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Why does DIRAC completely remove bass response (KEF R3 + sub + minidsp flex)

abdo123

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Dirac use a massive of 9 (as I remember) measurements, and if they are done correctly from many random spots in the listening area, a speaker with a flat on-axis response and smooth directivity would measure flat (with some HF decline, but Dirac also has decline in target curve).
Well OP's measurements show an insane amount of resonances in the low mid-range even though they have one of the best measuring speakers in the world so there is that.
 

ELberto

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I feel your pain. Eventually I returned my Flex for a full refund after their software bricked it. It took a month of back and forth with customer support before they finally accepted responsibility. I hope you get your issue sorted without having to resort to shipping it back to them.
 

olegtern

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Well OP's measurements show an insane amount of resonances in the low mid-range even though they have one of the best measuring speakers in the world so there is that.
Well, how do you know, OP didn't post how Dirac measures them or I missed something?

The reasons for the resonances in this case (judging by the REW file) in the unsuccessful placement. No "one of the best measuring speakers in the world" can't do anything about it. Of course, Dirac algorithms may have limitations in such cases, but this is not because they are incorrectly created.
 

abdo123

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Well, how do you know, OP didn't post how Dirac measures them or I missed something?

Second post on this thread.

The reasons for the resonances in this case (judging by the REW file) in the unsuccessful placement.

And no not really, placement isn't going to do anything at 500Hz to 1KHz. His measurements are tell-tale sign of an under treated room. low bass hump, upper bass dip and a lower mid-range hump.
 
OP
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Geertidow

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Look guys, I have an undertreated room. It's my attic and it's spacious enough. I really like the sound wihtout any adjustments whatsoever.
I am no professional musician, dj or audio tech. I just listen a lot of music.
What is frustrating though is that a suberb product as the minidsp flex completely messes up DIRAC.
I just wanted to see what it could do (I wanted to use it up to 200 hz at most). But all it does is removing the bass. completely.
Resetting some stuff here and there worked earlier on, but now it doesn't. And that is just really frustrating.

I would still very highly recommend these KEF R3 speakers.

This was a few days ago with DIRAC (different measurement). But I've replaced the speakers back to there original position 50 cm from the back wall (back of speaker) and 50 cm from the side wall (from side of speakers). I really like the sound stage from that position even though it measures worse. But the fact that remeasuring DIRAC results in the graph shown in previous post seems to show that something in the miniDSP is off.
 

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olegtern

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Second post on this thread.
My fault, sorry.
And no not really, placement isn't going to do anything at 500Hz to 1KHz. His measurements are tell-tale sign of an under treated room. low bass hump, upper bass dip and a lower mid-range hump.
Placement has a strong effect on this range.

And with the correct measurement technique, when you spread the measurement points, you largely minimize (by averaging) room effects in this range.

If the placement and measurements are performed incorrectly, the results can be anything. So are the EQ effects.
 
OP
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Geertidow

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I have owned other dirac devices and never had this problem. Also the problem was recently gone and I have no idea why.
So it is definitely not the measuring. Hopefully another reset will fix this weird phenomenon but everything is just so much more hassle this way :-(.

Here goes:
1. Remeasured the whole (focused) room (13 measurements) again, same result, everything from 300 hz and down is gone.
2. Loading my 2.0 measurements (no sub, no xo) works perfectly in the 2.0 setting (created another preset with 2.0 setting and the 2.0 dirac measurement

So very strange, but for now I will enjoy music without DIRAC untill hopefully the tech guys at MiniDSP come up with a solution.
 
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D

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Well OP's measurements show an insane amount of resonances in the low mid-range even though they have one of the best measuring speakers in the world so there is that.
Again, room and speakers combined. And to EQ I don't know what goes wrong when OP tries to correct it, but Dirac only goes so far, when it is a bad example of acoustics I guess.
 
D

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Look guys, I have an undertreated room. It's my attic and it's spacious enough. I really like the sound wihtout any adjustments whatsoever.
I am no professional musician, dj or audio tech. I just listen a lot of music.
What is frustrating though is that a suberb product as the minidsp flex completely messes up DIRAC.
I just wanted to see what it could do (I wanted to use it up to 200 hz at most). But all it does is removing the bass. completely.
Resetting some stuff here and there worked earlier on, but now it doesn't. And that is just really frustrating.

I would still very highly recommend these KEF R3 speakers.

This was a few days ago with DIRAC (different measurement). But I've replaced the speakers back to there original position 50 cm from the back wall (back of speaker) and 50 cm from the side wall (from side of speakers). I really like the sound stage from that position even though it measures worse. But the fact that remeasuring DIRAC results in the graph shown in previous post seems to show that something in the miniDSP is off.
You are not very concrete in your description. "Resetting some stuff here and there" I mean, if you don't describe what you do and what your settings are, then it gets hard to guide you. Reading your posts from start to end my advice to you is to read the manual a bit more and maybe then you see what goes wrong.
 
OP
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Geertidow

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Dear fellow forum members,

First of this forum has helped me a lot with choosing my speakers.
Hopefully you can aid me in my DIRAC problems.
I have used DIRAC extensively in the past on my NAD C658, I'm familiar with how everything works.
Hence my suprise to what happened when I applied DIRAC to my new KEF R3 with custom build subwoofer.

Setup:
Speakers: KEF R3 + Push/Pull subwoofer (10").
Amp: NC252MP for the R3 + NC500 mono for the sub.
Source: MiniDSP flex (balanced) with USB attachted to computer for measurment.
Mic: UMIK-1 (with cal file)
Crossover: 60 hz with a 24 db/oct roloff
DIRAC in shown measurements: +2db harman kardan with a slight -1 dB roloff in the higher region (standard starting curtain), full range.

You see what happens to the spl curve and waterfal with and without dirac.
The final images are a waterfal and spl curve when I apply some mild EQ manually (max Q = 3, max gain = 3 dB) and a HK + 4db curve from 200 hz.

Why does DIRAC completely cutoff the suwoofer and lower part of the KEF's?
This did not happen when I used DIRAC on a pair of genelecs 8030c in the same setup.

Thanks for your advice!
My fault, I really assumed this was pretty complete and specific :)
 

Tangband

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Look guys, I have an undertreated room. It's my attic and it's spacious enough. I really like the sound wihtout any adjustments whatsoever.
I am no professional musician, dj or audio tech. I just listen a lot of music.
What is frustrating though is that a suberb product as the minidsp flex completely messes up DIRAC.
I just wanted to see what it could do (I wanted to use it up to 200 hz at most). But all it does is removing the bass. completely.
Resetting some stuff here and there worked earlier on, but now it doesn't. And that is just really frustrating.

I would still very highly recommend these KEF R3 speakers.

This was a few days ago with DIRAC (different measurement). But I've replaced the speakers back to there original position 50 cm from the back wall (back of speaker) and 50 cm from the side wall (from side of speakers). I really like the sound stage from that position even though it measures worse. But the fact that remeasuring DIRAC results in the graph shown in previous post seems to show that something in the miniDSP is off.
You probably need to reinstall your gear.
Knowing installation of speakers , I will give you some Christmas advices.

Put away your microphone as a start. Roomcorrection shall only be done as the ”icing on the cake ” - the last thing you do.*

1. Plug the basstubes in you Kefs.

2. Put your main speakers on 50 cm high loudspeakerstands without subwoofer at the best sounding position in your room . Listen to bass melodies from the listening position to do this. Move your speakers distanse to the frontwall, and the distance between them. Where can you hear the bass melodies with a clear pitch without disturbing boominess ?

3. Start with moving your speakers 10 cm at each listening , narrowing down to centimeters in the end . Stop this when the best sound is obtained. This will take a couple of hours of fun listening.
You will find that only a couple of cm in different placement of the speakers can change the perceived tunes in the bass.

4. When your Kef sounds really good AND can play basstunes in an acceptable way without subwoofer its time to put your mono subwoofer exactly in the middle of your two Kef loudspeakers. Push the subwoofer against the frontwall. Start with a crossover frequency at 50 Hz - and then go upwards in frequency listening to the bassplayers melody in the bass from listening position.

Use 18 dB HP ( electrical ) for the main speaker and 30 dB LP ( electrical ) for the subwoofer , using your minidsp flex to do this . This will give you a slightly better sound than a 24 LP/12 HP crossover .

The power response in the room will be better using an odd order crossover .

Try 50 Hz , 55 Hz, 60 Hz , 65 Hz , 70 Hz and 75 Hz . All those with 30dB LP/18dB HP .
Adjust the level of the subwoofer.

During this - no measurements is needed. Save the crossover frequency that makes your speaker system play bass melodies in the clearest way, using your ears and listen to the tunes.

If correctly installed- the whole sound including subwoofer in the system will sound better than without it.

Use this record by Robert Plant to tune your system - the song ” little by little ” .
The sound will be better with TIDAL.


5. After this is done - correct the rooms fundamental resonances. You will have three of those in a normal rectangular room , all below 80 Hz . This has nothing to do with your speaker placement but depends entirely on the geometry of the room.

Those 3 fundamental room resonances will be : Wall/wall , floor/roof, wall/wall.

Use a sinesweep measuring from listening position ( from only one point ! ) and you will see that you have three big peaks in the response below 80 Hz.

Use the mini dsp flex to correct those resonances with HALF THE VALUE that the measurement microphone shows.

One example : If the measurement shows +12 dB at 44 Hz , you print - 6 dB at 44 Hz with a similar Q as the resonanse.

After you have done this - the music will sound better and not worse with correction. As I have shown, Dirac is not needed at all. This method can also be done manualy in GLM with Genelec monitors, or with any dsp crossover with DIY speakers.

————

*Playing with roomcorrection programes can be a serious waste of lifetime searching for the best possible sound, which is impossible without doing correct installment of the speakers in the first place .

Edit: correcting frequencys that are reflections and not fundamental room resonances, are never entirely beneficial to the sound - be very careful to correct reflections between 80-250 Hz, measured from listening position. From 250-20000 Hz , nothing can be corrected with good results from listeningposition .
 
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D

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My fault, I really assumed this was pretty complete and specific :)
How does the Dirac correction (filter design) look like? In you initial image it doesn't really look like it does much correction which seems odd.

Should look something like this?

17-12-2022 - DIRAC.JPG
 
OP
G

Geertidow

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You probably need to reinstall your gear.
Knowing installation of speakers , I will give you some Christmas advices.

Put away your microphone as a start. Roomcorrection shall only be done as the ”icing on the cake ” - the last thing you do.*

1. Plug the basstubes in you Kefs.

2. Put your main speakers on 50 cm high loudspeakerstands without subwoofer at the best sounding position in your room . Listen to bass melodies from the listening position to do this. Move your speakers distanse to the frontwall, and the distance between them. Where can you hear the bass melodies with a clear pitch without disturbing boominess ?

3. Start with moving your speakers 10 cm at each listening , narrowing down to centimeters in the end . Stop this when the best sound is obtained. This will take a couple of hours of fun listening.
You will find that only a couple of cm in different placement of the speakers can change the perceived tunes in the bass.

4. When your Kef sounds really good AND can play basstunes in an acceptable way without subwoofer its time to put your mono subwoofer exactly in the middle of your two Kef loudspeakers. Push the subwoofer against the frontwall. Start with a crossover frequency at 50 Hz - and then go upwards in frequency listening to the bassplayers melody in the bass from listening position.

Use 18 dB HP ( electrical ) for the main speaker and 30 dB LP ( electrical ) for the subwoofer , using your minidsp flex to do this . This will give you a slightly better sound than a 24 LP/12 HP crossover .

The power response in the room will be better using an odd order crossover .

Try 50 Hz , 55 Hz, 60 Hz , 65 Hz , 70 Hz and 75 Hz . All those with 30dB LP/18dB HP .
Adjust the level of the subwoofer.

During this - no measurements is needed. Save the crossover frequency that makes your speaker system play bass melodies in the clearest way, using your ears and listen to the tunes.

If correctly installed- the whole sound including subwoofer in the system will sound better than without it.

Use this record by Robert Plant to tune your system - the song ” little by little ” .
The sound will be better with TIDAL.


5. After this is done - correct the rooms fundamental resonances. You will have three of those in a normal rectangular room , all below 80 Hz . This has nothing to do with your speaker placement but depends entirely on the geometry of the room.

Those 3 fundamental room resonances will be : Wall/wall , floor/roof, wall/wall.

Use a sinesweep measuring from listening position ( from only one point ! ) and you will see that you have three big peaks in the response below 80 Hz.

Use the mini dsp flex to correct those resonances with HALF THE VALUE that the measurement microphone shows.

One example : If the measurement shows +12 dB at 44 Hz , you print - 6 dB at 44 Hz with a similar Q as the resonanse.

After you have done this - the music will sound better and not worse with correction. As I have shown, Dirac is not needed at all. This method can also be done manualy in GLM with Genelec monitors, or with any dsp crossover with DIY speakers.

————

*Playing with roomcorrection programes can be a serious waste of lifetime searching for the best possible sound, which is impossible without doing correct installment of the speakers in the first place .

Edit: correcting frequencys that are reflections and not fundamental room resonances, are never entirely beneficial to the sound - be very careful to correct reflections between 80-250 Hz, measured from listening position. From 250-20000 Hz , nothing can be corrected with good results from listeningposition .
So far I have done step 1 to 3 and I end up with 50 cm from the side wall and 25 cm from the back wall. Measuring then shows the 80 hz dip is mostly gone, so measurements fit with what I do.
To continue excellent tutorial, I need a bit more information:

1. "When your Kef sounds really good AND can play basstunes in an acceptable way without subwoofer its time to put your mono subwoofer exactly in the middle of your two Kef loudspeakers. Push the subwoofer against the frontwall. Start with a crossover frequency at 50 Hz - and then go upwards in frequency listening to the bassplayers melody in the bass from listening position."
- The input for my subwoofer is now L + R, should I use only the L or R input?
2. "Use 18 dB HP ( electrical ) for the main speaker and 30 dB LP ( electrical ) for the subwoofer , using your minidsp flex to do this . This will give you a slightly better sound than a 24 LP/12 HP crossover"
The minidsp gives me the option for a BW or an LR filter (or Bessel at 6db/oct). With HP do you mean BW?

Thanks
 

abdo123

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So far I have done step 1 to 3 and I end up with 50 cm from the side wall and 25 cm from the back wall. Measuring then shows the 80 hz dip is mostly gone, so measurements fit with what I do.
To continue excellent tutorial, I need a bit more information:

1. "When your Kef sounds really good AND can play basstunes in an acceptable way without subwoofer its time to put your mono subwoofer exactly in the middle of your two Kef loudspeakers. Push the subwoofer against the frontwall. Start with a crossover frequency at 50 Hz - and then go upwards in frequency listening to the bassplayers melody in the bass from listening position."
- The input for my subwoofer is now L + R, should I use only the L or R input?
2. "Use 18 dB HP ( electrical ) for the main speaker and 30 dB LP ( electrical ) for the subwoofer , using your minidsp flex to do this . This will give you a slightly better sound than a 24 LP/12 HP crossover"
The minidsp gives me the option for a BW or an LR filter (or Bessel at 6db/oct). With HP do you mean BW?

Thanks
BW is butterworth, but his advice will not net a perfectly summed crossover, either the speaker or the subwoofer will be overdriven.
 

Tangband

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So far I have done step 1 to 3 and I end up with 50 cm from the side wall and 25 cm from the back wall. Measuring then shows the 80 hz dip is mostly gone, so measurements fit with what I do.
To continue excellent tutorial, I need a bit more information:

1. "When your Kef sounds really good AND can play basstunes in an acceptable way without subwoofer its time to put your mono subwoofer exactly in the middle of your two Kef loudspeakers. Push the subwoofer against the frontwall. Start with a crossover frequency at 50 Hz - and then go upwards in frequency listening to the bassplayers melody in the bass from listening position."
- The input for my subwoofer is now L + R, should I use only the L or R input?
2. "Use 18 dB HP ( electrical ) for the main speaker and 30 dB LP ( electrical ) for the subwoofer , using your minidsp flex to do this . This will give you a slightly better sound than a 24 LP/12 HP crossover"
The minidsp gives me the option for a BW or an LR filter (or Bessel at 6db/oct). With HP do you mean BW?

Thanks
Use L+R For the subwoofer.
Use BW 18 dB HP ( high pass ) for the kef speakers ( plugged) and 30 dB LP ( low pass ) BW for the subwoofer. 50 Hz is a good start.
This will give you a 30/30 dB crossover ( acoustically ). This is because a closed box ( Kef ) drops 12 dB/oct below the box resonance.

THX crossover is also faily good with 12 dB HP ( KEF plugged ) and 24 dB for the subwoofer. Here you can try Linkwitz Riley also.
This will give you a 24/24 dB crossover ( acoustically ).
 
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OP
G

Geertidow

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BW is butterworth, but his advice will not net a perfectly summed crossover, either the speaker or the subwoofer will be overdriven.
Yes but he is referring to HP. I don't understand that term. I am familiar with Bessel, BW and LR :)
Use L+R For the subwoofer.
Use BW 18 dB HP for the kef speakers ( plugged) and 30 dB LP BW for the subwoofer. 50 Hz is a good start.
This will give you a 30/30 dB crossover ( acoustically ).

THX crossover is also faily good with 12 dB HP ( KEF plugged ) and 24 dB for the subwoofer. Here you can try Linkwitz Riley also.
This will give you a 24/24 dB crossover ( acoustically ).
So it all butterworth unless you mention LR? I dont know what HP means.

And, plugging really feels difficult for me. Must it be with plugging and can it be without and EQ? I have so far used open ports.
 
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Tangband

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Yes but he is referring to HP. I don't understand that term. I am familiar with Bessel, BW and LR :)

So it all butterworth unless you mention LR? I dont know what HP means.

And, plugging really feels difficult for me. Must it be with plugging and can it be without and EQ? I have so far used open ports.
HP = high pass
LP= low pass.
Use two socks as plugs. If you dont like the sound from my advices, its easy to use open ports again. :)
With my advice , the Kef should with closed ports then behave much like a closed box , falling about 12 dB/oct below the loudspeakers box resonance.
In reality, in a real room, its much more complicated because of the room gain. But its a good start.
 
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D

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BW is butterworth, but his advice will not net a perfectly summed crossover, either the speaker or the subwoofer will be overdriven.
In theory. In reality it depends on the sum of all speakers in his room. In other words; the best crossover config is done by measuring and listening.
 

abdo123

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In theory. In reality it depends on the sum of all speakers in his room. In other words; the best crossover config is done by measuring and listening.

Not really, if the crossover is not summing to zero anechoicly then one of the two drivers is receiving a significantly higher voltage than the other. there is no other way around it.
 
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