How to think about room correction settings like frequency range and gain?

[dominikz]

The low bass response is a problem thats been puzzling me. It is in fact so bad that Wiim Ultra and Audiophonics sound terrible with flat EQ.

Right speaker is approx 2 meter from wall to the right. The left one (unfortunately) don't really have a wall to the left of it since it is just an opening there leading to the hallway. No way to place it in any other way before we move to another apartment I'm afraid.

Actually I'd say the right speaker is the more problematic one; that SBIR dip between 40Hz and 50Hz is where a lot of your low bass is lost. In this sense your left speaker is benefiting from not having a left wall close to it.

Could you perhaps move the right speaker even further away from the right wall? An extra 0,5m should help already, but the more you can move it the lower in frequency the dip will shift.

You could also move it closer to the right wall and thereby shift the bass dip to a higher frequency, then see if you prefer that. But IMHO that would likely make the problem worse, as you'd most likely get the dip in the bass guitar range.

Alternatively you could probably get a smoother low bass response with a dedicated subwoofer, since you could then place it independently from the mains.

 

[dominikz]

I have the WiiM Ultra and a pair of Triangle BR03 Connect speakers. I also have a Klipsch sub. I have been trying to do the room correction. I even got the UMIK-1 mic and downloaded the relevant file. I tried so many variations (with and without the sub) but whatever I do I end up with very weak bass outcome (below is a sample). Could you please give me some advice?View attachment 19458

Hello!

Have you already tried these placement and RC settings suggestions?

Also I'd suggest to use "Individual channel" RC option, that will give you roughly 3dB more bass compared to "Stereo" RC in practice.
Make sure to disable "Precision" RC - that currently has a bug resulting in decreased bass response.

If you still want more bass after doing all of the above, try using the Harman target instead of B&K.

Good luck!

 

[Frans]

What seems to work fairly well in many cases (and is relatively physically inobtrusive) is to push the speakers close to the wall behind them (but keep about 5cm of gap to the wall if speakers have a bass-reflex port in the back), and to put the subwoofer in a room corner. Of course it may not work in every room and every layout, but it is a reasonable place to start with.

If you are interested to know more about why these are solid choices I suggest to read this article by Genelec.

In short, pushing speakers close to the wall behind them and subwoofer in a corner will push the main SBIR cancellation to a much higher frequency where it is audibly less problematic. Additionally, putting both speakers and sub close to boundaries will increase bass output, which you will anyway tame/knock-back later by EQ (i.e. room correction) - so it gives you more headroom for EQ.

Note that EQ is very good for reducing resonances/peaks in the response, but is not ideal for boosting dips in the response - this is what is driving placement suggestions mentioned above.

After you have optimized placement you should set subwoofer crossover frequency (typically at 80Hz) and match its level to your loudspeaker. Don't be afraid to have the sub slightly louder at this point - that will anyway be fixed by RC later.
If you can measure the in-room response with REW to fine tune the crossover that is even better, but if not you should still be able to achieve solid results by ear.

Once this is done use the automatic WiiM Subwoofer & Speaker Sync function in the WHA to tune the relative delays of the loudspeakers and subwoofer.

After that use the WiiM Room Correction function - I propose to use the following parameters to start:

• Target curve: B&K
• Correction range: 20-400Hz
  • This type of EQ much above the specified range can no longer be considered "room correction" but rather "loudspeaker correction". This can easily make the sound worse, especially if you have good loudspeakers.
  • Note: If you don't have a sub that goes down to 20Hz use instead the lower-bound frequency from the sub spec sheet.
• Max gain: 12dB
  • You need to have a high value here for the app to be able to bring down severe room resonances. A current limitation in the app is that the same max gain control affects both positive and negative gain filters, but this will apparently improve soon.
  • After the separate positive/negative max gain controls are implemented I'd suggest to keep the max positive gain below 3dB (preferably 0), and keep max negative gain at 12dB.
• Max Q: 5
  • Note that the default value of 10 is IMHO fine in case no EQ boosts/positive filters are applied.
  • If you want to be more conservative, especially until separate positive/negative max gain controls are introduced you can use a lower value like "5", but note that that will also be less precise in knocking down resonance peaks.
• Smoothing: 1/12 octave
  • IMHO 1/12 octave is the best choice to have any precision in addressing resonant peaks.
  • It would be better if WHA offered progressive variable smoothing (like in REW), but this is not implemented.
• Subwoofer Calibration: enabled if you have a sub, disabled otherwise.
• Multiple Measurements: enabled
  • Not critical either way, but I prefer to have it enabled and move the mic a little bit between the attempts to get some spatial smoothing.
• Precision Room Correction: disabled
  • I wrote about this function here, including why I wouldn't recommend it in most cases.
• Import a Calibration File: yes (if you have an external calibrated measurement microphone)

This should already give you solid results - you can share WHA screenshots here and we may be able to help you fine tune if needed.

Hope this is helpful!

You mean you only bring the front loudspeakers 5 cm from the wall when you measure RC in combination with a subwoofer or you do that as well if you measure without subwoofer? Thanks

 

[dominikz]

You mean you only bring the front loudspeakers 5 cm from the wall when you measure RC in combination with a subwoofer or you do that as well if you measure without subwoofer? Thanks

It is a solid option in both cases (with and without a sub).

If you have a sub (with 80Hz crossover) a better placement option is to move loudspeakers >1,1m away from any walls, and to have the sub right against the wall.
Hovever, having loudspeakers that deep in the room is physically quite intrusive so not really an option for many people.

 

[Frans]

It is a solid option in both cases (with and without a sub).

If you have a sub (with 80Hz crossover) a better placement option is to move loudspeakers >1,1m away from any walls, and to have the sub right against the wall.
Hovever, having loudspeakers that deep in the room is physically quite intrusive so not really an option for many people.

I have no subwoofer but I will do a measurement based on your recommendations. Very helpful. Thanks.

 

[Frans]

It is a solid option in both cases (with and without a sub).

If you have a sub (with 80Hz crossover) a better placement option is to move loudspeakers >1,1m away from any walls, and to have the sub right against the wall.
Hovever, having loudspeakers that deep in the room is physically quite intrusive so not really an option for many people.

I did a measurement based on your recommendations and……..it sounds great!! Thanks again.
-Frans

 

[dominikz]

I did a measurement based on your recommendations and……..it sounds great!! Thanks again.
-Frans

Happy to help and glad to hear you're happy with the results. Enjoy!

 

[Mesen]

Hello!

Have you already tried these placement and RC settings suggestions?

Also I'd suggest to use "Individual channel" RC option, that will give you roughly 3dB more bass compared to "Stereo" RC in practice.
Make sure to disable "Precision" RC - that currently has a bug resulting in decreased bass response.

If you still want more bass after doing all of the above, try using the Harman target instead of B&K.

Good luck!

Thanks. I tried so many versions of the recommendations that I am on the verge of giving up. It does not makes sense to see that kind of magnitude of correction in the lower range starting at 40Hz. After the correction parameters are created I have to manually raise the bass to make listening enjoyable.

 

[slartibartfast]

Thanks. I tried so many versions of the recommendations that I am on the verge of giving up. It does not makes sense to see that kind of magnitude of correction in the lower range starting at 40Hz. After the correction parameters are created I have to manually raise the bass to make listening enjoyable.

If you are accustomed to listening to your system with +30dB at 50Hz then listening to a more correct response will sound bass light to you.

 

[dominikz]

Thanks. I tried so many versions of the recommendations that I am on the verge of giving up.

I can completely understand that.
When I first looked into room correction I felt really overwhelmed too. Most things didn't seem to work for me and when they did, I couldn't really understand why.
Unfortunately, sound reproduction optimization through room correction is still not very user-friendly - in part because it relies also on the reproduction system specifics and room layout. A lot of competence is still expected from the end-user to optimize the results.

The upside is that if you do persist, it is one of the most rewarding upgrades of sound quality. For me a large part of the "audio hobby" now is learning how to optimize loudspeaker/sub placement, EQ and room correction.

It does not makes sense to see that kind of magnitude of correction in the lower range starting at 40Hz.

It is very common to have such strong resonances in low bass range. This is not unexpected.

After the correction parameters are created I have to manually raise the bass to make listening enjoyable.

However, your measurement screenshot looks like you might have used "stereo" correction together with "precision room correction". Both of these will reduce bass (at least in current form) - in total probably by about 5-10dB, which is a lot indeed. This could explain why you found bass was deficient after the correction. For this I can only suggest to try the variants I proposed in post #62.

Lastly, note that the total amount of bass is a personal preference thing - there's research showing that most listeners prefer reproduction without audible null and resonances (RC addresses this in bass) but the *level* of bass people prefer varies significantly.

So it is absolutely fine to manually raise or lower the bass (after you perform room correction to smooth it out).
Note that room correction is really only meant to smooth-out the irregularities in the response, but you are still free to tune relative bass level to taste. You can do this either by using a different target for RC (e.g. "Harman" for more bass or "flat" for less bass), by using the new Ultra beta function that separates EQ from RC, or with a bass/treble tone control (if you have one elsewhere in the chain).

 

[Musician]

What seems to work fairly well in many cases (and is relatively physically inobtrusive) is to push the speakers close to the wall behind them (but keep about 5cm of gap to the wall if speakers have a bass-reflex port in the back), and to put the subwoofer in a room corner. Of course it may not work in every room and every layout, but it is a reasonable place to start with.

If you are interested to know more about why these are solid choices I suggest to read this article by Genelec.

In short, pushing speakers close to the wall behind them and subwoofer in a corner will push the main SBIR cancellation to a much higher frequency where it is audibly less problematic. Additionally, putting both speakers and sub close to boundaries will increase bass output, which you will anyway tame/knock-back later by EQ (i.e. room correction) - so it gives you more headroom for EQ.

Note that EQ is very good for reducing resonances/peaks in the response, but is not ideal for boosting dips in the response - this is what is driving placement suggestions mentioned above.

After you have optimized placement you should set subwoofer crossover frequency (typically at 80Hz) and match its level to your loudspeaker. Don't be afraid to have the sub slightly louder at this point - that will anyway be fixed by RC later.
If you can measure the in-room response with REW to fine tune the crossover that is even better, but if not you should still be able to achieve solid results by ear.

Once this is done use the automatic WiiM Subwoofer & Speaker Sync function in the WHA to tune the relative delays of the loudspeakers and subwoofer.

After that use the WiiM Room Correction function - I propose to use the following parameters to start:

• Target curve: B&K
• Correction range: 20-400Hz
  • This type of EQ much above the specified range can no longer be considered "room correction" but rather "loudspeaker correction". This can easily make the sound worse, especially if you have good loudspeakers.
  • Note: If you don't have a sub that goes down to 20Hz use instead the lower-bound frequency from the sub spec sheet.
• Max gain: 12dB
  • You need to have a high value here for the app to be able to bring down severe room resonances. A current limitation in the app is that the same max gain control affects both positive and negative gain filters, but this will apparently improve soon.
  • After the separate positive/negative max gain controls are implemented I'd suggest to keep the max positive gain below 3dB (preferably 0), and keep max negative gain at 12dB.
• Max Q: 5
  • Note that the default value of 10 is IMHO fine in case no EQ boosts/positive filters are applied.
  • If you want to be more conservative, especially until separate positive/negative max gain controls are introduced you can use a lower value like "5", but note that that will also be less precise in knocking down resonance peaks.
• Smoothing: 1/12 octave
  • IMHO 1/12 octave is the best choice to have any precision in addressing resonant peaks.
  • It would be better if WHA offered progressive variable smoothing (like in REW), but this is not implemented.
• Subwoofer Calibration: enabled if you have a sub, disabled otherwise.
• Multiple Measurements: enabled
  • Not critical either way, but I prefer to have it enabled and move the mic a little bit between the attempts to get some spatial smoothing.
• Precision Room Correction: disabled
  • I wrote about this function here, including why I wouldn't recommend it in most cases.
• Import a Calibration File: yes (if you have an external calibrated measurement microphone)

This should already give you solid results - you can share WHA screenshots here and we may be able to help you fine tune if needed.

Hope this is helpful!

Pushing the speakers near the wall will make SBIR look better, at the same time you loose some quality because of early reflections, and this will muddy up fine details in the music. One can treat this with some damping material behind the speaker, and around it, about 1 meter. Genelec dont mention this, probably because their studiomonitors is ment to be placed in a studio with damping material on the walls.

This is how it can be done.
Picture of newest Carlsson speaker, OA61

 

[Musician]

In an ideal world we could all put speakers in the best position but in reality how many of us can do that if we don't have a dedicated music room?

True, but if one has the abillity to place the speakers at the best place before doing any room correction, the sound will be better.
Roomcorrection with bad speaker installation cant be as good sounding as having the speakers perfectly installed in the first place.

You can spend thousand of hours trying to correct for perfect sound with the dsp, but if the speakers arent at the right place in the beginning, its a waste of time.

 

[Musician]

I can completely understand that.
When I first looked into room correction I felt really overwhelmed too. Most things didn't seem to work for me and when they did, I couldn't really understand why.
Unfortunately, sound reproduction optimization through room correction is still not very user-friendly - in part because it relies also on the reproduction system specifics and room layout. A lot of competence is still expected from the end-user to optimize the results.

The upside is that if you do persist, it is one of the most rewarding upgrades of sound quality. For me a large part of the "audio hobby" now is learning how to optimize loudspeaker/sub placement, EQ and room correction.


It is very common to have such strong resonances in low bass range. This is not unexpected.


However, your measurement screenshot looks like you might have used "stereo" correction together with "precision room correction". Both of these will reduce bass (at least in current form) - in total probably by about 5-10dB, which is a lot indeed. This could explain why you found bass was deficient after the correction. For this I can only suggest to try the variants I proposed in post #62.

Lastly, note that the total amount of bass is a personal preference thing - there's research showing that most listeners prefer reproduction without audible null and resonances (RC addresses this in bass) but the *level* of bass people prefer varies significantly.

So it is absolutely fine to manually raise or lower the bass (after you perform room correction to smooth it out).
Note that room correction is really only meant to smooth-out the irregularities in the response, but you are still free to tune relative bass level to taste. You can do this either by using a different target for RC (e.g. "Harman" for more bass or "flat" for less bass), by using the new Ultra beta function that separates EQ from RC, or with a bass/treble tone control (if you have one elsewhere in the chain).

To get the prefered Harman curve below 100 Hz in the bass, one can use shelving . Frequency 60Hz, gain 3dB, Q=1