I like like the idea of rfz more that I do the non Enviroment direction I was originally going in.
Me too! Phillip Newell says a lot of good things, but I'm not with him on some aspects of NER ("Non Environment Room") design. RFZ makes more sense, to me. CID is another interesting option, but I'm not aware of many places actually built like that, except a couple of test rooms at the BBC. So I'm sticking with RFZ style, until something better comes along...
I notice in a lot of these designs the monitors are in the upper 1 / 3 aimed down at the listening position,
In large rooms, yes, some people do that, but I prefer not to. There's a pscyho-acosutical issue that Andre brought to my attention many years ago, and there's also a reflection issue, and comb-filtering issue.
First, the psycho-acoustic thing: Your ears and brain are really good at figuring out directionality in the horizontal plane. So when you are standing out in the open, looking around, and you hear a lion growl, you immediately can identify which direction that came from, and turn the exact opposite way, to run! But if you happen to be looking down at the ground with your head bent over, or up at the sky with your head bent back, at the moment when the lion growls, what do you do naturally? Very fist thing is to get your head back horizontal, and look around at the horizon, waiting for the next growl... Why? Because your ears are only good at determining direction when your head is level and looking at the horizon! If your head is titled up or down, then you CANNOT determine direction accurately! Because of the way your pinna are built (the curly twisty parts of your ear). The pinna are actually critical to determining two things: frequency and direction. They carefully re-direct incoming sound into the "hole" of your ear, and the make very subtle changes in the patterns of sound that your ear can then pick up, and your brain can process, so you can figure out which direction the growl came from, and how close the lion is. If you were looking up or down, then the FIRST thing your brain does is to get your head level and wait for another clue, because it could not determine the direction and frequency very well, with your pinna tilted up or down to the wrong angle! So your brain wants your head level, such that when the next growl comes, it can determine direction and distance accurately, and tell you which way to run. It doesn't want to run yet, because it doesn't know where the lion is. It would have known if your head would have been level, but it wasn't, so it has to wait for better info. It does not want to send you running TOWARDS the lion!
So what does that have t do with studios? There's no lions in your studio (I hope!) But there are sound sources, and there are ears. If the sound sources come from above or below the horizon, then your brain has the same "lion problem": it can't determine direction and frequency accurately. And since you sort of do need to know what direction each instrument is panned to in your mix, accurately, it's not a good idea to mount your speakers at a place where your brain has trouble determining direction! Yeah, you could just tilt your head up a bit to look at the speakers, every time you need to do critical listening for panning, or to get a good stereo image, but why do that? You'll end up with a sore neck! Tilt head up to speakers, listen, tilt head down to console, adjust, tilt head up to speakers, listen, tilt head down to console, adjust, tilt head up to speakers, listen, tilt head down to console, adjust, ... yo-yo, ping pong, bounce-bounce, up down... sore neck! Studio design is partly about ergonomics, not just acoustics, structures, HVAC, electrical, etc. And if you have to bounce your head up and down all day like a bobble-head toy on a spring, then that's not such a good thing.
OK, so what's the limit? Well, Andre led me on a long path to find out, may years ago, and I did a lot of research on that, eventually coming to agree with him that 7° is the limit. Your speakers should never be more than 7° above the horizon, meaning that they should never be angled down more than 7°. That's about the limit your ears can take and still get useful, accurate direction and frequency info from your pinna, with your head looking forward and not doing an imitation of a pogo-stick. Some places say 10° is the limit, others as much as 15°, but psycho-acoustics research suggests that 7° is as far as you want to push it. More than that, and you need to bounce your head on a spring.
In a large room, you can achieve that with speakers above the window tilted down, because the mix position is far enough back. But in a small room, it's not possible. However, some people do it anyway: I suppose its out of ignorance, or indifference....
OK that's the first reason.
Next, reflection: The higher you raise your speaker, the more reflections you are sending to your ears, from the surface of the desk/console/DAW! Think of this: If the speaker is directly in front of you at eye height, and the desk is also at eye height in front of you, then you are looking at the desk edge-on, so there are no reflections getting to your ears! You see the edge of the desk in front of you, and beyond that the speakers, in a direct line. So the desk cannot possibly be reflecting anything. Now imagine that you lowered the desk 2 feet (60cm). It's now below your line of sight, and there will be some sound waves from the speaker hitting the top of the desk and getting reflected up again... but they will mostly be hitting your chest, not your head. Your head is out of the direct reflection path, mostly. Now imagine that you raise up the speaker by another two feet, so it is higher than your head, and you tilt it down... now the sound waves are bouncing off the desk, directly into your face. So you have the direct sound hitting your ears, AND ALSO the reflected sound, delayed just a couple of milliseconds, or less. So you have interference, phase cancellation, comb filtering, and its at almost the same level as the direct sound, since it was a hard, clean bounce off the desk (no absorption or diffusion). That totally messes up your perception of the sound! Your brain can't handle that: it needs a delay of at least 20ms between the direct sound and a reflection in order to figure out that it was an "echo". If you don't give your brain that 20ms delay, then it cannot process that the reflection is a reflection: Instead, it thinks that it is hearing a
different sound from what really came in, and it had a
different frequency response from what it really had, and it came from a
different direction than where it really came from! So your brain loses the ability to determine phase, frequency, and directionality.
So add those issues to the first issue (that your brain is already having a hard time figuring out directions due to the pinna problem...), and you can start to see why raised, tilted speakers are not such a great idea in small rooms.
That's the second issue. The third issue is another form of frequency, phase, and comb filter artifacts, and it comes from the console surface. Your console surface is full of knobs, buttons, connectors, angles, meter bridges, dog boxes, cables (and probably half-empty beer cans and 3-day old stale pizza slices too), as well as other nasty things that mess up the way sound waves move over it. That causes several artifacts, starting with a general dip somewhere in the mid-range of the spectrum, and a whole bunch of ups and downs in the same region. If you look at the un-smoothed frequency response graphs for Studio 3, you'll see a tiny bit of that. It's not very pronounced, but it's there. If we move the measurement mic just in front of the desk, all of that goes away, and the curve is ruler-flat. It's one of the consequences you pay for having a large console in front of you. Plus, in Studio 3 the speakers actually are raised up slightly, and tilted down a bit (about 4.3°, to be exact), precisely because we needed to get the speakers above the large dog-box on the back of that console. So there are consequences to doing that, but I tried to minimize them as much as possible, by choosing that angle and the distances very carefully. Rod almost choked when I told he needed to build his soffits to angle his speakers down at 4.3°.... but he did it, accurately.
Right now I'm finishing up the design for a mastering studio where there will be no console at all: there's a desk, but it is small, the top face is very low down, and all of the surfaces are carefully angled to minimize reflections to your head. Mastering studios are even more critical than mixing studios, so this is very important. The customer does not want a large desk with a huge console in front of him, for the same reason: he wants clean, pure, line-of-sight to the speakers, so he hears only direct sound, no reflections or distortions from the desk. His gear will be embedded in the desk, mostly on two slightly angled "wing panels", and the angle is carefully set to minimize this "mid-range roughness" issue.
Excuse the long rant, but it's important to understand this stuff if you want maximum acoustic quality in your room!
So that's the long, involved, convoluted, explanation as to why I don't put speakers high up, tilted down greatly.
In fact, the "standard" correct height for speakers, according to international specs for critical listening rooms, is 120cm above the floor: that's 47.25". The reason? Because that's the height of your ears, while seated! For most people seated comfortably in typical office chairs, the average ear height is 120cm above the floor. So that's where you want your speaker, too!
One thing to be aware of: that's the height of the ACOUSTIC AXIS of the speaker, not the height of the top or bottom of the cabinet, nor of the woofer or tweeter. Most manufacturers publish diagrams of dimensions that show you where the acoustic axis of your speaker is located. For a typical two-way speaker, it will be on the imaginary line that joins the center of the woofer to the center of the tweeter, and much closer to the tweeter than the woofer. That's the point where sound seems to emanate from the speaker. If you close your eyes and listen vary carefully to just one speaker, and you were asked to point to the middle of where the sound is coming from, you would point to the location of the acoustic axis. That's the spot that you want 120cm above the floor.
However, I normally raise the speakers just a bit higher than that, for several reasons. It depends on the speaker, the desk, the room, the treatment, etc., but it might be around 122 to 130cm, give or take a bit. That will still keep your ears on-axis with most speakers, but you do have to be careful.
There's one "secret" I should mention here, though: Often those huge monster speakers you see up high and tilted down, are NOT meant for the engineer at the mix position! They are meant more for the client, sitting way back on the couch, at the rear of the room. They are often aimed at him, and he really is on-axis to them, with less that 7° tilt. Or even if it is more than 7°, it doesn't matter as he can sit there with his head slightly raised as he listens, because he doesn't have to look down at the console all the time to adjust things! He only needs to listen, so he can set there without bouncing his head at all, and he'll get food, clean, sound like that. Often, in that type of studio, the main speakers that the engineer uses are on stands behind the desk, or sometimes (gasp!) on the meter bridge!
which is a terrible place to put them... He might use the raised/tilted mains to get the feel for the full power of the mix every now and then, or to listen for specifics, but mostly he'll mix on another set of speakers. Not always, of course, but quite common.
Would there be a down side to keeping the monitors at the lower 1 / 3 room height but angled up a bit,
Same problem as #1, to a certain extent: pinna, directionality, frequency response, plus the additional issue that the edge of the desk, or the console, or DAW, will probably put your head in an acoustic "shadow": if your ear cannot directly "see" the speaker, with no objects in between, then that's a problem.
My rear wall is pretty close
How close? What are your room dimensions? Where is our head located in that room, with respect to the front and back walls? Where are the speakers located? Draw a diagram for us, and take photos, so we can see your room, to understand the issues.
I have been searching the web and haven't come across any pictures or designs like that.
Right! That's for a good reason!
Whenever you think up a "new" idea like that, and search all over but don't find any examples, then that's probably because it doesn't work!
If it did work, someone would have done it, others would have copied it, and someone would have done some research on it. If there are no examples, that usually means someone DID try it, and it was a failure. It's unlikely that you are the first person to ever think of that, although it could happen.
After looking at these rooms you have built I have completely changed my direction, ... they are amazing
Thanks! To me, that sounds like a compliment, so thank you!
And I'm glad that you have learned something from that, and can apply it to your own room.
and seeing the results in the room response shows how much the extra work pays off. Very very motivational.
As the saying goes, "the proof of the pudding is in the eating". Or maybe "put your money where your mouth is"! I can spout off about this stuff all day, but unless there's clear data to back it up, my words are pretty meaningless. If it tests well, and meets the design specs, and customer is happy, then clearly it works! I think the Studio 3 thread has a link to their own website, where there's a lot more info, including a long story about the design and build process. Rod was so happy with his studio that he asked me to write that up for him, and he put it in the website. So go looking for that link, and have fun reading about some of the "behind the scenes" info on how we designed and built that place. Some might find it boring, but you might be able to glean more info from there to use in your place.
A question, the front wall space between the 2 soffits should this also be like the baffle verry solid? Verry reflective? Or should i make this absorbant?
You can do it either way, but I usually prefer to keep it soft and absorptive. Sometimes that isn't possible, such as in this room I designed for a customer in Australia:
BRAUS--Rear-left-to-front-IMG_0261-ENH.JPG
As you can see, there are sliding glass doors in the space between the soffits, leading into the isolation booth, so it's impossible to cover those with insulation! So I had to use other "tricks" to make that acceptable...
The walls behind the soffit do i keep the construction the same as the rest of the walls of the room?
I mean by this completly finish the outer walls and built soffit seperatly within this room?
Yes, basically. But I normally do control rooms "inside out", all around, so the front wall actually has the studs facing you (with insulation between them, and the drywall on the other side of the studs, which makes it easier to tie the soffits into the front wall properly.
What do you think of making a verry tight closset and mounting this closset on to a plate mounted on vibration silencers , like they use in machinerie.
Would this work similar to the rubber pad approach?
You could, yes, but you'd still need to tune that to ensure that that resonant frequency is at least an octave below the lowest frequency that the speaker will produce. So you need to calculate that carefully.
And how do i calculate the needed rubber pads or vibration silencers neede for the speaker /closset?
That's a little more complex! The equations are rather involved, and you need to know things like the spring stiffness for the material you will be using, or the Shore hardness, or the resilience, and the weight (mass) of everything that you need to float... The basic equation is:
f= 1/(2 PI) x SQRT (K/N)
Where:
f = the resonant frequency
K = the stiffness of the spring you are using, and
M = the mass of what you are floating
However, there's more to it than that. You also need to take into account the damping, transmissibility, and other things.
There are other ways of calculating this, but it depends on the TYPE of spring you are using. There are differences between steel coiled springs, and rubber pad "springs", that you need to consider: coil springs are linear, for example, but rubber is not. However, rubber has some self-damping properties that steel springs do not. Etc. Damping decreases the amplitude of the vibration ant resonance, so it's a good thing, but it also flattens the Q of the resonance, which is both good and bad, from different points of view. Bad in the sens that it increases transmissibility around the resonant frequency more than dampened springs do, so you need to have a lower resonant frequency.
There's another form of that spring equation that might be helpful:
f= 1/(2 PI) x SQRT (g/Delta)
Where:
f = the resonant frequency
Delta = the static deflection of the spring when loaded down with your speaker (in meters)
g = the gravitational constant (in m/s^^2)
The best thing you can do is to decide on the type of spring that you will use, research all the properties of that type of spring, then use the equations for that type of spring to figure out how thick to make the spring, and how much it needs to be deflected (compressed) in order to provide the correct resonant frequency. I'm a big fan of Sorbothane rubber: I think it's the best stuff out there for floating speakers. Other people prefer EPDM, or Neoprene, or even products like Sylomer, or even natural rubber. All have their advantages and disadvantages, but for the way I do it, Sorbothane gives me the best balance of all factors. And they have software that helps you figure it out!
In very general terms, for most materials you are looking for a static deflection of about 10% to 20% of the unloaded spring, but the optimal deflection depends on the actual material.
I wish I could explain it more simply, but springs are strange things....
- Stuart -
