Likely, it's in a home office-like space involving bedrooms, living rooms, basements, armoires, desks, and table tops surrounded by latex painted drywall with carpet floors and flat/popcorn ceilings.
Therefore, the sensible thing to do is to replicate that "standard" and mix accordingly to what they're going to hear.
What you're saying sounds sensible in theory, in practice it's not though, because you are labouring under the false impression that as "home office-like spaces" are similar in appearance (size and furnishings) they are also similar in acoustic response and therefore represents some sort of loose "standard" which can be emulated. In practice though the acoustic similarities are going to be extremely generalized, so much so that trying to emulate this "standard" is completely unworkable and far more likely to result in a poor or unlistenable mix! We can make some generalizations, for example a home office like space is always going to have serious acoustic problems because they are generally built in a cuboid shape, which is the worst possible shape acoustically. The average home office-like space is packed with hard parallel surfaces (walls, floor, ceiling) and it's these which cause the vast majority of the most serious problems. So all we can say is that there will be serious problems but the reason why your theory doesn't work in practice is because even in two different rooms which appear almost identical, how many serious problems they exhibit and where in the frequency spectrum they occur will vary hugely.
Let's say you make a mix in your bedroom and one of the problems in your particular bedroom is a 12dB phase cancellation (loss) in a frequency range centered around 100Hz. 12dB is quite conservative by the way, it could be 5-10 times worse than 12dB and in some cases it could literally be infinitely worse! Your mix is going to sound like it doesn't have much bass, so you are going to add bass to make your mix sound good. Now here's the rub: Even in another room of the same class, a bedroom, and even in a bedroom which appears to be of very similar size and furnishings, the listener could just as easily be experiencing phase summation (gain) around 100Hz in their bedroom rather than the phase cancellation (loss) in yours. The problem of your mix (which has far too much 100Hz bass) is going to compound rather than offset the problems in this other, very similar bedroom. If for example you've attempted to compensate for the 12dB loss at 100Hz by adding 12dB to your mix and the other almost identical room boosts 100Hz by 12dB the listener is going to experience 24dB more in this frequency range than you intended. As an experiment, add 24dB at 100Hz to one of your existing mixes and see how good your mix sounds then! This example only covers one of the probably half dozen or more serious problem frequencies in your room (all of which will be different, even in a very similar appearing room). In fact, finding two untreated rooms with exactly the same acoustic response is not far off as likely as finding two people with the same fingerprint. Even finding two untreated rooms with a usefully similar frequency response is very unlikely. And don't forget, we are talking here about two rooms of exactly the same class and of very similar size and appearance, rather than the extremely very wide variety of rooms (at least as far as acoustics are concerned) you are talking about; basements, bedrooms, offices, studies, etc. In other words, as the "standard" to which you refer does not exist, your "standard" mix will only ever work even roughly as you intended for a small minority of those who ever listen to it. For a roughly similar minority your mix will sound terrible or even unlistenable and for the majority it will probably just sound quite poor!
Therefore, before we can progress with this conversation, you have to drop the whole notion of a "standard" untreated room or of trying to acoustically emulate one, because such a thing does not exist! So, what's the solution? Well, there is no solution per se, the best you can do is damage limitation. OK, so what's the best damage limitation? The best damage limitation is a mix room with a perfectly linear response, IE. A mix environment which allows the creation of mixes which are not influenced at all by any acoustic monitoring problems. In the example above, our friend in another bedroom is still going to hear 12dB too much at 100Hz and you are still going to hear 12dB too little but the majority of people (whose problems aren't centered at 100Hz) will hear at least that part of the spectrum as intended and, no one will hear a mix with a 24dB problem at 100Hz (unless their room has a 24dB problem!). This is because our mix is effectively neutral and therefore not compounding any of the problems in any of our listeners' specific environments. So next question is, how do we create a mix environment with a perfectly linear response? Unfortunately, you can't! Even with a virtually unlimited budget you can only get reasonably close and it starts with constructing a room with no parallel surfaces. This first and most important step is usually the most obvious difference between a fully professional/commercial audio facility and and an amateur/semi-pro setup.
So, getting a perfect mix environment or even just a very good environment is way, way outside the scope of even a well funded indie filmmaker (let alone a no budget film maker) and that's why so many commercial audio facilities exist.
None of this means to say there is a nothing a lo/no budget film maker can or should do about the situation!! There's an enormous gulf between a decent professional mix environment and the mix environment most no budget filmmakers attempt to work with. The reason for this is because generally no budget filmmakers tend to work in mixing environments at (or very close to) the worst imaginable mix environment! While this gulf cannot be bridged without a very serious investment, there are ways, even with an extremely restricted budget, which can elevate the quality of a mix environment well above "the worst imaginable".
Practical Advice Alert: The first step, IMHO, is to actually find out what the frequency problems of your room are. This will take time and study but NOT much money. You will need; a calibrated measurement microphone and RTA software (Real Time Analysis, acoustic analysis software). A decent measurement mic (
such as this one) will cost about $100 and REW is a good piece of RTA software and is free (Windows or Mac). Learning how to use the software, understanding what's it's telling you, will take sometime. You can start here, on the
REW Forum. Obviously, knowing what the problems are doesn't solve them but at least if you are aware of them you can be a little more circumspect about how you apply (or don't apply) EQ around those problem areas. You still won't be able to produce a good mix but it might just help you to produce a less bad one! The next step up the ladder is to treat whatever problems you've identified and of course that treatment is going to vary depending on what the problems are. Some of those problems will probably be quite easy to alleviate to some degree, changing the position of the speakers or the listening position for example, some might be quite effectively treated with $100 or less of cheap materials and a couple of hours of DIY, while other problems will likely be untreatable without tearing your house down and starting again. IMO though, just because you can't solve all the problems doesn't mean you shouldn't bother trying to treat some of them and improving your mix environment. "Not very good" is still way better than "worst imaginable" and to put it into perspective, "not very good" is not just a small almost unnoticeable difference from "worst imaginable", even a completely untrained ear will notice a considerable difference.
In order to put out a consistent product the speakers NEED to be set at a consistent level - THEN - have a mix mixed using those levels. By definition it's a two part process: Speakers/Monitors + Mix. One. Two.
Correct. So the obvious question is what do you set your speakers to before you start mixing? The process is called speaker or monitor level calibration and what exactly this entails has been covered on this forum previously. The reference level to which you calibrate will depend on which of the three standards (mentioned previously) you are talking about, in the case of music though the is no specific value as such. One of the big dangers, is how easy it is to calibrate incorrectly and is directly related to what I discussed above, as the level of the calibration signal will obviously be affected by your room's acoustics. The calibration signal is pink noise which contains all the audio frequencies in the spectrum (20Hz - 20kHz). As your room will have at least one big hole somewhere in the frequency spectrum you will have to turn the output of your speakers higher than they should be to compensate for the loss of energy in part of the spectrum, the result is incorrect calibration, possibly very significantly incorrect. Of course the situation isn't quite this simple because there will be other parts of the spectrum where your speakers/room are causing an artificial increase in the level, rather than a hole. Unfortunately though, the chances of all the increases adding up to the same amount and cancelling out all the holes is next to zero. Usually far more is lost in cancellations than is gained in summations (but not always!). Speaker level calibration is therefore always the last stage of the acoustic setup process.
BTW, your interpretation of the levels used for DVD/BluRay is not quite what I meant to convey. As there is no explicitly defined level DVD/BluRay, levels tend to be far more variable than say the TV standard, which is designed to be so specific and well enforced that there should be absolutely no noticeable variations in level whatsoever. Variations in levels on DVD/BluRay releases are noticeable and therefore a bit "all over the place", relative to TV content for example, but they are not "whatever you feel like". In practice the vast majority are at or near the TV spec.
My five bucks/pounds wagers 98% of the out-of-the-box 3" cr@ppy speakers (not monitors) sold with computers are placed somewhat symmetrically L/R of the monitor on a flat tabletop.
That's the arrangement the overwhelming majority of desktop users are listening to.
Agreed but as explained above you don't want to emulate what the end user is doing because there are too many small variables which have a large affect on the frequency response at the listening position. The size and distance of the speakers' cones from the desktop, the frequency output of the speakers, the horizontal angle of the speakers, the dispersion pattern of the speakers, the position of your head relative to the desk, the material the desk is made from, etc. Putting it musical pitch terms rather than in audio frequencies might help you to appreciate the variability of the issue: The variables above mean that going from one average desktop system to another, the problem frequency area could be different by more than an octave! In my experience, desktop reflections are usually centered on any frequency from about 150Hz to 500Hz and if you're very lucky only causes a 3dB-6dB error. 10dB -20dB is more common but it can be as much as 30dB or so. As explained previously, the problems are caused by the direct sound coming from the speaker interacting with the fractionally out of time reflections of that sound. It stands to reason therefore that placing your speakers directly on a large sonically reflective surface (such as a desk) is pretty much the worst place you could put them. Actually, it could be worse, the desk could be against the wall, now you have two large and very reflective surfaces in very close proximity to the speakers and therefore double the number of serious problems and/or double the severity of those problems.
Again Ray, you seem fixated on the idea of a standard where none exists. Desktop speakers might seem like a standard but they're not! And of course we are not even mentioning that not all of the listeners will be using desktop speakers, some will be using headphones, some a laptop, others a smartphone and some will even have a very high quality sound system/environment!
Practical Advice Alert: So where should you place your speakers? If you accept my argument above, logic would suggest anywhere but on your desk! Best place would be on speaker stands, which have a very small surface area supporting the speakers no bigger than the footprint of the speakers themselves. You can make speaker stands very cheaply but don't use an empty box type construction (which will act as a resonating chamber!), filling them with sand should do the trick. And don't place the speakers right against the wall or too close to your desk. Placing your speakers right adjacent to the edge of your desk is likely to make only a marginal difference or no difference at all. The usual arrangement professionally is to place your desk two-thirds of the way to the back of the room. The best option though is start two-thirds of the way back and move your desk to various locations around that point, measuring each location with a measurement mic and RTA (using the equipment I suggested above), until you find the position which has the least/fewest problems. You obviously have to measure at least twice, once for each speaker. BTW, you will be amazed at the amount of different in the frequency response of each speaker!
There's an easy informal test you can do yourself to prove most of the above, presuming your software has a signal generator. Set the generator to generate a sine wave at 3kHz and pan it hard left or hard right, doesn't matter as long the signal is only being output by one of your speakers. Set the output level of your speaker to be quite loud but not uncomfortably so and don't touch the volume control for the rest of the test. Now change the frequency to say 120Hz, immediately it should sound quieter (as our ears themselves do not have a linear response!). Now move around the room, stopping in various places and listening out for changes in volume. Change the frequency and repeat, say 100Hz, 150Hz, go down to 50Hz and up to say 800Hz. Change the output to the other speaker and try again, I'm sure you'll be surprised by what you hear! If you search around, you should even be able to discover at least one frequency and one position in your room which exhibits complete cancellation, IE. From quite loud at 3kHz to completely silent (inaudible), even though your speaker is still outputting exactly the same level.
Sorry, this post has ended up much longer than I intended!
G