I can see it is a very complex and trial and error process to achieve a fine tuned treatment but there is also a foundation that rules which is the room dimensions.
Room ratio (= room dimensions / room modes / modal behavior / modal spread) is just one aspect of studio design. There are many aspects that I take into account when I'm designing a room, and ratio is only one of them. It's not even the most important one (unless the ratio is really bad).
The current dropped ceiling is around 2,43
If you have a drop ceiling in your room, then start by taking it out! Drop ceilings are no use for studios, and they don't change the modal behavior in any case. Room modes are low-frequency standing waves. They form between the massive, hard, rigid, solid boundaries of the room. Light-weight thin soft "acoustic" drop ceilings do practically nothing to affect room modes. So take out the drop ceiling, and wither leave the original hard boundary ceiling as it is, or build a new "inner-leaf" ceiling below that, properly decoupled from the original ceiling. If you leave the original ceiling as it is (probably the best option), then you could improve modal response by hanging a hard-backed ceiling cloud at an angle of the front of the room (between the speakers and the desk), then putting absorptive treatment over most of the rest of the ceiling surface.
I've done a few room modal calculations inputing my dimensions and oddly enough it seems that a lower ceiling considering my WxL would be more beneficial.
True, but I would not do that in your room. If you lower the ceiling, you reduce the room volume considerably. That's not good. Your room is already small, with low volume, so you need to maximize that. The modal behavior would be better with a lower ceiling, but in your case total volume is more important. Lowering your ceiling by 15cm reduces room volume from 33m³ to 31m³. Not good. The improvement in modal response is small, but the loss of room volume is large....
In any case, those are the dimensions of the outer shell of the studio: the actual final dimensions for the inner-leaf will be less than that. Those are the dimensions you need to use.
Do you think it is possible to soffit mount the opals?
Yes, certainly.
I mean, they are active and really high power rated, I imagine they can get really hot so maybe it would require some kind of active cooling?
According to the manual, typical power consumption is around 250 Watts, with maximum peak power at 750 Watts. With a properly designed soffit, that should be possible to handle just with convective cooling, but to be safe you could put in some small fans somewhere, to ensure adequate airflow.
Rock wool 80 kg/m³.
That's too dense for good low frequency adsorption. Optimum density with most types of mineral wool is about 50 kg/m³, and you could go a little lower than that, if you wanted better low frequency absorption.
the recommendation was to stuff all empty space with rock wool panels as much as possible.
That recommendation is correct, but the density is not.
The test was done with both monitors positioned as such:
Should I repeat with one monitor only? if so where should I place the mic?
I thought the test was supposed to be stereo, my bad
, I will remeasure with one speaker only and include in the file.
OK, I took a look at your test data, and there are several things wrong with the way you are testing.
First, your levels are too low. You did the tests at a level of about 68 dB, but you need about 85 dB. Low level will probably not trigger all the modes. So check that your system is calibrated correctly (using a proper hand-held sound level meter), then repeat the tests at 85 dB.
Second, you only ran the tests from 30 Hz up! Your Opals are capable of much better than that, and you are not testing the low end of the room response. Run your tests from 15 Hz to 22 kHz.
Third, your speakers seem to be set up VERY differently: Check that all of the controls on both speakers are set to the "0" position, and that there is no EQ on your console, sound card, pre-amps or anywhere else in the signal path.
Fourth, your speaker/mic positioning is not correct. Set up your mic 145cm from the front wall, on the center-line of the room (equal distance form both side walls) and with the tip of the mic 120cm above the floor, angled upwards at about 60°.
Then set up the speakers so the
acoustic axis (
not the center of the woofer cone!) is 120cm above the floor, and 84cm from the side wall (so the speakers will be 132cm apart). The acoustic axis of the speaker is the point where the sound seems to come from. Most manufactures provide that information. You might need to contact them to ask, but I would estimate that it is about 30cm up the front baffle, roughly, and on the vertical center-line of the speaker. Angle the speakers so that they are both pointing at the same spot about 30cm behind the mic. Make sure that the rear corner of the speaker is about 10cm away from the front wall. That is approximately the correct geometry for your room (empty).
Run your REW tests like that. Also, use the "start delay" option on the measurement window of REW. Set that to give you enough time to get out of the room and close the door, plus a couple of seconds for the sound and air to calm down a bit. It's not good for you to be inside the room when you do the measurements, since your body can change the readings, and you would not be in the exact same position every time in any case. So it is better for you to be out of the room. Also set "Sweeps" to 2,
With the system set up like that, calibrate everything to do the tests at a level of 85 dB for each individual speaker, without clipping or distortion, then do not touch the settings after that!
Do one test with just the left speaker, one test with just the right speaker, and one test with both speakers. Mark each test in REW to identify it.
Oh, and one more thing: don't use the Eggs for this test. Use the Opals.
What do you think about a design like this?
I think that would cause rather severe artifacts in the mid range, and not provide enough bass trapping or first-reflection treatment...
It would be better to go with a conventional design concept that is known to work, rather than trying to invent an entirely new concept.
It is all absorbers
No it isn't! You have major diffusive and reflective elements all along the sides! Those vertical slats.... They are all the same size, depth and spacing, so they will be causing strong lobing patterns... As well as probably acting as tuned devices, absorbing some frequencies more than others...
but maintaining the idea of splaying and angles.
I'm not seeing that in the design you showed. You are splaying your TREATMENT, not your WALLS. In order to created an RFZ concept, the actual walls (or soffits) need to be splayed. Your angles are also wrong. You will need much larger angles than that in small room, to create a proper RFZ.
Calibration MIC is a SonarWorks with calibration file for 0degree position.
Nice mic, but your photo shows the mic pointed directly towards one of the speakers. That's fine if you want to measure the SPEAKER response in an anechoic chamber, but not for measuring ROOM response. Point the mic straight forwards, and angle it upwards 60°. Make sure the tip of the mic is 120cm above the floor.
Have never seen a spectrogram and waterfall like that lol , looks like a mess
Right! That's because you did not do the measurements correctly, and also because you are not looking at the data correctly...
Please set up the room as I described above, and do those three tests, then post the new MDAT file for us to look at and analyze properly.
Here is a conceptual modular idea based on the previous post.
... and it still has numeric-sequence diffusers in it!
Forget about those in such a small room. Read the book by Cox and D'Antonio on diffuser theory and design, to understand why this is a bad idea...
You also need to adjust your camera parameters in the render engine to something more realistic! The settings you have right now are hugely distorting the perspective. Use real-world camera settings.
- Stuart -
Double glazing????