Place for little Studio ok?

[headbanger70]

Hi guys,
I want to integrate in my flat a little place for a small studio.
Exactly I want to buy a pair of studio monitors to mix better my music.
But there is a little problem I think....the place is not really perfect for integrate some studio monitors. Because they must placed in the corner of the room.
Now I have heard and read that this would be a really problem for bass frequencies. What do you think?

For better understanding I have made a little sketch of the room situation.

thanks in advance for your help.

Cheers headbanger

[UltramegaOK]

Place the speakers on your desk on either side of your monitor. Better?

[Soundman2020]

Hi. Please read the forum rules for posting (click here). You seem to be missing a couple of things!

Because they must placed in the corner of the room. Now I have heard and read that this would be a really problem for bass frequencies. What do you think?

Why "must" they be placed in the corner? I don't see any imperative reason for that.

The correct location for your speakers is on stands behind the desk (between the desk and the window), about 40cm away from the walls, and 10cm away from the window. That 10cm gap is where you will need to put a 10cm thick panel of suitable porous absorber, such as OC-703 insulation or something similar. The height of the speakers is 120cm.

All of the above dimensions refer to the location of the SPEAKER AXIS, and not to the location of the sides, top or bottom of the speaker box, nor to the location of the woofer or tweeter. If you don't know where the acoustic axis of your speaker is, ask the manufacturer.

Do not , ever, put speakers ON the desk! That's a huge mistake. Very commonly seen, but a big mistake for oh-so-many reasons. Only ever put them on stands, and the stands must be massively heavy. Some people use stacked up bricks, others use staked up concrete blocks, and still others use hollow steel frames filled with sand.

You did not mention the size of your room, so it's impossible to give you more instructions than that.


- Stuart -

[headbanger70]

The correct location for your speakers is on stands behind the desk (between the desk and the window), about 40cm away from the walls, and 10cm away from the window. That 10cm gap is where you will need to put a 10cm thick panel of suitable porous absorber, such as OC-703 insulation or something similar. The height of the speakers is 120cm.

Thanks 1st for your feedback.
As I unterstand you right I should install between the speaker and the window this absorber. But then I will put them in front of the window.
Theoretical I could move my desk a little backwards into the room. So I can put between the desk and window on stands my speakers. But then I would have my mentioned problem as written above....covering the window with absorbers.
So is the only chance for a placement the corners or near the corners of the room

And the height of the speaker is not to high? Your have written 120cm....
This one are approx 30cm --> https://www.thomann.de/de/jbl_lsr_305.htm

[UltramegaOK]

Stuart, do you suggest not placing speakers on desk due to vibration concerns coloring the sound? Or is the concern reflections? Would placing them on mopads or similar on top of a raised heavy platform, like 6 inches of wood block or just more vibration resistant foam reduce the vibration concern? And, would placing angled reflection wedges on the desk in front of the speakers help? I've seen some pro desks incorporate angles to direct the reflections below ear level and wondered about the effectiveness.

And, I've read that SBIR is a common issue when speakers are placed off the front wall. Some suggest closer to almost touching the wall is better than placing them off thr wall and using 703 behind them. If i understand the theory, 703 or other thin treatment behind the speakers just isn't effective below 125Hz. What are your thoughts about the omni nature of LF from speakers and would the location of the speakers port front or back change your recommendation?

Thanks.

[Soundman2020]

As I unterstand you right I should install between the speaker and the window this absorber. But then I will put them in front of the window.

Correct. Yes. You have no choice: with speakers inside the room, there will ALWAYS be SBIR artifacts (SBIR = Speaker-Boundary Interference Response), caused by the major reflection coming of the wall that is directly behind the speaker (in your case, the wall is the window). This is unavoidable. The only question is: "What will the SBIR frequency be?". That depends on one single thing: the distance between the speaker and the wall. If the distance is very large (more than about 3m), then the frequency will be so low that it is below the lowest frequency that humans can hear. If the distance is between 3m and about 60cm, then the frequency will be in the range 30 Hz to 130 Hz, where the wavelength is way too long to be treatable, so those distances must ALWAYS be avoided. If the distance is less than about 60 cm, then the frequency will be above 180 Hz, where the wavelength is short enough that it CAN be treated, and MUST be treated... by a thick porous absorber. If you don't put treatment there, then you WILL have SBIR artifacts in your frequency response.

But then I would have my mentioned problem as written above....covering the window with absorbers.

You don't really have a choice, if you want to avoid the SBIR problems...

And the height of the speaker is not to high? Your have written 120cm....

Correct. The ACOUSTIC AXIS of the speaker should always be roughly 120cm ABOVE THE FLOOR. I'm not talking about the physical size of the speaker cabinet itself! I am talking about how high the entire speaker must be ABOVE THE FLOOR, and that is measured from the floor to the ACOUSTIC AXIS of the speaker.

---

Stuart, do you suggest not placing speakers on desk due to vibration concerns coloring the sound?

Both of those, and many more. Putting the speakers on the desk or on the console meter bridge, is about the worst possible place you can have them. They speakers will transmit sound into the desk or console structure itself, and that sound can then be re-radiated from other parts of the desk or console, and arrive at your ears BEFORE the direct sound form the speakers (because sound travels much faster in solids, such as wood and metal, than it does in air). You will also get reflections from the desk or console surface into your ears, which cannot be treated (well, you COULD treat it, but it's hard to operate a console that has a 4" wad of insulation on top! ), as well as comb filtering caused by the desk/console itself, and all the things on top of it. And your frequency response in the lower mid range will be messed up.

Would placing them on mopads or similar on top of a raised heavy platform, like 6 inches of wood block or just more vibration resistant foam reduce the vibration concern?

That would help a bit to reduce some of the transmission into the desk structure, yes, but it wont do anything for the reflections, comb filtering, and frequency response issues.

And, would placing angled reflection wedges on the desk in front of the speakers help? I've seen some pro desks incorporate angles to direct the reflections below ear level and wondered about the effectiveness.

If the speakers are far enough beyond the desk, then yes, that can help. But if they are ON the desk or close to it, then all bets are off. Also, don't forget that placing barriers in front of a sound wave does not actually "stop" the sound wave: it can reflect some of it in different directions, yes, but based on frequency: it will only reflect waves that are significantly shorter than the dimensions of the "barrier". Waves that are a lo longer will g around the barrier as though it were not even there, and waves with wavelengths around the same size as the dimensions of the barrier will be partly reflected and partly diffracted around the edges, once again creating artifacts. With careful design, those issues can be minimized, but they will still be there.

And, I've read that SBIR is a common issue when speakers are placed off the front wall

Exactly. Which is why speakers can only be placed away from the front wall if the room is large enough to do that. And since the effect depends on the frequency response of the speakers, if you have large speakers that go low, then you need a very large room. For example, if your speakers are putting out significant energy down to 43 Hz, then you cannot place them closer to the front wall than about 2m. If they go down to 30 Hz, then you need at least 3m. Of course, I'm assuming that you are also playing music with significant content at those frequencies: if not, then you probably wouldn't buy speakers capable of going down that low!

Some suggest closer to almost touching the wall is better than placing them off thr wall and using 703 behind them.

Not true. The artifacts will just be higher up the scale. Which is probably even worse! If the artifacts are up in the center of the mid range, then they will be VERY audible if not treated. SBIR is a comb filter, so the issue STARTS at a certain frequency, then the comb-filter pattern extends from that point all the way to the top end. If you don't damp it, then you have problems...

If i understand the theory, 703 or other thin treatment behind the speakers just isn't effective below 125Hz.

The manufacturer of OC-703 does not agree with you:

OC-703-specs.jpg

According to that, 4" (10cm) of 703 is VERY effective at 125 Hz, and much lower too. In fact, theoretically porous absorption is effective down to wavelengths that are only about 3% of the absorbers thickness.

In any event, 125 Hz is already plenty low enough, since the SBIR dip will occur at frequencies that are much higher than that for all distances below about 50cm. Which is why the speaker should be about 10cm away, with 10cm of OC-703...

What are your thoughts about the omni nature of LF from speakers

I'm not sure what you mean: low frequency sound is omnidirectional, yes, in the sense that our ears find it hard to determine the exact direction from which it is coming, but even low frequencies still reflect from solid surfaces, which is what causes SBIR. And even at higher frequencies, there are other nasty artifacts, such as edge diffraction.

would the location of the speakers port front or back change your recommendation?

No, not really. As long as you compensate for the proximity, there should not be a problem. Rear ported speakers can still be placed close to porous absorption panels. Rear ported speakers can even be fully enclosed in "soffits" (flush-mount systems), provided that the correct precautions are taken. For example, in this studio: www.johnlsayers.com/phpBB2/viewtopic.php?f=2&t=20471 those speakers are Eve Audio SC-407's, which have huge bass reflex ports on the rear. Yet they are fully enclosed in a soffit mount system. As you can see, the final response that we achieved in that room did not suffer at all, and in fact was enhanced to a large extent. As long as you understand what you are doing, what the consequences are, and how to deal with that, then there's no issue with the vast majority of rear-ported speakers. And of course, front-ported speakers are not a problem at all.

- Stuart -