I'll clarify.
By off axis I meant the side walls or the ceiling.
I was referring to anything off axis is not at 90 degrees or 180.
I'm still not understanding the question: By definition, axial modes are always perpendicular to the boundary surfaces. By definition, tangential and oblique modes are never perpendicular to the boundary surfaces. It's impossible for axial modes to be "off axis", and it is impossible for non-axial mode to be "on axis". In acoustics "off axis" is pretty much always with respect to speakers, where "on axis" means that you are located directly in front of the speaker, and "off axis" means that you are a bit off to the left or right. There's no relationship at all between the speaker axis and the modes in a room. Modes are relate ONLY to the boundaries of the room, and have nothing to do with speakers (except that they are triggered by the sound that came out of the speaker, but apart from that, there's no relationship to speaker axis.)
That's why I'm confused here: I think you might be muddling up your terminology. "Off axis" relates only to speakers and listeners, "mode" relates only to room dimensions. There's no connection other than that. Modes related only to the side walls are STILL axial modes, just in the side-to-side axis (0.x.0). Modes related only to the ceiling and floor are still axial modes, just in the vertical axis (0.0.x). And all of them are absolutely 100% perpendicular to the surfaces that define them in a rectangular room..
I'm describing the side walls having an offset of approximately 800 mm over 3.5 metres
If you splay your walls by such a large amount, then standard room mode calculators will not be able to accurately predict the modal response of the room. They only apply to rectangular rooms with six sides, arranged as three sets of mutually perpendicular boundaries.
Next question: Why do you want to angle your walls so much? For what acoustical reason? Are you aware that it is a myth that studio walls must always be angled?
I haven't worked it out yet. I just set the timbers by feel based on studios I've worked in. Crude I know but that's why I'm researching further.
Designing a studio by "feel" is doomed to failure. It should be designed on the basis of actual principles of acoustic design, and the physical laws that govern how sound behaves. Trying to build a studio based on other places that you have been inside, is like trying to bake a cake that you have only seen when finished, when you have no prior cooking experience. All that you have is the visual impression, and the taste, but no knowledge of what ingredients went into it, how they were combined, what sequence was used, what precautions where taken, etc. The same is very much true of a studio: You might have been inside some very good ones, looked around at the visual aspects, and liked the "taste" (how they sound), but that tells you nothing at all about the design process, what materials were used, how they were combined, what sequence was used, what precautions were taken, etc. You might well be able to build a studio that looks identical to one you have been in, but I can guarantee that it will sound very, very different, unless you understand the acoustic "recipe" that was used to make it.
This will allow an air gap for the extreme summer heat here in Brisbane
The purpose of the air gap in studio isolation walls and ceilings, has nothing at all to do with heat. Zero. Nada. Zip. It is all about acoustic isolation. As a secondary effect it will ALSO give pretty good thermal isolation, but that's not the purpose at all. Take a look at the equations for studio isolation, especially two-leaf MSM isolation, and you'll clearly see what the purpose of the air gap is.
and a ventilation system will remove hot air from around the room outer cavities etc.
No it won't. At least, not if you want a studio that works, is properly isolated acoustically, and properly isolated thermally, and complies with your local and international building codes, and is legal!
Once again, the wall cavities in a studio are not related in any way to thermal issues. They will ALSO be very good with thermal issues, due toe way they are built: Far better than normal house, office, shop, school, church, etc. walls. But that's not the reason why the air gaps are there, and has nothing to do with determining who big those gaps should be. That's entirely dependent on the acoustic isolation needs.
From what I've seen of mixing and mastering suites.. The rooms are built wedge shaped. Outer wall is rectangular..
Once again, what you think you see, and how the studio is actually made, are two different things. When you look at a cake in the bakery window, you have no idea of how it was made. Unless you get to see the recipe, and already have the necessary cooking skills, and have the necessary equipment, you will not be able to copy it.
Most northward acoustics rooms for this purpose have the monitors flown in decouplers and flush mounted on chamfered wall sections..
In other words, what studio designed refer to as "soffit-mounted speakers in RFZ walls". Here's an example:
http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471 Those "chamfered wall sections" are actually commonly referred to as "soffits", and the concept of flush mounting speaker in them is usually referred to as "soffit mounting".
You really should try to use the correct terminology, to avoid confusion ans misunderstanding. If you don't know what something is called, then take a photo and post it here, along with the question.
Then the dude walls continue at angle with abutments fab ing the monitors. If possible. If probably use panels if required when tuning.
I'm not sure what you mean by "dude walls". I've never heard that term before. The rest of that paragraphs seems to be a bit garbled. Maybe you left something out when you wrote it? It's not at all clear what you wanted to say.
my experience of mixing in re t angular rooms has not been a good one .
Perhaps you've never been in a well designed rectangular room?
I'd agree that non-rectangular rooms have their advantages, and in fact almost all of the rooms I design are not rectangular. I have had pretty good success with RFZ style rooms, as that's about the best possible shape... but only if you understand the theory behind it and know how to do it right. The one in the link above is RFZ, and you can see the results in the acoustic graphs. Hard to beat that! But there's nothing wrong with rectangular rooms if they are designed, built, and treated correctly. They can be every bit as good as an RFZ, NER, or CID room.
Resonance and loves build up in the corners and at points along the walls
Sorry, but no it does not. Bass may well build up in corners and close to walls, but resonance most certainly does not. Resonance involves the entire room. You seem to be confusing resonance with something else.
this could be minimised by bass traps.
Bass traps do not treat resonance. They treat room modes, which is a form of
reverberance, as well as SBIR, and other related issues.
But if we're building inner walls here.. why not address to challenges with one solution ?
That's actually what studio designers do! We design rooms to be as efficient as possible. We do that by first choosing a volume, shape and size for the room that fits in with the building, then refining it through prediction software and experience, then adding theoretical treatment to the usual key locations to see how that would affect the response, then running more software simulations and making more adjustments based on experience, until we settle on the best possible layout and treatment for that room. But we don't guess or try to do it by "feel". There's a process, and guidelines, and "rules of thumb", and equations, and stacks of research. We take all of that into account when designing a room.
The room will be an edit suite for my own work. . Plus a mixing and mastering room
If it is going to be used for mastering, then that's the way it should be designed: as a mastering suite. You can certainly mix in a mastering room, but you can't necessarily master in any old mixing room. So you have already defined one of the very first questions a studio designer would ask you: the primary purpose of your room is a mastering suite, and since you mentioned local competitors, it should be specifically designed to by much better than their facilities. So it would be necessary to analyze their rooms, and make sure yours is designed to be superior in every aspect.
We've got a lot to learn. That's life. We're up for it
Cool! Then my number one suggestion would be that you buy and study two very important books: "Master Handbook of Acoustics" by F. Alton Everest (that's sort of the Bible for acoustics), and "Home Recording Studio: Build it Like the Pros", by Rod Gervais.
I'm not competing nor necessarily following existing mastering suites on this build.
You should be! There's a very well defined, very clear set of specifications that a mastering studio MUST meet, if it is to be successful. You can find those in the documents ITU BS-1116-3 and EBU TECH-3276, among others. If your studio does not meet those specs, then it is no use as a mastering studio. It might be OK for ordinary mixing, but not for mastering. The basic requirement is that the room must be totally neutral: it must add nothing to the sound coming out of the speakers, and it must take nothing away. What you hear at the mix position must be exactly what came out the speakers, pure, clean, unchanged. That sounds like it should be easy to do, but it's actually incredibly hard. Unless you design your room by following the known and proven methods for achieving that, it's not going to happen. There are only a handful of possible methods for doing this, and you MUST follow one of those, or you are doomed to failure.
We want to function as the mixing and mastering part of the equation now and if I can get the room essentially right in shape and design.. I can tune it with panels and a London system plus acoustic panels we have as required.
Sorry, but no, you can't. That's not the way it works. The treatment inside a mastering room is not something that you throw in afterwards to try to make it better! It's something that is designed in from the start, specifically to create the acoustic response that the room needs in order to meet the specs. Yes, the treatment might need some minor modifications to fix unexpected issues, but that's all. If you think you can sort of build a room roughly, then make it into mastering room by hanging a few panels... well, all I can say is that you are going to be very shocked, because that will not work.
I can tune it with panels and a London system
I'm not sure what you mean by "a London system". I googled that, and only found references to opening moves in a chess game, and I'm pretty sure that's not what you meant! If you are referring to using so-called "room correction" software or hardware, then I'd be very careful about that! To start with "room correction" systems do not correct the room at all! All they do is modify some aspects of the signal BEFORE it gets to the speakers, in order to minimize the acoustics problems in the room. The problem does not go away: it is still there. The system just distorted the signal in a certain way so that the problem is less audible than it was before. In other words, your speakers are no longer telling the truth! Since the signal was distorted before it reached the speaker, what comes out of the speaker is no longer a true representation of the original audio coming out of your DAW or console.... Ummm... so you are not hearing the actual mix. Don't get me wrong: It is possible to successfully use certain high precision digital filter techniques to fine-tune the response, but that can only be done AFTER the room has been fully treated acoustically, and as is good as it can be. In technical terms, the response of the entire system (sound system, speakers, and room) must be "minimum phase" before it is possible to do that, or close to minimum phase, and in the vast majority of rooms, that is not the case. Yes, I do use these techniques myself, but I do not recommend them ever on the forum, because it is very, very hard to get the room to the condition it needs to be in order to do that, and then very hard to use the tools for the final tuning. That's why I have to laugh at the claims of the manufacturers of some of these systems, where they imply that you can put a special mic in the room, press a button, and magically the software makes your room now acoustically perfect! Nope. Nope. Nope. It does not work like that in the real world.
A few snaps of the equipment in the current room under the house.
Excellent! You've got some nice gear there, for sure! So you are going to need a few racks, and possibly a machine room to put that in. Not all of it can fit in the control room. Some can (and yes, I see that some of it is certainly necessary for mastering), but a lot of that is stuff used more in mixing, so that can either go in racks under the desk, behind the desk, or in a separate machine room. Especially the equipment that makes a noise (fans, hard disks, electro-mechanical stuff). Those will have to be outside the master suite, since one of the specs is for NC-20 or lower....
Im not a full time producer and I have a family .. but ill throw as much timber .. insulation. . Plasterboard .. lighting and furniture at it as we can make or buy.
I would suggest you start by NOT doing any of that... yet! I would suggest that you star with those two books: read them carefully until you fully understand them in all aspects, then design your studio, based on everything you learned. Then, and only then should you start thinking about timer, insulation, and plasterboard. By all means, post the various stages of your design here on the forum as it progresses, so we can comment on it, and guide you.
Not bad acoustics actually.
I bet you'd be shocked at just how bad it is, if you run an acoustic test on that room!
If you are game to try, then I can walk you through how to do that, using REW (a free acoustic package).
Working. A good layout for writing but not for mixing.
... and certainly not for mastering!
Is that an old Soundcraft Live console on the rear wall? Looks like it. Nice. I used to use one of those.
This is the wall the engineer will face when working.
Whooaaaa!!!! You have him facing the LONG wall? Meaning that the speakers will be firing across the SHORT axis of the room?
Are you kidding? Or am I misinterpreting what you said? Surely you realize that the room is not wide enough to be able to set up cross-ways? Did you not notice that if you set it up that way, the mix position (engineer's head) will be in the worst possible acoustic location in the room?
Also, regarding that "front" wall: I see no sealing of the outer-leaf, no usable mass, no insulation in the air gap, no caulk under the sole plates, only one top plate, and several other issues. That wall is no use at all for what you want to do. It will have to come down, so you can build it again, correctly.
View showing the rhs area and remaining unused area along roller door side
What do you mean be "rhs area"? I googled that term too, and the top hit is something about mental health, so that's probably not it!
Right Hand Side, maybe? If so, then no, that is not the right hand side of your room. That is the front of the room. The speakers MUST fire down the long axis, in order to maximize the time delay between the direct sound and rear-wall reflections, to be well outside of the Haas time. If you don't know that that means, then google it until you understand it, since it is a key aspect of mastering studio acoustics.
- Stuart -
Good! Smart move.