared to other speakers - particularly those in its price class. The first time I really noticed this treble character in a speaker was when listening to Revel m106 speakers.

 

[QMuse]

Hi,
After reading the review of the JBL 305P mkII speaker (that I own), I decided to try and equalize them according to the measurements that were published.

The two conditions for the equalization to succeed were that the directivity indices are smooth, and that my own pair sounds exactly the same as the one measured by Amir.

We can see in the review that the first condition is met, and that these speakers are good candidates for equalization.
The second condition seems to be fulfilled according to my own measurements (see my post here with the curves : https://www.audiosciencereview.com/...pro-monitors-review.10811/page-19#post-302946 )

I thus generated a set of eq filters in the REW software that should compensate for the JBL's frequency response, as measured by Amir (on-axis and listening window curves).
Here is the equalization curve that I managed to generate. It is displayed upside down, and I have overlaid it on Amir's graph. It is the light blue curve. I am very happy with the accuracy that I got while playing manually with all the PK coefficients, just looking at Amir's picture.
I didn't set any correction above 14 kHz for the time being, as I am completely deaf above 13.5 kHz anyway.

View attachment 45745

Once applied to the speakers, it sounds... a bit weird.

I then measured the frequency response before and after the correction from the listening position. I use the moving microphone method for this purpose, drawing the cumulated RTA of a Pink periodic noise.
Unfortunately, I can't measure the windowed response of the speaker alone, as I can't apply the correction to the REW signal. I can only apply it to music played by the Foobar2000 software player, with its convolver plugin. What we see here is the room curve in addition to the speaker curve :

View attachment 45738

The left part of the curve, up to 500 Hz, can be ignored. It represents the room's response rather than the speaker's response, with a correction setup for the Neumann KH-120 monitors, that are front vented, while the JBL are rear-vented.
The right part, from 1000 Hz to 20000 Hz, is supposed to decrease gently as the frequency goes up, as expected in any room.

View attachment 45739

Oops ! My correction obviously created some problems that were not there to begin with. Let's compare this curve with the correction itself :

View attachment 45740

The part around 500 Hz is difficult to interpret. On one hand, it looks like the correction is too strong, but on the other hand, this frequency range is supposed to by higher than the treble frequencies, measured from the listening position. Let's put it aside. The real problem is obvious : from 4000 Hz and up, the correction is useless. The original curve was neutral and didn't need any correction.

Let's drop this part from the eq and keep only the useful corrections, up to 4000 Hz.

Making a "half correction" is something very difficult, because there is no reference level for the part that is not corrected. In my first try, I just naively drew a straight line from 4000 Hz upwards. But the result didn't sound good. The treble were muffled. I realized that I had not calculated any target level for the part that is above 4000 Hz.
So I went back to Amir's graph, and tried to evaluate the average level measured above 4000 Hz. I restricted my reading to the 5000 to 15000 Hz range, ignoring what's happening above. I tried to draw a straight line so that half of the curve is above, and half is below. Then I noticed that this level was exactly the same as the 150 Hz peak. That would be my reference point.
Reading now my REW correction overlaid on Amir's graph, I noticed that it was accurately following it at 150 Hz. I therefore set the shelf level of my correction above 4000 Hz exactly identical to my 150 Hz peak (I mean 150 dip, since the curve is displayed upside down).

View attachment 45741

I generated the impulse response of the new correction and loaded it in Foobar's convolver and... wow ! Now, that sounds really great !!!

Here is how it measures from the listening position :

View attachment 45742

When I say it sounds great, I'm talking about medium and high frequencies. The low frequencies need re-equalization, as the bass reflex of the JBL is on the back of the speaker, and the MiniDSP room correction (still active from 35 to 600 Hz) was setup for the Neumann.

The measurement shows yet a little problem around 1000 Hz that was not there before correction. Here is the response without eq, the final correction, and REW's prediction of the result.
View attachment 45743

We can see that the level is unduly decreasing from 1000 to 1400 Hz, while it was not the case before correction.
Comparing with the first picture with Amir's graph, we can see that the correction is supposed to be ok. Since I'm not sure what's happening here, I didn't try any other adjustment.

The forum doesn't allow audio nor binary attachments, so here are links to my correction :

44100 Hz impulse response for convolvers : JBL 305P mk2 equalization.wav
Eq filters for REW : JBL 305P mkII eq filters.req

Important :
The correction is valid for JBL 305P mkII speakers, not for regular LSR 305 speakers.
The impulse response works at 44100 Hz only. The convolver must be preceded by a 44100 Hz resampler, or have a built-in resampler. Otherwise, if a file with a sampling frequency different from 44100 Hz is played, the correction will be wrong.

If you want to test correction you made based on Amir's measurement you need to take pseudo-anechoic measurements. That means taking speaker in the middle of your room and puttng it on a stand between floor ane ceiling, gated HF measurement, near field bass an port measurement joined, etc.

 

[edechamps]

Thanks for the tip. Unfortunately, I run REW and everything else in Linux, not Windows.

PulseAudio and ALSA have their own plugin systems that can be used to insert filters into the audio path. A quick search reveals the existence of stuff like this.

 

[Pio2001]

If you want to test correction you made based on Amir's measurement you need to take pseudo-anechoic measurements. That means taking speaker in the middle of your room and puttng it on a stand between floor ane ceiling, gated HF measurement, near field bass an port measurement joined, etc.

I did the gated HF measurement, tweeter's axis :

Purple : raw frequency response (ignore the bump at 350 Hz, it's a gating artifact, and the ripples from 5 to 15 kHz : reflexion on my hand holding the microphone)
Cyan : correction
Pink : predicted result

There is something wrong with this graph, taken from REW's EQ panel. In the original measurement, the 15 kHz peak is above the 9.5 kHz peak, while in the predicted result, 15 kHz is below 9.5 kHz.. while the correction is flat from 5 to 25 kHz. Which is impossible !
I don't understand what's wrong.

PulseAudio and ALSA have their own plugin systems that can be used to insert filters into the audio path. A quick search reveals the existence of stuff like this.

Thanks for the tip.

 

[QMuse]

I did the gated HF measurement, tweeter's axis :

View attachment 53646

Purple : raw frequency response (ignore the bump at 350 Hz, it's a gating artifact, and the ripples from 5 to 15 kHz : reflexion on my hand holding the microphone)
Cyan : correction
Pink : predicted result

There is something wrong with this graph, taken from REW's EQ panel. In the original measurement, the 15 kHz peak is above the 9.5 kHz peak, while in the predicted result, 15 kHz is below 9.5 kHz.. while the correction is flat from 5 to 25 kHz. Which is impossible !
I don't understand what's wrong.

Maybe you were too close to the speaker? What was the measurement distance? I usually do it from 70-100cm distance pointing the mic directly to the tweeter.

Just to be sure as both colours are similar - pink is the lower (brighter) curve?

 

[Pio2001]

Yes, pink is the bright one.
Measurements taken 70 cm away from the speaker.

Anyway, Amir's measurements are much more accurate.

 

[QMuse]

Yes, pink is the bright one.
Measurements taken 70 cm away from the speaker.

Anyway, Amir's measurements are much more accurate.

I agree, you probably moved the hand at the end of the measurement. Try repeating it several times and apply averaging.

 

[akarma]

It's better to use MMM technique

 

[QMuse]

It's better to use MMM technique

For what?

 

[akarma]

For equalization in room