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Discussion Starter #1 (Edited)
Hi guys, i'll introduce myself as most of you dont know me.

My name is Matthijs, 28yo and i'm from the netherlands. (so my writing might nog be perfect :))


Im currently setting up my new room which is meant for professional mixing purposes.

The lengt of my room is 5.65 (Meters)
The width is 3.48 (meters)
The highest point is 2,75 (its not a flat ceiling)

So with this information i made up some calculations where to put my speakers
and where would be my listening position. I had read the listening position should be around 30 till 38 % from your
front wall. So i did.

I placed everything (besides the lengt of course) exact in the middle and have setup the triangle as precice as possible.

My listening position is now at : 2.05 from the front wall which is 36 %

Im giving all this information becouse my graph gave me a big dip around the 100 hz and im being told i should experiment with
moving my listening position and or my speakers position. The only thing im concernt about is how to go about it becouse
every inch would make a big change in the symetry and even possibilities of placement.

So my question is, what would be the best and most effective way to find out where the dip is comming from whitout constantly changing my whole setup just to test if something changed, i mean there should be some guidelines right which makes things easyer ? Isnt there a way to find the source with the information given in the graphs ?

Here are some photo's of my measurements and the room im working in.

As you can see the dip is around 15 db, tho this is probably 5 db to much becouse my spl reading gives 5 db lower when doing the subwoover test.

I tried diffrenct mic placements with symetric angle towards my speaker, and i tried putting a absorb panel in front of my tv just to see if it does something with
reflections or buildups, and i checked to see if it makes a diffrence when i put my refference monitors away. Not big diffrences on all.
 

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First, When you are making changes, all you move is the mic. If you move the speakers and the mic, you have 2 variables and no idea what changes are related to what. You always only want to only change one thing at a time. Also, you appear to have a very high level of smoothing applied which makes it pretty much impossible to determine really where things are. Turn the smoothing off when trying to identify where things are coming from.
 

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Discussion Starter #3
Okay, thank you, that makes sense indeed.

I removed the smoothing, and of all tests moving the mic was the one which gave the best results.
i moved it 20 cm towards the speaker which gives me less spikes and is overall a bit better but it doenst look like the source of the problem.

Do you have any sugestions on how to find the source more accurate ?
 

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Just to understand a little more about your speaker setup are you using a small subwoofer?
 

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Bryan would be the best person to talk to but until he responds Im thinking because you have many reflective surfaces in the room that could be causing cancellation. Have you tried putting down a thick throw rug on part of the floor?
 

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How far are the speakers from the wall you are facing and what position is the mic in for this measurement?
 

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Discussion Starter #8
Tonyvdb, thank you for your input, i tried the floor on diffrent locations but it didnt make any big changes, some frequenties went a tiny bit better but it also created extra spikes.

@ bpape : from front tweeter to wall is 1 meter (diagonal)
76 cm when measured from the back of the speaker. (diagonal)

Sidewall till tweater is 87 cm by the way.

My mic is pointing up.
 

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Tonyvdb, thank you for your input, i tried the floor on diffrent locations but it didnt make any big changes, some frequenties went a tiny bit better but it also created extra spikes.

@ bpape : from front tweeter to wall is 1 meter (diagonal)
76 cm when measured from the back of the speaker. (diagonal)

Sidewall till tweater is 87 cm by the way.

My mic is pointing up.
I hazard a guess that going by 87cm that it could be a sidewall 1/4 wavelength cancellation?
Caveat being I am no expert and just trying to learn
 

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Discussion Starter #10
How is that a 1/4 wavelength cancellation ? woudnt 1/4th be 25 cm ? or maybe im missing the point , but from what i have read is that the sidewall length shoudnt be an equivalent of the length from the wall behind the speaker. so if im right, that would mean cancelations would be most probably at 25, 50 75 in my case or maybe i didnt understand this part well enough, im curious as well :)
 

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How is that a 1/4 wavelength cancellation ? woudnt 1/4th be 25 cm ? or maybe im missing the point , but from what i have read is that the sidewall length shoudnt be an equivalent of the length from the wall behind the speaker. so if im right, that would mean cancelations would be most probably at 25, 50 75 in my case or maybe i didnt understand this part well enough, im curious as well :)
395.4Hz = 87cm
395.4Hz/4 = 99Hz

or

speed of sound 344.5/87cm = 396 Hz /4=99 Hz
or
99Hz = 347.47cm /4 = 86.8cm

As I say I am a novice so could be looking at this completely wrong

Move the speaker and see if 100Hz changes.
Please let me know if it helps
 

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I would get the speakers closer to the front wall. I still don't know where your head is.
 

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Discussion Starter #14
Oh im sorry i didnt get that, i thought you where refering to pointing up or pointing at the speakers. My head or mic posistion is 1 meter 50 from tweaters till head . I tried allot of diffrent things today, I found that changing the length to sidewall mostly just shifts the frequentie dip. Placing it more to the front wall did made a change and even some out around that area, gained 6,7 db there so thats great but still not perfect. The subb is a diffrent story tho, i had found one position where the sub and the 100 hz where pretty good but i could only get this to work in a direction where its not pointing to the center of the room. Is this useless information or can i do something with it ? obviously i cant make a working triangle this way.
 

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I need to know where your head is in relation to the wall, not the speakers. Don't worry about the sub not being pointed out into the room. Bass is omni-directional.
 

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Discussion Starter #16
Ah okay, i posted this in my first post i think, its 2.05 from the front wall which is 36 % from the whole length of the room. I had read that this (1/3 till 38 %) would be the most ideal position for the listeing position to be in.
 

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Sorry - didn't remember that. Honestly I would try to get the monitors as close to the wall you are facing as possible and then set up in an equilateral triangle about 3.3 meters.
 

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Discussion Starter #19
its not possible that way , The width of my room is 3,50 besides that the foot of the stand also takes some space and theres also a wooden box that covers some gas pipes. the best i can get is (from tweeter to tweeter) 2.50 at an equilateral triangle. maybe a little bit more if i buy diffrent stands and cut som of that box away. but 3.30 is pretty much impossible.

If im not wrong this 3.30 would also be the minimum for it to work right ? it looks to me this settup is using the same principle as i aplied before only then backwards. like a third from the back wall in stead of the front, is that right?

I did some measurements annyway to see what it does. And it helps at the 100 but it creates some other problems as well.
 

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Get it the best you can and then treat the wall that you are facing with some panels that are 4-6" thick.
 
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