Building a studio in Norway

[Soundman2020]

Oh yeah! Now it's really starting to look like a studio. Nice work!

Have you done any acoustic testing yet, with REW?

- Stuart -

[joakims66]

No, i have not..thinking about doing it this weekend, but i have not got the spotlights for my roof hangers, so its a little difficult. Also, should i make the first reflection points dampers on the wall first? are they always needed? think there is a little too much reverb in the room right now when i clap my hands..thanks.

[Soundman2020]

It's always a good idea to do a "before" test, then a series of "after" tests, to see how the room responded originally, and how it responds after each new addition of acoustic treatment. That way, you can see what is working, what is not working, how well it is working, and how much you still need to do to get it where you want it.

So I'd suggest testing it now, just the way it is (and maybe taking out some of the treatment, if you can do that easily, to test it in a more "empty" state), then test it again after you put each device in place.

One major point with this approach: measure the exact location of the mic in the room the first time you do the test, then put it back in the precise same position every time you test, accurate to within a 1/4" or so. It is very important that you always test with the mic exactly in that spot. Even moving it a small amount will make your comparisons invalid. The readings will still be valid, but for a different spot in the room. If you want to compare graphs from different treatment additions, then the mic has to be in the same location every time.

- Stuart -

[joakims66]

thanks mate!

[joakims66]

Hi stuart, or anyone. I tried a rew test, but cant say i understood too much of the program. I have not taken any steps to the acoustics besides a cloud over the mixing board (for spotlights) and the room is furnitured as it is ment to be.. And i did the test on the KRK in front of the desk, not on the soffit mounted speakers.

http://www.filedropper.com/apr20104922krk

thanks!

[joakims66]

rew test.jpg

[Soundman2020]

Joakim, please read the forum rules for posting (click here). You seem to be missing something very important...

I tried a rew test, but cant say i understood too much of the program.

Did you calibrate REW using a hand-held sound level meter? The data you posted shows that the tests were done at a level of about 70 dB, but they really should be done at around 85 dB, which is the "standard" reference level for calibration. So please calibrate properly, and re-do the test.

But based on data, the decay time for the room is far too long and uneven. It is over 500 ms for low frequencies, and under 300 ms for the high end. There is also a large "hole" at around 81 Hz, and a smaller hole at 104 Hz., which could be due to many things, but I suspect floor resonance, or room modes. What are the dimensions of the room?

There's also a lot of early reflections within the first few milliseconds, which is going to cause problems, and those are most likely due to having the speakers so low and so close to the desk. That's probably also the reason for the dip in the low mids.

Also, you should do the test using the soffit-mounted mains, not the little speakers on the desk, and you should do one test for each speaker individually (Left and Right), as well as one test with both speakers on.

- Stuart -

[joakims66]

Stuart, not sure what you are reffering to about the forum guidelines. I included a location in my profile, if that was what you were thinking about. If not, please let me know..

Think i mentioned the room in my first posts, its about 5 meters long, and 4 meters wide. The roof is rising left to right from about 2.20m until 2.70m.

I included 2 resent pictures of the front and back of room. When i did the tests, the wool curtains in front of the windows were closed.

studio front.jpg

studio back.jpg

[joakims66]

here is a new test, calibrated with c weighted slow response SPL. used the soffit mounted event 2020 for the test, they are both turned down full on the bas response (-3 or -6?).

http://www.filedropper.com/krksplmatch_1

[Soundman2020]

I included a location in my profile, if that was what you were thinking about.

Yup, that was it!

here is a new test,

I clicked on the link, but there's nothing there: just the Filedropper web site itself, asking if I want to join up...

- Stuart -

[joakims66]

Sorry stuart, maybe it passed out on a time limit or something. ill try again..

http://www.filedropper.com/eventcal

[Soundman2020]

ill try again..

Great! OK, now I downloaded it fine.

Think i mentioned the room in my first posts, its about 5 meters long, and 4 meters wide.

Actually, the first posts just say: "The control room is about 24sq meters". And now you say it is only 20 m2. None of those are any use: we need exact dimensions, not approximations. Modes occur at very specific frequencies that are directly related to the dimensions of the room. The modes are very narrow-band resonance, so precise dimensions are necessary for predicting the modal response of the room. The REW data is showing lots of things that could be modal, but I need the dimensions of the room to be able to determine for certain.

The other thing I noticed is that there is a very, very large difference between the overall response of your left speaker and your right speaker, implying that the room is not symmetrical. You did mention that "the roof is rising left to right from about 2.20m until 2.70m", and that is probably part of the problem, but there seems to be more to it than just the difference in ceiling height. However, I would suggest that you start by fixing the ceiling problem, then look for what else might be causing the asymmetrical problem. It is absolutely essential that the room must be perfectly symmetrical, at least for the front half. The left side must be the mirror image of the right side, in all senses. Right now, there seems to be something very large and reflective close to the left speaker, which is not the case with the right speaker. That needs to be fixed.

Apart from that, the response is fairly typical of an untreated home studio, so that can be improved a lot with proper treatment. But first solve the problem with symmetry, then do another REW test to see what treatment is needed where. And also please provide the exact dimensions of the room.


- Stuart -

[joakims66]

Hi, yes the roof is rising. I put one cloud above the mixing position and was thinking putting up a couple more further back in the room.

I tried to make a drawing of the room, marked with inches. Is this room a problem?

room drawing.jpg

Here is my latest picture from the control room.

siste studio.jpg

Thanks! joakim

[Soundman2020]

Hi, yes the roof is rising. I put one cloud above the mixing position and was thinking putting up a couple more further back in the room.

Unfortunately, clouds will not fix the problem with symmetry of your ceiling: you need to physically make it symmetrical, by taking off the drywall, adding new framing, then putting new drywall on.

- Stuart -