euhm... I've been reading about soffit mounting and it essentialy made me rethink/ question my whole front side of the room. I mean speker angle, listening position etc...
Great! If you have been researching it, and you are now confused, then that's a good sign! Because it is confusing, and in addition there's a lot of terrible advice floating around the internet than can confuse you even more, and lead you astray...
So let's try to work through the myths and snake-oil, and get down to reality...
I read a lot about the 60 degrees speaker angle that it gives a bigger sweet spot for the highs when moving around on the desk
Speakers and angles alone do not create the sweet spot: The entire room design does. First, the speaker: The off-axis and on-axis response of YOUR speakers is the starting point for figuring out where the sweet spot can potentially be. It's simple math (or rather, simply geometry). If the dispersion angle of your speaker is, for example, 20° then obviously your sweet spot can be no wider than that! Depending on how far away from the speaker you are, that would tell you the actual possible width, in cm, for the sweet spot. Because as soon as you get outside the region of the speaker "dispersion" that still has flat response across the entire spectrum, you no longer have a usable response. You can plot this on a piece of paper: draw a triangle with the same dispersion angle as your speakers, then measure out the distance form the speakers to your ears (scaled, obviously), and measure the width of the tiriangle at that point. That's the MAXIMUM size that your sweet spot can be.
So that's the first issue: find out what the dispersion angle is for YOUR speakers. Most good studio monitors have wide dispersion angles, so this is probably not an issue, but you MUST check to make sure. Some excellent speakers are still flat out to 40°, others don't even make it to 30°.
When I design a room for a customer, I start with the speakers for this very reason. I need to know where the sound is going to go at what frequency, and how smooth the distribution is, so I can design the room around that.
but i don' t have a big desks so no prob.
Then you probably don't
need a broad sweet spot!
You might still
want one, but you don't
need one.... As long as the sweet spot is wide enough to cover the full area where your head will be while you are working, that's all you need.
now my speaker angle is 73 degrees.
You mean the axis intercept angle, right? 73° intercept implies that each of your speakers is toed in 36.5°, and therefore they must be spread a bit further apart than for a typical 60° setup. That's fine, as long as you understand what it will do to your sound-stage, as well as your sweet spot. Common confusion: sweet-spot is not sound-stage. Two different things. The sweet spot is the place in the room where you can hear the sound evenly (good frequency response, smooth decay times, good balance between left and right speakers, good phantom center, etc.) The sound stage is how the stereo image is laid out in front of you, left to right: do all the instruments sound like they are tightly bunched up all together in the middle, or do they sound like they are spread out widely across the room in front of you, some on the left, some on the right, some in the middle? You can sit in a nice sweet spot and have a terrible sound stage, or you can have a nice sweet spot and a broad sound stage. But you can't have a good sound-stage if you are way outside the sweet spot.
To get a better idea of how this works, think o the extremes: First imagine that you have both of your speakers pushed together in the middle of the room, directly in front of you. You can have a nice sweet spot like that, but very poor stereo image: it will sound like all of the instruments are in pretty much the exact same location, piled on top of each other in front of you, with nothing out to the sides, because both of your ears are hearing almost exactly the same thing. Now imagine the opposite extreme: that you move the speakers out directly against the walls to your left and right, in line with your ears, and rotated 90° so they point exactly at your head. You will have an "amazing" stereo image like that, with all the instruments spread out very widely, because each ear is hearing pretty much only the speaker on its own side. However, it will sound unnaturally wide, and not very convincing, since your left ear hears almost nothing that is coming from the right speaker, and vice versa. Your head itself blocks most of the sound. So your brain can't use it's normal tricks of sensing the timing difference and level difference and phase difference between the SAME sound arriving at BOTH ears, to determine directionality, so the stereo image will sound "flat", with no "depth" to it. It will sound like it is all along a piece of string that goes through your head, but NOT in front of you.
So clearly, you want something in between these two extremes. You do want your left ear to hear some of the stuff coming from the right speaker, without being completely in the "shadow" of your head, and vice versa. So you do want the speakers to be angled less than about 60°, absolute maximum, such that your left ear really can "see" some of the sound form the right, etc. But you also don't want them too close together, so that both ears hear roughly the same thing, so you want the angle to be more than about 15°, absolute minimum. Hence, the textbook recommendation for 30° angle: It's mathematically the "best", in theory. Both ears get to "see" both speakers, and the angles are optimal for good stereo imaging.
But what happens if you make that 31° or 29°, instead of 30°? Well, basically nothing happens! You are no longer at the theoretical perfect point, but the offset is so minor that it makes no audible difference at all. If you check the mathematics, the cosine of 30° is 0.866, and the cosine of 31° is 0.857. That's a difference of just barely 1%. I terms of decibels, that means that one of your ears is now hearing the opposite speaker exactly 0.0432 dB quieter. Since the absolutely minimum change in intensity that people can hear is about 1 dB, and this change is just 4/100ths of a dB, clearly you won't hear any difference at all.
OK, so how about if we go to 40° and 20°, instead of 31 and 29? Well, the cosine of 40° is 0.766, which is now a change of (1-(0.766/0.866)*100) = 11.5%, and that's a change of 1 dB, so it is audible, but only just. And at 20°, the cosine is .939, so the change is 8.5%, just a bit less than 1 dB. And if we go up to 50°? Cos(50°) = 0.642, which is a difference of 28.5%, which is 1.5 dB, so definitely audible.
Thus, you should try to keep your angles with a reasonable range, of about 45° maximum and maybe 20° minimum, realizing that the higher the angle is, the wider the sound-stage is, but the flatter as well.
Those are individual speaker angles, so the intercept will be twice that: this, an intercept between about 90° max and 40° min is probably OK for most rooms. So you 73° intercept should be OK. Personally, I try to keep intercept a bit tighter than that, around 75° down to about 50°.
OK, but now for the kicker: most o the "text-book" diagrams state emphatically that it absolutely must be 30.0000000° on the dot, also then show that they want that apex of that perfect equilateral triangle to be smack bang in the center of your head! And if you do that, then the speaker axes are aligned perfectly... with your EYEBALLS! but not your ears.... I never have figured that out.... why would you want the speakers aimed at your eyes? You don't hear with your eyeballs! If your eyes are on-axis to the speaker, then your ears are obviously NOT on axis!
Yet, that's what the diagrams show, and the text books recommend... Hmmmm... go figure.... So it simply makes sense to adjust the speaker angles, and the listening position, and the speaker locations, such that the speakers are aiming at your EARS, not your eyes. In fact, it seems the best setup is when the speaker axis grazes just past the tip of your ear-lobe, and therefore the point where the axes intercept will be many cm behind your head, not inside the middle of your head.
I read the listening position should be 1/3 of the room length. Why?
Smart question!
The actual "perfect" spot is supposedly 38% of room length, which is theoretically where the modal problems are least noticeable. Note that I didn't say there are no modal problems at 38%! They are still there, and might still be terribly bad if the room is not well treated, but that's the point where they are LESS bad. The WORST points are 25% and 50%, since those are where the quarter-wavelength and half-wavelength peaks and nulls are at their maximum intensities, which is why you should avoid the middle of the room, and the 1/4 length locations.
That said, this is just a theoretical best spot in a perfectly rectangular room. It is not written in stone, and the Modal Correctness Police will not arrest you if you choose another location! It's a guide-line, a good starting point, nothing more than that. You will very likely find that there's a better spot just behind that, or just in front of it. I find that it's usually a bit in front of that "perfect" spot in most rooms. Hence, I suggest 1/3 (which is 33.333333%, to be exact!
), since it is easier to remember, and easier to visualize.
and if i make my speaker angle 60 degrees my listening position shifts more to the mid of the room. is this a problem?
If it goes too far back, then yes, that's a problem! I try to stay within about 31% to 45% of room depth. But do be careful! In a small room, if you have your head at 45% when it is above the console concentrating on mixing, but then you sit up straight and lean back a bit in your chair, your head will now be at 50%....
My plans are to soffit mont adam's A7X.
Smart move! Good speakers, too.
Now i read that one should be carefull soffit mounting nearfield monitors beacause they need to be near the listener.
is this true?
Nope! Not true at all... Because there's actually no such thing as a "near field" monitor!
And you should NEVER listen in the "near field" anyway!
Bold statement? Yep. But true. Here's why:
The "near field" is a property of the ROOM, not the speaker. This comes from the book "Architectural Acoustics":
what-near-field-really-is.jpg
That's pretty clear, isn't it? That's from a leading text book on acoustics, not on marketing hype, so it tells the truth about what "near field" actually means.
If you say that a speaker is a "near field" speaker, then you are using pure marketing drivel, not actual technical term.
As you'll note in that image above, it clearly says"Sound pressure levels can fluctuate dramatically in the near field .... sound pressures cancel and enhance each other near large reflective surfaces [such as a desk, console, etc.], so sound pressure level measurements should be avoided in the near field." I kind of think that's what our ears do: they make "sound pressure level measurements".
So according to Architectural Acoustics, you should not try to listen in the "near field", since levels fluctuate, and pressure cancel each other out, or enhance each other... So why on earth would anyone make a "near field monitor", and tell you to listen in the "near field"? ??? Beats me...!!!
Not convinced? Then maybe listen to what one of the world's leading experts on speakers says: I quote Floyd Toole himself: "In recording control rooms, it is common to place small loudspeakers on the meter bridge at the rear of the recording console. These are called near-field or close-field monitors because they are not far from the listeners. ... the near field of a small two-way loud-speaker ... extends to somewhere in the range 21 in. to almost 6 ft (0.53 to 1.8 m). Including the reflection from the console under the loudspeaker greatly extends that distance. There is no doubt, then, that the recording engineer is listening in the acoustical near field, and that what is heard will depend on where the ears are located in distance, as well as laterally and in height. The propagating wavefront has not stabilized, and as a result this is not a desirable sound field in which to do precision listening, but as they say, perhaps it is “good enough for rock-and-roll.”
Your honor, I rest my case! As the man says: "this is not a desirable sound field in which to do precision listening".
OK, maybe this calls for a more complete explanation:
If you set up a speaker at one end of a large room and play music through it, that sound spreads out through the room, bouncing back and forth between the room boundaries and objects in the room. If you suddenly turn off the speaker, that sound continues to bounce around for a while, slowly dying away. How long that takes depends on several factors, but the point is that the sound does NOT stop instantly when you cut off the speaker: it carries on "reverberating" around the room. When the speaker is on, that "reverberation" is obviously still taking place, and still filling the entire room, along with the direct sound from the speaker. The sound that remains when you cut off the speaker is called the "reverberant field", and the level is more or less constant and even throughout the room (this is a large room that we are talking about). It doesn't matter where you are in the room, as soon as you cut the speaker off the remaining level is roughly the same all over, since it is just reflections that are bouncing around randomly.
So with the speaker turned on, if you go all the way to the other end of the room to listen, as far away from the speaker as you can, then what you will hear is practically all "reverberant sound" that has been reflected off the walls / floor / ceiling / furniture / etc., and practically nothing that comes directly from the speaker. Everything you hear has bounced off at least one surface before reaching your ears, and most likely has gone through several such bounces. So you are totally in the reverberant field.
On the other hand, if you were to put your ear right in front of the speaker, just a few inches away, then what you hear is practically all coming directly from the speaker, and almost nothing at all from the room. Everything you hear has not touched any room surfaces, and is exactly what came out of the speaker. In this case, you are totally in the direct field from the speaker.
The point in the room at which the reverberant field and the direct field are exactly the same, is called the "critical distance".
This isn't just a theoretical concept: it can be measured in practice. In that room, use a sound level and stand as far away as possible from the speaker while it is playing at a constant level. Move towards the speaker slowly and watch the level on the meter. Throughout most of the room the level will remain the same, since you are measuring the reverberant field, which is roughly the same throughout the room. But eventually as you get close to the speaker, the level will start rising as the meter "sees" mostly the speaker. At the point where you get a 3 dB increase, that is the "critical distance" for that room. Any closer than that and you are in the "near field": Any further away and you are in the "far field" or "reverberant field".
It's that simple.
As the image I posted above shows, there's a region between the near field and the critical distance, called the "free field", where things are nice and smooth. That's the best place to be.
There's a lot of people who should know better than continue to buy into the "near-field / mid-field / far-field" marketing hype. Fact is, those are all just fictitious names made up by manufacturers, and gullibly swallowed by some sound engineers, studio owners, and producers, who never bother checking. Most of those would probably be shocked to learn that there is no technical definition for what constitutes a "near-field monitor", or a "far-field monitor", and even less for the mythical, non-existent "midfield". If you don't believe me, do a google search for "technical definition of near-field monitor"...
Enjoy your search....
Here's a smattering of definitions that I've picked up over the years, not one of which is true:
"Near-field monitors are short throw, narrow dispersion, limited range units."
"Nearfield is a reference to the range of frequencies the speaker is capable of replicating."
"Nearfield monitors are designed to be positioned approximately one to two metres away from the listener"
"Near-field: a compact studio monitor designed for listening at close distances, typically between three and five feet"
"Nearfield monitors are designed to sit on or just behind the meter bridge of a mixing desk, within a couple of feet of the engineer"
"Nearfield monitors are small speakers which you sit fairly close to."
"Nearfield is if your ear is closer to the speaker than it is to any reflective surfaces."
"The whole point of small near field monitors is that you sit close enough that you don't need a treated room. Amazing how many people don't seem to get that"
"Near-field studio monitors are small speakers that minimize the effects of your room on the sound source."
"For nearfield monitiors, you need a listening distance that's at least 3 times the distance between the woofer and tweeter"
"Near field monitoring is a way to sit closer to your monitors with the idea that sitting closer to the speakers say 3′- 4′, will reduce the sound of the room in the mix."
"Nearfield simply means "close distance."
"Nearfield means so close that the SPL no longer increases if you move even closer."
"Nearfield means less than 2.50 meters
"Near field is the critical listening distance"
"Nearfield means that your ears are closer to the speakers than they are to any of the room boundaries".
"Near field refers to the size of the monitor in relation to the listening distance"
"Near-Field monitors are designed to be placed less than 6 feet away from the listener."
"Near field listening: set them up 4 feet apart, from 4 feet away. They will sound great regardless of the room from that close".
"Nearfield monitors"? = No bass, no hope of bass, let's not pretend."
What a wonderful hodge-podge of garbage answers! Most are totally off, a couple get sort of close, but they are all still absolutely wrong! And mostly they contradict each other. The worst thing is, all of those come from "experts" offering thier opinions on how to set up speakers and rooms...
The issue is that there's no such thing as a "near field" monitor, since the term "near field" refers to the ROOM; not the speakers. If your head is closer to the monitors than the critical distance and free field for the room then you are in the near field. If you are beyond the free field or the critical distance, then you are in the far field. Period. That's it. The "critical distance" is a well defined technical term that can be predicted mathematically, and it can be measured. There's no question about where it is, or what it is. That distance varies for each room, and each set of treatment, but does NOT vary for different speakers in the same room. For a smallish to medium room that is treated one way, the entire room might be in the near field, regardless of what speaker you use, but if you take out that treatment then the near field might only extend a couple of feet beyond the speakers. In a small, badly treated room that is poorly laid out, there might be no free field at all. And in a large room, the free field might extend several meters, starting quote close to the speakers.
There is nothing at all that you can do to a speaker to ensure that it will always be a near-field monitors, since that depends entirely on the room, and on where you place the speakers and your head in that room.
And as both Floyd Toole and Architectural Acoustics point out, the near field is a terrible place to listen!
Sorry about the rant again! But my point is that you can use pretty much whatever speakers you want to use in your room (within reason!), regardless of what it says on the box they came in. You do not have to listen close to near-fields, and you do not have to be 20 feet away to listen to far-fields or "mid-fields". And you can soffit-mount pretty much any speaker you want to, with only a very few exceptions. So chose the best, acoustically flattest speakers you can get, with the spectrum range that you need for your music, put them in properly designed soffits at the correct locations in the room, and then design the room around them, and treat the room according. If you like your A7X's, then keep your A7X's!
or can i perfectly soffit mont the A7X's
Simple answer:
A7X-soffit-mounted-01--SML.jpg
A7X-soffit-mounted-02--SML.jpg
A7X-soffit-mounted-03--SML.jpg
What is rule of thumb for speaker placement angle and listening position within a room???
Supposedly, 30° angle centered on 38% of room depth... but see above... that's not true at all....
Thanks to anyone who can help me out.
You have your speakers centered in your soffits (same distance from the speaker to each edge of the front baffle): that's not necessary, and not even a good idea! You should aim to have different distances on each side, to prevent "lobing" and "focusing". I try to aim for having the speaker centered at 5/8 the width, but that isn't usually possible for construction reasons, or for room geometry.
You could also consider making your soffits deeper, so the sit out further into the room. Which indirectly makes the room appear a bit shorter, acoustically, so you could slide your mix position back a bit too...
- Stuart -
It took a lot of work to get it that good, but I think it was worth it.