Subwoofer didn't help fixing null. What do? (not buying 2+ subs) (presonus sub8 vs kali lp6)

[Slyman]

Dear scientists

So in my hifi quest i've always had a problem with nulls. And always the same two... Specially one at 80hz and another at 55hz.

Reading upon the subject i've now bought a subwoofer and i've spent the evening moving it around my desk (far left to it, left to it, under it, right to it, far right to it) and to my surprise...

The nulls were there even with a sub!

So am i stuck forever with these nulls and uneven bass in my european medium sized rectangular room? Do i turn the sub up and eq harshly down to try to even it? What's to do?

Heres the measurements of presonus sub8 vs kali lp6:

 

[sigbergaudio]

Your subwoofer level seems very low. It should be at least level with your 100-400hz area, so at 60dB minimum, probably more like 65dB.

Is it even turned on? There's no more level than with your Kalis without sub?

 

[anotherhobby]

Not to be fatalist, but you won't ever get rid of those nulls without multiple subs, DSP (manual or automated), and all the fun and learning that comes with it. You are facing the reality of small room acoustics. It took 4 subs to get rid of all the nulls in my 10' x 10' x 8' (3m x 3m x 2.5m) office. You may not need 4, but you probably need at least 3 if you want zero nulls. I can see where the effort and expense may not be worth it for many people, but unfortunately that's generally how you make it work if you decide a smooth frequency response with no nulls below 100 Hz is something you want.

That's not to say you can't improve your situation, but you will not get rid of the nulls without multiple subs. I accept nulls in my living room system with 2 subs because 3 or 4 subs there is impractical.

 

[TimW]

I was going to say the same thing about level. Also there are big differences between each measurement in the upper frequencies where the sub shouldn't have an effect. Were the measurements taken from different positions? I would recommend taking the measurements using the MMM technique rather than a single location.

 

[sigbergaudio]

Not to be fatalist, but you won't ever get rid of those nulls without multiple subs, DSP (manual or automated), and all the fun and learning that comes with it. You are facing the reality of small room acoustics. It took 4 subs to get rid of all the nulls in my 10' x 10' x 8' (3m x 3m x 2.5m) office. I can see where the effort and expense may not be worth it for many people, but unfortunately that's generally how you make it work if you decide a smooth frequency response with no nulls below 100 Hz is something you want.

That's not to say you can't improve your situation, but you will not get rid of the nulls without multiple subs.

If he puts it somewhere other than his speakers, he should be able to get rid of at least one, and get the general bass level up. Currently there seem to be basically no bass.

 

[anotherhobby]

If he puts it somewhere other than his speakers, he should be able to get rid of at least one, and get the general bass level up. Currently there seem to be basically no bass.

Yes, you can improve the situation! I mentioned that.

Probably not getting rid of all the nulls with one sub though.

 

[radix]

Could you please describe the whole audio chain?

 

[voodooless]

… and what happened around 4 KHz? Certainly there is more to this story then just the sub… That 10 kHz dip should not be there either.

 

[Slyman]

Your subwoofer level seems very low. It should be at least level with your 100-400hz area, so at 60dB minimum, probably more like 65dB.

Is it even turned on? There's no more level than with your Kalis without sub?

I was going to say the same thing about level. Also there are big differences between each measurement in the upper frequencies where the sub shouldn't have an effect. Were the measurements taken from different positions? I would recommend taking the measurements using the MMM technique rather than a single location.

The Kali LP6 goes down to 39hz... The sub8 to 30hz. And i have a big wide peak in my room at 104hz, 132hz and 174hz which is why the 100-170 is elavated and the <100 might look low volume. I thought that matching the volume of the sub to the kali response would be optimal given it should be engineered for a linear response unlike the standalone sub8.

Anyways i adjusted SPL (roughly with iphone app and sub 2-3db the e5 below with pink noise). When turned up the sub8 produces a huge 35hz peak instead of the smaller null. 80hz main null still visibel:

And the sub8+e5 alone:

Sigberg you were right about the 55hz null but it is heavily outweighted with a 35hz superspike .

Could you please describe the whole audio chain?

Sure. Macbook -> audient id4 -> eris sub8 -> eris e5 with HPF on and low cut at 80hz.

Not to be fatalist, but you won't ever get rid of those nulls without multiple subs, DSP (manual or automated), and all the fun and learning that comes with it. You are facing the reality of small room acoustics. It took 4 subs to get rid of all the nulls in my 10' x 10' x 8' (3m x 3m x 2.5m) office. You may not need 4, but you probably need at least 3 if you want zero nulls. I can see where the effort and expense may not be worth it for many people, but unfortunately that's generally how you make it work if you decide a smooth frequency response with no nulls below 100 Hz is something you want.

That's not to say you can't improve your situation, but you will not get rid of the nulls without multiple subs. I accept nulls in my living room system with 2 subs because 3 or 4 subs there is impractical.

Yes this was i was dreading. As a music producer those nulls really suck. Very obvious when recording bass, synth or kick drums.

… and what happened around 4 KHz? Certainly there is more to this story then just the sub… That 10 kHz dip should not be there either.

I was going to say the same thing about level. Also there are big differences between each measurement in the upper frequencies where the sub shouldn't have an effect. Were the measurements taken from different positions? I would recommend taking the measurements using the MMM technique rather than a single location.

I have no idea what's happening at 4khz and 10khz and at this point i'm afraid to ask lol. However since i'm producing/mixing i have a fixed listening position. I'm no need to move around in a living room. And at 4khz and 10khz i guessed it's solely the speakers since the wavelengths are so short that theres no room interaction. Also the graph is smoothed at 1/24.

 

[HarmonicTHD]

The Kali LP6 goes down to 39hz... The sub8 to 30hz. And i have a big wide peak in my room at 104hz, 132hz and 174hz which is why the 100-170 is elavated and the <100 might look low volume. I thought that matching the volume of the sub to the kali response would be optimal of what it should be engineered for (assuming the kali lp6 aren't recessed in bass response).

Anyways i adjusted SPL (roughly with iphone app and sub 2-3db the e5 below with pink noise). When turned up the sub8 produces a huge 35hz peak instead of the smaller null. 80hz main null still visibel:

View attachment 258154
And the sub8+e5 alone:
View attachment 258153


Sure. Macbook -> audient id4 -> eris sub8 -> eris e5 with HPF on and low cut at 80hz.


Yes this was i was dreading. As a music producer those nulls really suck. Very obvious when recording bass, synth or kick drums.



I have no idea what's happening at 4khz and 10khz and at this point i'm afraid to ask lol. However since i'm producing/mixing i have a fixed listening position. I'm no need to move around in a living room. And at 4khz and 10khz i guessed it's solely the speakers since the wavelengths are so short that theres no room interaction. Also the graph is smoothed at 1/24.

Where is the sub placed with respect to the mains in the room?

How do you (electronically) align the sub to your mains (xover and delay)?

Can you only measure the sub alone?

 

[Chrise36]

The Kali LP6 goes down to 39hz... The sub8 to 30hz. And i have a big wide peak in my room at 104hz, 132hz and 174hz which is why the 100-170 is elavated and the <100 might look low volume. I thought that matching the volume of the sub to the kali response would be optimal given it should be engineered for a linear response unlike the standalone sub8.

Anyways i adjusted SPL (roughly with iphone app and sub 2-3db the e5 below with pink noise). When turned up the sub8 produces a huge 35hz peak instead of the smaller null. 80hz main null still visibel:

View attachment 258154
And the sub8+e5 alone:
View attachment 258153
Sigberg you were right about the 55hz null but it is heavily outweighted with a 35hz superspike .


Sure. Macbook -> audient id4 -> eris sub8 -> eris e5 with HPF on and low cut at 80hz.


Yes this was i was dreading. As a music producer those nulls really suck. Very obvious when recording bass, synth or kick drums.



I have no idea what's happening at 4khz and 10khz and at this point i'm afraid to ask lol. However since i'm producing/mixing i have a fixed listening position. I'm no need to move around in a living room. And at 4khz and 10khz i guessed it's solely the speakers since the wavelengths are so short that theres no room interaction. Also the graph is smoothed at 1/24.

Try to cut the sub a bit higher than 80hz

 

[Slyman]

Where is the sub placed with respect to the mains in the room?

How do you (electronically) align the sub to your mains (xover and delay)?

Can you only measure the sub alone?

It is placed under my desk In the middle of the mains. I tried in in about 8 different positions around the desk which either didn't help or helped a little but was noticeable that the 60-100hz bass was coming from a direction.

The sub has a built in HPF and low frequency filter. the HPF is fixed at 80 and the frequency filter at the same as recommended in the manual.

Sure. The sub alone is:

 

[radix]

I'd move the filter to 100Hz or 120 Hz. You likely need to move the sub around the room to find the spot that works best for your MLP.

A 80 Hz half wavelength is about 7' or 2.1m. So try moving the sub left/right by up to that amount, or putting it on a different wall, even if you have to temporarily run the cable across the floor. once you find a good spot, you can use a wireless transceiver if needed. You might also try the 0* vs 180* setting, to see if that helps.

 

[sigbergaudio]

Peaks are better than nulls (easier to fix). I would try a corner placement if you have one nearby. Now that you've got the volume up you may see different results than the first time you moved it around.

Surely there are some eq software available for Mac that can fix that peak.

 

[sigbergaudio]

The large dip is shared by the speakers so try to move the sub out of line with the speakers, so don't align them. Move it closer to you or further away, or into a corner.

 

[HarmonicTHD]

Where is the sub placed with respect to the mains in the room?

How do you (electronically) align the sub to your mains (xover and delay)?

Can you only measure the sub alone?

As long as your sub alone and your mains alone (full range not high passed) both exhibit the same dip you can only move the sub and or experiment with delay of the sub vs the mains signal but for that you would need something like a miniDSP.

But as said before only multiple subs AND them being phase aligned eg by a miniDSP can significantly improve the dip. The Genelec GLM or the Neumann MA1 do a good job within the limits of physics with one sub but are of course are at a different pricing category.

Meanwhile you can just for the heck of it if the 180deg phase switch on your sub changes something.

 

[czt]

Move the sub along the front wall with the driver facing left or right, starting with ~1/3, 2/3 width positions.

 

[HarmonicTHD]

… and if moving it around does not help at all it could be that your room has a mode caused by the height at this frequency. You can use some room mode sims to confirm but other than phase alignment of multiple subs there is nothing you can do but learn to live with it. Once you become used to what your system sounds you can compensate in your mastering. Many sound engineers don’t have perfect systems but learned how to compensate.

(Still look at what voodooless said this 10kHz thing is strange. Do you have you mains on stands? All tone control at the back of the mains on neutral? Any windows tone control accidentally engaged? ….)

 

[TimW]

As has been clarified now, the difference in high frequencies in the measurements was due to different speakers being used (LP-6 vs Eris E5).

I still don't know which measurement technique the OP is using. If it is just a single point measurement the peaks and dips may not be as audible as they look. Multiple measurements averaged or the MMM technique would give a more realistic view.

 

[HarmonicTHD]

As has been clarified now, the difference in high frequencies in the measurements was due to different speakers being used (LP-6 vs Eris E5).

I still don't know which measurement technique the OP is using. If it is just a single point measurement the peaks and dips may not be as audible as they look. Multiple measurements averaged or the MMM technique would give a more realistic view.

Ah. Thanks. I missed that.