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PostPosted: Fri Jan 01, 2021 1:19 pm 
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Joined: Mon Dec 28, 2020 7:05 am
Posts: 6
Location: Patterson, Louisiana
Hello all. Just need a little help interpreting my mdat.

Room Size:
18.3ft x 14.5ft x 8ft

All internal walls and ceiling are 3/4" T&G Plywood

All exterior walls are hardplank (Composite lap siding) EXCEPT: Rear wall (External is brick)
KRK V10's toe-in: 30 and 60 degrees. 6 ft apart acoustic axis at a height of 54in

Mic (DBX-M), at same height at 60 degree angle inside 6 ft triangle 38% from front wall (84 in).

12/31/2020 Tests:

Broadband panels (See photos):

5ea 2x4 Panels (6 lbs per/sqf density 4" Rocksul) ER Points Side wall seated 3" off wall

1ea corner trap in front-left corner (Same ROXUL)

1ea Cloud 4x6ft (Same ROXUL) with hard peg-board backing angled 12 degrees towards LP

2ea Tube Absorbers at rear corners stuffed with ROXUL but sealed (No holes).

Couch or sofa will be added to middle of rear wall soon.

Thanks in advance for any help.

Image

Image

MDAT:
https://www.dropbox.com/s/dogmw4mxifny97o/123120_plusPhotos.mdat?dl=0

Folder with photos and notes:
https://www.dropbox.com/sh/teu8m0etvlcoea0/AABK7-qLY-u9nOMMdJDigegGa?dl=0

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18.3’ x 14.5’ x 8’


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PostPosted: Sun Jan 03, 2021 10:20 am 
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Joined: Tue Mar 25, 2008 3:31 am
Posts: 520
Location: Cork Ireland
Looking pretty good to me. I expect your TnG is absorbing LF, something Newell calls a 'Limp Bag'
I would get free of all rules of thumb regarding location of your speakers and listener.
Find the optimum by testing.
I would start with the speakers almost touching the Front Wall. This should help a little with SBIR and gain you some free extra LF power. I think I see Reflex Ports on a picture of the V10s. I would fill them with cotton wool or polyester speaker batting. Check for heating many ask KRK is this is safe. It should diminish your currently excessive LF a bit and tighten it. Use the level control or Eq to further adjust the tonal balance. You may want to turn the HF down a bit also. Particularly if you go for more absorption.
I would definitely use these speakers vertical.
Haven't seen the photos but I would generally expect at least two traps per side, more welcome, four or more in the Cloud.
Any Corner Traps go floor to ceiling. Maybe test the bigger ones in the front two corners at some stage.
With three way speakers you have ability to control tone. I recommend going for the classic Bruel and Kjaer curve.
For more sophisticated speaker control we have Dirac Live and Sonarworks.

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DanDan FitzGerald MIOA MAES
http://www.irishacoustics.com
http://www.soundsound.ie


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PostPosted: Sun Jan 03, 2021 1:42 pm 
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Joined: Mon Dec 28, 2020 7:05 am
Posts: 6
Location: Patterson, Louisiana
Thanks for your reply. I was having an issue getting the photos to upload here (They are under 500kb), but I will try again soon.

The V10’s are against the wall. And since the most recent measurement, I have notched the bass control down a little on the monitors (It’s a broad but gentle shelf). Also, I’ve inserted a high pass on my monitor outs around 40hz (Recommended per John Brant’s spreadsheet room calc). This has helped a little. My rear wall is lacking absorption which is still a work in progress.

I’m still trying to figure out how to interpret the impulse response. I zoom way in and see the spikes that indicate specular reflections but where and at what frequencies?

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PostPosted: Mon Jan 04, 2021 9:56 am 
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Joined: Tue Mar 25, 2008 3:31 am
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Location: Cork Ireland
Sealed Woofers have lovely way of rolling off gracefully, while keeping the joys of hearing a clear 30Hz and even lower presence.
Personally I wouldn't HPF. I would experiment with closing reflex ports try soft close with fibre to actually sealing them off.
This is very different to Eq. Many of us rely on a single narrow Parametric Filter to hit our lowest mode which we can't afford to treat.
This also preserves the pleasures of the Sub world.
The ETC, I like to rename EchoGraph. Try the Filtered IR graph. The ETC shows an early one. 1mS perhaps from your Desk and a later one, 11mS probably the Back Wall.
The classic rule of thumb is to strive for no reflections above -20dBFS during the first 20mS.
I have a tiny desk, just enough for the keyboard and trackpad. It is slightly angled toward me, which bounces that very early ping away from my ears. I also have a fluffy black towel covering it. You can apply third octave fllters to the ETC.

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http://www.irishacoustics.com
http://www.soundsound.ie


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PostPosted: Mon Jan 04, 2021 11:04 am 
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Joined: Mon Dec 28, 2020 7:05 am
Posts: 6
Location: Patterson, Louisiana
Hope these photos work:

You can see the front door and plenum cover (Upper Left ceiling/wall running room length), And seems to create an issue with symmetry:

Attachment:
Front Wall.jpg


Attachment:
Left Speaker.png


The right side oddly seems more comb-filtered in the 100-200hz range but not sure how to treat that corner due to the door.

Attachment:
Right Speaker.png


The dip at 107hz on the right side is also pronounced in the L-R graph:

Attachment:
Left and Right.png


The rear of the room is still in need of some treatment. Those tubes are concrete forming tubes filled with 4lb/ft Roxul. I have no holes in them yet. I'm in doubt they are having any effect as testing before and after showed no difference. There is however a 4in broadband absorber at the top center of the wall behind the curtain:

Attachment:
Rear Wall.jpg


And filtered impulse response of Lt and Rt to 70ms:

Attachment:
LR IP 70ms.png


You do not have the required permissions to view the files attached to this post.

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PostPosted: Mon Jan 04, 2021 11:06 am 
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Joined: Mon Dec 28, 2020 7:05 am
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Location: Patterson, Louisiana
BTW: Thank you for your help. I will try out your suggestions regarding those ports.

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PostPosted: Tue Jan 05, 2021 3:47 am 
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Joined: Tue Mar 25, 2008 3:31 am
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Location: Cork Ireland
Treatment needs to be big. Deep and with a lot of area. Up to 60% of the volume of a Pro Studio may be hidden trapping.
The simplest cheapest corner traps are just rolls of attic insulation, left in the bags, bedspreads or whatever for appearance.
SoffiTraps are decent performers. The bigger StudioTips Superchunks. But you need to do floor to ceiling.
Note the Neumann KH310 Monitors have a 10" Woofer in a sealed box.

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http://www.irishacoustics.com
http://www.soundsound.ie


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