Help! Nulls needing treatment

[NoDad]

Depends on what you can do aesthtically etc. But I would recommend at least one absorber of minimum 120x60 cm on each inside of the speaker. It should address at least down to 200 Hz area. You need to disregard measuring data from most companies at these are quite misleading. RPG Broadsorbor with both 3" and 4" will work great, but not sure if you can buy those were you live. With other absorbers, they generally need to be twice as thick for the same low frequency absorption. DIY is also an option of course.

You have strong specular reflection from nearest sidewalls and ceiling. This is also very important to treat. Not sure though you can treat the sidewalls considering the windows on one side. A movable absorber could be an option there.

Thanks. Unfortunately I cannot put anything on the ceiling either, as it's a cloth stretched across and only connected on the sides of the ceiling. I'm going to start with absorbers behind the speakers. GIK is having a Cyber week sale. Hopefully it will work.

 

[NoDad]

Can you upload .mdat?

Yes, I uploaded the file. Not from the original measurements, but the latest. Which was made where the speakers are placed now.

 

[Keith_W]

I took the curve "M30-Subs-70-100Hz-PEQ" which I presume is your whole system with DSP and applied 1/6 smoothing (green) and ERB smoothing (red) to it. Here it is compared to a target curve.

First, let's look at that dip at 120Hz. Despite its horrible appearance on some of the other graphs, it is probably not audible once it has ERB smoothing.

The other thing to say is that your bass is about 10dB too hot. Some people like a "hot" bass, especially HT enthusiasts. But those guys tend to boost freqs below 40Hz. Yours is boosted up to 150Hz, that would be enough to make music sound plodding. I think your subs are XO'ed too high, at that frequency it will be easily localisable. You can get away with a higher XO point for subs if they are positioned between the speakers, but it's undesirable if they are off to the side or behind you.

 

[sigbergaudio]

View attachment 495783

I took the curve "M30-Subs-70-100Hz-PEQ" which I presume is your whole system with DSP and applied 1/6 smoothing (green) and ERB smoothing (red) to it. Here it is compared to a target curve.

First, let's look at that dip at 120Hz. Despite its horrible appearance on some of the other graphs, it is probably not audible once it has ERB smoothing.

The other thing to say is that your bass is about 10dB too hot. Some people like a "hot" bass, especially HT enthusiasts. But those guys tend to boost freqs below 40Hz. Yours is boosted up to 150Hz, that would be enough to make music sound plodding. I think your subs are XO'ed too high, at that frequency it will be easily localisable. You can get away with a higher XO point for subs if they are positioned between the speakers, but it's undesirable if they are off to the side or behind you.

How do you figure the bass is 10dB too hot (I assume this is taken at the listening position)?

If we look at the ERB smoothed graph, the lift from around 2khz down to 50hz isn't even 10dB alltogether. Do you target negative bass tilt? The target curve looks very lean.

 

[Keith_W]

How do you figure the bass is 10dB too hot (I assume this is taken at the listening position)?

You caught me. Careless eyes. 5-6dB too hot.

 

[sigbergaudio]

You caught me. Careless eyes. 5-6dB too hot.

I still think your target is lean, I would at least target something like the red line below. And since you're target alignment is a bit below the actual response up to 1khz, he's actually not that far off. He's 1-2dB hotter in the bass than my suggested target, something not to uncommon, even my target is pretty neutral. He's also possibly slightly too lean in the 100-300hz area.

 

[NoDad]

I took the curve "M30-Subs-70-100Hz-PEQ" which I presume is your whole system with DSP and applied 1/6 smoothing (green) and ERB smoothing (red) to it. Here it is compared to a target curve.

First, let's look at that dip at 120Hz. Despite its horrible appearance on some of the other graphs, it is probably not audible once it has ERB smoothing.

The other thing to say is that your bass is about 10dB too hot. Some people like a "hot" bass, especially HT enthusiasts. But those guys tend to boost freqs below 40Hz. Yours is boosted up to 150Hz, that would be enough to make music sound plodding. I think your subs are XO'ed too high, at that frequency it will be easily localisable. You can get away with a higher XO point for subs if they are positioned between the speakers, but it's undesirable if they are off to the side or behind you.

You're correct, the PEQ is the whole system with DSP. You're also correct that it's too much bass. For some reason the autoeq didn't adjust it. As soon as my wife wakes up I'll redo the measurements and settings.

The reason I have the lowpass set to 100 Hz is that the main speakers have a dip from approx. 65 to 185 Hz. By setting the crossover at 100 Hz the subwoofers fill in part of this. I'll test later today to lower this.

I finally read your manual. I guess I did a few things incorrectly. It's quite a lot more involved than I thought. I only did one measurement and with the microphone pointed straight forward.

A question - What smoothing is the best for applying EQ? I have read everything from none to Psychoacoustic. In the REW help I just found they recommend Var.

Have fun - Hans

 

[janbth]

A question - What smoothing is the best for applying EQ? I have read everything from none to Psychoacoustic. In the REW help I just found they recommend Var.

The smoothing depends on what you want to achieve. It is usual to separate the bass region (modal region) from the high frequencies. The division happens gradually around the Schroeder frequency (or transition region), about 200 Hz for normal rooms.

For bass you want no smoothing, or minimal smoothing, lets say 1/48 or 1/24. You basically want to knock down the peaks in the response. These peaks, or modes, are resonances that have a specific Q value. You want REW to compute PEQ filters with the same Q values. Smoothing the response before computing filters would produce broader filters (lower Q), which would be wrong.

At high frequencies you want some smoothing. The details of the measured response are not audible, so shouldn't be corrected. Only overall features are audible. (But be careful, correction at high frequencies may lead to degradation, and may not be what you want.)

Var smoothing achieves both, which is why REW recommends this. In addition, I think Var smoothing gives the most informative feedback for viewing a frequency response, so I think Var should be the go-to smoothing for most cases.

 

[NoDad]

The smoothing depends on what you want to achieve. It is usual to separate the bass region (modal region) from the high frequencies. The division happens gradually around the Schroeder frequency (or transition region), about 200 Hz for normal rooms.

For bass you want no smoothing, or minimal smoothing, lets say 1/48 or 1/24. You basically want to knock down the peaks in the response. These peaks, or modes, are resonances that have a specific Q value. You want REW to compute PEQ filters with the same Q values. Smoothing the response before computing filters would produce broader filters (lower Q), which would be wrong.

At high frequencies you want some smoothing. The details of the measured response are not audible, so shouldn't be corrected. Only overall features are audible. (But be careful, correction at high frequencies may lead to degradation, and may not be what you want.)

Var smoothing achieves both, which is why REW recommends this. In addition, I think Var smoothing gives the most informative feedback for viewing a frequency response, so I think Var should be the go-to smoothing for most cases.

Thanks. Glad you added the last paragraph as I have spent today redoing the measurements and used the VAR smoothing for the EQ. I ended up EQ-ing up to 700 Hz as there are rather large peaks. I EQ'ed (and programmed my miniDSP SHD) with both Toole's trained listener target and Harman target curves. That way I can pick and choose depending on my mood (and the recording) Attached is the latest mdat file.

I have listened some to the result and so far it sounds pretty good. It can get a little sharp sometimes, especially women's voices can have some sibilance (hope this is the correct word).

Will I gain anything more by adding front wall absorbers?

Have fun - Hans

 

[NoDad]

Here's a screen shot of the three measurements, with Var smoothing. The DSP was applied from 30 - 700 Hz. Is that too much? Should I restrict it to, let's say, 400 Hz?

Is there anything else I can do to improve this more?

Have fun - Hans