My long, one-car garage studio, construction phase

[Bigsby]

That's encouraging, Stuart--thanks!
I didn't touch the high shelf and tweeter level controls--those are both set straight up at 12:00. The bass shelf I set all the way counter-clockwise, to -4 db.

Any thoughts about my treatment plan?

As always, thank you so much, Stuart!

Mark

[Soundman2020]

By the way, I should have mentioned that, if anyone doubts the effectiveness of John's soffit system design, your build has demonstrated definitively that it Sure Does Work Great! Even with a relatively small enclosure, and just three smallish hangers, you got pretty good results: a reduction in RT-60 of around 100 to 200 ms in the problematic low mids, plus some rather decent damping in the low end.

The graphs speak for themselves: John's designs work, when implemented right and built carefully, with attention to detail.

I have a feeling this thread might become a "sticky" one day, when the room is finished: I get the impression it's going to be be good!

I didn't touch the high shelf and tweeter level controls--those are both set straight up at 12:00. The bass shelf I set all the way counter-clockwise, to -4 db.

Great. Leave it like that for now: you might need to tweak a bit here and there later, but that's fine for now.

Any thoughts about my treatment plan?

Looks good to me. I'd start with the superchunks, then another REW to see how that worked, then the ceiling/cloud, and another REW...

And since you already proved just how effective John's hangers can be, you might want to consider using them in your rear soffits, where you don't have much depth but pretty decent width...

Just a thought...


- Stuart -

[Bigsby]

I have a feeling this thread might become a "sticky" one day, when the room is finished: I get the impression it's going to be be good!

Wow, Stuart--I'm flattered! Thanks for even considering that!

And since you already proved just how effective John's hangers can be, you might want to consider using them in your rear soffits, where you don't have much depth but pretty decent width...

The only issue with that is that I have my fresh air duct cutting through one of those soffits, which would make the hangers on that side pretty funky. I'll post photos to illustrate. In the meantime, I'm working on my superchunks; photos and new REW tests soon.......

Thank you!
Mark

[Bigsby]

I've been "stickied!" I'm not worthy....I'm not worthy.......
But I'll try my best!

[Soundman2020]

I've been "stickied!" I'm not worthy....I'm not worthy......

.



Credit where it's due! Your doing a great job of building your place, based very much on John's designs and principles, and the results are already clear!

But actually, I didn't "sticky" your thread: I think you've had the great honor of John himself "stickying" it...


- Stuart -


PS. Hmmmm. The verb "to sticky". Mmmm "he stickied" .... hmhmhmh -- I kind of like using "sticky" as a verb! It never occurred to me before... Nice ring to it.

[Bigsby]

Thanks for your kind words, Stuart, and thank you, John, for the sticky and this wonderful forum! I would be so lost without it!

I've now completed the next round of control room treatment--putting the super chunks together. Sorry for the quality of some of these pictures--I guess my camera was having trouble focusing.
I put Roxul Sound Stop in all the stud bays:

left wall before fluffy insulation.jpg

...and then stacked fluffy insulation for my super chunks:

rear wall right.jpg

Stuart, the photo below shows the fresh air duct I mentioned (the rectangle above the stainless steel cover plate), which was the reason I felt that I should just stick with super chunks on the back wall:

IMG_1436.jpg

rear wall with fluffy insulation.jpg

...and then I installed another layer of Roxul on the face (these next shots are panoramic, so they're kind of warped, but you get the picture):

finished back wall.jpg

Finished left wall and front.jpg

finished front and right wall.jpg

As you can see, I stole Simo's idea of painting the framing in hopes that it doesn't show through the cloth.

With that completed, I ran another REW test, which seems to be a significant improvement, at least to me with my limited understanding....
https://www.dropbox.com/s/dz211o06kdc3t ... cloud.mdat

I'm planning to start working on my cloud next, which will be 3 1/2" thick, filled with more Roxul Sound Stop, with a hard top of 1/2" plywood, angled at at least 12 degrees. Does that sound like a good approach for the cloud, given what the REW tests look like so far? I've posted this picture a few times, but this is what I have in mind:

new cr treatment plan.jpg

Thank you in advance for any feedback!

Mark

[Soundman2020]

Code: Select all

which seems to be a significant improvement, 

That's the understatement of the year!

Let's take a look at a few "before" and "after" pairs...:
First, the waterfall plot:

Bigsby-low-end-waterfall--baseline.png

Bigsby-low-end-waterfall--insulation.png

Now frequency response:

Bigsby-low-end-frequency-response--baseline.png

Bigsby-low-end-frequency-response-insulation.png

And impulse response:

Bigsby-low-end-impulse-response--baseline.png

Bigsby-low-end-impulse-response--insulation.png

RT-60:

Bigsby-rt60--baseline.png

Bigsby-rt60--insulation.png

And finally the spectrogram:

bigsby-low-end-spectrogram--baseline.png

bigsby-low-end-spectrogram--insualtion.png

So, yeah, it looks like there's just a tiny change here and there!

In fact, those are pretty massive, amazing changes, across the board! The low end response is way, way cleaner, smoother, tighter, and it looks like all of your modal issue are under control. The "tails" you see on teh waterfall plot are not decaying at all, so they are most likely caused by something humming or buzzing physically. You might want to go looking for that. Maybe a fan, pump, motor, or some such? You can also change the s"start frequency" in the REW settings, to start measuring from maybe 25 Hz or so, since all that garbage below there is not real, and not part of what you should be worrying about.

And its clear that you are sucking too much out of the high end (to be expected) so you might want to put plastic over most of your insulation, to help get the highs back into the room. The only place you don't want to do that, is on your first reflection points.

angled at at least 12 degrees. Does that sound like a good approach for the cloud, given what the REW tests look like so far? I've posted this picture a few times, but this is what I have in mind:

You might not even need the hard back: The low end is looking pretty good just like it is. So maybe try two tests, one without hard back and the other with something clamped up there temporarily. Also, a 1/2" back is probably not enough: I would go for 3/4.


And looking in my crystal ball, I some some slot walls in your future...

- Stuart -

[Bigsby]

In fact, those are pretty massive, amazing changes, across the board!

I was hoping you'd say something like that!

A couple questions:
One of the reasons I was thinking about doing a cloud with a hard back was because of my vaulted ceiling--trying to avoid having reflections bounce off the ceiling from two different directions toward my listening position. Or am I thinking about that wrong?

I'm happy to put plastic over my rockwool, but I have a couple questions about that:
My understanding from reading Simo's thread is that I do not want plastic where I'm planning to have slats (on the entire length of left and right walls), because that will prevent the slats from working properly, correct?

http://johnlsayers.com/phpBB2/viewtopic ... &start=195

In addition, part of the function of the slats will be to bring back some of the brightness, correct? So I wouldn't need the plastic underneath anyway?

Assuming the points above are correct, that leaves the front wall between the soffits and the rear super chunk wall, where I was just going to cover them in fabric. My only concern there is regarding effectively having a vapor barrier in the wrong location, which xSpace cautioned me against earlier in this thread:

http://johnlsayers.com/phpBB2/viewtopic ... 0&start=30

However, I did notice in a comment in Javier's thread, that John puts plastic everywhere as a matter of course ( maybe even where the slats go?):

http://johnlsayers.com/phpBB2/viewtopic ... 5&start=15

so I'm a bit torn about all of this.

Thank you for any light you can shine!!

Gratefully,

Mark

[Soundman2020]

One of the reasons I was thinking about doing a cloud with a hard back was because of my vaulted ceiling--trying to avoid having reflections bounce off the ceiling from two different directions toward my listening position. Or am I thinking about that wrong?

The idea is right, but you don't seem to be having much of that problem right now. There are some reflections at around 5ms which might be coming from the ceiling, but they are very low level (already about -16dB, and that will go down still more with the cloud), so you probably will be OK there. You are right to be concerned about it, as it could have been an issue, but it looks like it didn't turn out to be important.

My understanding from reading Simo's thread is that I do not want plastic where I'm planning to have slats (on the entire length of left and right walls), because that will prevent the slats from working properly, correct?

Right! The insulation inside your slot walls must be right up against the slats, with nothing in between (except black fabric to hide the "ugly"). Plastic in there would totally kill the Helmholtz effect.

In addition, part of the function of the slats will be to bring back some of the brightness, correct? So I wouldn't need the plastic underneath anyway?

Right again!

that leaves the front wall between the soffits and the rear super chunk wall, where I was just going to cover them in fabric. My only concern there is regarding effectively having a vapor barrier in the wrong location, which xSpace cautioned me against earlier in this thread:

True, and where you live that probably would be an issue. So you could do the plastic "incomplete": in other words, don't do it completely across everything and fully sealed. Rather, do it in several very broad "bands" of plastic with small gaps between them. For example, 12" bands with 1" gaps, or something like that. So it would no longer be a vapor barrier, but would still be reflective to highs, mostly.

That's what I would do. Basically, leave very large holes in that potential second vapor barrier.


- Stuart -

[Bigsby]

Hello again....

Stuart, great idea regarding installing a "non-vapor barrier." Your advice is always so appreciated! Quick question on that back super chunk wall: I will do exactly as you said, stapling up plastic with gaps cut into it on that wall, so I get the benefit of high-end reflectivity without creating a vapor barrier in the wrong location. I think I would like the look of just a cloth wall to finish, but I'm concerned about people leaning against the cloth and damaging it, especially in such a small room. I know that people on this forum have addressed that problem by widely spacing slats over the cloth so that it has a minimal effect acoustically, but protects the cloth. I'm wondering what the size of the slats and size of the gaps between them should be in order to accomplish that?

Now onward to my cloud. I ended up building it almost exactly as designed, except for the fact that I made it one piece instead of two.
Here it is with the basic framing done:

cloud framing.jpg

Here's a closer view--the three holes are for LED lights that will be placed there:

cloud framing closeup.jpg

I decided to staple string on the underside of the cloud to help hold up the rock wool:

cloud framing with string.jpg

I then stapled plastic over the framing--this is a view of the top side of the cloud:

cloud top with plastic.jpg

This is a closeup of where one of the lights will be (I haven't cut the circle in the plastic yet). The white border you see is 1/4" thick screen molding that I nailed around the perimeter. Before I installed the plastic I nailed up 1/4" plywood to attach the lights at the same "height" as the perimeter. The idea here is that I'm hoping any irregularities in the cloud framing will be invisible because the cloth will be only be touching the underside of the cloud at the perimeter and where the lights are attached. Kind of hard to put into words; we'll see if it works...

cloud light closeup.jpg

I then put in the Roxul Safe N Sound batts:

cloud top with rockwool.jpg

And finally lifted it into place. There are four anchor points in the ceiling, two in front:

cloud above 1.jpg

...and two in back:

cloud above 2.jpg

Here's what it looks like from below:

cloud installed under.jpg

cloud under side view 2.jpg

cloud under front view.jpg

There is about an 8 1/2" gap between the front and sides of the cloud and the front and sides of the control room walls. The cloud is hanging at about 12 degrees.

Once I got the cloud up there I ran another REW test; the link to it is here:

https://www.dropbox.com/s/cj3ytpl3ekr8e ... cloud.mdat

It looks like things are continuing to improve, to my untrained eye. I'm eager to see what your thoughts are, Stuart, and especially eager to come up with a plan for the slats. I'm assuming that will be the next step, is that correct?

Thank you!!

Mark

[simo]

Looking great Mark !! very good

[Soundman2020]

Nice looking cloud!

A couple of other suggestions: On those square patches of wood around where the lights will go, you might want to bevel and round off the edges so that they don't make hard lines in the cloth when you put that on.

For the chains: I'm not too keen on using S-hooks or any open hook for hanging things above my head, especially where I live (Earthquake capital of the world!). For the sake of safety, I would replace those with safety links, clips, snaps, something like these:

http://www.pacifictrailers.com/chain-ca ... ins-82930/
http://www.pacifictrailers.com/chain-ca ... ins-82930/
http://www.etrailer.com/Accessories-and ... 81360.html
http://www.kingsnaps.net/index_down.php

OK, those were the first I found with a quick Google search, and some are from mountain climbing gear, so perhaps not appropriate for your application, but that's the type of thing that you need: A link that you can close and lock somehow, so that the chain can't come loose and drop the cloud on your head, even in an earthquake.

I'll take a look at the REW, and get back to you!


- Stuart -

[Soundman2020]

About the REW file: PLease name your tests! These a text box at the top of each measurement thumbnail that has the date and time in it, but it would be better to change that to describe what it represents, such as "empty room - left", "superchunks - right", "clouds - both", etc., It just makes it easier to navigate when you are comparing different tests...


- Stuart -

[Bigsby]

Thanks, Simo and Stuart!

Stuart--great idea about easing the edges of the square patches where the lights will go--I'll do that. And good point about my hooks--I'll swap those out for something safer--they're always telling us around here that it's not if but when the "big one" will hit!

Sorry about not naming my REW measurements more descriptively. I changed them to reflect what they are, in order of treatment. I couldn't fit as many characters as I wanted, so to clarify, #3 and #4 include the treated soffits:

1. no treatment
2. soffits only
3. walls
4. walls and cloud

Here's the link to the updated REW file, with names:

https://www.dropbox.com/s/24tabvck5p4d1 ... names.mdat

Something else I've been thinking of--I have quite a bit of empty space above the cloud. Any reason I shouldn't attach a thick layer of fluffy insulation up there, hoping to tame my 60 Hz bump a little more? (FYI--that light in the second photo is temporary--it will become just a junction box for the cloud lighting)

cloud above 1.jpg

cloud above 2.jpg

Thank you!

Mark

[Bigsby]

While I'm waiting for some feedback on my latest REW measurements, I thought I'd get started on the finish layer of my bezels. I picked up some 3/4" maple plywood for the bezels and also for my slats. Quick question: I'm planning to coat the maple with polyurethane to protect it. My understanding is that the more coats of poly you apply, the more reflective the surface becomes. Any advice on this topic? should I just stick with one coat of a satin sheen poly, or a different sheen/more coats?

Thank you!