House built around studio design/build thread

It looks interesting, but hard to understand from just a single 2D plan view... :) - Stuart -

Does this make more sense? I'm really having to think through light placement so that it covers everywhere well but doesn't screw up my RFZ! Greg

I also called around/looked around at different insulation available in my area and wanted to compare price differences. There is no 701 around. There is only 1" and 2" thick 703. I can get FRK 3" 703 but it's super expensive in comparison. So anywhere I need 3" I will use a layer of 2" and a layer of 1". For 4" needs, I'll use two layers of 2". Where I need super thick insulation (like in my inside out ceiling skeleton where I will need 5 1/2" of insulation) I'll use OC R24. For places I don't need amazing acoustic treatment (like inside wall cavities), I'll use 3" Rockwool Safe'n'Sound. Dimensional lumber is always 1 1/2", 2 1/2", 3 1/2", 5 1/2". For the smaller dimension wood, I can't get exact sized insulation. So, this will force me to get creative with what lumber I use where and how I will frame fabric cover frames. I'll try to eliminate gaps where possible, but I think it's inevitable in spots. This is just making the design process harder :-( Here are the prices I can obtain the three different models of insulation for: $0.916 per 1” 1’x1’ for 703 with no discount $0.209 per 1” 1’x1’ for OC R24 $0.300 per 1” 1’x1’ for Rockwool Safe’n’Sound Now, for the 703, I can get a discount based on how much I buy at once. So I'm going to figure out roughly how much I need and buy it all at once. The place doesn't carry R24 or Safe'n'Sound as they only carry industrial grade insulation. I'm also able to get Roxul ProRox SL960 (which is the new name for RHT80) or ProRox SL930 (which is the new name for RHT40) from a 4th place (I've bought some in the past) but I don't have those prices handy. Anyway, sorry if this hasn't been an interesting post, but it's what's on my mind. Greg

Does this make more sense?

OK, that makes a bit more sense. I was actually looking at it backwards! :oops: But now I got it. Have you thought of putting small hangers above parts of your cloud? Like this? Not sure if you have enough space for that, but it might be an idea.

I'm really having to think through light placement so that it covers everywhere well but doesn't screw up my RFZ!

Be careful with light glare on your front window too. You can ray-trace for light glare just like you do for speaker reflections. There should be no direct light that is visible from the mix position as you look through the window, AND ALSO nothing that is illuminated directly, visible in the window. If you have things that are visible directly in the window (such as your own head, for example!) try to only get indirect lighting on those, or diffuse lighting (not a direct spotlight, for example). It's surprising how annoying light glare can be: especially seeing your own reflection in the window as you try to look through it.

I also called around/looked around at different insulation available in my area and wanted to compare price difference.... :blah:

Your insulation plan sounds about right, except maybe for this part:

For places I don't need amazing acoustic treatment (like inside wall cavities), I'll use 3" Rockwool Safe'n'Sound.

You are talking about your MSM cavities? Between inner-leaf and outer-leaf? Those should always be filled with insulation. If you have a 6" air gap, the you should have 6" of insulation in that, for maximum isolation. Also, this:

Dimensional lumber is always 1 1/2", 2 1/2", 3 1/2", 5 1/2". For the smaller dimension wood, I can't get exact sized insulation.

Right! So for treatment devices, either go one size larger with lumber and leave an air gap behind the insulation, or rip the lumber down to the same size as the insulation. In general I prefer to use larger lumber than the size of the insulation, and leave a small gap on BOTH sides. The gap at the front is to ensure that any insulation bulging out a little too far does not also cause a bulge in the fabric covering. So, for example, if you need 4" thick insulation for a hypothetical wall absorber, then use 1 x 6 lumber to frame it (which is 5-1/2"), and leave a half inch at the front for "bulge" factor, and an inch air gap at the rear, which will help extend the effective frequency range down a bit lower. And if you are talking about wall cavities, then you can overfill them SLIGHTLY, with care. Eg. if you have a 5-1/2" gap, then you can put 6" of insulation in there as long as it it not rigid. You can compress the insulation up to about 10% with no flanking problems. (some say 20%, but I'm not too keen on that...)

I'll try to eliminate gaps where possible,

Gaps are your friends, not your enemies! :) An air gap behind the insulation helps extend the frequency, and an air gap at the front helps aesthetics. - Stuart -

Have you thought of putting small hangers above parts of your cloud? Like this?

I was planning either hangers or super chunk style. I have 3 cloud portions before the flat hanging cloud (the one that I'm trying to design the cool shapes on). The first cloud portion right above the window will not be hard backed. The next two will be hard backed. All 3 will have insulation above them. I think I've decided to frame the first 3 cloud portions out of 2x4's and the big flat one out of 2x3's. Then I will take some 1x2's and make the fabric face frames out of those and brad nail them on. This would make a depth of 2.5" + 0.75" = 3.25". Just shy of a 2x4 on edge.

Be careful with light glare on your front window too. You can ray-trace for light glare just like you do for speaker reflections. There should be no direct light that is visible from the mix position as you look through the window, AND ALSO nothing that is illuminated directly, visible in the window. If you have things that are visible directly in the window (such as your own head, for example!) try to only get indirect lighting on those, or diffuse lighting (not a direct spotlight, for example). It's surprising how annoying light glare can be: especially seeing your own reflection in the window as you try to look through it.

Thank you for mentioning the ray tracing idea for lights and the indirect lighting idea. I've angled my control room window to help with this, but I'll do everything I can to prevent glare. It would drive me bonkers to see myself!

You are talking about your MSM cavities? Between inner-leaf and outer-leaf? Those should always be filled with insulation. If you have a 6" air gap, the you should have 6" of insulation in that, for maximum isolation.

That's what I meant. I can rip Safe'n'Sound down to size if need be to fill the MSM cavity as precisely as possible. Pink fluffy might be harder to rip accurately (my last attempt ripping it for a drum riser didn't yield very clean/accurate results). The R24 is the cheapest though, so I guess I'll have to make that decision.

Right! So for treatment devices, either go one size larger with lumber and leave an air gap behind the insulation, or rip the lumber down to the same size as the insulation. In general I prefer to use larger lumber than the size of the insulation, and leave a small gap on BOTH sides. The gap at the front is to ensure that any insulation bulging out a little too far does not also cause a bulge in the fabric covering. So, for example, if you need 4" thick insulation for a hypothetical wall absorber, then use 1 x 6 lumber to frame it (which is 5-1/2"), and leave a half inch at the front for "bulge" factor, and an inch air gap at the rear, which will help extend the effective frequency range down a bit lower.

Thanks for the words of encouragement! My current treatment is 1x6 lumber with 4" insulation. Since I'm going all out on this build, I was planning on avoiding the air gaps, but it makes sense to consider fabric bulge. I'll be lenient with thickness.

And if you are talking about wall cavities, then you can overfill them SLIGHTLY, with care. Eg. if you have a 5-1/2" gap, then you can put 6" of insulation in there as long as it it not rigid. You can compress the insulation up to about 10% with no flanking problems. (some say 20%, but I'm not too keen on that...)

That's awesome to know. I certainly don't want flanking or the compression to raise the density too much. As a small update, I've started to design the centre section of my front wall as it will have the first section of cloud anchored to it. Playing around with the REW speaker placement simulator, I'm really wondering where I should fit my sub (I know I won't know for sure until I run acoustic measurements in real life). My from section certainly is not deep enough to hold my 12" sub. It's really going to be a trade off of bass trapping below the window, or sink the sub into it. I wish the REW program had flush mounted speakers on their simulator :-( Any words of wisdom on this topic? And, Stuart, I never showed you the updated hanger configuration for the my soffit. Here it is. Thanks for the suggestion on this as well! Greg

Thanks for the words of encouragement! My current treatment is 1x6 lumber with 4" insulation. Since I'm going all out on this build, I was planning on avoiding the air gaps, but it makes sense to consider fabric bulge.

Also, if you are going to put fabric on those frames, then bevel or round the inner edges of the frame, so that they don't make unsightly lines in the fabric, Route or sand, or even run it through the table saw at an angle.

Playing around with the REW speaker placement simulator, I'm really wondering where I should fit my sub (I know I won't know for sure until I run acoustic measurements in real life). My from section certainly is not deep enough to hold my 12" sub. It's really going to be a trade off of bass trapping below the window, or sink the sub into it. I wish the REW program had flush mounted speakers on their simulator :-( Any words of wisdom on this topic?

I'm giving away all my secretes here! :) Don't plan on any treatment under the center section of your soffit, between the two actual soffits. Leave that totally empty for now (you'll add the treatment right at the end. That's the zone for "playing" with your sub, to find the correct spot with the smoothest response. You can project and predict and calculate all you want, but there's no substitute for actually nudging it around the floor in that area, while you use your ears (and REW) to optimize the position, orientation (yes, that matters too!) and adjustments (phase, level, cross-over). You can also use the "reverse" trick: put the sub on a tall stand at the location where your head will be, and move your head around the floor until you find the best spot. Bass works in both directions... Once you have found the perfect spot THEN fill in that area between the soffits with hangers, insulation, or whatever. And AFTER you have done that, try tweaking the position again, since you will have changed the tuning by adding that treatment. It's quite surprising the difference that just a few inches move of the sub can make to the low frequency response. Worth spending time on. And frustrating, too! Do the moves in small steps.

Stuart, I never showed you the updated hanger configuration for the my soffit. Here it is. Thanks for the suggestion on this as well!

:thu: :oops: - Stuart -

I've been working and studying very hard on this stuff lately! Here is the cloud module framing I've come up with. It's a lot busier than Id like, and maybe too messy. It's just hard to hit ideal anchor points on both the centre frame as well as my inside out modules on the ceiling. I've thought about building actual modules and just hanging them off of wire but I decided that I don't want to do that. I want clean lines. The downside to the framing scheme I have here currently is that hanging hangers will be hard and I might just have to stuff insulation batts in there the best I can. I have ideas to maybe clean things up though. In other news, I came across a recent thread that mentioned Tim Perry's diffuser design. That lead me to ditch my current studies and jump in head first into diffusion. After reading all of the QRDude info I could find, I played around with his calculator and thought I had a plan of attack with a 5 panel N13 array with a constant introduced into the mod operator, having 1 inverse panel as per the Barker Code. Then I read Tim Perry's thesis paper and it threw me for a loop. Initially I was under the impression that the fins were crucial. Tim's thesis says otherwise. I really dig the benefits of fractalization even though it will make the build way harder. So, now I'm leaning towards Tim's design purely due to the increased bandwidth. Does anyone have reasons why I would build a QRDude version with fins over Tim's design? I can easily fit a 5 panel version of Tim's on the back wall of my control room. I want the room to sound awesome for me. If it doesn't sound amazing for the people at the back of the room, I'm okay with that. Greg

It's just hard to hit ideal anchor points on both the centre frame as well as my inside out modules on the ceiling. I've thought about building actual modules and just hanging them off of wire but I decided that I don't want to do that. I want clean lines.

Why? :) I don't mean "Why do you want clean lines?". I mean "Why would hanging the cloud NOT give you clean lines?". Look at at Studio Three: That's a multi-segment cloud, that is hung on chains. I think it looks like "clean lines". In fact, you can't even see how it is hung at all! It's all hidden, and it just sort of seems to "float" there. Rod was originally planning to put concealed lighting on top, but he didn't do that in the end. If you try to frame up your cloud support, you'll use a lot of wood, you'll connect it to your soffits (!), and you won't have any way of adjusting the angle after it is hung, if it turns out that you are getting an unexpected reflection from it, or maybe light glare, or some other unwanted issue... Chains work very well, you can attach them wherever needed up above, and you can adjust them. Of course, do follow all the usual safety precautions for stage rigging.

Initially I was under the impression that the fins were crucial. Tim's thesis says otherwise.

Right! Not just his thesis. People have been building them without fins for quite a while. Even ordinary QRD's do not need fins either. Here's a view of the QRD's that I did for the rear wall of Studio Three: They work just fine. It isn't necessary to have fins.

I really dig the benefits of fractalization even though it will make the build way harder.

It's not really that much harder: just tedious. All of the strips for Tim's design can be cut on a table saw very easily, then assembled into sub-modules that get assembled in other modules that get assembled into yet others... Use a dado blade, or even a router, for the smallest elements. Make a jig to help you assemble the parts, and it goes fairly smoothly. Smoother than assembling a QRD, actually: With a QRD it's too easy to accidentally put the wrong length piece in the wrong place without noticing...

Does anyone have reasons why I would build a QRDude version with fins over Tim's design?

Having used both, I would go with Tim's design. Here's a pic from a studio I'm working on in New Orleans right now: Guess what goes in that large empty hole in the middle of the rear treatment section ? :) Yup, a full 7-panel version. Currently under construction. Should be done in a week or so...

I want the room to sound awesome for me. If it doesn't sound amazing for the people at the back of the room, I'm okay with that.

In a small room there's always going to be bass issues at the rear of the room. There's just not enough space to be able to fully treat that. The bigger the room, the easier it is. You can get it sounding pretty decent in a small room, for sure, but the back isn't the best spot, and you aren't tuning the room for the couch anyway! You are tuning it for the mix position, where it MUST be perfect. So having a large diffuser back there isn't going to "destroy" something that was otherwise going to be fantastic: it never was going to be fantastic back there. The diffuser just adds some uncertainty to the mid range, in addition to the less-than-tight-but-too-powerful bass. It's probably not a big deal. If you have a producer or musician back there who isn't happy with the mix, saying it's too "heavy" or not "spacious" then let him sit in your chair for a couple of minutes, and explain that the entire room is focused on that chair, not his chair. He can stand behind you or next to you if he wants a more even sound. It's only in fairly large rooms, where there is space to pull the couch a few feet forward, away from the wall, that you can get good coverage back there as well, in addition to the mix position. In the room above (which is still small, but larger than many) the ear location for people on the couch is over 4 feet from the actual rear wall, and over two feet from the diffuser. The bass is fine for them, that far in, but the mid range is going to be a bit off. But as you say, you can live with it. It's not a huge issue for a WAG just sitting in, listening, and for someone who need to do critical listening, he can always take a few steps forward to where you are. It's not the end of the world! - Stuart -

After some thought, messing around, and getting advice from the pros, I decided to just hang the front 3 cloud modules. I also did a quick framing of the top cloud. I need to adjust it as I want wood trim. Here are some pics. I've also started drawing up the diffuser. Hopefully I have some more design progress pics to share soon. Slowly but surely! Greg

I snuck away to get a bit more done on the design this evening. I finished the diffuser. Here's some info on the design: - Based on Tim Perry's Leanfractal A1-Frac diffuser - Built around his imperial measurements (1/2" thick wood) found on his FAQ page (one of the 7 wells ends up being 2 5/16" instead of 2 9/32". I put the 2 5/16" well as the middle one) - The base structure (or LF module) depths were built around Tim's fabrication specs, just converted as 10mm being 1/2". So, that is 0", 2", 2 1/2", 1 1/2", 2 1/2", 2", 0" - The fractals (or HF modules aka 2nd Stg. of Fractal) I built according to "Schaap's" sizes as per Tim Perry's instructions on his FAQ page. These sizes are 0", 13/16", 1", 9/16", 13/16", 0" - The profiled modulation for the 5 panels follows Tim's fabrication design, but imperial as: 0", 2", 2 3/8", 2", 0" - I took resonance and weight into consideration and removed as much material in behind as I could while retaining stuctural integrity. I should be able to fill the backs of the modules with insulation. - There is enough material at the top of the modules to screw into through the top and bottom of the surround while installing one module at a time. For my top cloud, I was thinking, I still dislike the shapes I came up with. It reminds me of 1970 cowboys for some reason. I may experiment using depth. What I mean is, have some of the shapes not drop down the 2 1/2" and just be the black fabric frames nailed to the LVL stud and/or I/O module frames. Bedtime. Greg

Really liking the progress so far on your design Greg. It's really coming together! I really liked the look of those Leanfractal and Leanfuser designs. You picked the hard one to build! I'm looking into options for scattering and diffusion in my one room studio design, but I've got to be careful with the min critical distance as my room is pretty small. I've got the recommended distance behind my listening position to place a diffuser on my back wall, but like you say the sofa is going to suffer from bad acoustic distortion. Have you got any good links to stuff I can read about diffusion in a tracking room environment? I'm rereading MHOA, to refresh my memory for continuing my design. Keep up the good work!

The best is still "Acoustic Absorbers and Diffusers" by Cox and D'antonio. That's THE definitive text about diffusers. A little heavy on the theory and math, maybe, but still a lot of good stuff in there!

but I've got to be careful with the min critical distance as my room is pretty small.

Have you consider a set of true catenary-curve based poly-cylindrical diffusers? The can do nice things for the rear of a control room if number-based diffusion is "iffy" for your room. - Stuart -

I've started to solidify my rear wall hanger design. Homasote is just over $57 + GST of 5% here for a 4'x8' 1/2" thick sheet. Each hanger on the back wall would take half a sheet. So for every two, it will cost me ~$120 for just the Homasote. I know that hangers will work better with 2" insulation on them rather than 1". 703 is expensive, but it's much cheaper than Homasote. Therefore, I'm toying with the idea of using 2" insulation and skipping every second hanger (to hit the 1/2, 1/4, 1/8, 1/16, etc as per John's design). Do you think this is a reasonable trade off, or should I fork out the extra $1000 to do the rear wall with twice as many, half as thick hangers? The guidelines are where the 1/2, 1/4, 1/8, 1/16, etc are. I will cut the tops off of the middle hangers as they will have the diffuser at them. Also, this is clearly just half of the room. Greg

Therefore, I'm toying with the idea of using 2" insulation and skipping every second hanger (to hit the 1/2, 1/4, 1/8, 1/16,

That should work fine, as long as there's a little space between the hangers. They can't be touching. - Stuart -

I know this thread has been quiet for a while. I've been studying a ton - thousands of pages of pretty heavy acoustics theory. Also, I've been doing normal life stuff like work, raising kids, and spending quality time with the family. I learned a lot with Blender, the 3D modelling program, but was disappointed with it's lack of inferencing, measuring, and unit protocol. I feel like I wasted so many hours exploring it. However, it is a very very amazing program. Blender just doesn't work well for designing studios! Our house is almost done. We should move in in a month or so. That's where a lot of the lack of updates has rooted. Until I can spend some serious time taking more measurements in the basement, I'm not sure how much space I have for my designated HVAC system and silencer boxes that live outside of my recording area. There are a few specific topics I want to try and find some literature on, but for the most part, I've studied everything I have. So now, it's time to put it into practice on my personal design. I'll get back to finishing details, but to utilize my time I figured I should cover my ass and make sure I go to the building permit people with all of my ducks in a row. So, last night I started drawing up 2D building details. Here's the first easy one I did. I'll make a bunch so there is no chance of denial. Greg

I'm sure these need tweaking. I need to do the window detail next but I think it's going to be a way bigger job than these ones. I believe I will have to do it in a 3D detail like in Rod's Build It Like The Pros book. Anyway, here are the details so far! Obviously the insulation is not to scale, but I figure it makes the detail cleaner for the building permit people. Also, specific details like caulk, cleats, screws, etc are omitted for the same reason. Greg

Small amount of progress here. I've drawn up the basement portion of the studio (phase 1 for my building permit). It's the basic layout that I'll use for drawing the electrical and HVAC plans for the permit approval. It's obviously way too late in the game now, but looking at the space, I wonder if I should have gone with a different layout that gave me a bigger ISO booth. Mind you, I'll only be using this room for things like vocals, guitar amps, and acoustic guitar so maybe I'm over thinking it. I guess I feel that having a larger control room was the better decision. I'm also studying HVAC in more detail now. I almost wish I was using a ductless mini-split for my basement as the ventilation design would be much more simple. Getting zoning and relief air and mixed air ductwork in order is a pain in comparison! Also, fitting all of this duct work is going to be a task. Greg

I've kept quite busy on the design. I made a list of over 200 things I need to address for phase 1 of my build. VERY slowly checking them off. It's things like "where to buy desiccant" or "where to put smoke detectors" or large items like "ISO room side wall treatment". A few of those items specifically addressed the desiccant for my window cavity. The window cavity gets larger on the ISO room side, so I had to average the measurements to come up with a total area. 27571.25 cubic inches Which means I need 20 units 1 unit = 1 ounce 1 ounce = 28.3495 grams 20 units = 20 ounces = 566.99 grams I found a bag of 30 packets. Each packet is 20 grams. So I'd need 29 packets. They measure 3"x4". I sure hope my calculations are right! Here's a picture of them placed in between the windows. For a clearer picture I turned off the ISO room window layer. I asked this in a designated thread, but I still need to figure out whether or not the HVAC silencers should have radius type heels. I'll keep bumping that thread until someone chimes in! If they do have radius type heels I'll have to spend some serious time reworking the designs in SketchUp :( Greg

It's things like "where to buy desiccant"

Try your local printing shop: Printers ink (and other printing supplies) usually come in large vats or boxes, packaged with large bags of silica gel. I picked up a couple of 1kg bags for free at a printing plant I visited a while back. They just throw it out, usually... You seem to be using an awful lot of desiccant. For silica gel, I normal use 200 grams per cubic meter of air space in the cavity. So your 27500 cubic inches is about 0.5m3, and that would be about 100 grams. It's OK to overdo it a bit with the quantity, but don't go too far, or the air inside will be too dry: the wood of the window frame might dry out and crack after a few months / years. Use the right amount, and up to about 30% more, but don't go too crazy. And do make sure you "cook" for several hours, to make sure it is perfectly activated, before you put it in and seal up the windows. In other words, if it is the type that changes color, make sure it is the right color before you put it it! Either blue or orange, depending on the type. But never pink or green! If it is the wrong color, or if it is not colored at all and you don't know if it is dry or saturated, then heat it in an oven set to about 125 °C (about 250°F) for several hours, then put it in the cavity and seal the glass in place as soon as possible afterwards. It's OK for it to sit for a few hours while it cools, and while you get things in place, but don't let it sit for days, as it will start adsorbing moisture from the atmosphere and already be partly saturated by the time you put it in. Silica Gel is pretty inert: it's actually similar to quartz or sand, chemically, so you can put it on or in pretty much anything, to hold it. Those labels that say "Do not eat! You will die!" or whatever, that you see on the packs of silica gel in cameras, shoes, pills, handbags, etc. are because of the additives that they put in so that it changes color when dry / damp: That color-change chemical stuff is poisonous, but not the actual silica gel itself. It's no more dangerous than sand. If you got the stuff that does not change color, then you could use pretty much anything you want to make the "tray" to hold it. If you got the color-change stuff, then I'd go with plastic: you can find plastic "profiles" in hardware stores, such as Home Depot, and use that to make small trays to hold it, then glue and staple those to one side of the frame gap. Don't use metal or wood for the color-change stuff, as there might be reactions with the color chemicals. Spread out the silica gel as much as you can in the "trays", to get maximum surface area exposed to the cavity air. - Stuart -

Stuart, Every single place I've looked online comes up with this same chart: For 200 grams, it works out to ~ 7.05 units. According to the chart, that would be the correct amount for a space that is 9996 cubic inches, equaling 0.1638051 cubic meters. Either I'm understanding this wrong or else you're short by about 83.62% Can you share a link where you got your 1m³ requires 200 grams figure? I 100% will follow what you suggest as your designs have clearly stood the test of time, but I like I said, there are conflicting tables online. Lastly, would you care to share your thoughts on the HVAC question I posted? Thanks again for everything! Greg

I've been working hard on this sucker! I have a long ways to go yet, sadly. Here is the basement mechanical so far. It's rough, I know. But I'm not going to waste time putting perfect corners in the duct work as I just need to make sure it will fit and it will get where I need it to! I have to redesign and solidify positioning for the two lower left silencers now that I've solidified duct work. Getting into the HVAC final design, I realized that the AHU I originally planned to use just won't work well. I'll admit, I haven't solidified a model yet, but I've found some models that would work. Plus, I'm friends with a few guys who work for a local company which is well respected for inventing some crazy HVAC technology. It sounds like they could customize a unit for me. I ended up deciding to throw more money into the HVAC and get a designated HRV for the studio system. So, two HRV's in the basement I guess. I have to draw in where I'll put balancing dampers. I'm planning on "zoning" the two rooms in the basement. Also, I'm going to have to find out what joists the central vac come through and find a way to route that 2" PVC into the garage. So much crap to fit into such a small space. Oh how I wish I had 16" ceilings and more square footage! If you're wondering why that one silencer box is so square and large compared to the others, here's why: It was the only way I could make it fit in that space and work properly. In other news, yesterday we did a final walk through of the house. We pointed out things that needed repaired. Due to the builder being crappy, there are things that "aren't readily apparent" so they won't get fixed. I'm over it at this point. The house is still beautiful and I'm grateful to have this place, period. If something drives me nuts bad enough, one day I'll just fix it myself. So, it sounds like we will get the keys to the place on the 1st of November. Sadly, I'm SUPER booked up for recording and live sound work for most of November so finding time to get moved in and started on the place will be challenging. It will be nice to get in there and have the ability to get exact measurements for some things I'm just guessing about at the moment. Greg

I just finished calculating the total pressure of the duct work, silencers and linear slot diffusers/plenums for the control room and iso room combined. The two air handler models I'm looking at come in either low velocity or high velocity fan coils, the latter of which can handle high static pressure. I just need to determine the pressure introduced through the coil modules and filters. Anyway, it was a bit of a grueling process as it's a quite large design with lots of corners and such! Maybe I went overboard, but that's how I do things I guess! So without the AHU, it looks like I'm sitting around 1.20 in. wg I'm still up in the air whether I want to take advantage of the 90 degree corners in the silencer boxes or not. There are pros and cons to each. The angle of incidence is a huge benefit to the 90 degree corners. I want to recap my studies and then report back with my decision. I wish someone would chime in with some more nerdy reasons to go one way or the other! After reading a ton about achieving insertion loss, it's pretty depressing to see the results achieved by ONLY doubling the cross sectional area of the path: From my studies, I think if I shift my baffles around inside the boxes, I can achieve more drastic cross sectional area ratios. I will do a bit of experimenting with the static pressure effects of such changes and then make a decision about which route to take. I have way too much recording work lined up right now so even though we move into the house on Thursday, I probably won't be able to start any real studio design work for a while. When it rains, it pours. I'll do my best to keep some progress posts coming in. Greg

So without the AHU, it looks like I'm sitting around 1.20 in. wg

That's pretty high, Greg. You will likely need booster fans at some points. Even with the AHU, that's still high. Have you considered running some paths in parallel? It's like electrical circuits, in that sense: series paths add up, but parallel paths divide...

it's pretty depressing to see the results achieved by ONLY doubling the cross sectional area of the path:

Yup. That's why I'm always harping on the change being at least double/half, and needing several places where that happens... plus the baffles...

I think if I shift my baffles around inside the boxes, I can achieve more drastic cross sectional area ratios.

That can help, yes, but don't forget that it will change the velocity too, and fast-moving air makes more turbulence (and noise) then slow moving air, so you might be trading off better isolation in once sense, for greater noise in another.... - Stuart -

That's pretty high, Greg. You will likely need booster fans at some points. Even with the AHU, that's still high. Have you considered running some paths in parallel? It's like electrical circuits, in that sense: series paths add up, but parallel paths divide...

If you look at my pressure sheet, pretty much all of the crazy high values are coming from the right angled silencer box turns and abrupt exits (for gross impedance mismatching). My next step might be to run the calculations again with radius heels in the boxes. As you can see from the pictures I've posted, my runs and boxes are all quite massive.

That can help, yes, but don't forget that it will change the velocity too, and fast-moving air makes more turbulence (and noise) then slow moving air, so you might be trading off better isolation in once sense, for greater noise in another....

Oh yes, the juggling act! Greg

Sorry about the lack of updates guys! I didn't have internet for 3 weeks once we moved into our new place. I've spent all of my time installing appliances, mirrors, moving, running central vac (so that it wouldn't interfere with my studio areas), installing 240v electrical out to my garage to run my tools, removing a bunch of crap the builders put in that needed to be ripped out, installing a low handrail to the basement for my kids to hold on to, worked for 19 days straight and looked after my kids. It's been busy and productive, but over the last few days I've actually been able to work on my stuff. I have squeezed in some SketchUp time, but nothing post-worthy yet. Basically, I did some modifications now that I have the ability to check exact measurements in the basement. Also, I bought 3 different caulks to try out. I made some progress sealing the subfloor above and luckily, I found some cheap caulk that works well for what I need. For anyone interested, it is DAP Dynaflex 230. It has a lot of bad reviews for outdoor use, but for me inside, it applies clean and easy, dries pretty fast and remains nice and flexible. Also, since it's a small tube, it is way easier on the wrist than the Green Glue stuff. I also bought 30 sheets of drywall and 10 sheets of 1/2" MDF for my outer leaf ceiling beef up and seal. I took a good chunk of time to get my table saw all set up and true with the extension wing. Yesterday I took out 3 lengths of shorter LVL stud to sell to my buddy and bought one long length. My needs changed after the house rough ins happened. Unfortunately during the LVL moving, my brother and I had my basement door off (hollow core, but still pretty heavy) and leaned up. It was sturdy. My daughter went in behind it and pushed it over on top of my boy. His head put a hole in the door and it cut his forehead. There was blood everywhere. So I spent the entire evening in the hospital getting him stitches. I feel horrible about it. From now on I'm going to be a lot more cautious about where and how I store supplies. Luckily my wife wasn't too upset. I'm just thankful it was as minor as it was. Anyway, you can see that I've been working hard. I'll hopefully have more progress to share soon (30 joist spaces is overwhelming though!). Greg