UAN - new Control Room build

[RJHollins]

the DIY formula that I've located is
http://www.ehow.com/how_4705220_make-fi ... spray.html
Which seems to be ...
"Pour 7 oz. of Borax, 3 oz. of boric acid and 2 quarts hot water into funnel.."

I went to JoAnns, ACMoore Crafts, Home Depot ... they do NOT have any flame retardant
treatment.

Here's a question: say the fabric for the corner traps is cotton. When you WET this fabric
[with the flame retardant spray], does the fabric shrink or expand ? Since the fabric is going on a
open frame [2x2] ... would it be best to treat BEFORE or AFTER mounting the fabric ?

A second question ... what about the rigid 2" Knauf fiberglass that'll be stacked in the corners?

[gullfo]

best bet is to soak it then lay it out to dry. then iron etc as desired. then install. other options including spraying it on after generally leaves things messy and soaked... if you don't put it into a dryer the shrinkage should be minimal.

[RJHollins]

... if you don't put it into a dryer the shrinkage should be minimal.

hmm ... that's what SHE said.


OK ... well, despite another holiday to contend with ... the 2nd coat of final color paint
is complete.

Still waiting for the flooring to be delivered and then get that installed.

Meantime, I've started cutting some 2"x2" for the corner traps. Seen several different
ideas on doing them ... basically I'd like to have 3 corner 'triangles' of 2x2's, one on the
floor, one midway up, and another at the top. I'm looking to use these to suspend the
rigid insulation, AND, provide a surface to mount the fabric panels to. Going to see if
the 'Industrial Strength' Velcro is up to the task for that

also ... been reading up on 'REW' software, and following various threads on using it. Still
need to get some equipment together, but what I'd LIKE to do is measure a 'base-line;
response of the empty room BEFORE doing any treatment.
Looks like I have to replace my old RShack level meter ... getting screwy readings even
after battery change [always more things to buy]

Any specific links or instructions on base-lining the room are always welcomed!

[RJHollins]

Progress Report ...

Once I get past Saturday, I should have time to get a few pix posted ... Had a busy
week with the Band Doing an afternoon show on Sat ...

In the meantime ... we now have flooring cut and in place My installer wants
to wait till Sunday for the 'glue-down'. [give this fiber flooring a chance to level & adjust
before getting locked down. The ONLY complaint ... the smell of this new material
Fans are blowing to clear the air ASAP. I'm sure the glue won't smell bad either right

OK ...

Picture proof is coming ... HOWEVER ...

I do want to take advantage on the empty shell ... and 'shoot' the room using REW. Just
picked up a new SPL meter from the Shack, got my ECM8000, mic cables, test speakers, etc.

If I recall ... Glenn had mentioned setting up 1 monitor, placed in the front corner floor, and
then in the opposite corner, ceiling, place the measurement mic.

If this is ANYTHING close to how I should first measure ... then, are there any specifics I
should be aware off when doing this 1st test ... like ... how close to corner boundaries should
I be with the speaker AND the mic ???

2. Should I also get a measurement from my 'start' point [38%] from front wall at ear height,
with the speaker in equilateral position ????

Guidance on base-lining the room much appreciated !!

[gullfo]

the corner to corner measures the overall room response. you will also measure with the mic in the listening position and the monitors in their location as well. you will use that as your starting point to find the best position for monitors and listening positions and also what needs to be done to get the overall room response reasonably "flat" and the resonance decay rates to where you want them.

[RJHollins]

Alright Glenn ... Thanks for outlining that for me !

Say ... I posted a question on another thread that didn't get a comment, so let me repost
it here in my thread.

It regards the 'Chunky Corner' traps. 2'x2'x2" wedges, stacked floor to ceiling.

This is more for understanding, as I've not seen this talked about nor clarified as to:

? Why are the wedges stacked 'tight' to the corners ? It seems that only the front surface
would be exposed to the room. Is the concept that much different compared to the broad
band wall absorbers that have ALL faces exposed ???

Is one of the reasonings, that the corners are unique, in that they consist of several
boundaries that [in and of themselves] raise the amplitude of the lower freqs? and because
of these meeting boundaries, the 'MASS' of absorption is the critical factor ... and NOT
the exposed surfaces of said absorbers ???

If the above is totally wrong ... then WHY are the chunks NOT pulled back [even an inch
from the corners].

The only other possibility I can reason is that these wedges, that lightly touch the corners,
are also providing some DAMPING to the wall surfaces ???

Thanks for any info that may help me better understand this part of the treatment !

[RJHollins]

Progress Report ...

Floor installation is complete

Went with the 'ArmStrong' Parquet de Luxe 2 - Natural. It is an, optional, NO GLUE
flooring. Letting it lay out on the floor for 2 days allowed it to settle. The decision was
to use double-sided Fiberglass tape. Got to say, this flooring is very nice. It's quiet, AND
it has a little cushion to it.

PL_PID_1000000417.jpg

PL_PID_1000000419.jpg

PL_PID_1000000420.jpg

As you can see, the lighting is still questionable

Anyway, I have a few left over floor pieces that will be used in the door threshold area.
I wanted to wait on that till I get the jamb fully caulked at the bottom.

Meanwhile, I started testing an idea for the corner traps. [this was BEFORE the flooring]

PL_PID_1000000404.jpg

PL_PID_1000000405.jpg

Basically using PT 2x2's. The insulation used in this test was some extra ceiling tile. The real
stuff will be the KNAUF 2".
The 'plan' is to mount 3 of these per corner. Floor, Ceiling & midway. Hoping that this will
work, AND, that it gives me a mounting surfaces for the open frames to attach to. Will see
if Industrial Strength Velcro is up to the task

Today, I also moved in speakers, amp, and the ECM8000 cal mic into the room for the initial
base-lining. I've been trying to read up on this REW software ... I have signals going, and
I have data being displayed ... but I must say, this ain't lookin' like I thought it would !

rew - baseline - 1.jpg

rew - baseline - freq-1.jpg

I'm not speaking of the 'data' so much as getting the proper graphing.
The dB scale does not seem right ... was going for 80dB actual level in the room.
As a side note ... I've seen other posts here that upload a pile of graphs. I would like to
avoid doing that [if possible].

Is there a 'sticky' or something that stipulates what I should be posting from the REW
software ???

I'll do more searching here and at HomeThreatreShack.

I should point out that I'm using a full-range 2 channel system [no SUB].
Appreciate any help!!
Thanks

[RJHollins]

... more playing with REW revealed 1 op error
Now the SPL scaling is correct.
I did a plot from the start mix position, with one speaker at a time, then overlayed the graphs.

l&r monitor @ mix position - overlay - 1.jpg

Gold-Left GRN - Right

do I need a redo on the overall [again] with correct scale ?

[gullfo]

i think the scale looks right. this is untreated correct? basically +/- 10db with a few nulls. on the super chunks, the positioning of it full into the corner is the only commercially tested configuration i know of. so if you wanted to experiment with moving the stack out an inch, nothing lost really. it may simply be that flush to the wall offered better support for the stack and left more room. in your space you actually have 2 back corners you can stack into which is nice plus some big absorption up top over the couch position and over the desk (generally unused space).
if you have the option to post the mdat files on a file share somewhere I can download them and check rather than trying to post a lot of images (a few can be useful - frequency response, waterfall, and ETC when you get the equipment in).

[RJHollins]

Hi Glenn !!

I'll look to get the 'mdat' file posted ASAP!

After your last post, I started getting the corner traps together.

Here are some of the important tools ...

PL_PID_1000000421.jpg

Beside the usual ones, I must say, the purchase of an electric knife was GREAT ! I mean,
I ain'ts no good at cavin' up a turkey ... but this handy knife cut like butter

First cut the 2'x4'x2" panels in half

PL_PID_1000000422.jpg

Then a diagonal cut into wedges.

PL_PID_1000000423.jpg

After Shop Vac'ing the pieces, moved them into the room. I was surprised the change in
the room 'sound' just stacking these pieces into a couple of piles on the floor. Definite drying
the room down ... which it needs !
Had my 2"x2" ready, and installed the base with screws.

PL_PID_1000000424.jpg

Then proceeded to stack the fiberglass to the ~half way point, which was 20 wedges. I wanted
to see how the stack holds up, so I used this first bag to fill the back corners half way.

That's about all I could get to before darkness set in ... which was fine to see how this was
going to work out. The stack seems VERY stable. I still want to have a middle connection
point for the frame, along with preventing TOO MUCH compression on this fiberglass. [especially
over time]. At this point, we are looking at 20 wedges, 2" thick, stacked to a 40" height.
It looks alright currently, but those more experienced doing this technique, please let me
know if you see an issue

Tommarow I want to continue on the front corners [again half way up] and see how stable
everything is ... PLUS, I want to hear what new sounds are emerging in the monitors !!

Something quite interesting is trying to emerge [especially in the bass area]. Even though I
have only 1 bag installed, the sonic change is VERY noticed

Ahhh ... I'm getting psych'd ... yeah, I know I still have much to do [some MAJOR stuff], but
MAN ... there was this bass note I hadn't heard [just started to peek out] in sooo long.

Big THANKS!!!

I'm going to see about the mdat uploading!

Thanks!

[gullfo]

very cool!

[RJHollins]

Hi Glenn,

It was suggested that the site 'Speedy Share' may be a suitable free service to host
the mdat file.

I'm giving this a try .... please let me know if this works !

http://www.speedyshare.com/files/294256 ... R_-_2.mdat

Thanks!

[gullfo]

i've downloaded it. overall the data looks good for an untreated space. it may be some adjustments in speaker and measuring position for the mix position is needed as some of the side to side measurements have some differences.

[RJHollins]

Progress Report ...

We now have 'Chunky Corner' traps installed in the 4 main corners

I've also assembled 2 temporary monitor stands using the, ever so lovely, concrete blocks.

Pix will be posted soon ... in the meantime ... we must also get the HVAC system finalized.

From what it looks, the duck-less mini-split stills seems the better option for my situation.
Due to short ceiling height, and limited access, here is a unit being considered:
"Sanyo 11,900 BTU Wall Mount Low Ambient Air Conditioner Kit"
here's a link:
http://www.minisplitsystems.com/cgi/dis ... um=12KLS71
It's been suggested that a 'Low Ambient' model is best for those of us who have winter
longer than summer [it seems ] , and that for a 12'x16'x7'+ room, that this BTU rate
should be enough. Also the
♦ Operation Sound Indoor Unit, Hi 36 (dB-A) Medium 33 (dB-A) Low 29 (dB-A)
♦ Operation Sound Outdoor Hi 47 (dB-A)
seems like as low as I've been able to find [although the A-weighting is not much help].

Anyway ... just wanted to fly this out there for comments or experience ... or even a better
choice!

As always ...... BIG THANKS.

BTW .... there has been an incredible transformation in the rooms acoustics

[gullfo]

very cool! on the AC - consider some commercial plenums inside the room to expand the air volume before flowing in - say an 8" duct into a (eg) 48" wide plenum 16" deep, 6" high, will reduce the air velocity quite a bit and make it quieter and also disperse it more. the plenums are aluminum or light steel boxes with a wide air diffuser across the face or bottom. they bolt up onto the ceiling. you would fit them in-between clouds and lights etc as needed.