Should we correct to Schroder, or full range?

[HarmonicTHD]

Have you ever made a gated measurement from the same toe-in angle as your listening position, to confirm that your non-gated measurements lines up with the direct response from your loudspeakers? Otherwise, it really doesn't matter how many positions you take your measurements from if none of them shows the accurate direct response.

Hmm. Interesting thought. Never thought about this one tbh. So you would not correct for “reflections”? Could you elaborate some more, so I am sure I fully understood your thought.

 

[Deleted member 48726]

Have you ever made a gated measurement from the same toe-in angle as your listening position, to confirm that your non-gated measurements lines up with the direct response from your loudspeakers? Otherwise, it really doesn't matter how many positions you take your measurements from if none of them shows the accurate direct response.

Can't see why I should do that. I will correct my sound so it sounds the way I like it, at the position I am at. Reflections incl.
The reflections are part of it all anyway, it is not logical to me why they should be ignored and I will not be persuaded to look at it any other way..

I have come up with a curve in Dirac that sounds great from my listening position. I also don't know how Dirac does its calculations anyway. I just know it works wonders in my room. Something that I couldn't achieve with REW and rePhase and manual tuning.

 

[goat76]

Hmm. Interesting thought. Never thought about this one tbh. So you would not correct for “reflections”? Could you elaborate some more, so I am sure I fully understood your thought.

For the bass region, you should make adjustments based on the in-room response as the room reflections are the dominant factor for that frequency range.
Adjustments made from about 500Hz and up should be based on a gated measurement or an anechoic measurement as the direct sound from the loudspeaker is the dominant factor.

In short: Under 500Hz you make the frequency adjustments based on the room response, and over 500Hz you make the adjustments based on the loudspeaker response.

If you find the overall sound to be too bright or the other way around after you have done the above adjustments, you can use a high-shelf filter to tilt the response to you liking.

 

[Deleted member 48726]

For the bass region, you should make adjustments based on the in-room response as the room reflections are the dominant factor for that frequency range.
Adjustments made from about 500Hz and up should be based on a gated measurement or an anechoic measurement as the direct sound from the loudspeaker is the dominant factor.

In short: Under 500Hz you make the frequency adjustments based on the room response, and over 500Hz you make the adjustments based on the loudspeaker response.

If you find the overall sound to be too bright or the other way around after you have done the above adjustments, you can use a high-shelf filter to tilt the response to you liking.

What you should do is what gives the best result in your room with your speakers. These two divergent sides always come up when discussing room correction.

I can't see why you would not correct for the sound that reaches your ears at the listening position, which is primarily (hopefully ) direct sound but also consists of reflections.

 

[Haskil]

After using several manual or "automatic" correction systems including Tact 2.2X single point, YPAO single point then multipoint with speaker angle measurements, I switched to Audyssey Multi EQ X T 32 on a Denon 3600 purchased after testing on ASR, with the addition of the iPhone application which allows me to draw a target curve.

I used full band corrections and correction limited to what happens below 300 Hz. I did not make immediate comparisons because it is impossible to do. So my opinion is based on my use in a room of 36 m2 Widely open to two rooms of 20 and 28 m2 and a stairwell open to two floors and 10-12 meters in height. This room is very furnished and very cushioned: carpet on almost the entire floor, a large fabric sofa, four fabric armchairs, lots of beams on the ceiling... I listen either 2 m from the speakers or 3.5 mr. The measurements were taken at 3.5 m...

Result of the races... I prefer correction under 300 hZ to full band correction. I just find the sound freer that way. I listened to full band for a long time, then one day I took the application again and limited the correction to 300 Hz... I listened to the same piece again; It seemed better to me. I never went back...

But since I have been correcting after measurements (more than 20 years), I have noticed three things:
1) absolute compliance with the measurement instructions with a given software influences the result much more than anything else...
2) the choice of the target curve is important: personally, I prefer a rounded curve in the bass and descending regularly towards the treble...
3) If I am involved in the protocol of measurements and manual parametric adjustments, I find it much more difficult to calmly estimate the result than if someone else does it for me. When I corrected after measurements with the Clio system, I asked someone to do it and integrate them into a Beringher... and I then judged the result... so as not to influence myself...

With Tact, YPAO and Audyssey it's different: but it's my psychology that is different... above all else because with Audyssey and TACT I carry out the corrections manually.
I use old speakers now - 1999 - but very carefully designed by the professional division of Focal and my goodness, it is rare that I am very impressed when I listen to speakers somewhere other than at home. An exception is the Revel Salon 2...

 

[goat76]

What you should do is what gives the best result in your room with your speakers. These two divergent sides always come up when discussing room correction.

I can't see why you would not correct for the sound that reaches your ears at the listening position, which is primarily (hopefully ) direct sound but also consists of reflections.

The sound that reaches your measuring microphone above 500Hz at the listening position is not the same as the sound your sense of hearing receives at the same position.

A simple test you can do to confirm this is to make a recording of one of your loudspeakers from the listening position, and then compare that recording to how the loudspeaker sounds to you “live” in the room from the same position. I can assure you that the recording of the loudspeaker will sound way more roomy than hearing it “live” as our sense of hearing filters out most of the reflective sound from the room. The microphone and our hearing simply don't work the same way.


You can do whatever you like, I’m just making a suggestion that has the potential to make it sound even better in your room.

 

[Sokel]

It has been said again and again from people who really know what they're talking about.
We can only correct the anechoic response above schroder (not the in room one) and even then,with a very light hand (better tilt like correction,like the old amps had) if we really have to do it.

It's not intuitive,I know,and the storm of all this "correction" apps makes it seem legit.
It's not.

 

[Deleted member 48726]

The sound that reaches your measuring microphone above 500Hz at the listening position is not the same as the sound your sense of hearing receives at the same position.

You can do whatever you like, I’m just making a suggestion that has the potential to make it sound even better in your room.

Of course it's not. I have made small corrections to my curve twenty times or so to get it to sound just right to me. It's not like you don't have a choice to tailor it.
I have also run my speakers without Dirac. Four different ones to be precise. There was not one of them I preferred the sound of compared to after a full range EQ.

 

[daverosenthal]

Can't see why I should do that. I will correct my sound so it sounds the way I like it, at the position I am at. Reflections incl.
The reflections are part of it all anyway, it is not logical to me why they should be ignored and I will not be persuaded to look at it any other way..

Whenever someone says they can’t be persuaded, I feel like that’s a challenge Here goes… To cut to the chase, there is not a single frequency response for your system once you take psychoacoustics into account. If you model how the human auditory system turns sound pressure into brain stimulus, you’ll find that the frequency response depends on the source sound. For example, a click running through the system will be subject to a transient analysis by your brain that will mask some of the effects of reflections. A steady-state tone on the other hand will take them into account. That’s the logic. (And that’s without even getting into the HRTF type effects that can mean two sound fields that sounds identical to a microphone can sound different to physical ears.)

 

[Tangband]

For the bass region, you should make adjustments based on the in-room response as the room reflections are the dominant factor for that frequency range.
Adjustments made from about 500Hz and up should be based on a gated measurement or an anechoic measurement as the direct sound from the loudspeaker is the dominant factor.

In short: Under 500Hz you make the frequency adjustments based on the room response, and over 500Hz you make the adjustments based on the loudspeaker response.

If you find the overall sound to be too bright or the other way around after you have done the above adjustments, you can use a high-shelf filter to tilt the response to you liking.

Agree to everything.
Can add that measurements to use for corrections from 500 Hz and up should be made with the microphone rather near the loudspeaker , between 0.5-1.2 m depending on the loudspeaker size .

 

[goat76]

Agree to everything.
Can add that measurements to use for corrections from 500 Hz and up should be made with the microphone rather near the loudspeaker , between 0.5-1.2 m depending on the loudspeaker size .

I heard it's even better if you can measure with a 2-meter reflection-free window, that way you can be more certain that the sound from the drivers has summed properly.

 

[Digital_Thor]

Heard so many speakers, where people just auto-eq the crap out of them from the MLP - maybe with FDW, and it sounds so bad or sometimes weird.
The problem is that they often do not understand the speaker they are working with, and often hope for some auto miracle.
IMO it is important to know what you work with, what kind of speaker, room and equipment you have.
Getting a nice flat curve, is often "just" a matter of taking simple measurements and EQ the hell out of it and believe headstrong that you did it right. But it won't necessarily sound good - well - sometimes it helps, but sometimes it just becomes some kind of weird worse or different.

Understanding a given driver, cabinet, room, amplifier and DSP - is actually quite important, or else you'll easily go too far and oversteer/over compensate and ruin more than you actually correct.
Having a powerful DSP is no more of a wonder-tool than the person using it and/or the speaker/room that it has to compensate for.

I love my DSP and mostly the result I can get, but damn did it take long to learn how to use properly - especially the fact that I had to get into my thick skull, that it is better to correct by the root, rather than gloss over the whole thing

But I would any day chose a well-designed speaker like KEF or Revel with one or two simple PEQ's in the bass, rather than a less good speaker with any sort of full range advanced EQ.

 

[Deleted member 48726]

Whenever someone says they can’t be persuaded, I feel like that’s a challenge Here goes… To cut to the chase, there is not a single frequency response for your system once you take psychoacoustics into account. If you model how the human auditory system turns sound pressure into brain stimulus, you’ll find that the frequency response depends on the source sound. For example, a click running through the system will be subject to a transient analysis by your brain that will mask some of the effects of reflections. A steady-state tone on the other hand will take them into account. That’s the logic. (And that’s without even getting into the HRTF type effects that can mean two sound fields that sounds identical to a microphone can sound different to physical ears.)

Where is this documented? (bold text)

It doesn't sound very logical to me.
If you stand up and clap your hands you'll notice the reflections in a room much better than if you run a tone. You can try it out.

I'd say it works opposite of what you wrote.

 

[ozzy9832001]

What you should do is what gives the best result in your room with your speakers. These two divergent sides always come up when discussing room correction.

I can't see why you would not correct for the sound that reaches your ears at the listening position, which is primarily (hopefully ) direct sound but also consists of reflections.

I would agree with this, except in a more nearfield setup. When we measure the body and chair are usually not taken into account. I, personally, have found better results, removing the chair from the measurements, especially when making correction above 1khz.

 

[Deleted member 48726]

I would agree with this, except in a more nearfield setup. When we measure the body and chair are usually not taken into account. I, personally, have found better results, removing the chair from the measurements, especially when making correction above 1khz.

Yeah, a bit of experimentation is needed to get the best measurements.

 

[jhwalker]

I used to do full-range corrections ("why not?" I thought) but recently, I gave it a go just up to 150 Hz.

I like that a lot better My speaker setup was already pretty smooth above Schroeder (and sounded pretty good), and the correction at 150 Hz and below really pulls down some peaks / reinforcements in the bass range.

Don't think I'll go back to full-range unless there is a significant improvement / advancement in tech.

 

[3ll3d00d]

I gave it a go just up to 150 kHz.

You must have v good hearing! (Assume it's a typo...)

 

[jhwalker]

You must have v good hearing! (Assume it's a typo...)

LOL - fixed.

 

[daverosenthal]

Me: For example, a click running through the system will be subject to a transient analysis by your brain that will mask some of the effects of reflections. A steady-state tone on the other hand will take them into account.

Where is this documented? (bold text)

It doesn't sound very logical to me.
If you stand up and clap your hands you'll notice the reflections in a room much better than if you run a tone. You can try it out.

I'd say it works opposite of what you wrote.

Psychoacoutics by Fastl and Zwicker, chapter 4 (masking). Dirac also published a PDF talking about room correction (see "The Fourier transform and the concept of frequency" section) that takes about this effect: "As Dennis Gabor noted in 1945, the Fourier representation of a signal shows significant departures from the human sensation of frequencies". So you don't have to believe me, Gabor has a Nobel prize

I agree that if you clap your hands in a room you'll hear an echo. That's because the reverb tail in a normal room lasts longer (~500ms) than the masking effects (~50ms), but that doesn't mean that the psychoacoustic effects don't exist.

The bottom line is that human hearing is a "time-variant" system. However, when you play a continuous tone in a room it has the effect of eliminating the time-variant aspects of human hearing! That is because a continuous tone played in a room turns into a steady state vibration at every point in that room. In this special case, both an FFT and the human ear will process the (steady state) sound the same way. But, when you have normal sounds with temporal variation (i.e. not continuous tones) the human ear will hear them differently than an FFT.

We can simulate how the human ear hears with a set of frequency and time dependent filters collectively called an "auditory filter bank". Using this we can (and do) see how the FFT and human perception differ depending on the sound. This is the basis of the statement I bolded in my post.

 

[Deleted member 48726]

Psychoacoutics by Fastl and Zwicker, chapter 4 (masking). Dirac also published a PDF talking about room correction (see "The Fourier transform and the concept of frequency" section) that takes about this effect: "As Dennis Gabor noted in 1945, the Fourier representation of a signal shows significant departures from the human sensation of frequencies". So you don't have to believe me, Gabor has a Nobel prize

I agree that if you clap your hands in a room you'll hear an echo. That's because the reverb tail in a normal room lasts longer (~500ms) than the masking effects (~50ms), but that doesn't mean that the psychoacoustic effects don't exist.

The bottom line is that human hearing is a "time-variant" system. However, when you play a continuous tone in a room it has the effect of eliminating the time-variant aspects of human hearing! That is because a continuous tone played in a room turns into a steady state vibration at every point in that room. In this special case, both an FFT and the human ear will process the (steady state) sound the same way. But, when you have normal sounds with temporal variation (i.e. not continuous tones) the human ear will hear them differently than an FFT.

We can simulate how the human ear hears with a set of frequency and time dependent filters collectively called an "auditory filter bank". Using this we can (and do) see how the FFT and human perception differ depending on the sound. This is the basis of the statement I bolded in my post.

I didn't say psychoacoustics didn't exist.

I said that clapping reveals an audible echo in a room very clearly. Playing a tone doesn't.