Here´s my graphs. Comments please :-)

[Mastergod]

Here I managed to get the pics as thumbnails :-)

[jim1961]

Id like to see 1/24th smoothing over the whole band.

[Mastergod]

Here it is...

[Glenn Kuras]

For the room being pretty much square and that small it is not looking all that bad. Would have liked to have seen decay times shorter below 100 hz though. I have seen a lot worse though.

[Mastergod]

Hi Glenn.

Thank you for your comments!

How do I make the decay times below 100hz shorter?

Is this done with more bass trapping? I have not yet
trapped floor - wall corners.

/Henning

[Glenn Kuras]

Is this done with more bass trapping? I have not yet
trapped floor - wall corners.

Basically yes and for your room make them as large as possible. You will only get a square room so far. In the end you will know how well the room is when you do a mix. Either it translates well on other systems or not. That truly is the test of all tests. . I went though your build thread and did not see anything about the back wall. I might have missed it, but you want THICK absorption in that area also.

[jim1961]

The low end looks pretty reasonable, but that lull from about 1800hz -5k I would address.

[Mastergod]

Thank you for your answers!

Glenn:

Yes, there are three panels on the back wall. The same as on the side walls.
I will do more bass trapping.

jim1961:

About that that lull from about 1800hz -5k. How do I address that issue?
Any ideas?


I have no carpet on the floor in the listening position.
I have not bass trapped any floor - wall corners.
I have the possibility to add to more panels on each side wall.
I have the possibility to add two more panels on the back wall.

/Henning

[Yosem]

I usually test speakers and microphone in free field at the same position that in room, and after that i can compare to what the room is doing with the sound.

Maybe your problem with high frecuencies is the measurement microphone...

[jim1961]

There is no quick or packaged answer. I do agree making sure your mic is performing accurately maybe a good place to start.

Otherwise, try changing your setup. Moving speakers farther apart, farther from close surfaces, enlarging your triangle, downsizing your triangle, changing the toe-in, changing speaker and/or listening height.

[Yosem]

Mastergod, do you measure both speaker at he same time?, are both exactly at the same distance to the microphone, more or less is not valid

[jim1961]

Originally Posted by Yosem

Mastergod, do you measure both speaker at he same time?, are both exactly at the same distance to the microphone, more or less is not valid

That is a good point. I get something very to similar as Mastergod (upper midrange null) if I run both channels at once.

[Mastergod]

Hi.

I am measuring using both speakers at the same time. Should I not?

I have now added one more panel on each side wall and added a rug under the listening position. I addition I added a little bit of bass trapping floor to wall on the back wall (I will bass trapp more, but didn´t have more at the moment).

The blue is the new graph.

I also see that the decay below 100hz have been shorter. It also seems like something positive thing has happened to 1800hz -5k.

The blue is the new one....

[Mastergod]

The microphone is placed the same distance away from both speakers.

[jim1961]

Originally Posted by Mastergod

Hi.

I am measuring using both speakers at the same time. Should I not?

NO, you should not.

[Mastergod]

Hi there.

According to this article on Real Traps you should use both speakers at once (and it says it is a good idea to also do each speaker seperatly).

RealTraps - Room Measuring Series

[Mastergod]

Here is measurement of each separate speaker also.

Blue = Left speaker
Green = Right speaker
Blue = Both Speakers

All the best!

[Jens Eklund]

Originally Posted by Mastergod

According to this article on Real Traps you should use both speakers at once (and it says it is a good idea to also do each speaker seperatly).

The opposite is the normal procedure: measure each speaker separate but combined might also be useful but normally not needed. If 2/5/7 (or whatever) .1 systems, you naturally want to measure each (or at least L&R) speaker with (and possibly also without) the subwoofer.

[jim1961]

Originally Posted by Mastergod

I also see that the decay below 100hz have been shorter. It also seems like something positive thing has happened to 1800hz -5k.

The blue is the new one....

If you thicken your panels, you may reduce / eliminate that wavy nature. Something to try.

[Mastergod]

Hi again.

What does the wave nature mean? What is the issue when the graph look like it does?

/Henning

[jim1961]

An issue like this is getting a bit out of my area of knowledge, but its probably some sort of oscillation or resonance.

You get that wavy nature when a freq bounces back and forth between two surfaces. Their maybe other causes as well. When you added some more panels, you got those 1.8-5k frequencies responding higher, but there is something going on and I suspect a better more broadband absorber may help things. The panel you are using I suspect is only partially mitigating the problem.

[Mastergod]

Thank you for your answers.

I will continue testing tomorrow, add more bass traps and wall panels. Move things around, try alternative speaker placements etc.

/Henning

[Mastergod]

Hi there...

I have now added more bass traps and two more panels on the side walls. It seems like the bass trapping again made the low end decay shorter, but except from that, the graph seems more or less the same to me.

I will add even more bass traps during the weekend which means that more or less all corners will be covered top - down (wall - wall, wall ceiling, floor - wall).

The name of the pictures tells if the graph/waterfall is left, right or both speakers (I see the whole name when I open them).

Red = Left speaker
Purple = Right speaker
Green = both speakers

How does it look now?

All the best,
Henning

[Glenn Kuras]

Keep in mind that getting a room +/- 7 db or so is considered pretty darn good and you have a small, close to square room so it might be about as good as you can get. The key is to reduce decay times which is more important, IMHO. Getting the decay times in line on the low end will result in clarity.

[Mastergod]

Hi Glenn.

Thank you for your replay!

I am not sure what you are saying. Do I have +/- 7db?

I see that the low end decay is getting more and more in line and shorter when I add more bass traps. I still have the possibility to add more bass traps (floor - wall) and will do that tomorrow.

/Henning

[jim1961]

Originally Posted by Mastergod

Hi Glenn.


I am not sure what you are saying. Do I have +/- 7db?


/Henning

He is saying that you have a 14db deviation from your highest peak to your deepest lull.

[Glenn Kuras]

Originally Posted by jim1961

He is saying that you have a 14db deviation from your highest peak to your deepest lull.

Yes

Note to self, I need to write an article on this.

[Mastergod]

Okey, but +/- 7 db, a 14db deviation is good if understand you right Glenn? So if I get the low end decay in line, my room is in pretty good shape given the shortcommings of small room like mine?

/Henning

[jim1961]

Originally Posted by Mastergod

Okey, but +/- 7 db, a 14db deviation is good if understand you right Glenn? So if I get the low end decay in line, my room is in pretty good shape given the shortcommings of small room like mine?

/Henning

How good something is based on its context. Small rooms with less than ideal dimension ratios are harder to deal with than larger rooms with more ideal ratios. Thus, +/- 7db is good, considering your constraints, but not ideal. +/- 5db would be better, +/- 3db approaches as good as anyone gets in any room @1/24th octave measurements.