# Looking for advise on room calibration software



## babylonwaves (Nov 21, 2015)

hi guys,
we have a acoustically treated studio here with focal be6 monitors including a sub. it sounds pretty good but the bass end could be better. it's the usually problem: loads of bass in the corners and room modes that cancel out frequencies in the sweet spot where you sit.
i wonder if somebody can share some experience using room calibration software such as Sonarworks Reference 3 or Real Sound Labs Coneq? Our room is simply to small to cramp more bass traps in and I wonder how far we would get by adding some software based optimisation.


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## muk (Nov 21, 2015)

Some time ago I tested some of the software solutions. Standouts were Dirac Live and Python Open Room Correction (Porc). Dirac is very user friendly, quick and easy to set up, and quite customizable. Porc is rather tedious to set up (no GUI, you use command prompts), but it basically offers the same correction capabilities as Dirac for free.
The corrections that Arc2 and Sonarworks offered didn't convince me. That's a personal experience though and may be very different depending on your speakers and room.
There are also some hardware options - Trinnov, for example. I didn't look into them. Too expensive for me.


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## Gerhard Westphalen (Nov 21, 2015)

I got the Sonarworks a few weeks ago and it seems to be working well although I'm not very experienced with mixing and know how things should sound. You can get a 30 day trial and use your own mic to calibrate it.


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## babylonwaves (Nov 22, 2015)

Gerhard Westphalen said:


> I got the Sonarworks a few weeks ago and it seems to be working well although I'm not very experienced with mixing and know how things should sound. You can get a 30 day trial and use your own mic to calibrate it.


can you use your own calibration mic in the full version or do you have to use theirs? i know that in older version you had to use their mic.


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## wst3 (Nov 22, 2015)

I've posted about this previously, but since it came up again I thought I'd repeat myself...
ET
In order to use 'acoustical correction' software you first need to know what's wrong with your space. These tools can correct a very small subset of problems, but they will not correct time based problems. The day may come when a complete transfer function can in fact be processed and corrected, but we are not there yet, and most of the promises made by the companies that sell these tools are - at best - shaded.

There are tools that can accurately, and completely characterize an electro-acoustical system, TEF, EASERA, and TDA come to mind, but there are others. They are expensive, and require a fair amount of training. I use TEF25, but I've only owned it for a short time and I am still deep in the learning phase.

I have tried several of the low cost systems, out of curiosity (and a naive hope that someone has in fact violated the laws of physics<G>), but they disappointed me. The corrections they provided made a small difference, but not nearly enough, at least for me.

The only way to truly solve problems such as bad reflections or low frequency build up is to correct them physically. The tools at our disposal include reflection, absorption, and diffusion... well, and room geometry, but that last one is a bear unless you are building a purpose built space from scratch. Few of us have that luxury.

In the meantime, my recommendation remains simple (simple usually works):
1) get the best monitors you can afford - and best means a well behaved dispersion pattern, low distortion, reasonably flat frequency response (something the magic software can correct), and most important, a sound you like for your application.
2) work with then in the near field - not a panacea, but it removes at least part of the room contribution.
3) optimize the placement of the monitors and your ears - you'll be amazed at the difference this one step can make.
4) apply (minimal) broadband treatments - absorption, diffusion and reflection - to solve the gross physical problems. The consulting services provided by the popular vendors are much better than you might expect, I'd suggest getting recommendations from at least two such vendors just to see if they agree.

Once you've done all that you can experiment with correction software, but you might find you don't need it after all.


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## ed buller (Nov 22, 2015)

That is good advice. I've just notched out 127HZ on my mix buss ( remembering to take it off when I'm printing ) and so far all the mastering has had no complaints. Know your speakers !

ed


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## Gerhard Westphalen (Nov 22, 2015)

babylonwaves said:


> can you use your own calibration mic in the full version or do you have to use theirs? i know that in older version you had to use their mic.



You can buy it without the mic which is what I did since the behringer measurement mic. When you go to their shop website there are quite a few options. Just make sure you get the right one.


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## babylonwaves (Nov 22, 2015)

wst3 said:


> In the meantime, my recommendation remains simple (simple usually works):
> 1) get the best monitors you can afford - and best means a well behaved dispersion pattern, low distortion, reasonably flat frequency response (something the magic software can correct), and most important, a sound you like for your application.
> 2) work with then in the near field - not a panacea, but it removes at least part of the room contribution.
> 3) optimize the placement of the monitors and your ears - you'll be amazed at the difference this one step can make.
> 4) apply (minimal) broadband treatments - absorption, diffusion and reflection - to solve the gross physical problems. The consulting services provided by the popular vendors are much better than you might expect, I'd suggest getting recommendations from at least two such vendors just to see if they agree.



hi bill,
thanks for all the inside. i think i'm am at this exact point. we have Focal BE6 Trios and a room which was professionally treated. but the room is not perfect, so in order to squeeze the last 10% out of it, i'll give software a shot. what you say about monitor placement is interesting. maybe that's something we can optimize further as well. any tips for a good article on that? most of my knowledge i got from this article but i'm sure there is more: http://arqen.com/acoustics-101/room-setup-speaker-placement/

thanks!


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## Nick Batzdorf (Nov 22, 2015)

That Argen.com thing has a few good points, but it also espouses the conventional wisdom, which in my opinion - not just mine - is totally wrong. The equilateral triangle story is silly and arbitrary (you want to sit where the speakers sound right to you in that room). And muffling the sides does nothing other than screwing up the frequency response of your room and messing up the stereo image; it has no scientific basis.

But we've had that argument here lots of times.

Bill's advice is great (except for where it diverges from what I wrote above  ); the idea that you're going to accomplish anything good with software is dubious at best.


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## Nick Batzdorf (Nov 22, 2015)

Expanding on the equilateral triangle canard, I'm a whole lot less committed to the "eliminating the room" nearfield narrative than most people seem to be. Speakers are going sound right to you from a certain distance, and then you want them spaced apart so you can pinpoint the phantom center. But in reality that's a really wide range in small rooms.

I'm also not at all sold that you need to be in the front 40% of the room or whatever it is. You only hear "comb filtering" when it comes from the same angle as the speakers, i.e. the front of the room. I've been convinced to use diffusion at the rear, not absorption.


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## wst3 (Nov 22, 2015)

Nick and I converging???

I was maybe oversimplifying when I said eliminate the room, I should have said eliminate the room problems. That's where near field monitors CAN shine, but they don't always.

The equilateral triangle - it's a great starting point, or it was once upon a time. Most of us have one or more computer monitors sitting between the monitors - which pretty much kills the triangle idea. But you have to start somewhere. And that's as good a starting point as any.

If you want to see just what your computer monitors are doing to your audio try setting the loudspeakers up in the dreaded equilateral triangle without the computer monitors in place. Give it a good listen. Now put your computer monitors back - you'll probably end up saying something to the effect of "what happened to my stereo image?"

I'm definitely not sold on the front 40% myth, but again it is a great place to start... or rather a place to start. You don't want to be mid-way between any two surfaces if you can avoid it. Again there are exceptions, and again if you want to have some fun set your speakers or your ears at the mid-line front to back and then move them even a little one direction or another and listen to the difference.

I will question the "wide range in a small rooms" comment... in my experience (limited of course) most small, minimally treated rooms have a fairly narrow range of placements that work well. I'd be interested to learn the error of my ways.

Here is an outstanding series of articles and white papers on small room treatments, and loudspeaker placement: http://www.rpginc.com/Technology.cfm - some of it is insanely technical, but there is a lot of great information there. Specifically, read http://www.rpginc.com/docs/Technolo... Acoustical Distortion in Project Studios.pdf - one of the best survey papers I've read.

Once upon a time RPG used to sell two software tools - Room Sizer and Room Optimizer, but they are no longer available. They weren't brilliant, but they were quite educational!

If you want more suggestions for resources let me know


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## Nick Batzdorf (Nov 22, 2015)

I disagree that we disagree most of the time, Bill. 

To be clear, obviously you want a triangle so that you're in the middle. It's the equilateral part that I disagree with, although sure, as a starting point of course it makes sense; why not.

As a practical matter, I have my small speakers about 6' apart - toed in to point toward me (that's another factor) - and I'm maybe 4' away from each one. Even with a whole bunch of crap in the middle (a 30" monitor with equipment on either side of it) the image is excellent. If I stand back 6' it's still excellent.

What changes the most as you move forward and back along the center is... the sound. That's where the subjective part comes in. If you're too close to the speakers you get glorified headphones with your room problems.  Too far back and you stop hearing as much detail.

At least that article didn't tell you to set up a 3' equilateral triangle, or whatever the usual silliness is. That's like saying the ideal color for a house is green.


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## babylonwaves (Nov 23, 2015)

Nick Batzdorf said:


> the idea that you're going to accomplish anything good with software is dubious at best.


i find that a bit generic but thanks for your input, this is why i opened this thread in the first place.


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## mc_deli (Nov 23, 2015)

babylonwaves said:


> i find that a bit generic but thanks for your input, this is why i opened this thread in the first place.


Very good experience with Sonarworks here. Had a friend bring his Sonarworks mic and calibration file over first and did the room measurement routine with the free trial. Was so convinced I bought our studio the mic and plug ins (haven't tried the headphone correction for my HD650 yet).

The multi spot measurement took a little while - lots of points and distances. Software is easy to use and you can very clearly limit the correction if you want. I canvassed some opinions from pro mixers. The main thrust is if it helps your mixes translate then it has to be useful. I also had the chance to quiz a monitor speaker manufacturer on this the other day. His comment was that he has no objection but feels that room correction should be used sparingly on higher frequencies i.e. good for bass management.

I think that it is the measurement process that is actually the ear opener, rather than the correction. If you know you have a hole at 150, a dip at 250 and a hump at 60 then you can make sure you are not overcompensating - whether you choose to use a correction curve during tracking/mixing or not. Or you can e.g. just use correction for self-mastering.

The one hassle is that I have tried to set up SW3 on my rMBP output using Soundflower and AULab, rather than on the Logic output, so I don't have to switch it off for bouncing. But Soundflower is not playing nice yet.

(Professionally designed rooms here. The small room is small so needs bass correction. Big room is designed for wall mounted 8260a so nearfields benefit from correction.)


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## wst3 (Nov 23, 2015)

babylonwaves said:


> i find that a bit generic but thanks for your input, this is why i opened this thread in the first place.



Maybe it is generic, I thought of it as somewhat kind.

At the risk of repeating myself, there is a very limited number of acoustical problems that can be solved with equalization and that is the only tool you have to work in the frequency domain, which is where these sorts of tools work. You can NOT solve time domain problems in the frequency domain. In order to solve time domain problems you would need hundreds - probably thousands - of band limited delay lines.

Presently it is fair to say that it is unlikely (dubious?) that small room acoustical problems can be solved with software.

What you can do with software is that "last 10%" - if you have a well designed room then you will probably hear an improvement, but it won't likely be dramatic.

And an analog - there are symmetrical power systems that promise to solve power line noise problems. In fact there are only one or two specific issues that symmetrical power can fix, and those fixes won't be audible if everything else isn't done properly. AND, these specific problems (leakage currents for the most part) are generally resolved through proper grounding and power distribution. None-the-less, it's a very dramatic (and effective) sales tool to walk into a studio, plug in an old guitar amplifier, and make it quiet. Very effective<G>!

I am not suggesting that these software room correction tools are all snake oil, and I don't think Nick is either (can't really speak for him now can I?) What I am suggesting is that the marketing applied to these tools is generous, and they will not do what most folks want - or expect.

In fact I'd say that the only people that will hear a difference are folks with rooms that are properly designed, and they are looking for that last little improvement, and folks with rooms that are so awful that they will hear a difference, maybe even an improvement, but it still won't rescue their room.

I hope that is specific enough, but feel free to let me know if it isn't.


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## babylonwaves (Nov 24, 2015)

wst3 said:


> At the risk of repeating myself, there is a very limited number of acoustical problems that can be solved with equalization and that is the only tool you have to work in the frequency domain, which is where these sorts of tools work. You can NOT solve time domain problems in the frequency domain. In order to solve time domain problems you would need hundreds - probably thousands - of band limited delay lines.


Dirac for instance claim that their software works in the frequency and time domain. But as you say, there is loads of marketing involved and you're certainly right about the transfer function issue. You know, I believe I'm as skeptical as you when it comes to all that. But I'm not in the market for a simple Better Maker, I just want to evaluate my options. More bass traps would result in my studio not having an entrance anymore. That's a serious problem too  And if it is a simple matter of positioning everything right, we have either done something wrong so far or we did it all right and this _is_ about the remaining "10%" I've mentioned in my first post.

I think I'll invest time and evaluate what the try out versions can do.


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## muk (Nov 24, 2015)

To measure your room is indeed a good idea. If, and how much, digital room correction to apply after that must be decided on individual basis. DRC is often used to apply house curves as well. The Brüel & Kjäer variants are often mentioned. So there are a few things that DRC is useful for, though it is certainly no replacement for proper speaker setup and room treatment. If you happen to have a calibrated microphone there's nothing to loose by trying one of the demos, or the free Porc.

@mc_deli I use Pedalboard2 (http://www.niallmoody.com/apps/pedalboard2) to host the DRC outside of the DAW. It's a small footprint, completely free VST host. I made a batch file to have it on autostart. That way all audio goes through it without affecting the rendering of files in your daw.


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## mc_deli (Nov 24, 2015)

muk said:


> To measure your room is indeed a good idea. If, and how much, digital room correction to apply after that must be decided on individual basis. DRC is often used to apply house curves as well. The Brüel & Kjäer variants are often mentioned. So there are a few things that DRC is useful for, though it is certainly no replacement for proper speaker setup and room treatment. If you happen to have a calibrated microphone there's nothing to loose by trying one of the demos, or the free Porc.
> 
> @mc_deli I use Pedalboard2 (http://www.niallmoody.com/apps/pedalboard2) to host the DRC outside of the DAW. It's a small footprint, completely free VST host. I made a batch file to have it on autostart. That way all audio goes through it without affecting the rendering of files in your daw.


Looks interesting - what OS are you using?
(The problem with Soundflower seems to be Yosemite compatibility causing clicks. And Pedalboard was last updated in 2011...)


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## muk (Nov 24, 2015)

Windows 10. It works without a problem here, might be worth a try on a Mac too. Other than that there is also Minihost Modular. It's newer, and if I'm not mistaken it still gets updates.


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## Beat Kaufmann (Nov 25, 2015)

Nick Batzdorf said:


> At least that article didn't tell you to set up a 3' equilateral triangle, or whatever the usual silliness is. That's like saying the ideal color for a house is green.


What a comparison... a bit a special one...
Nick, can you tell us where you are sitting while you are checking different postions in a mix, the correct volume of left and right and all these things? Beside the speakers? in the kitchen? in the bath? Can we listen to such a mix, done in the bath?
Remark: Do not take my text here too serious...

Best
Beat


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## germancomponist (Nov 25, 2015)

I am working in a well treated room, but for best bass-listening, I have to move my listening position ca. 15 cm to the front of my room. Not a best solution, but I can handle it.


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## Nick Batzdorf (Nov 25, 2015)

Beat, we've discussed this before. I know you're committed strongly to the conventional wisdom. If it works for you, fine, and if laughing at what I post makes you feel good about what you believe, even better.

But there's simply zero scientific basis for saying that X' behind your speakers is always the correct distance. Even if you ignore personal preference, that makes no sense on the face of it! How wide is their dispersion, for example?

Nor is there any truth to some of the other stuff you've passed on before - that one should muffle side reflections to avoid comb filtering. It looks like it should work that way on paper, but it's categorically wrong, because it doesn't take into account how the human brain works.

There's a reason I don't mix in the bath, which is that what Bill says about there being three parameters (absorption, diffusion, and room geometry) is still true. The question - the art - is in how you deploy them!

***
Now for a personal opinion: I've tried eq-based tools, i.e. you record a sweep at your listening position with a calibrated mic, and it generates an inverse filter to compensate for the lumps.

To my ear all it did was mess up the sound of my really nice speakers. Part of the problem is that all bets are off as soon as you move the mic (or your head) a fraction of an inch. But I think the main reason is that you can't fix room problems with eq.

That doesn't mean calibration software has no use, just that in my opinion it's only useful if you're planning on calling in the architects to change your room ratios. Or if you're going to build a room like a friend has, with $ thousands of acoustic products everywhere there's a reflection. That's a certain kind of room that you may like, but it's not automatically "correct."


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## Nick Batzdorf (Nov 25, 2015)

Also, software that works in the frequency and time domain... well, delaying certain frequencies doesn't fix the room problems either.

There are some high-end speakers that do that kind of thing with the bass, but what they do is far more specific than just "use our software to fix your room."


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## mc_deli (Nov 25, 2015)

Nick Batzdorf said:


> Part of the problem is that all bets are off as soon as you move the mic (or your head) a fraction of an inch. But I think the main reason is that you can't fix room problems with eq.


Interesting. But your head is moving all the time and you are still able to judge the stereo field. The point of multiple point mic measurement is to make some kind of compromise adjustments possible. In the same way as dip switch boosts or cuts on the back of speakers. And the "sweet spot" is generally a compromise and far from exact or accurate in most cases, no matter how you have your room and speakers and chair and coffee mug and the door open etc etc.

And I disagree with that last point. I think you can exactly help your listening by compensating for room problems at the bottom end with advanced EQ. With this room correction stuff though, I don't think whether you use it or not matters. If your mixes translate and you can hear what you are doing then all is well. My impression is, for most people, they would benefit from at least knowing where in the frequency spectrum their system is hyped or holed, and it can help answer a lot of questions (where did that low G# go?)

(Obvs have spent 200 sovs on room correction and enjoying it so have a nag in this)


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## mc_deli (Nov 25, 2015)

Nick Batzdorf said:


> There are some high-end speakers that do that kind of thing with the bass, but what they do is far more specific than just "use our software to fix your room."


Go on then... tell more

I have used the Genelec DSP that comes with the 8260a and the Sonicworks. They both use software to fix the room based on multiple position pre-calibrated mic measurement. They both do stuff that is much more complex than just EQ. Some little features like DSP gives you a secondary sweetspot (IIRC), SWx gives clear GUI representation of the correction, correction limiting, acts as a plug in etc.

The both do basically the same thing IMHO though the SWx is vastly easier to use and get results IMHO. We can scour the various speaker mftrs and software mftrs sites for their mktg gubbins but all of them "use software to fix the room"


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## germancomponist (Nov 25, 2015)

No EQ can fix your room problems!


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## mc_deli (Nov 25, 2015)

germancomponist said:


> No EQ can fix your room problems!


You are right, no EQ can fix your room problems, or my amnesia. What were we talking about again?


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## babylonwaves (Nov 25, 2015)

Nick Batzdorf said:


> Now for a personal opinion: I've tried eq-based tools, i.e. you record a sweep at your listening position with a calibrated mic, and it generates an inverse filter to compensate for the lumps.
> 
> To my ear all it did was mess up the sound of my really nice speakers. Part of the problem is that all bets are off as soon as you move the mic (or your head) a fraction of an inch. But I think the main reason is that you can't fix room problems with eq.



some years back i had a KRK Ergo for a couple of days. and my impression was very similar to what you describe above. but things have changed on a lot in the meantime. there are many people who find what Genelec DSP system do is helpful to their mixing. and no, it doesn't fall apart when you move you head.


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## Nick Batzdorf (Nov 25, 2015)

You guys are right - I shouldn't generalize about the Genelec or other systems I haven't heard, and yes, things really do advance over time when talented engineers work on the problems.


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## Nick Batzdorf (Nov 25, 2015)

Also, there's eq and there's E-freaking-Q. Just a little overall tilt brighter or maybe less bassy is one thing; trying to reverse every lump at your listening position is (in my opinion) extreme.

By the way, if this isn't obvious: the reason eq doesn't fix room problems is that the room just inflicts the same problems on the eq-ed signal!


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## Nick Batzdorf (Nov 25, 2015)

mc_dell:



> But your head is moving all the time and you are still able to judge the stereo field.



Sometimes.

It's no secret that standard amplitude-based panning - i.e. the standard pan control that lowers one side and raises the other as you sweep it - doesn't produce a very stable image. You can spend a lot of time positioning everything with it, but the image shifts as soon as you move your head.

And that's why delay-based panning is more exact, or panning using a convolution processor (which incorporates delay and other things). Place a signal 100% dry hard to the left, and run it through a .1mS delay 100% wet to the right, you'll hear the image shift. By the time you get to .9mS it'll have moved way over.

The problem with that is mono compatibility, but it does lock the image.


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## babylonwaves (Nov 28, 2015)

hi guys,

i've done some tests with Dirac Live and below you can see the results. Purple is the original room, Blue is Dirac Live in low latency mode and green is the same with max performance mode on.

As you can see, both 40z and also 80hz suffer from room modes which the acoustic treatment made much better but didn't entirely remove. DL smoothes both out and you can clearly hear it. I have to do some mixing with this configuration and see how this turns out. But so far, the correction software does something good i wasn't able to imitate with simple EQ.


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## mc_deli (Jan 8, 2016)

Sonarworks have a discount promo on:

"a *-20% discount* on all Sonarworks speaker calibration software to give to your friends. 
Here's the discount code - *XTFSCQ2IAMS*
Once you tell them about your experience, they’ll want to check it out.

As a thank you for helping your friends and us, we want to make your monitoring even more transparent. If one of your friends uses the code we will give you a *FREE*Sonarworks headphone calibration plug-in licence. If three friends will use the coupon, we will give you *FREE* calibrated Audio Technica ATH-M50x headphones!

There’s no catch. Just share the coupon on your Facebook or even better - let your buddies come to your studio and let them hear how it sounds with Sonarworks calibration!"

I don't need the "prize" but, dear VI friends, please enjoy the discount


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## muk (Jan 8, 2016)

And by the way, you can not trust Diracs optical feedback about the correction it achieves. That's just an estimation about what it thinks it can do, not an actual measurement of it's real effect. If you want to know you have to measure your room with and without the Dirac filter and compare the curves. Room Eq wizard is a very good free program you could do it with.


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