Hi all,
My name is Frank and I am a client of Stuart's. I'm currently in the treatment stage of the CR in what has turned out be an amazing project IMHO...The studio also consists of an LR that's in the neighborhood of 375 sq ft and a hall way/half bath.
I've been at it for about 3 years and it has been quite a journey indeed! Looking forward to getting through this last bit.....This particular room is about 144 sq ft due to size constraints and my desire for a larger LR.
Stuart is well acquainted with the project , so not much need for extraneous details. I'm excited, and feeling confident that I will end up with a very satisfying result!
Here is what the finished product will basically look like:
Here is the state of things now:
So, I'm starting the process and Stuart will be chiming in along the way....
CR Treatment and Tuning---The home stretch!!
Originally posted at johnlsayers.com, topic 21368.
I should add that Frank has built this place from the ground up, and done the majority of the work himself, which is pretty amazing. To get some perspective on what he's accomplished so far, here's a view of the partly completed studio, at various stages of construction, starting with the rough outer-leaf framing and up to the currently finished Live Room:
Frank is getting better than 50 dB of isolation to the outside world at present, which is very respectable. He could have gotten a bit more than that if he would have used non-operable windows, but he really wanted the option of being able to open the windows, and didn't mind sacrificing a few dB to get that. The original design was for 55 dB, so achieving more than 50 dB with opening windows is pretty darn good!
Congratulations, Frank, on what you have done so far! :thu:
Now Frank is at the stage of completing the CR, and treating it, and tuning it. We just did the first acoustic "baseline" test of the CR with the speakers in place but no treatment at all, and it's already looking quite nice. Frank suggested that we start posting images and descriptions on the forum for others to learn from, and I love the idea! It's not often that a client wants to do that, since it's his money, his investment, and his design (since he paid for it!), so I'm grateful for Franks generosity in wanting to share this with the forum.
Hopefully it will be interesting and useful for forum members to watch the Control Room treatment and tuning process as we work through it. It will take quite a few weeks still, of course, since Frank only has one pair of hands, and needs to eat and sleep every now and then... :) Plus he still has to work, so he can make more money to buy the stuff to finish the place! So if you are interested in seeing how this works out, check in to this thread regularly.
We'll try to show as much of the process as we can, warts and all, so forum members can get a good handle on how to do it themselves for their own rooms. However, there's a couple of things that we won't be going into full detail about: one is my proprietary "fully floated" mounting system for the speakers (which is something that I'm not prepared to share with the world, and is carefully tuned for each room and each speaker individually anyway), and the other is the final digital tuning process (probably a couple of months away still).
I'll explain why we wont be going into detail of how that digital tuning works, when we get there, but basically its because: "Kids, don't try this at home! You might hurt yourself!" :) It's a complicated precision process that requires certain acoustic prerequisites that are just too complex to explain in enough detail that anybody can do it, and doing it wrong without understanding what is going on will lead to worse performance, not better (even though you might think you made it better if you look at the wrong things...) So Frank and I agreed that it's not a good idea to try to show how that is done, as people would just try to copy it without any true understanding of what they are doing, and end up with a room that sounds ugly, even though some of the squiggles on the graph say it should sound good. We'll show the "before" and "after" graphs, so you can get an idea of what it does, but not the in-between details.
This process is sometimes incorrectly called "room correction", and it's one of my pet peeves. There is no such thing as "room correction" in reality, despite the marketing hype! I call it "digital tuning", which I think is a more accurate description. More details when we get to that point. But that's one of the reasons why I wont share that part: You MUST get the acoustic treatment maxed out to the limit first, BEFORE you can successfully use digital tuning. Trying to do this without having the acoustic treatment perfect is a recipe for disaster. For an example of how it can turn out in a large room taken to the absolute limit, take a look here: viewtopic.php?f=2&t=20471
I did also want to mention that this is an usual control room design, called a "corner control room", since it is set on the diagonal across the room, rather than facing one of the walls. We decided to go with this design right form the start of Frank's project, because as he mentioned, he wanted the largest possible live room that we could fit on the size slab he was permitted to build in his area, and the corner control room allowed for that. So this is an interesting and challenging room to treat: there will be some strange and unconventional stuff going on here....
Anyway, stay tuned: :snack: We'll be updating this thread each time there's an interesting advance. Bookmark it, and make sure you check the "Notify me when a reply is posted" box if you add a comment or question, so that you'll automatically get notified of updates.
- Stuart -
From the man himself! Thanks for the kind words Stuart.....I should repay the compliment by saying that Stuart has proven to be very bright and generous with his knowledge as many of you out there can attest..
Having him in your corner is a big asset... :mrgreen:
It will be 1-2 weeks to get the ceiling, back walls, and bass trap done. That will be my first stretch. Will post pics along the way of course.. 8)
and just for fun, as few more pics of the finished LR. I'm very proud of the way that turned out!
I built a workstation in the LR because I find it more comfortable and inspiring to compose in a bigger room. I'm loving the space!
Wow! That's amazing work Frank! Looks great and I'm sure it'll sound great as well! Keep us posted!
I can't wait to get started on the execution of my studio. It's been an intense learning experience so far and I would not be where I'm at without the help of Stuart either so I also appreciate the help he's provided me.
Thanks... Will do!!
Hi Stuart
Done as much as I can with the ceiling. Going to need the bass trap detail so I can move forward on the ceiling and back walls. I can start on the soffits if your confident that the details are sufficient.
Feel free to give me simple instructions for the bass trap changes if any. I don't need detailed documentation if it saves you time.
Thanks
Frank
PS...I'm fine changing the soffit dimensions on my own to accommodate the speaker change. Chime in if you have any issues with that.
Hi Stuart,
After reviewing the dims for the new speakers, I discovered that I'm going to need to lower the speaker platforms about 3.5", otherwise the tweeters will be too high. Won't be too much trouble for me, but wanted to make note in case you had an objection.
I adjusted the dims for the soffit boxes from the pdf not the model. Ready to go as long as you let me....
Frank,
For any future pics, could you make them higher resolution/larger? I'd love to see the three pictures you've posted already, in more detail, but they're too small to see anything really :-(
What speakers did you end up going with in your soffit? You have three different sets in the speakers Stuart posted.
Would you ever upload an .skp file for us to check out your layout?
Great work and I look forward to seeing your progress.
Greg
Hi Greg,
I fixed the first 3 you mentioned.
I went with the Focal Trio monitors. I have the Focal Twins in at the workstation in the LR. The bottom picture is the way the workstation is now. I've become a big Focal fan. I just love them. I still have a set of BM15 passives with a Bryston 3B amp that I'll use for secondaries in the CR.
I can't upload an .skp here due to file size restrictions, but I put a screenshot in the first post...
Thanks
Frank, I'd hold off a little on redoing the soffits: I know it looks easy in the SKP, but there's a lot more to it than meets the eye! I'd also like to do some other changes to the design that weren't in the original, for the Focals.
I'm nearly done with the update for the rear corner treatment: That has also changed a bit, based on the initial REW measurements. Hang in there a bit! I know you are raring to go, and start building stuff, but control room tuning can't be done in a day! :) It's better to take it slow, and make sure you aren't making things worse, instead of better, or getting the tuning wrong, or designing things that can't actually be built... :)
The weekend is almost over, and I promise I'll give your rear wall treatment top priority when I get into the office tomorrow. And as soon as that's done, I'll get into the soffit modifications.
- Stuart -
Thanks Stuart,
Awesome! I respect the weekends...... 8)
I stopped working on ceiling panel fabrication for the reasons you mentioned. I'll wait to resume working.
back on track.... :arrow:
Yup! Update for the folks following this thread: Frank is now valiantly building some rather complex stuff I designed for him, for the rear corner of the room. We did a REW test of the empty room, I analyzed it and figure out some of the bigger issues that need treating, then designed "stuff" to deal with that. So here is what Frank is working on right now: Basically there's a small superchunk right at the back, floor to ceiling, as an anchor for the other things, with a tuned slotted poly-cylindrical device at the top and bottom, an un-tuned one in the middle, hangers in between, and un-tuned slats across the front. I won't go into all the details, but this bunch of devices is a total of about 39" deep (far tip of corner to front face), and does a bunch of things in different places across pretty much the entire spectrum, but mostly in the bass. It will hopefully do some nice things to the modal response, SBIR, and overall low end, while at the same time NOT killing the high end too much. It's designed to be balanced: it targets some specific things while actively NOT targeting other things. He has already built the center slotted-poly unit: And now he's working on the top and bottom units. More updates to follow... Stay tuned! - Stuart -back on track.... :arrow:
... I also just made the thread a "sticky", so it's easier to find, and edited the title a little, to make it more descriptive. Hope you don't mind, Frank!
- Stuart -
The title seems appropriate... :thu:
Thanks for posting that Stuart... 8) you saved me the trouble and right about now I'm covered in damp sawdust from dealing with light rain throughout the day. No fun!! :ahh:
I will certainly be proud if I pull this one off.....running into some trouble getting accuracy on angled rip cuts but working through it...
Hope to have this done in about 5 days days, maybe sooner. The resonators will be the deciding factor for sure!
Well,
Struggled with this a bit today but am getting closer to a working product..I think.. :shot:
Got some minor leveling issues to sort with the lengths, but otherwise the unit seems doable.
One down one to go!
Great work Frank!
Just curious, is there some insulation material behind the wood? or is it a blank space behind. Stuart's put a lot of details on this thing. Very very cool! 8)
Cheers!
He had me put a small 1/2" thick bit insulation up against the posts, I used a shred of pink fluffy. Also a 1" piece of 703 against the back wall and 1/2 of the floor. The idea is that the box is an air spring for the resonator rather than an absorber. Because the tuning of a resonator is dependent on the volume of the air spring and size of the opening, you don't want to fill the space with insulation which would thereby change the math.
Should have the project completed by tomorrow's end. rain has been cramping my style a bit and the resonators took focus and attention to detail of course...will post more pics in a bit!
There's a thin layer of light insulation right up against the rear of the "slats" (which are actually trimmed-down 4x4's), and there's also a thin layer of of 703 up against the back wall and on half of the "floor", but most of the cavity is empty space. This is Helmholtz based, so it has to be that way. It is tuned, but not too tightly. Reason: It's notoriously hard to tune Helmholtz devices accurately! They normally have very sharp tuning (high Q, very narrow bandwidth), and the issues they are designed to hit also have very high Q, so it's not a simple matter at all to line up the tuning with the problem. And if you miss, then it doesn't work. Slight inaccuracies in materials or construction can shift the tuning way off. Even having the wrong air temperature or air pressure can move the tuning far enough off that it no longer hits the target at all. So on a cool day, or a hot day, or when a weather system moves through, that would change the tuning of a high Q Helmholtz device (very tightly tuned). In this case, I have tuned it with lower Q so it works less effectively, but across a broader region, regardless of inaccuracies or changes in the weather. More accurately, I have "de-tuned" it slightly, so that even if the tuning is off, it will still hit the problem frequencies, albeit with lower effectiveness. In other words, the sharply tuned peak is lower, but broader: it covers a wider range of frequencies, but with lower intensity. The thin insulation on the rear wall and floor of the cavity does that. The even thinner insulation behind the slats is what damps the resonance, removing the energy from the room. It's a common mistake to completely fill the cavity, thinking that "if some is good, then more is better". Wrong. "Some" is best, "More" is far worse. In fact, filling the cavity completely will pretty much kill the devices, so it won't work at all. To convince yourself of this, try making a classic "Helmholtz" resonator with a small empty glass coke bottle: Blow across the top of the bottle neck, to make it "sing": that's a classic demonstration of Helmholtz resonance. Now put a tiny little piece of something light and fluffy in the bottle neck, such as a small wisp of cotton wool that you have gently pulled apart and "fluffed out" with your fingers, and blow across the top again: the tone will have gone down a bit, and it will now be rather dull and muted: you have effectively damped the device, and it will absorb rather well at that frequency. Now fill the entire bottle cavity, all the way, top to bottom, with insulation (eg, pink fluffy, 703, etc). Stuff it completely full. Blow again. Nothing happens. There is no tone at all! It no longer resonates, not even slightly, because it is severely over-damped. If it doesn't resonate, then it isn't working... You killed it.... :) So that's the principle here: Yes, there is some thin insulation in there, carefully placed, to slightly de-tune the device so that it covers a broader range, but without killing it. - Stuart -is there some insulation material behind the wood? or is it a blank space behind.
And of course what he said...lol
Sorry Frank! Looks like we posted at the same time! I hadn't seen yours when I posted mine... Nice work, by the way! It looks pretty good! :thu: - Stuart -And of course what he said...lol
Thanks Stuart,
I'm feeling pretty confidant. I can easily access the boxes to tweak them right behind the cover if we need to. I was wondering, If we use veneers will they insert into the slots or go over the face?
As always thanks for the explanation! I figured there had to be something behind those pretty wood slats. :)
I fully understand how you're trying to "tame" a certain frequency range versus trying to kill-it completely. I can also imagine how complex it would be to figure out what to build in order to do it effectively without over killing it or lacking.
Great work! I can't wait to be at the "treatment" stage of my build.
Cheers!
They would have gone into the slots, but there's no need for that, as far as I can see. Your measurements are within spec, and in fact having the posts slightly narrower is working to our benefit: It is tuning them a little higher, which is good. To keep things simple for you, I approximated to the nearest 1/16", which turned out to tune them all a little low. I wasn't worried about it, as the detuning still had them covering the problem issues, but now they are closer than they would have been, so all is well. No laminated needed. For example, there's an issue in the room at 131 Hz, and with the original dimensions the tuning for that would have been at about 128 Hz. Allowing for +/- 5%, that's fine (128/131 = 97.7%). But now it is tuned up to 129 Hz, which is 98.4%. So no problem. Of course, if it was NOT de-tuned, then it would have been a problem.... :) Just a word of caution here: These things are not magical "mode killers"! People tend to expect spectacular results from complex devices, but the effect won't be huge. Just a few dB, and a few dozen ms. It's the combination of all the treatment that does the trick, not one single device. One step at a time, with each step doing "something but not a lot" is how it works. Think of it this way: If you can do ten small things that each flatten out the response by just 1 dB and 50 ms, then in total you flattened it by 10 dB an 500 ms! So don't get disappointed and discouraged when you see only small gains with each round of treatment... It's the end result that matters. - Stuart -I was wondering, If we use veneers will they insert into the slots or go over the face?