Hi all, my name is (Ivan) Osorio, and I'm new here! Have been reading this site for a while, since I decided to build my own studio in the back of the house... Been reading up for about 2 months (not much, I know...) and I now THINK I have a VERY BASIC idea of what I need to learn, so I can start the design process. Obviously, it's not like those are my only doubts, I have a lot of them, but I'll carefully deal with each one on due time...
First of, I would like to apologize if this is not in the right place on the forums, or if the question ends up a tad big... But, let's have at it:
It is my main intent to build a studio for myself. I thought of a LEDE room which triples as Tracking/Mixing/Master room. That per se is difficult enough, but it get's slightly trickier... As I said, this all needs to be in ONE room, no walls in between. Is it doable?
These are the really important and main question right now for me:
The room is 6.2m x 4.3m (this is a 5x7m room -which is the space I have available- minus projected sound insulation), the console would be on the dead-end of the room, but I'm "worried" about the 38% rule and speaker placement. I wouldn't want to put my desk too far down the room so as to not "invade" the space I thought of for the "tracking", live-end.
Why is 60% better than 90% for speaker angle? How "far" can I "ignore" the 38% thing?
(now a totally not related question)
Is it worth flush mounting a 5" reference monitor? I get no idea about the size of monitors on pictures and stuff.. and a 5" seems like a pretty small monitor to put up "on the wall"... But, as I said, I have no idea; if flush mounting benefits ANY speakers as long as you do it correctly, that's what I'll do.
Thnaks a lot! All the best,
Osorio
introduction and a few speaker design placement questions...
Originally posted at johnlsayers.com, topic 14285.
Please read this document to understand better that the 38% rule is not a rule but a starting positioning suggestion that Wes Lachot uses in his work. In fact it is a placement "guideline" of the listener more than it is placement of speakers.
At the end of the day you could set your starting position anywhere you want so this "rule" can be ignored completely. But be prepared to deal with the issues that arise from being in the center of a room and getting no good response from your monitors, or finding that with your monitors shoved up against the wall and your head 12 inches from them doesn't seem to give you the separation you had hoped for and puts all the sound directly in your face ;)
The 38% Rule from Wes Lachot (Thread started by Eric.Desart )
http://forum.studiotips.com/viewtopic.p ... =guideline
From the first post by Eric Desart:
This is what I want to know... How can I compensate for the 38% "starting point" so I can be a little close to the speakers and not get undesirable effects? Would opening up their angle a little bit help? Could I extrapolate the 90º angle and maybe do a 100º junction and not have serious separation? I'm not sure if this part was clear, but I don't really have a starting point because I don't actually have a room yet. What I imagine is that, since I'm still going to build the room, maybe there is something I can do to put that "38% sweet spot" a little bit closer to the wall. 38% on a 6.2m room is about 2.3m from the wall, that's really far... I don't own a gigantic mixer, a lot of that space is simply "wasted" on the sweet spot. If I could take 1 step further and reduce that distance to about 1.9m (or miraculous 2 steps further, and reduce it to about 1.7m or 1.6m) that would make a pretty large difference to me. The thing is that the actual length of the room is not corresponding to the area I had originally thought out for the "control room" area. I would really want to know if this "double room" set up is actually doable (or if it is even a good idea, for that matter). Since I work alone pretty much always, the idea of putting a wall between me and my computer when I'm playing seems... counter-productive, at best. I'm aware that guitarists often play in the control room, but there still needs to be a tracking room where the sound is actually recorded.. Maybe the best bet is to build the 2 rooms separately and use the tracking room like a big recording box that I'll use just a "hide out" for when I just feel like playing? This would probably require some tricky cable-work... All the best, Osorio PS: I noticed that in the thread, at some point Eric states that a tracking room and a recording room are two "entirely different thing"s... This is new to me, I have been told since day-one that "tracking" was just jargon for recording... Could anyone clarify this?"Anyhow having such a starting number for control rooms feels as a good thing to me, knowing that a serious amount of reasons can cause this number to be adjusted and knowing that measuring is always the safest way."
Osorio, You are very fortunate to have a room that is 6.2m in depth. (By the way, just a little shorter, about 6m, would actually be a better ratio with the width.) Here's the thing: with a room that size, if you get a lot closer to the front wall than the 38% spot, you'll start "hearing" the wall, if you know what I mean. The 38% point is usually pretty close to where I end up with rooms this size, and I have listened to many rooms this size, over and over, testing them, etc. Your milage may vary, of course. Incidentally, the 38% guideline has for me always been more exactly true for soffited monitors than for free-field monitors. There are so many different kinds of free-field monitors, each with it's own issues, that it's hard to generalize. For instance, some have rear-firing ports, which is a huge hassle in my opinion. But still, with free-field monitors just as with soffited monitors you are faced with the fact that you need to be 3.8m or so off the back wall if you want to keep the null frequency from that wall below the important bass range (30 Hz or so, as per the 1/4 wavelength equation), so that puts you somewhere near the 38% point right there. And, like I said, if you get much closer than 2.4m from the front wall, you'll start hearing bass reflections off that wall very prominently (at least I do). Then there's the modal footprint of the room to consider... The really tough question is where to put the monitors--that is, how close to the front wall to put them. I sometimes use the RPG program Room Optimizer to help with this, but I've found it really varies depending upon the monitors themselves. It's truer than true that some serious bass-trapping behind those monitors is a very good thing in any case. And yes, xSpace is correct that for me the 38% spot refers to the position of the engineer's ears, with respect to the (hard) front wall, and 62% from the (hard) rear wall. -WesFrom the first post by Eric Desart:This is what I want to know... How can I compensate for the 38% "starting point" so I can be a little close to the speakers and not get undesirable effects? Would opening up their angle a little bit help? Could I extrapolate the 90º angle and maybe do a 100º junction and not have serious separation? I'm not sure if this part was clear, but I don't really have a starting point because I don't actually have a room yet. What I imagine is that, since I'm still going to build the room, maybe there is something I can do to put that "38% sweet spot" a little bit closer to the wall. 38% on a 6.2m room is about 2.3m from the wall, that's really far... I don't own a gigantic mixer, a lot of that space is simply "wasted" on the sweet spot. If I could take 1 step further and reduce that distance to about 1.9m (or miraculous 2 steps further, and reduce it to about 1.7m or 1.6m) that would make a pretty large difference to me. ..."Anyhow having such a starting number for control rooms feels as a good thing to me, knowing that a serious amount of reasons can cause this number to be adjusted and knowing that measuring is always the safest way."
Wes,
Thanks a lot for taking the time to explain! I think I have a better understanding of the concept now. As I take it, it would be optimal to take the 38% mark as a starting point in building a reflection free zone? Hope that is correct, that seems a lot more doable than what I thought at first.
I'll adjust the plans for a 6m interior space and add those 20cm extra to wall treatment... Would that be OK? On that merit, just a quick question: When you say "hard wall", do you mean the "outer wall"? As in the one build of concrete or brick instead of studs, gypsum and insulation?
Considering speaker placement: I am still trying to figure out if a simple 5" monitor is "worth" flush mounting... I read "somewhere" (I'm aware of how much lousy of a source that one is) that a small monitor should optimally be "at arms length"; about 1m of me, diagonally. And, honestly, that makes sense to me. But I don't know what I'm talking about in that regard (yet), so I'm trying to research it further.
Depending on how the budget will be, I might build the soffiti cabinet for a 8" speaker (which I plan to buy in a while) and adapt it for a 5" in the mean time.
The thing about letting the 5" free-standing, specially if I'm going to put it at arms length, is something you mentioned. Speakers that have "passive radiators" or whatever they call it; sending bass signal through the back... I can't even begin to imagine the kind of treatment a set up like that would require. Too much "vacant" space in between things.
All the best,
Osorio
If you mean wall treatment inside the room, then that wont change anything: The room dimensions are measured from the inside walls of the room, regardless of treatment. In other words, room dimensions are the distances between the actual inner surfaces of your inner leaf., prior to putting anything else in the room. In order to take 20cm off the room, you have to physically move the wall. ( Or you could add another 12 layers of drywall on top of the existing surface! :) ) - Stuart -I'll adjust the plans for a 6m interior space and add those 20cm extra to wall treatment...
The 38% point is a good starting point for the engineer, and that means 38% from the front hard wall (not soft treatment--that stuff isn't really a "wall" as far as bass frequencies are concerned). The inside of the inner leaf of the sound isolation system is where you measure your room dimensions. This is the same thing Stuart is telling you in his post above. You may have been figuring your room ratios wrong if you were measuring from the inside of the wall treatments. As for soffit mounting smaller speakers, I don't think it really makes sense. The reason we soffit mount large monitors is to smooth out the low frequency response anomolies caused by speaker-boundary interactions, but very small nearfields don't even put out that much low frequency information to begin with. I think you may be better off just treating the front end with bass-traps, and using a sub so that you can hear some bottom end. -WesWes, Thanks a lot for taking the time to explain! I think I have a better understanding of the concept now. As I take it, it would be optimal to take the 38% mark as a starting point in building a reflection free zone? Hope that is correct, that seems a lot more doable than what I thought at first. I'll adjust the plans for a 6m interior space and add those 20cm extra to wall treatment... Would that be OK? On that merit, just a quick question: When you say "hard wall", do you mean the "outer wall"? As in the one build of concrete or brick instead of studs, gypsum and insulation? Considering speaker placement: I am still trying to figure out if a simple 5" monitor is "worth" flush mounting... I read "somewhere" (I'm aware of how much lousy of a source that one is) that a small monitor should optimally be "at arms length"; about 1m of me, diagonally. And, honestly, that makes sense to me. But I don't know what I'm talking about in that regard (yet), so I'm trying to research it further. Depending on how the budget will be, I might build the soffiti cabinet for a 8" speaker (which I plan to buy in a while) and adapt it for a 5" in the mean time. The thing about letting the 5" free-standing, specially if I'm going to put it at arms length, is something you mentioned. Speakers that have "passive radiators" or whatever they call it; sending bass signal through the back... I can't even begin to imagine the kind of treatment a set up like that would require. Too much "vacant" space in between things. All the best, Osorio
Stuart, Wes;
I think we have a slight terminology and cultural issue here! See, I'm from Brazil; though walls made of studs and gypsum maybe be common place in the US (I've no idea how a house on Chile is built), here a house wall is pretty much always concrete or brick (not counting apartment buildings). So I have a hard time considering a "stud wall" an ACTUAL wall.. I usually refer to it as part of an acoustic treatment, because, here, that's basically what they are. The only reason I would raise up a stud wall with mineral fiber on it is to treat a room acoustically.
I'm counting space from the inner-most "finish" layer of the "acoustic wall".
Image attached to facilitate, down below.
My room here is (will be) 7x5x3 (m) counting from the OUTSIDE of the concrete wall, that's the total area of construction I have available.. I'm projecting a 6 x 4.2 x 2.4 (m) from the inner-most acoustic wall, like on the picture. Additional acoustic treatment (like bass traps, foam, slot resonators and stuff) are not computed just yet. In the case of "transforming the extra 20cm", It could be anything, from extra air between the mineral fiber to more gypsum boards to whatever else in between... What budget and effectiveness allow.
Sorry for the misunderstanding! (I really hope there is a misunderstanding here, otherwise I'm doing A LOT of stuff wrong :oops: )
And Wes, thanks for the insight on the speakers! Whenever I think about it.. I just can't seem to be able to figure out how flush mounting a 5" would be that much of a deal... For the time being, I'm fairly certain I'm better off with wisely-placed bass traps and acoustic treatment.
Stuart, this is HARDLY in case, but I stumble upon one particular post in which you said you wanted to build a concrete soffiti.. Did you ever got around that? I'm interested in the matter...
All the best,
Osorio
We're all three saying the same thing here. What I am refering to as the "hard wall" is what you are pointing to with your arrow saying "start of my measurements of room active area". The only confusing thing is that you are calling it an "acoustic wall", which is not the best choice of terms under the circumstances. In a studio design context, "acoustic walls" usually refers to walls made of fiberglass (or a similar material) and covered in fabric, wood slats, diffusors, or some other strictly "acoustic" covering, but normally not gypsum. Your wall diagram is not all that different from the type of building that was ubiquitous in the States during the 50's and 60's--the so-called ranch style where everything was brick on the outside and stud walls and gypsum (or plaster) on the inside. These days in the States many houses are built with stud walls only, with some sort of siding on the outside, so no one here would have a hard time considering a stud wall an actual wall. So there is nothing wrong with the way you figured your ratios-carry on! -WesStuart, Wes; I think we have a slight terminology and cultural issue here! See, I'm from Brazil; though walls made of studs and gypsum maybe be common place in the US (I've no idea how a house on Chile is built), here a house wall is pretty much always concrete or brick (not counting apartment buildings). So I have a hard time considering a "stud wall" an ACTUAL wall.. I usually refer to it as part of an acoustic treatment, because, here, that's basically what they are. The only reason I would raise up a stud wall with mineral fiber on it is to treat a room acoustically. I'm counting space from the inner-most "finish" layer of the "acoustic wall". Image attached to facilitate, down below. My room here is (will be) 7x5x3 (m) counting from the OUTSIDE of the concrete wall, that's the total area of construction I have available.. I'm projecting a 6 x 4.2 x 2.4 (m) from the inner-most acoustic wall, like on the picture. Additional acoustic treatment (like bass traps, foam, slot resonators and stuff) are not computed just yet. In the case of "transforming the extra 20cm", It could be anything, from extra air between the mineral fiber to more gypsum boards to whatever else in between... What budget and effectiveness allow. Sorry for the misunderstanding! (I really hope there is a misunderstanding here, otherwise I'm doing A LOT of stuff wrong :oops: ) And Wes, thanks for the insight on the speakers! Whenever I think about it.. I just can't seem to be able to figure out how flush mounting a 5" would be that much of a deal... For the time being, I'm fairly certain I'm better off with wisely-placed bass traps and acoustic treatment. Stuart, this is HARDLY in case, but I stumble upon one particular post in which you said you wanted to build a concrete soffiti.. Did you ever got around that? I'm interested in the matter... All the best, Osorio
I'm a bit confused about your diagram, Osorio: When I look closely, I see something labeled "brick wall", then what looks like a thin air gap, then "concrete wall", followed by a thin air gap, then gypsum with a bigger air gap (partly filled with mineral wool), then the final inner-leaf gypsum. To me, that is a FOUR LEAF wall! :shock: That could give you problems with low frequency isolation.
Even if the brick and concrete are totally coupled (joined together and acting as only one wall, with no air gap) then it it still a three-leaf wall, and would still bring you issues with low frequency isolation.
I'd suggest that you leave off the first layer of gypsum on your diagram, and move it to the inner leaf. That would give you a much larger air gap, and it would put all that mass on only one inner leaf, where you want it. That will increase the low-frequency performance of your wall substantially.
Your wall should be only two leaves, not three or four, to improve your low-frequency isolation (although, with both concrete and brick on the outer leaf, the difference might not be large).
And like Wes said: That isn't an "acoustic" wall. It is an "isolation" wall. The purpose of that wall is not to treat the room acoustics at all. The purpose of that wall is simply to isolate the room from the outside world. Isolation and acoustic treatment are two different things. The isolation wall stops sound getting in and out, and the treatment deals with the acoustic issues of the room itself.
All of your treatment goes inside the room that is defined by the inner-leaf, and the dimensions of the inner leaf are the dimensions that you use for calculating your ratio.
The isolation wall should ideally be a two-leaf MSM system, meaning that you have only one outer leaf ("M"), only one air gap ("S"), and only one inner leaf ("M"). If you have more than one air gap then you no longer have a 2-leaf MSM system, and your isolation will suffer at the low end of the spectrum (kick drum, toms, bass guitar, low end of the keyboard, etc.). It gets even worse if you have several very thin air gaps, which is what I see on your diagram. I'd suggest that you re-design your wall so that it is only two leaves.
And yes, I'm somewhat familiar with construction in Brazil: I go there regularly, to install and calibrate post-production systems. The way you build in Brazil is pretty much the same as the way we build here in Chile, except that we build everything a lot stronger, due to the earthquakes.
Yep, that's still the plan. The build is on hold right now, as part of the "agreement" with my wife is that I have to finish building a new upstairs bathroom first, and I'm still working on that. But when I get to building the studio, yes my plan is still to cast the speaker soffits in concrete. It will be supported by a sand-filled welded steel frame, of course, not wood. The frame will be bolted to the floor, for safety: I don't want all that lot falling on me in the next earthquake! - Stuart -Stuart, this is HARDLY in case, but I stumble upon one particular post in which you said you wanted to build a concrete soffiti.. Did you ever got around that? I'm interested in the matter...
Wes,
I see the confusion, I'll try to adapt my terms. What the arrow is point too, however, is a wall I'm building to "emulate" an american wall, and, as far as I could gather, no contractor I've come around here in my city knows how to do that, it is a very... unusual.. build. Meaning I'll be most likely doing either a lot of inspection or a lot of DOING.
But at least the measurements are right!:D
Thanks for all the explanations, and I'm sorry if my calling of it "not an actual wall" might have come across rude (to you or anyone that might read this in the future). It's just a really unusual way to build a wall around here; some contractors don't even think it would actually work and be able to sustain a ceiling or stay up at all!
Stuart,
Yes... You see, about that diagram... There is a lot of.. "work" going around it that I need to revisit. Context time! : As I said a couple of times around the thread, this room is still about to be build... I'm building it in a "partnership" with my father, in the back of the house (my father is a civil engineer, he has all the permits and licenses needed to construct and etc. He engineered, architectured and designed the house we live in). Thing is, my mother, suggested an "external brick wall" for aesthetic purposes. I said I would have to check around (here) later to see if there would be any implications in isolation because of it (the whole "Mass-Space-Mass" deal you just explained), but I drew it in the diagram anyway to calculate my "projected loss in real-state".
There are A LOT of structural "flaws" or draw-backs in that design that I have to look in carefully before start constructing. The one that is mostly terrifying me right now, is the very real possibility of a floating floor being ACTUALLY necessary... I plan to open a thread in the "construction" forum later to deal with this, but right now, my father doesn't really have a lot of the answers I need, and I can't really just go and check because the studio requires that a little part of the house be demolished... So it's not like I can jump back there and go "so this is what is here". That part is not in the original plants as well because it has been modified before, that leaves me in a very precarious position here, at least before anything starts. I'm doing a lot of guesswork as it is...
I'll be doing a construction diary here when time comes around! I plan on doing this as right as I can, but I AM worried about a lot of stuff...
That is FAR from a finished design, but it is good to know that it is not performing well... So a big air gap is better than two thin air gaps? I really thought it would be the other way around... Thanks for the correction!
Can I bother you A LOT in the future? :D I have a lot of doubts in regard to construction materials and such, things more on the practical level then on the theoretical level; maybe you are just the guy to help me out, everyone in this city is clueless about this... And best of luck with the bathroom, and I'm eager to hear about how the concrete soffiti goes, seems like a really good idea! Have you opened a thread here about it yet? All the best, OsorioAnd yes, I'm somewhat familiar with construction in Brazil: I go there regularly, to install and calibrate post-production systems. The way you build in Brazil is pretty much the same as the way we build here in Chile, except that we build everything a lot stronger, due to the earthquakes.
Thanks for your input Mr. Lachot it is always welcome to have the myth put to rest by those who have fallen into mythology. Brien.... that for me the 38% spot refers to the position of the engineer's ears, with respect to the (hard) front wall, and 62% from the (hard) rear wall. -Wes