Dirac looks into mixed and minimum phase issues, I am sure other software packages do too.But what is that "more required" by the average audio enthusiast that REW simply cannot function?
Dirac looks into mixed and minimum phase issues, I am sure other software packages do too.But what is that "more required" by the average audio enthusiast that REW simply cannot function?
Manual PEQ's works better for me in the time domain than auto-generated biquads with Minidsp. And yes, too much EQ will not sound good. I recommend taking a few measurements around the LP both in height and width just to get a sense of the overall picture before hammering the response completely flat.
In theory you can get this kind of response if you use one point in space and try to hammer it flat;
View attachment 37768
I tried Dirac measured in only one spot. Same smoothing in both sets of lines, Minidsp was before and Dirac was on top of that. Insanely smooth lines, but sounded awful. The same is true if you try to equalise in Minidsp with Biquads in several channels to get a smooth frequency response.
I agree completely with Armin, above the transition-area, it's all about tone adjustements. As to differences between room correction systems, it's not black and white. Dirac relies heavily on good spacing between measuring points in order to sound good. Audiolense works with one point, but is so customizable that you can alter how and where it will correct and by how much. You can get Audiolense to sound insufferable, but you can also make it sound extremely good. Regardless, here's a comparison between standard default settings between the two;
Dirac - Red
Audiolense - Purple
View attachment 37769
Interesting. Is there a before correction image for reference?
I can agree if you talk about room correction.I agree completely with Armin, above the transition-area, it's all about tone adjustements.
Sorry, I have so many measurements stored with insufficient description, so I don't know which ones. Here's an example of Audiolense vs only minidsp-correction in the bass and broad-band tilt from about 3 khz. It should be somewhat similar measurement from the ones above;
(Note that the fuzzy behavior in the high frequencies are due to stupid placement of the microphone stand)
View attachment 37774
Here's an example, with "flat" as the target curve.
AcourateDRC creating the FIR and IIR filters for a MiniDSP OpenDRC-DI, 1/12th octave smoothing
Red = Raw
Black = Corrected
View attachment 37806
48Hz hole is phase cancellation in my asymmetrical room at the listening position, 220 and 440Hz is (probably) the bounce off the back wall - dipole speakers.
The FIR filter generated can move the phase (unsmoothed ):
View attachment 37787
The discontinuity, at 400Hz in this graph, is related to the crossover from panel to woofer at 180Hz - sometimes the jump is reported at different frequencies, but it is always there someplace.
Distortion is not adversely affected:
View attachment 37788
The high distortion levels reported around 48 and 220Hz are due to the lower SPL at those levels as mentioned above
Impulse Response:
View attachment 37789
Step Respnse:
View attachment 37790
A little rise before the step since the bass is moved relatively forward in time.
Group Delay (1/12th smoothing):
View attachment 37791
Ray, I don't think I've ever seen something like that negative group delay effect before -- after your Acourate correction. Although you did say it 'time corrected' the impulse response. Still, it looks rather a bit strange.
While I'm quite certain that you likely would have noticed much improvement in the bass... to you, were there any marked improvements, audibly, that is, correcting way above that?
The room is a rectangle on the right, and open on the left rear corner. that makes the left side both deeper and much wider than the right side.
At 48Hz the left and right bass is 180 degrees out of phase at the listening/measuring position.
So, looks weird there.
L, R, and Both speakers, corrected frequency response,
1/12 smoothing, Neither right nor left has the big dip at 48hz, but combined, they cancel.
View attachment 37828
Phase:
Left, right and both. 180 degree difference in phase at 48Hz.
View attachment 37830
Group Delay:
Left, right, and both
I have no idea how two positive group delays combine to create a big negative.
View attachment 37831
Step Response
Left, right and both
View attachment 37832
I don't notice any harm.
Hopefully the idea that there is, per se, such as thing as too much EQ has diminished.
The fave speakers of this forum (and others) like Kii, D&D, Neumann, etc only get their perfect responses by aggressive full range EQ.
The supposed danger is when you apply that approach to room EQ.
But I'm not sure that is the case these days. For a start, the supposed Schroeder FQ in any room I've had speakers in does not match where the response goes wonky. These days I do a measurement, see where the wiggles start and go from there.
Fortunately, the smart EQ systems do fine-grained stuff down low and sweepy EQ things above.
I think the new variable smoothing on REW is an excellent starting point.
I would separate the 2 ch vs Mch issue.
Spectral harmonizing by Eqing the whole frequency band might not be that big a deal with two speaker. They are mostly placed in similar sounding places and then there is no soundstage reconstruction from 2 speakers anyway.
For Multichannel the issue is different and I guess a lot of the new EQ interest comes from there. Not many people have 5+ identical speakers. And not many people have a perfect shoebox with a chair in the middle (and a transparent screen for video). And with 3 speakers in the front one might start illuminating the sound stage a bit if all is balanced well.
So my take is, that for Mch full frequency EQ & time alignment is great, for 2 ch it depends.
Like everything else, I do believe that there is such a thing as too much EQ. Sounds rather common sense to me. It's obviously not a prescription for one not to do EQ. But there's a very good reason why sound reinforcment guys don't use automated EQs willy nilly, but rather do it manually, and with much careful consideration to other variables.
I'm not sure I understand what you mean with your second statement. I have no idea about the Kii and D&D, but the KH120 already measures well minus the room -- and with zero EQ in place. I've already posted my manual PEQs for the KH120s here (for my listening space) and none of it looks overly aggressive/full-range to me.