Hey Kevin - actually the Ruby Housebuilder plugin does it all for you - you just tell it whether you want 16oc or 24"oc, the plate height, header height, lumber size, and how many top / bottom plates and it builds it all for you.
Your plans look really good - are these some you've been working on for the new house?
Do let me know anytime you're heading out this way - would be great to meet up for a beer and a chat.
All the best,
Andy
I'm back seeking design ideas for basement studio #2
Originally posted at johnlsayers.com, topic 18547.
Well I finally have a plan to show you all and would really welcome your constructive criticism. I've tried all manner of orientations and approaches - splayed walls, non-splayed, Louden, Sepmeyer, CR at the North, CR at the south etc etc. But so far this seems to be the one that achieves the following:
- Maximum Use of Space
- Ability to add future walk out to north wall
- Access to Fireplace Ashbox on south wall
- Largest possible Control Room (>1500 cubic feet)
- Acceptable Room Ratio's as a starting point
- Line of sight and good visibility for video feed
Andy,
I think I understand your layout, why you have chosen the specific order for the rooms. I'll take a closer look, but one comment off the top of my head... If you are not highly concerned about absolute isolation between rooms, then I'd be tempted to move your control room door forward about 3ft. I would get rid of the airlock and use it for a closet storage, or just add it to the live room... my reasoning would be, by putting a door in the corner, you remove the ability to put in a super chunk low end absorber, or at least on both sides of the cr... and the whole symmetry might mean you cant do the other corner either... however, since the teh room is so long in general, if you were concerned about isolation of the CR and live room, it isn't that much room to build a true double wall, and then use a solid double door. I was very pleased with teh double wall assembly i did in my past studio, and even used some standard lowes full light exterior doors (a pair), and the isolation was good enough for my purposes. since the door is behind the mix position, you could prob get away with just a solid core steel exterior door (well two)...
I haven't quite gotten around to doing your layout... i've been selfishly working on a new design for my house... I started from scracth basically... but I should be able to get something soon, and not sure if it would be much different than what you have already done...
kevin
Yep that's a really good point you raise about bass trapping both corners. The reason I had the sound lock was to enclose the structural support that you can see there behind the second door. I forgot to list that in my list of design considerations but it was definitely a key contingency. It looks like I could move the door and still enclose the pillar though - the only drawback would be that the door would swing into the drum room and take up some space. I will give it some more thought. Thanks so much for thinking of that - it's exactly the kind of feedback I was hoping for!
Talk with you soon,
Andy
A couple of curve balls for ya:
1) Have you considered putting the control room in the middle, with the drum booth on one side, and the guitar booth on the other?
2) Have you considered a "corner control room" layout?
:)
- Stuart -
Hi Stuart,
I did try doing a corner CR design a while ago inspired by the one in Rod's book, but I really struggled to get one to work with a door out of the CR in a sensible location, and I was also concerned about the soffit and not being able to calculate room modes or use ratios. At least with rectangles or trapezoid shaped rooms I can do some type of predictions.
As for positioning the CR between the two live rooms - this is not something I had yet considered. Mainly because I saw the middle part of the basement as being the preferred location for the noisiest area - the drum room; due to it's lack of external windows (or fireplace ash box I the case of the south wall). A second factor is my desire to have the two live rooms feel like one room to the performers, with the ability (if possible) to open up the two rooms into one large room. Or at the very least I had hoped to have good site lines between the two live rooms. I realize at some point I have to start making compromises though. :cry:
I will definitely give your comments great reflection and see if it stimulates any new solutions. I'm all ears btw if you had something specific that sprung to mind. What comes naturally for you in 2 minutes takes me weeks of going back and forth following lots of research and deliberation :roll:
Many thanks as always for your valuable time and kindness,
Andy.
So I spent all day yesterday playing with various different room shapes and sizes. I attempted the middle control room and the corner room with a number of sizes (using known good ratios as a starting point) but just couldn't get any to work - something always seemed to make it fail - a window location, the support pillar, wasted space, lack of sight lines. I'll post some pics below of some of the best failed attempts. I'm kind of at a loss :cry:
One other thing based on Kevin's feedback. I recall watching a video on Mitch Gallagher's home studio where he talked about using a "leaky wall" as a bass trap at the back of the room. This leaky wall was basically framed and insulated and then used pegboard on the front face. I was wondering if that might provide a possible solution to the door / bass trapping issue that Kevin raised. Attaching a quick pic of what I mean if that helps....
Andy,
Thats funny, i just watched that a couple weeks ago.. from sweetwater right? Anyways, I think thats a good idea, and definitely worth considering... I'd be even tempted to not make it reflective at all... and just keep the entirety of the back wall absorbent... or if you need to keep some of the highs, use a pvc / plastic sheeting on top of the rockwool and cover with a cloth... the lows will still be absorbed...
slightly related to your post...
I was wondering what would happen if you keep the CR at the end, and just rotate the design to face outward to the tracking rooms... so where the window is now, install a larger sliding glass door... yes, you'd have to walk around your desk everytime you get in and out... but, you could treat the walls however you like, and open up the middle room for a kit... plus, facing the musician while recording is always nice... like your last posted picture suggests... (i just saw that)...
as for stuarts suggestion, i'd be hesitant to put the CR in the middle... (no offense!!!) it's just that lugging amps or drums through the CR seems like a pain, if not a danger. I think it would be different if it was just a vocal booth or for acoustic stuff...
kevin
Yes that's the one Kevin - here's the video in question for anyone else that is interested:
http://youtu.be/FuRiqoNRDmc
The discussion about the leaky wall starts around 36m40s
I've continued trying additional approaches, shapes, orientations and ratios over the last 48 hours but have still yet to find anything that works any better. I have been keen to find an approach as you suggest where the CR looks into the drum room by way of the window although I've yet to find a way to do that while still be able to use a sound-lock approach, hence I suspect your suggestion to use the sliders. While I'm not oppose to using SG doors per se, I'm really not sure that I could get used to me (or worse still others) navigating their way around the console to get to the door. I think I'd be very nervous! I should also point out that I have a vested interest in using doors and a window if at all possible, as I was able to salvage the four doors (including the closers and adjustable seals), and window from my last studio when I moved. I will say also that from my last studio, and given how much I tend to run back and forth between the CR and live room during a session; that I love the pull / push doors with automatic closers.
I've also been keen to find a solution where I can splay the walls to help with the flutter echo, but given the other design constraints I'm really struggling to find a working design. I wish that support column weren't there, and that the mechanical room didn't notch out into the space - but it is what it is and I have to find a solution that works around them and the other constraints (exterior windows, duct soffit etc.)
In other news the Structural Engineer finally came back to me with the numbers for under the kitchen. They were all hand-written (take a look here)and this time he e-mailed them to me with no seal / stamp so I asked if he could mail me the final signed and sealed report (since this is what I'm paying money for) and he said "sure - it'll be another $200 for the extra calculations". I don't mean to split hairs, but I was very clear from the get go that the under-kitchen area was the area of greatest concern (given the dead load in there and the wider joist spacing) so I'm not sure why he failed to provide them in the initial calculations nor if I should have to pay for him to do "additional calculations".
Anyone have any thoughts on the matter? Am I being overly sensitive? Perhaps the frustration from weeks of not getting my studio design to work is causing me to act irrationally. :x
And here's my latest sketch (.skp file is here). As you can see it's a variation on the previous design using the "leaky wall" at the back of the CR, but splays the front half walls by 6 degrees. I have also opened up the live room and gotten rid of the lounge. The door in that room would go into a closet area that would eventually serve as an air-lock if and when I add a walk-out exit there.
Let me know what you think...
Andy
I've created a slightly improved sketchup file here that took care of a couple of issues:
1. Created access to the Fireplace Ashbox on the south wall by starting the splay after the Ashbox
2. Adjusted the average room width to better match the Sepmeyer 3 room ratio based on a rectangle with the same volume.
What do you guys think? Would you go with something like this? See any "gotcha's"?
Many thanks and wishing all a wonderful weekend,
Andy
So I've been doing further tweaking to the plan (not to be confused with twerking of course) and you can see the latest Sketchup File here...
However, having lived with this plan for a number of days now and having gone down into the space and tried to imagine working down there I find myself questioning whether or not I can live with it.
The biggest issue that I see is the lack of space in the Control Room. There's just no room for a Sofa and people to sit at the back of the room due to the "leaky wall" bass trap idea. In my last space the Control Room became the hang out spot between takes or for my own band after Jamming - and I don't know that it's doable with this configuration. That's kind of a deal breaker.
There were other concerns regarding where to place bass trapping in the Booth etc., but the above is perhaps my biggest concern right now.
So I think it may be back to the drawing board again.
Please please please - if you have ANY ideas - please let me know. I'm starting to get desperate!!! :cry:
Okay I think I may finally have something here. :idea: I have rotated the CR 90 degrees counter clockwise which allows me to add the door away from the bass trapping area. Sketchup file is here for anyone that wants to see in detail. Stuart I am attaching JPG's for you in case you still are unable to upgrade.
As you can see I would still need to add treatment to the CR. The large sound lock to the side of the CR would also serve as storage space and could perhaps double as a booth / isolation space if needed.
Would love to get some feedback from any of you :)
Now THAT I like! that makes a lot more sense, Andy! :thu: If you slide the entrance door a bit further back, and put in a window to that "hallway", it would make a great emergency vocal booth... However, you do still need inner-leaf walls for that hallway/booth: right now, it is in the air cavity of your MSM system. That will make it narrower, of course, and will create an issue with the door to the drum booth, but if you splay your CR walls a bit more (aiming for a true RFZ design... :) ), then the door should still fit in just fine. But I really do like this a lot more: the CR is much bigger, can have a better ratio, and has good sight-lines to everything else. I think you are on the right track with that! - Stuart -Okay I think I may finally have something here. :idea: I have rotated the CR 90 degrees counter clockwise which allows me to add the door away from the bass trapping area
:D :D :D :D :D :yahoo: :yahoo: :yahoo:
You have no idea how happy your reply made me Stuart! Seeing your thumbs up means the world to me!
So naturally I have a few questions and comments...
Yes I was thinking about using it for something like that but hadn't considered adding a window and making it a legit booth - interesting idea :idea:If you slide the entrance door a bit further back, and put in a window to that "hallway", it would make a great emergency vocal booth...
Yes, this was actually my intent. Kind of like an oversized air lock that could perhaps double as a booth / isolation space if needed. I figured that I could add fabric over the framing and insulation and it would be kinda like one of John's inside out rooms. Would you advise against that or is there perhaps an issue that the building inspector might have? As you can see I was planning to do something similar, albeit much smaller, for the sound lock going to the future walk-out door from the live room (the room furthest from the CR). Is that wrong also - I figured there was some benefit to having this be a large spring. Ahhhhhh (lightbuuuulb) - is that why perhaps your saying I would need to finish the other area to use it as a booth? Since if it's a spring and someone is jamming on the drums in the adjacent room - this area would be picking up a lot of residual sound energy from that room. I guess then it's only an issue if I plan to record in that small hallway rather than use it for storage. For storage it would be fine to leave it without Sheetrock?However, you do still need inner-leaf walls for that hallway/booth: right now, it is in the air cavity of your MSM system.
I may need a few pointers here. I've been doing some research over the past few days on Ray tracing and how to predict reflections (MHOA, Newell, and online threads - including your very own discussion here that I found very useful). I tried drawing a line directly from the midpoint of my HR824mkI's in Sketchup to see where the first reflection would be point would be and it seemed to be back to the corners where the bass traps are - so I know I'm doing something wrong here. If I use a cone rather than a straight line - what should be the angle inside the cone? Also is it only truly an RFZ if i soffit mount my speakers? I am leaning towards leaving them as near fields - would that then affect the need to increase the splay angle? Many thanks again Stuart for making my day - it's great to know I'm finally getting close to having a working design, and thanks as always in advance for your time and insight with my endless questions :) Kind regards, Andy.if you splay your CR walls a bit more (aiming for a true RFZ design... ), then the door should still fit in just fine
Yup! You got it. If you are standing inside the "spring" of the MSM system, then you are in the acoustic war zone! Don't forget that that's a two-way street in there: It's two different MSM systems at once: one with respect to the CR, and the other with respect to the LR. So there's two different wars going on at once. If you are in there, then you only have one leaf between you and each of those noisy things, but also you are part of the dueling MSM battle zones. That's probably not a place you'd want to set up a mic to record vocals! :)Ahhhhhh (lightbuuuulb) - is that why perhaps your saying I would need to finish the other area to use it as a booth? Since if it's a spring and someone is jamming on the drums in the adjacent room - this area would be picking up a lot of residual sound energy from that room.
I would drywall it regardless: If you don't, then anyone walking through that space is only one leaf away from either room: a cough, a sneeze, a cell phone ringing, a chat with the guy walking next to him, things getting dumped on shelves, dragged off shelves and dropped on the floor... I think you get the picture!I guess then it's only an issue if I plan to record in that small hallway rather than use it for storage. For storage it would be fine to leave it without Sheetrock?
OK, it's easy and hard! :) Easy in concept, hard in the sense of boring, repetitive, figuring angles, drawing lines, figuring more angles, drawing more lines, rinse, repeat.... The basic idea is this: Start from the acoustic center of your speaker, then looking directly down from above, draw a line at 90° to represent the acoustic axis. Then draw some more lines angled at 10°, 20°, 30°, 40°, 50° and 60°, going BOTH ways: to the left and to the right of the axis. Now follow each line in turn across the room, to see what it hits: wall, window, door, another speaker, etc. At the point where it hits that surface, figure out the angle of incidence, then draw another line bouncing off that surface starting from the very spot that the first lie touched it, but at the exact opposite angle. For example, if the incoming line hit the surface at 27.3°, then the reflected line must bounce off at 27.3° going the other way. You measure all of these angles with respect to the "surface normal", which is just a fancy way of saying "a line poking out of the surface perpendicular to it, at the point where the incoming line hit it". You always measure all your incoming and outgoing angles with respect to the "normal". So, then you follow this new reflected ray across the room again, to see where it goes: Hopefully it heads off to the back wall, where you will absorb it. It might also head off towards another surface in the front half of the room, in which case: "rinse, repeat".... same procedure for another bounce. As you follow each line, you want to make sure that it does NOT get close to your ears at he mix position! That's the entire point of the exercise. So draw a circle at the mix position to represent the size of your head, then draw a couple of bigger circles, about 1 foot radius and about 2 feet radius. Ideally, you want no rays at all passing through the 2-foot circle, and definitely none in the 1-foot circle. If a ray gets into the 1-foot circle, then you need to change the angle of the surface that the ray bounced off and rinse-repeat until the ray no longer gets into the circle. It might not be possible to keep all rays out of the 2-foot circle, but do your best to minimize them, and keep them just passing through the edges, as far away from the 1-foot circle as possible. OK, have you done all that, and gotten all your rays out of the circles by carefully angling the walls, doors and windows? Great! Now it's time to do it all again, but this time starting with a SIDE view of your room, instead of the top view. This time you'll be making rays that spread out upwards and downwards from the acoustic center of your speaker, towards the ceiling... and towards the desk, console, video monitors, etc. When you are done, you'll have dozens of lines running all over the room in all directions, both vertically and horizontally, but hopefully there will be a clear area around your head at least 12" to 18" on each side of your head, and with a bit of luck, as much as 24" each way. But 24" is really hard to do in a small room. OK, adding to the above: If you do find lines that are getting into your 2-foot circle (actually, it's a 2-foot sphere, really, since it goes out in all directions...) then you can also do a bit of "devil's advocate" prioritizing, by seeing which ray it actually is, and deciding if you will allow it to live or not... If it is a ray that started out with an angle of 10° or 20° from the speaker, then you really cannot allow it, since that is practically on-axis for most studio monitors. If it started out as 60°, on the other hand, then it's probably not too much of a problem, since that is pretty far off-axis, so it is going to be a mostly lower frequencies on that path, which are probably not too directional anyway. Don't forget that each time you change the angle of a surface, you need to go back to Square One with this whole procedure, and start again, since you might have also moved some part of the surface into a position where a different ray now also hits it, at a different point.... rinse... repeat ... rinse ... repeat.... Did I mention that this is boring? :) :roll: :blah: - Stuart -I may need a few pointers here. I've been doing some research over the past few days on Ray tracing
Sorry, I missed a part in my answer above:
Well, you can do an RFZ that is pretty decent without soffit mounting, but you'd still be left with all the usual artifacts of speakers that are NOT soffit mounted: SBIR, edge diffraction, phase shifts, comb filtering, and all the other nasties that mess up your speaker response, in both the frequency and time domains (and phase domain too, but that's sort of time domain anyway... ). If you soffit-mount, then all of those go away... :) If you do soffit mount, then half of your ray-tracing is taken care of anyway, since a large piece of your front wall is already angled correctly: Your soffits are angled at about 30° (give or take) since they match the speaker angles, which is almost always more than plenty for RFZ, in the majority of rooms. So the only part that you still need to ray-trace is the surfaces that blend your soffits into the side walls. - Stuart -Also is it only truly an RFZ if i soffit mount my speakers? I am leaning towards leaving them as near fields - would that then affect the need to increase the splay angle?
my brain hurts too much reading this now... let alone trying to make an intelligent comment... I'd blame my current sinus cold, but i'm not so sure thats it ;) so i did want to cheer you a bit, keep up the good work andy, stuart, again, this is really helpful!
kevin
On no - feel better soon Kevin!
Ok Stuart - so I took a quick stab at following your superb instructions (many thanks for the explanation) and am pasting a shot below so that I can ask a few follow-up questions. I did this really as a trial to see what would happen with the existing room shape (12 degree splay) if I added soffit mounts for my HR824's (it seems quite a few folks have done this successfully even if Mackie don't advise it).
So on to the questions:
- Since I don't have the space to angle my ceiling and planned to just add a hard-backed cloud above the mix position - is it worth conducting the exercise again for the vertical axis?
- Since my room is symmetrical - do I only need to conduct this for one of the speakers? Won't the other be a mirror image? (assuming there is no furniture or other items to interfere with the wave)
- Even with just the 12 degree splay and soffit mounting it would appear that none of the 1st reflections travel through the 1ft radius circle, and the only ones entering the 2ft circle are first reflections from further off axis (50 and 40 degrees). So is it worth angling the walls further or should I just treat that first reflection point? I'm guessing it would take some significant splay to angle that 50 degree reflection back behind the mix position.
- Am I right in thinking that as well as having the bass traps in the rear corners I would want to make the rest of the rear wall absorptive, and / or diffuse to help dissipate or randomize those reflections?
- Is there value to me adding absorption around the front wall window (between the two soffits)? It would appear that none of the primary on-axis rays appear to hit back there.
ok, my intelligence be damned, but i have a question at this point...
If your ray tracing at given angles, 10, 20, 30... this is only to give you an idea of incidence of reflection on the wall correct? but to confirm, there is no "ray", it is a continual wave, so all angles are to be accounted for correct? If so, then in my crude sketch, the blue line is probably about 35degrees... which does run through your 1ft area of concern... and if you were thinking the RFZ, then your gonna need to have a panel absorber at that first reflection point, which would be i guess anywhere between -0 and 60 degrees.... correct? I know John and others in the forum have dealt with this in the past for the window, by puttin in a heavy drape for mixing, then just open for tracking...
but am i understanding this right?
if so... then if you angle the front wall less, don't you push back that first reflection point, by aiming the speaker soffits more toward the back fo the room? is that a valid strategy? or does that kill the point of an angled soffit? what if he pushes the desk forward 1ft... it looks like your almost 50%, shouldn't ypu be somewhere like 38% or about that?
... guess i was asking both of you ?
Right! The "rays" just mark a few points on the continuous range of angles that a sound wave expands along. The higher the frequency the more it acts like a ray, but the lower the frequency, the more it spreads out in all directions.there is no "ray", it is a continual wave, so all angles are to be accounted for correct?
yup.If so, then in my crude sketch, the blue line is probably about 35degrees... which does run through your 1ft area of concern...
actually, no. :) For RFZ, the solution is to angle that section of wall more steeply, until the reflections no longer hit the mix position at all: That usually means pretty large angles, for small rooms. If you put perfect absorption there, then you could theoretically fix the problem, but of course there is no such thing as perfect absorption... There would always be some type of reflection coming back. So for true RFZ, angles is all you have.and if you were thinking the RFZ, then your gonna need to have a panel absorber at that first reflection point,
Right, but that's not for true RFZ rooms. That would be for other room concepts, not based fully on RFZ.I know John and others in the forum have dealt with this in the past for the window, by puttin in a heavy drape for mixing, then just open for tracking...
Yes, but you shouldn't change your soffit angles to fix reflections! You should change the angle of the section of side wall where the problem is occurring. Your soffit angles and positions should be set for the basic room geometry, and shouldn't be changes unless there is no other option, as a very last resort. Sliding the speaker along the soffit face is one possibility, either left or right, but without changing the angle. Of course, that changes the location of the mix position... :) Don't you just love studio design? Change one tiny thing, and the entire room changes! Sometimes it seems that just turning the lights on is going to destroy the room! :) :shock: 8) :!:if so... then if you angle the front wall less, don't you push back that first reflection point,
Right again! :) -----what if he pushes the desk forward 1ft... it looks like your almost 50%, shouldn't ypu be somewhere like 38% or about that?
You should still do it, yes, and use the hard back of the cloud as though it were the room ceiling.Since I don't have the space to angle my ceiling and planned to just add a hard-backed cloud above the mix position - is it worth conducting the exercise again for the vertical axis?
Right. In fact, if you make your speaker, soffit and ray tracing into a component in SkethcUp, copy it, then flip it along the appropriate axis, you are all done with both! The copy will the follow exactly what you do with the original. Add a piece inside the component, change something, delete something... what ever you do on either of the copies will also be done on the opposite one, correctly mirror imaged...Since my room is symmetrical - do I only need to conduct this for one of the speakers? Won't the other be a mirror image?
See above: Sandlefoot has it right. Those 10° rays just mark some of them; you have to imagine the others in between (or draw them too, if you feel like it!).Even with just the 12 degree splay and soffit mounting it would appear that none of the 1st reflections travel through the 1ft radius circle,
Don't forget that each degree of wall angling greatly increases the the reflection angle, since you are using the surface normal as the point of reference. So a small change in the wall angle can produce a large change in the reflected ray...So is it worth angling the walls further or should I just treat that first reflection point? I'm guessing it would take some significant splay to angle that 50 degree reflection back behind the mix position.
Absolutely! The entire back wall should be absorptive. Thick.Am I right in thinking that as well as having the bass traps in the rear corners I would want to make the rest of the rear wall absorptive, and / or diffuse to help dissipate or randomize those reflections?
Some people do that. It can help. Your first axial room mode, for example, is associated with that front wall, as are some of the tangentials, and all of the obliques... - Stuart -Is there value to me adding absorption around the front wall window (between the two soffits)? It would appear that none of the primary on-axis rays appear to hit back there.
Thanks to you both - this has really turned out to be a great learning experience and my Sketchup chops just keep on getting better. It's funny to think that only a month ago I dreaded using it and found it frustrating at best. Now I find it really quite intuitive and quick to use. I have been using a Ruby Plugin called RayTrace to help expediate this part of the process - very hand indeed. I mention this only to bring reassurance to anyone struggling with it. Perservere, practice, and you'll have it in no time. If you can edit in a DAW you can learn this I promise you.
So then, on to the topic de jour and some responses / more questions along with updates to my raytracing efforts.
That item on the Right hand wall is actually a LCD TV, not a window - so it can be relocated without any issue. So on to the RayTracing... I updated the 9 degree ray trace by adding more rays in the 40 to 60 degree area and also adjusted the circles to the 38% position (while I had previously setup the chair to be located at 38%, I forgot that I had it centered in the middle of the chair rather than the back headrest where these first circles originated from - thanks for picking that up Kevin), and then did the same ray tracing for 12, and 18 degree's to see what effect it was having. Here is the 9 degree splay ray trace: 1st reflection issues appear to exist between approximately 41 and 55 degrees. Now the 12 degree 1st reflection issues appear to exist between approximately 42 and 57 degrees. Room volume decreases to 1515 cubic feet And finally the 18 degree. 1st reflection issues appear to exist between approximately 43 and 60 degrees. Room volume decreases to 1366 cubic feet So from looking at these it would appear that as I increase the splay angle, the first reflections get angled further back, however - even with an 18 degree splay I am unable to fire all of the first reflections out of my 2 circles. In fact some of the further off-axis rays (55 to 60 degrees) have been brought into the circles. Further, by increasing the angle to 18 degrees I lose enough room volume that my CR is now below 1500 cubic feet (this was my minimum goal for CR volume). So, here then would be my questions following this analysis:I know John and others in the forum have dealt with this in the past for the window, by puttin in a heavy drape for mixing, then just open for tracking
- If I increase the angle to the extent that I lose room volume, should I compensate by increasing the room width? Will that throw-off, or improve my alignment to my room ratios?
- Given that most of the troublesome first reflections are coming from the further off-axis rays (41 degrees and up), and anything below that is going to the back wall - can I treat these front splayed wall areas with broadband absorbers spaced an inch or so off the wall? At approximately what angle are the off-axis rays could one consider - "it's low enough frequency so I'll live with it". I recall you mentioned the higher ~60 degrees ones are less of a concern for this reason, but is there a cross over angle? Does it depend on the speaker? I've looked at the specs for the HR824's MK1 and don't see anything. I guess I'm hoping the answer is 40 degrees is the magic crossover point to LF :)
- If it's not possible to create a true RFZ and I'm treating the first reflection points as mentioned in my question above - is there then much value in increasing the splay angle given that it will reduce room volume. Which would you be inclined to go with - 9, 12, 18 - something else?
- Am I right to not be concerned about my HRS120 subwoofer? I had read that it doesn't need to be in the soffit, and the frequency's are low enough that they won't be directional right? Any reason to be concerned about there being less low-end coming out of the mains in the soffits due to using this sub i.e. does any of this affect the ray-tracing? I should point out that I have the sub on a foot switch so that I can switch it on and off.
- Should I be concerned about that external window on the back wall to the left? It's really not that large, but is it going to mess up my ability to effectively treat the rear wall?
You are missing something rather important in your model, Andy: Your soffits! Most of those problematic rays will be hitting your soffit baffle, not the walls, and the baffle is angled at 60°... :)
Also, to avoid losing so much room volume, angle less of the front wall. In other words, extend the parts of your side walls that are parallel much further forwards. Now that you are ray-tracing like a pro, you can optimize the position of the point where the splay starts: it can go several feet further forward.
Right. Directionality starts at about 70 to 100 Hz, which is more or less where your crossover point is probably set, so subs don't need to be soffited, and indeed doing so might mess things up, since may subs are ported at the back, sides, or even underneath. - Stuart -Am I right to not be concerned about my HRS120 subwoofer? I had read that it doesn't need to be in the soffit, and the frequency's are low enough that they won't be directional right?
Hi Andy!
I'm sorry if I missed it somewhere but what are the dimensions of your CR?
If it helps at all mine are 16x14 and my design is RFZ going with soffit mounted A8x's, I splayed my side walls at 19 degrees and I have plenty of clearance in regards to no reflections around my mix position.
Allen