Should we correct to Schroder, or full range?

[kemmler3D]

I say correct full-range, but only if the filter is at least a couple octaves wide, or you are actually going to put your head in a vise. If you do MMM with pink noise and your filters are really wide, I think you can derive some benefit from correcting above schroeder because at that point you're really correcting the power response in the relevant area, which to me seems pretty low-risk.

 

[FrantzM]

Hi

I have found that running Audyssey full range sounds best in my room...
This said, at an intellectual level, I believe the answer is with blind testing. For many of us, knowing that a correction has been applied may bias our perception/evalution. I tend to think that the better DRC may clean up the sound above Schroeder. Conjecture until a blind test.

Peace.

 

[AudioJester]

@mitchco - do you still do full range with Audiolense?

I guess sometimes to correct below transition you need to pull the whole curve down?

 

[tmtomh]

Hahah, I have tried everything With DSP, the only thing it costs me is time! This is what I tried:

- extremely generous smoothing (FDW setting of 1 in Acourate)
- spatial averaging over the entire listening position with generous smoothing
- quasi anechoic using beamforming technique (link and link)
- different target curves

In the end, what sounds best is doing nothing above Schroder. Every time I correct the full range axial response to look nice, it sounds awful. So I have stopped doing it.

Like I said in my first post, I suspect it is system dependent. I have a few friends who use DSP, and I am the exception in that all of them are doing full range correction, whereas I am the only one correcting up to Schroder. I am somewhat surprised to see responses in this thread with so many people only correcting up to Schroder and not above, I was expecting to see more people doing full range correction!

I initially did full-range correction - in fact, when I first started using Dirac, I wasn't even aware that correcting anything less than full-range was even a thing. I arrived at correcting only to Schroeder on my own, as part of my experimentation trying to get Dirac correction to not be a two steps forward, one step back thing (for example, improving bass and imaging, creating or exacerbating unpleasant weirdness in the upper mids/lower treble). Only after that did I do some reading on the subject and discover there's a whole group of folks - including Floyd Toole - who have written that correcting above Schroeder can create problems.

My main issue with Dirac is that one would think that you take multiple measurements from different locations in the room so that the software can make an educated, if crude, guess about what's the speaker and what's the room. But I'm led to believe that multiple measurements are mainly about averaging and making the smoothed response the best fit for a narrow vs medium vs wide listening area, depending on the user's preference.

I could be wrong about this - perhaps Dirac does a bit of both with those multiple measurements. But even if it does, I'm not thrilled with the idea that the only way I can help the software figure out what stuff to correct and what stuff to let be is to simultaneously widen the listening area, resulting in a compromise correction that creates a result that's not as good as it could be from my main listening position.

And while I never gave it a thought while using Dirac, once I used GLM I realized that it's really dumb to not provide the user with the option to un-link the target curve from the automated room EQ - because if you don't want to do full-range correction with Dirac, then the only way to EQ to a target curve is to do so manually with PEQ. Not a huge deal, but still kind of a drag.

One thing I do like about Dirac, though, is that it corrects timing/impulse response full-range no matter what. So theoretically you could set Dirac's correction frequency sliders so it's not doing any correction at all, and you'd still get the benefits of the timing correction. (Not a factor with GLM since the Genelec Ones are physically phase-aligned.)

 

[Blumlein 88]

Have you all forgotten that Harman did test various Room EQ devices full range and did find some of them improved speaker scores in their testing. One of them was the Tact system. I'm pretty sure the Trinnov is a derivative or update of what Tact was doing. So there is a little data that full range corrective DSP is helpful. Even while Harman's people hold the view working at and below Schroeder is the way to go.

 

[Gringoaudio1]

What is your favorite house curve

OK. Next question for you folks. As far as I can tell there is no spinorama for the Focal Aria 926's, which happen to be my main speakers. However, Amir did do a spinorama for the Aria 906 standmount speakers. They use the same tweeter and mid driver as the 926, but lack the two woofers as they...

www.audiosciencereview.com

While interesting, this letter from Floyd Toole doesn’t say anything to insist on only EQ below Shroeder. And it makes a very big assumption early on saying to choose a well measuring speaker. Not all of us have such a speaker. I use Equalizer APO software for EQ. And I measure with REW and a UMIK-1. The EQs generated by REW when exported into Equalizer APO are not sufficient and I add any number of parametric filters to get a descending house curve at my seated listening position. I have taken recent advice to not boost very much and to boost with a wide Q. In the letter you referred to he says boost no more than 6db.
Whatever is best for sound quality I am enjoying the journey of playing with REW and Equalizer APO. Hopefully I am improving the sound. Who knows!?

 

[goat76]

I have only four EQ corrections for my speakers, all of them are below 80 Hz.

Here is the gated measurement of my ATC SCM40. They have a dip in the direct sound in the frequency area from 4.5 kHz to 6 kHz, I have tried to equalize that but prefer the sound without the correction with a good margin. The small dip at 3.5 kHz is the crossover point between the midrange driver to the tweeter.

It's fairly easy to do a gated measurement in REW, that way you will see if the direct response of your speakers may need corrections or not:

What is your favorite house curve

OK. Next question for you folks. As far as I can tell there is no spinorama for the Focal Aria 926's, which happen to be my main speakers. However, Amir did do a spinorama for the Aria 906 standmount speakers. They use the same tweeter and mid driver as the 926, but lack the two woofers as they...

audiosciencereview.com

 

[Keith_W]

All right, one of my motivations for starting this thread is because software developers like Uli (Acourate) and Bernt (Audiolense) make a lot of effort to provide full range frequency correction. Bernt has mentioned complex smoothing as a mechanism for full range correction in Audiolense, and I imagine that Uli is doing something similar.

Amir has previously said (sorry I am unable to find a link) that in-room measurements of upper frequencies do not correlate with what we hear. It is not clear to me whether he means all in-room measurements, or only single point measurements. Regardless, I at least agree that a single point measurement does not seem to correlate with what I hear when it comes to upper frequencies.

I am agnostic on this issue. Just because I currently only correct to Schroder does not mean I am not open to other approaches.

 

[dasdoing]

I say full range on a FDW window with apropriate target.
objects and first reflections will act like an EQ, so you have to counter this to a point

 

[ozzy9832001]

I have only four EQ corrections for my speakers, all of them are below 80 Hz.

Here is the gated measurement of my ATC SCM40. They have a dip in the direct sound in the frequency area from 4.5 kHz to 6 kHz, I have tried to equalize that but prefer the sound without the correction with a good margin. The small dip at 3.5 kHz is the crossover point between the midrange driver to the tweeter.

View attachment 300644

It's fairly easy to do a gated measurement in REW, that way you will see if the direct response of your speakers may need corrections or not:

What is your favorite house curve

OK. Next question for you folks. As far as I can tell there is no spinorama for the Focal Aria 926's, which happen to be my main speakers. However, Amir did do a spinorama for the Aria 906 standmount speakers. They use the same tweeter and mid driver as the 926, but lack the two woofers as they...

audiosciencereview.com

I only have 7. But I do a minor correction from 160hz to 300hz because a convergence of room modes causes some very annoying effects. And the others are actually a 3dB boost at 63hz to bring that inline and then a shelf from 120hz to make the entire region a bit louder.

 

[ozzy9832001]

All right, one of my motivations for starting this thread is because software developers like Uli (Acourate) and Bernt (Audiolense) make a lot of effort to provide full range frequency correction. Bernt has mentioned complex smoothing as a mechanism for full range correction in Audiolense, and I imagine that Uli is doing something similar.

Amir has previously said (sorry I am unable to find a link) that in-room measurements of upper frequencies do not correlate with what we hear. It is not clear to me whether he means all in-room measurements, or only single point measurements. Regardless, I at least agree that a single point measurement does not seem to correlate with what I hear when it comes to upper frequencies.

I am agnostic on this issue. Just because I currently only correct to Schroder does not mean I am not open to other approach

I can see that as being true. I think in the end it really comes down to what sounds best for you. To my ears, any corrections over 3000hz never sound right.

There are a lot of differing opinions on the matters of EQ in general.

Another thing in the same realm is most people won't boost with EQ only use negatives. You obviously can't boost out of a null, but most of the dips we see aren't true nulls and can be boosted out of. There is a cost of headroom of course, but that can usually be easily remedied.

 

[Deleted member 48726]

Full range that sucker. How am I otherwise supposed to EQ the sound to my taste?

The way Dirac Live does it with 13 position measurements works absolutely fantastic in my room.

I think it's safe to say that people have very different experiences with this and should do what sounds best to them regardless of theoretically pros / cons.

 

[dasdoing]

How am I otherwise supposed to EQ the sound to my taste?

but but but, you need to hear the music "as the artist intended"

 

[Deleted member 48726]

but but but, you need to hear the music "as the artist intended"

Yeah. Flat. And mine aren't flat "ab std."

 

[CapMan]

I always used to correct for room modes only, but recently used MMM to get an averaged response to which I added three very gentle and relatively wide PEQ filters to straighten out the very obvious humps over full range.

Also added a slight 1dB upward tilt from 2kH by ear to brighten things up a tad.

Subjectively this sounded more right / natural than using full range convolution with Acourate when I tried it .

 

[sarumbear]

Rule of thumb: No EQ above 500hz, rarely above 250-300hz.

@amirm will disagree.

 

[Ron Texas]

I recall some quote by Dr. Toole that EQ could go up to 400 or 500 Hz. My opinion is beyond that one might want to correct flaws in the speaker design. For example, the non meta LS50 has a 2 dB peak at 2.2K Hz which could brought down to flat or even a 2 dB dip to make it sound like the Meta version.

 

[sigbergaudio]

@amirm will disagree.

View attachment 302026 View attachment 302027

He is allowed to do that. To add to my answer a bit: Wide tonal adjustments like shelf filters to reduce/increase treble will be fine. If you have other issues that cover a relatively wide frequency that is consistent across listening positions, using low Q (1 or less) PEQ filters may be worth testing as well. Anything beyond that I would be sceptical, but everyone is free to do whatever they want.

And of course, if you happen to be Amir and have a Klippel, so that you know for sure that you are in fact correcting inherent speaker problems, and that said speaker has a dispersion characteristics implying that it will be succesful, it's a somewhat different story. We are not all in that position.

 

[sarumbear]

And of course, if you happen to be Amir and have a Klippel, so that you know for sure that you are in fact correcting inherent speaker problems, and that said speaker has a dispersion characteristics implying that it will be succesful, it's a somewhat different story. We are not all in that position.

But we are.

@amirm is publishing his measurements, so does others. We don’t need to measure our speakers ourselves. Why can’t we use EQ based on those measurements?

 

[sigbergaudio]

But we are.

@amirm is publishing his measurements, so does others. We don’t need to measure our speakers ourselves. Why can’t we use EQ based on those measurements?

This is up to you. My understanding of this thread was that is was about room correction (as Schroeder was the topic), not speaker correction.