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PostPosted: Mon Dec 17, 2018 5:24 pm 

Joined: Wed Mar 30, 2016 1:16 pm
Posts: 1
Location: Melbourne, Australia
I've just started renting a room off a buddy for the purposes of using as a home studio during the day.
I've dabbled with mixing and recording for quite a few years now but this is the first time I've had the option available to me to actually set up acoustic treatment and do things in a much more controlled manner.

I'll do my best to provide all details and measurements as accurately as possible, but I am a total noobie at this so I apologise if I leave anything out etc (I read all the rules about posting beforehand I promise).

Things I'd like to achieve with this post:

- Understanding where (and why) I should place my nearfield monitors (yamaha HS80m's)
- Understanding the least invasive methods available at my disposal to treat the room for reflections etc.

I've made a 3D representation of the room in sketchup (The red panel on the wall is a cupboard door) which you can find attached to this post.

I'll be using the room primarily for tracking DI guitars and mixing with occasional reamping and vocals done here as well.

My budget is roughly $1000au but I can be flexible with that if I need.

Thanks in advance!

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PostPosted: Tue Dec 18, 2018 1:22 am 
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Joined: Thu Aug 21, 2008 10:17 am
Posts: 11888
Location: Santiago, Chile
Hi there "Theo-g" and Welcome! :)

Congrats on setting up your first studio! There's a lot to learn...

Fortunately, you are not alone: A LOT of forum members have done the same thing you want to do. There's a lot of info on the forum, in their threads, and you can probably find some of those if you search through the forum. So I'll just give you a brief run-down of the main points.

(I read all the rules about posting beforehand I promise).
:thu: :)

First, your room is very small, so it will need a huge amount of treatment. Specs for control rooms call for a minimum floor area of 20m2: you have a little less than 10m2, including the alcove where the door is, so it's going to be a big challenge to get that room treated suitably for mixing.

- Understanding where (and why) I should place my nearfield monitors (yamaha HS80m's)
As I mentioned, it's a VERY small room, so the only possible locations for your speakers is tight up against your front wall. And the only possible "front wall" is the one to the right of the window. So the window will be on your left as you are sitting at the desk mixing, with the closet door on your right. That blank wall is your "front"- Set up the speakers on rigid, massive (heavy) stands that get them to the right height. The "right height", is 120cm above the floor. That is the height of the acoustic axis, not the height of the top or bottom of the cabinet, nor the height of the tweeter or woofer. The manufacturer of your speakers can tell you where the acoustic axis is. It should be in the manual, or on their website. If not, we can help you estimate it. In fact, the speakers can go a little higher than the "standard" 120cm: maybe 123 to 125. Reason: That's your ear height when seated! The speakers must be at the same height as your ears, such that your ears are on-axis to the speaker. On-axis is where you get the best, cleanest sound.

Those flimsy stands in your photo are not much use here, sad to say. The stands need to be massively heavy, and rigid. Reason: To prevent the speaker transmitting vibrations into the stands, which can re-radiate them into the room, and also transfer them down to the floor or desk, which in turn can re-radiate them into the room. Some people stack up concrete blocks to use for speaker stands, others make them from hollow steel or PVC tubes, pipes, or sections, filled with sand. Etc.

The speakers will need to go decently far apart, about 68cm from the side walls, which means they will be about 142cm apart. Once again, that is measured to the acoustic axis of the speaker, NOT the sides of the cabinet. So set them up like that, with a 10cm gap between the back of the speaker and the front wall. You will insert a large panel of porous absorber in that gap-. Reason: SBIR, meaning "Speaker-boundary interference response". That's a big subject all by itself, but basically your speaker sends out all low frequencies in a spherical form, all around it, meaning tht some of the energy goes backwards from the speaker. That wave hits the wall, bounces back, and interferes with itself, causing a massive dip in frequency response where the wave cancels itself out. The frequency of that dip depends on one thing only: the distance between the speaker and the wall. The further the speaker is from the wall, the lower down that dip is. IF the room is very large, you can move the speakers far enough away from the wall that the dip is below the cutoff for your speakers, or below the bottom end of human hearing. But that implies that the speakers would have to be several meters away from the front wall: not possible in most home studios. So the next best alternative is to push them up tight against the wall, so the SBIR dip occurs in the lower mid range. Why? Because in that range, it can be treated with porous absorption! If you leave the speaker 50cm or a 1m away from the wall, the dip is in the low range, where porous absorption can't treat it properly, but with just a 10cm gap the frequency is high enough that porous absorption can have a useful effect. By "porous absorption" I mean either fiberglass or mineral wool insulation, and a 10cm thickness of that is enough to have a decent effect. If you make it thinner, the speakers would be closer to the wall, so the frequency would be higher, which you'd think is good, but there would not be enough thickness to do the job, and if you make it thicker (eg, 20cm), then the speakers are too far from the wall, so the frequency is too low. 10cm is a good compromise.

So, at this point you have your speakers sitting on massively heavy rigid stands, with the acoustic axis about 120-125cm above the floor, and about 66cm from the side walls, and a gap of about 10cm away from the front wall.

Now comes the "toe-in" angle: how much the speakers need to be angled inwards. That depends on the location of your head. So next up, is setting the right spot for the "mis position": where your head will be.

There's a theory that says the best spot is 38% of the room depth (distance from front wall to back wall), which would be 118cm in your case. So that's where your EARS should be. However, this "rule" is not written in stone, and is not really a rule at all! Some people take it way too seriously: It's just a starting point, or guideline, and often the best spot i a bit in front of that (closer to the front wall). You can experiment later, but for now, start out with your chair set up such that your ears are 115 cm from the front wall.

Now, here's the strange part: If you google "speaker setup", or check most speaker manuals, or check manufacture's websites, or many other websites, they'll tell you all about the mythical "equilateral triangle", which apparently has some magical or sacred properties. Supposedly, if you have your speakers and your head set up like this, all the same distance apart, and with 60° angles all around, then the world will be a wonderful place, and you'll make perfect mixes every time! Except that it isn't true! Because if you do that, setting your speakers (for example) 2m apart, and with each speaker being 2m away from the middle of your head, on a perfect equilateral triangle, then a strange things happens: the speakers are now aimed at your EYES! Not your ears. :shock: :roll: So, if you want to get your ears surgically transplanted on to your eyeballs, then that myth might work. But for ordinary people whose ears are way out on the sides of their heads, a long way from their eyes, the speakers need to be angled further out, so that the speaker axis points a your ears, not your eyes. In fact, the axis needs to point a bit past your ear, just sort of grazing the edge of your pinna (that fleshy thing that sticks out the side of your head). Psycho-acoustically, that's the best spot to aim for.

To figure that out, set up a vertical pole about 30cm to 50cm behind where your head will be (a mic stand set up vertically, for example), and aim both speakers at that. If you check the geometry, you will find that the speaker axes are now grazing past your ears, when you are seated at the mix position, as it should be.

So, you might be wondering: If it is no use, then why do all those books, manuals and websites show that triangle? Simple answer: it works for pretty much every room, to give a reasonably decent response. But it is not optimal for ANY room! So the manufacturers give that layout that sort-of works everywhere, but isn't really good anywhere. In reality, one size does not fit all. Every room is different, and each needs it's own layout. They can't be bothered to go to all the trouble of explaining the above in their manuals, so they just take the easy way out: A "standard" layout that sort-of works usually.

There's another reason, too: supposedly to "standardize" control rooms, so that no matter which control room you go to, you will always hear the exact same stereo image and sound stage, so all mixes by all engineers in all rooms will always have perfect panning and stereo imaging and sound-staging. Except that they don't! If you listen to a dozen current top hits that are heading the charts, and look at them on a vectorscope (phase oscilloscope), or direction meter, or just plain listening to them, you'll easily see that they do NOT all have the same sound stage or stereo image! Some sound "wide", some sound "narrow", some have "depth" some are "flat", some are "enveloping around you" some are "stuck in the middle of your head". Yet all of them were mixed in top control rooms with the speakers set in the infamous equilateral triangle. So much for standardization! Clearly, it doesn't work. On the other hand, if you set up the room properly, so that it is neutral while giving you clear depth perception, a clean sound stage, and broad stereo imaging, then you can clearly hear exactly how you mix sounds, and make it sound any way you want it to sound.

OK [RANT-MODE = OFF] Back to your room.

So now you have your mix position and speakers set up in the theoretical best arrangement, psycho-acoustically speaking. Now just listen. Listen to songs you know very well, listening critically, and try moving the mix position and speakers just a little, to see of you can find a better spot. Move your chair forwards/backwards in small increments (a cm or two at a time), and the same with the speakers: set them wider apart, or closer together, 1 or 2 cm at a time, then re-orient them to point correctly behind your head, and listen again. Better still, use REW to help you find the best spot, instead of relying on your ears alone ( viewtopic.php?f=3&t=21122 . ).

As you do that, listen to the bass mostly, to find the spot where you have the smoothest, tightest, cleanest bass.

You will find that the very best layout is NOT far away from the initial theoretical "best" layout. It certainly won't be more than about 20cm away in any direction.

- Understanding the least invasive methods available at my disposal to treat the room for reflections etc.
Your room is very small: you will need major bass trapping. Reason; In small rooms, modal issues are huge. In very large rooms, there are no modal issues, so the don't need much bass trapping, because there's plenty of modes at all frequencies: thus, a true reverberant field. But as the room gets smaller, there's fewer and fewer modes in the low end, which is a problem. The smaller the room is, the worse it gets, and the more bass trapping you need. That goes on your rear wall, mainly, but also other places. Ideally, you would have full-size suerpchunk bass traps in all four vertical corners and at least a couple of the horizontal corners, such as the ones at the tops of your front and rear walls, and maybe at the tops of your side walls too.

Then you will need panels on the side walls at your first reflection points: at least 10cm of porous absorption. And on the ceiling too, also at the first reflection points.

Take measurements with REW at each stage, to see how you are doing: what is working, what isn't, what still needs to be done, etc.

That's the basic process!

But before you do any of that, you need to get rid of that carpet! It is doing more harm than good to your room acoustics. So that's the very first thing you need to do: take out the carpet. Then do all of the above.

- Stuart -

I want this studio to amaze people. "That'll do" doesn't amaze people.

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