# Studio Monitors EQ wizard?!



## disco violence

I was wondering if i could corect my home studio monitors by taking theirs freq. response graph and corecting it.I'm not talking about room here just about my monitors Adam A7.What do you think about the idea has anyone done that and where it will take me?Thanks.P.S.I have room that could not be treated.


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## Wayne A. Pflughaupt

Sure, lots of people here have used REW for their studio monitors. But the “correcting” will most likely require parametric equalization. Do you have that capability, either hardware or software based?

Regards, 
Wayne


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## disco violence

Wayne A. Pflughaupt said:


> Sure, lots of people here have used REW for their studio monitors. But the “correcting” will most likely require parametric equalization. Do you have that capability, either hardware or software based?
> 
> Regards,
> Wayne


Thanks for the answer everywhere i asked answer was negative or noone would talk about it.I want to know more about that,why it has to be parametic EQ,i only have software waves parametic eq but i'm not shure that it have enough bands for the job,what software eq would you sugest?This is the way i wanted to do the "correcting" take the sample of white noise 20hz-20Khz, then make make my monitors freq. response of it,i need god freq analyzer for this job,then i make wav file after that i need to go back use eq again and make flat sample of white noise out that wav file.Result should be eq for my monitors,or i am wrong?


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## Wayne A. Pflughaupt

Parametric equalization is best because it allows you to create precise filters to correct problems with your frequency response. Graphic equalizers can’t match the precision of a parametric EQ. This thread features an example of the improvement in sound quality that can be realized with parametric equalization.




disco violence said:


> ,i only have software waves parametic eq but i'm not shure that it have enough bands for the job,what software eq would you sugest?


Sorry, but I don’t know anything about software EQ programs. I’m a hardware guy. 




> This is the way i wanted to do the "correcting" take the sample of white noise 20hz-20Khz, then make make my monitors freq. response of it,i need god freq analyzer for this job,then i make wav file after that i need to go back use eq again and make flat sample of white noise out that wav file.Result should be eq for my monitors,or i am wrong?


Pink noise is a better signal for equalizing. Check out or REW program for an excellent frequency analyzer. It generates and measures a sine wave signal that you can use for equalization.

Regards, 
Wayne


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## DanTheMan

If you only try to EQ below 300Hz, you'll be alright. Do not try to boost a null--you'll do far more damage than good. Above there it gets more complicated. The measurements of the ADAMs I've seen say they won't actually need an EQ above there anyway. The ones I've seen are all essentially stellar! That said, I haven't seen good measurements of those particular ADAMs.

Dan


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## disco violence

DanTheMan said:


> If you only try to EQ below 300Hz, you'll be alright. Do not try to boost a null--you'll do far more damage than good. Above there it gets more complicated. The measurements of the ADAMs I've seen say they won't actually need an EQ above there anyway. The ones I've seen are all essentially stellar! That said, I haven't seen good measurements of those particular ADAMs.
> 
> Dan


I've got measurements from adam factory and they are little bit different than the others found on internet but the thing is that graph starts at 200hz.


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## DanTheMan

It goes from 200Hz to 20kHz? That's what I would hope for.

Below somewhere near there, 200-500(at most)Hz, humans hear the "in room" response. Above there, humans hear the anechoic response. So if they gave you the anechoic response above 200Hz, then they have given you what's most useful and you can EQ that if it needs it.

Below there, you need an in room, at the listening position response. Actually a 'listening area' set of responses would be more useful. Your head is larger that a microphone and moves around a bit as you listen.

ADAMs are great monitors. You are starting off on the right foot! Wish I would have had that insight.

Dan


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## DanTheMan

That last post is just about how we hear from a tonal perspective. Spatially, this change.

An equilateral triangle with those monitors and a good smooth bass response at the listening position will certainly go a long way.

Dan


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## disco violence

I've done the test with "white noise" equalization and the first results were very interesting on the first hearing it seems like it brough up some frequencies that were down in the mix,this was the first experimetal eq-ing it has to be done more precise but i think that i am on the good way.:sn:


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## Prodba

I know by experience that it's frustrating when you don't get answers on your questions, or even worse, you get misinformation.

On that note, I can inform you that you cannot correct the frequency response of your monitors with EQ (exept one exeption I will cover later).

The first reason is that the response at your listening position mostly won't resemble the frequency response of the monitor for it is altered by your room.
If you'd measure the response at one foot from the monitor you'll find the response getting close to the response graph, while 4 feet away at your listening position it will show a totally different picture.

The second reason is that standing waves cannot be corrected by any EQ, because they're caused by reflections of the walls in your room.
A standing wave (a dip or a bump) is the result of the reflection of a sound wave coliding with the direct wave from the source.
when the reflected wave colides with the direct wave at a point where the waves are out of phase in relation to each other, they will cancel each other out and result in a dip for that given frequency.
At another position in the room you'll find these waves meeting each other in phase, which will multiply in volume. And this will be happening at different spots in the room for different fequencies.

So, if you have for example a dip at your listening position for 200Hz, EQ cannot do anything to resolve that.
If you boost that frequency to +5dB, then amplitude of the reflected 100Hz (out of phase) wave will also increased to -5dB, so the result will still be 0. 
As you may understand; cutting the frequency will also alter the reflected wave in the same degree, so that also has no effect. The same goes for a bump.
The only way to solve this issue is to keep the waves leaving your monitor from coliding with their own reflection ( at least at you listening position). And the way to do this is to block the reflection by treating the reflection surfaces.

The exeption:
The only use for EQ for the frequency response of your monitors is when you place the monitors close to a wall. That is why (most) pro monitors (active) have a bass roll-off shelving possibility.
The reason is that whan a speaker is placed close to a wall, the omni-directional lower frequencies (up to +/-100Hz) emiting from the back of the speaker will be reflected by the wall behind, add up to the direct wave and cause a low-frequency boost in the frequency response curve.
Even though treating the reflecting wall behind would always be the best solution, this might not be very effective, or even possible, due to the lack of space between the monitor and the wall.
But as both the reflected wave and the direct wave are headed in the same direction in this case, the EQ can be effective here. 

I don't know why treating your room is not possible, but I'm sorry to say that that's the only way to get a decent response out of your monitors.
I hope that the above explanation has clarified the reason why, or at least has given you more understanding of standing waves.

Good luck,
Norman.


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## DanTheMan

I wouldn't worry much about bass decay--I wouldn't worry at all about bass below 80Hz decay. This is just by the perceptual evidence: http://dtmblabber.blogspot.com/2011/03/hearing-beyond-haas.html?m=1

Don't worry about proximity to the wall either(as far as setting the swithes on the back of your monitor). I'd keep the monitors away from the walls if possible. Take the measurements and go from there. The bass end in the room is very complex, but it can largely be corrected with good placement and EQ--I have http://dtmblabber.blogspot.com/2012/11/sound-audyssey.html?m=1proof.  
Read the last several posts on my blog: http://dtmblabber.blogspot.com/2012/11/sound-audyssey.html?m=1
No effective bass treatments there.

Dan


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## AudiocRaver

First you get no responses at all, and now you are probably getting more advice that you know what to do with. When it rains, it pours.

All of the previous posters are knowledgeable, I am not here to disagree with anything they have said, only to give you my two cents worth.

1. As long as you are not spending money on hardware or software, and it is free to try, why not? Prodba's comments are absolutely correct in that the results will be less than ideal. Do not expect to end up with perfect results. If you approach it carefully, though, it can help quite a bit.

2. Start with speaker placement. Away from the walls, as DanTheMan suggested, you are most likely to get the best sounding starting point without EQ, then you will have less to correct for. Try some different positions, take measurements, find the position that measures best and sounds best to you. Use pink noise (not white) for this, it gives you the quickest picture of what is going on. Move the measurement microphone a foot or so in each direction around the head position to see that the frequency response is fairly stable within that area.

Consider near-field placement, with the speakers only 2.5 to 3 feet away. It leaves you with a small sweet spot, true, but it also helps reduce room effects. Some will say that is too close, but with small two-way monitors it works quite well.

3. From your measurements, do your tuning by hand, any automated tuning approach will do too much. REW does have an automated mode where it "suggests" the parametric filter values for you to use, and allows you to limit the parameters of those suggestions to suit what you are trying to accomplish, that is the one automated possibility that might be helpful.

4. As suggested, you should pretty much forget about boosting. Concentrate on cutting down the highest, most annoying peaks, and your setup will sound a lot better. Sharp little peaks usually shift a lot with small changes in listener position, you're best off ignoring them. Peaks that are about 1/12 octave or broader are worth going after. Don't do anything too drastic, just try to tame the worst offenders.

5. As Wayne P. suggested, parametric EQ gives you the best control to work with. Reaper offers a free download of their core VST plug-ins, including ReaEQ, usable in any DAW. With it you can add as many parametric bands as you wish.

6. Tune each speaker separately. That said, if the difference between the two is very much, you need to pick a better starting position.

Best of luck. Let us know what you come up with.


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## Prodba

Agreed!

I had indeed neglected to mention that speaker placement is the very first step.

Whenever possible, speaker placement away from the front wall is also preferred, with special care at distances between 1mtr and 2.2mtrs where cancellations in the frequency region of 80 to 200Hz may occur. This applies to moderate sized speakers.

And of course, as far away possible from side walls and at equal distance to both sides.

Regards,


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## DanTheMan

There is no real 'ideal' is a current problem in control room acoustics. EBU, ITU, THX, etc... All have different requirements. That's why I posted the 'what matters most BY THE EVIDENCE' information. The couple things In Probda's post I corrected are the common dialog around the web, but they don't pan out in blind tests. If science were a democracy, that would be correct. That said, all of his advice is still good and reasonable, it will just cost more money and time and similar results. EQing the monitors above the transition zone is grounds the angels fear to tread--the informed but less savvy ones anyway. Read this, the links, and the posts afterwards: http://dtmblabber.blogspot.com/2012/10/pitfalls-of-room-correction.html?m=1

I wish the OP would post his graphs of the ADAMs. 

Dan


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## AudiocRaver

DanTheMan said:


> EQing the monitors above the transition zone is grounds the angels fear to tread--the informed but less savvy ones anyway.


Dan has referred to some great articles, well worth a read. I definitely agree with him on one thing: there are a lot of ways to waste a lot of time, and potentially a lot of money, trying to EQ a room with unrealistic expectations. And it is a good thing to learn the science involved, it will serve you well.

That said, you know not to expect perfection, and we are here to help, and depending on what your measurements show, you may be able to use some EQ to make a few "sore thumb" annoyances somewhat less annoying. And you will be learning and having fun at the same time. Ain't life great!:sn:


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## DanTheMan

Thank you sir! Learning the science of audio has been the biggest help to my mixing and home theater. I've had far more expensive gear in the past, but never a better sounding system than right now. It's all evidence based practice. Still, I want ADAM monitors! The evidence suggests the monitors are the most important link in the chain--the room isn't nearly as important, but is still certainly matters. My girlfriend would say that the room is "masterpiecing it". I don't have a single functional bass trap in my room, yet my bass response is smooth and flat, and fairly extended. It doesn't sound one bit boomy. Too bad I'm not getting into single digits, but I can live with 25Hz. No doubt it could improve, but it would take a lot of time and/or money and the best I could hope to do is not much better.

Hopefully the OP gets something from this. I was really surprised by a recording pro/studio owner who has been in the business a long time... Just a few months ago, he had never heard of the equilateral triangle and getting your early reflections symmetrical! Years and years of recording and somehow this very basic info had illuded him! I literally knew that was the start when I was 12. This guy is no moron either. He just somehow never received the info. I wonder how much frustration he would have avoided and how much joy he missed out on.? Learning is wonderful and the earlier the better.

Dan


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## Wayne A. Pflughaupt

Room treatments and equalization often (if not usually) do not have a lot do with each other. Check out this chart below I recently came across on another Forum that shows the effects of treatments in a room:










With the top row of boxes, the room has no treatment and has lots of reflections, as the ETC graph (column A) shows. The measurable effect of the reflections is seen in the ragged frequency response with lots of comb filtering (column B). Notice that as treatments are applied (e.g. the rows progressing top to bottom), frequency response becomes less ragged and more linear. 

But notice the “B” box in the last row: Even with optimal treatments in place, in this case at least frequency response is still in need of equalization. So, even though the treatments tamed the reverberation, they did nothing for the anomalies in response.

The comb filtering we see with the top row can easily be eliminated with REW’s smoothing feature and lets us see a response graph that’s more akin to the one we see in the bottom row. Equalization could easily be accomplished based on that. You’d get an improvement in sound quality even if you still have reverberation in the room.

Regards, 
Wayne


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## Wayne A. Pflughaupt

DanTheMan said:


> EQing the monitors above the transition zone is grounds the angels fear to tread--the informed but less savvy ones anyway.


 Hey Dan,

I noticed what you wrote on the last line of this blog, referring to this graph: “You can see that even though the microphone was in a very close position on all 5 measurements (each one had the microphone position marked), the measurements are significantly different above the modal/transition zone(s). So calibrating above the transition zone seems futile.”

It’s not necessarily futile. It’s largely a matter of being able to look at a graph and recognize which response anomalies would be audible and which would not. For instance, the sag in response one trace shows at ~ 8-10 kHz in all three colored groups _might _be audible, depending on the program material and one’s hearing capabilities (e.g., a young listener vs. an elderly one). The wide differences between traces in the 1 kHz range likely _would _be audible. Everything in between those two points – not so much. It would be impossible to audibly discern any audible differences in that range (between 1-6 kHz), despite what appears to be wildly divergent response to the untrained eye (e.g. one trace on the “upswing” and another on the “downswing” at a particular frequency).

The reason is that the ear is much less sensitive than the measurement mic. For example, if you were sitting at those mic locations where the measurements were taken you probably would not be able to hear any difference with program material.

Then there is the fact that if you take additional measurements in say, six months, you'll likely get a response graph that looks different than the first one. The temperature and humidity will be different on the latter measurement date, and that has an effect on the physical - and hence electrical - properties of the mic element. And as a consequence, any measurements it generates, even if everything sounds the same to you as it did when the first measurements were taken. To re-iterate, the ear is much more forgiving of these things than a measurement mic is.

Equalization in the upper frequencies isn’t about “correcting the room”, as you observed in one of the linked blogs. It’s merely about identifying trends in response that are significant enough to be audibly degrading, and correcting them. The results can be effective, as demonstrated in this thread. This is also true for recording: If you don’t address anomalies in response that your monitors have, you will simply end up compensating for that when mastering your recordings. For example, boosting frequencies where a trough might be measured, and cutting frequencies where the speakers might have a peak.

Since the ear isn’t as sensitive as a mic element, you can get satisfactory results simply by equalizing for the sweet spot - say, the center position of a couch - and they’ll be heard at the adjacent locations (naturally this can’t be an “absolute” rule given that every residential room is different). Personally I’m not fond of gating a measurement - perhaps for a FYI reading, but not for the purposes of equalizing: If room reflections happen to be effecting a measurement at certain frequencies enough to be audible, then that’s what I want to address, since that's what I’m hearing. Gating is most definitely not the same as smoothing. Gating removes the room reflections from the measurement, and as such is a useless measurement for equalizing and/or acoustical treatment.



DanTheMan said:


> I was really surprised by a recording pro/studio owner who has been in the business a long time... Just a few months ago, he had never heard of the equilateral triangle and getting your early reflections symmetrical!


Not sure what you mean by “symmetrical reflections," but Here’s an excellent article that dispels some common myths about early reflections and comb filtering.

Regards, 
Wayne


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## DanTheMan

Wayne A. Pflughaupt said:


> Room treatments and equalization often (if not usually) do not have a lot do with each other. Check out this chart below I recently came across on another Forum that shows the effects of treatments in a room:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> With the top row of boxes, the room has no treatment and has lots of reflections, as the ETC graph (column A) shows. The measurable effect of the reflections is seen in the ragged frequency response with lots of comb filtering (column B). Notice that as treatments are applied (e.g. the rows progressing top to bottom), frequency response becomes less ragged and more linear.
> 
> But notice the “B” box in the last row: Even with optimal treatments in place, in this case at least frequency response is still in need of equalization. So, even though the treatments tamed the reverberation, they did nothing for the anomalies in response.
> 
> The comb filtering we see with the top row can easily be eliminated with REW’s smoothing feature and lets us see a response graph that’s more akin to the one we see in the bottom row. Equalization could easily be accomplished based on that. You’d get an improvement in sound quality even if you still have reverberation in the room.
> 
> Regards,
> Wayne


The easier and free way would be to gate the graph.

Dan


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## DanTheMan

As far as EQing the trends, that's fine for HT. for recording it's really not. It's too easy to have a speaker hide one singer's sibilants or _____(name any sound nuisance).

As far as the reflections go, I wasn't worried about comb filtering at all. I was worried about source broadening. I'm picky about my soundscape.

Dan


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## DanTheMan

Here's the gated graph to that speaker next to the in room. Audyssey does a good job of getting it done actually even if it overcompensates a bit. It's also a very well behaved speaker. The one on Dr. Oliver's blog with the B&W is a different story-- though for HT, the Audysseyed version would be better. For recording, Audyssey would make it worse. ARC has override controls for this now I believe. Maybe the better versions of Audyssey do as well?

Dan


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