RoomEQWizard frequency graph for my room. Suggestions?

[Sid Menon]

Here's the frequency graph for my room at my listening position. The test was done with an NT1000 microphone, which I believe is relatively flat.

The room is roughly 21' Left to Right and 28' Front To Back. The monitors are about 2 feet in front of a short wall facing the opposing short wall, and my ears are about 7-8' back from the short wall.
The wall behind the monitors is covered, top to bottom, in R13, which heavy blankets over them. The rear wall has 4" of 703 bass trapping in each corner.
I have my overhead and right side first reflection points treated with auralex, and 2" of 703, respectively. The left side reflection point has an entertainment center, which limits first reflection point coverage, but it is angled, which i'm hoping is providing some diffusion.
There are no bass traps on the left and right corners behind the monitors, but as I said the wall consists of blankets in front of R13. I'm planning on putting 4" of 703 back there anyway on each corner.

Anyone have suggestions on how to improve this graph? The monitor end is where I mix, the rear end is where I track.

Thanks!

[steveschizoid]

call GIK! Although you might then feel obligated to purchase a bass trap, they really aren't that much more expensive then it costs to build your own. Unless you have ready access to OC 703 and 705. But GIK's actually look pretty good as well; some clients actually think they are here just to look cool.

also, shouldn't you be using a decible meter?

[Glenn Kuras]

Thanks ANDY!!!!!!!!!!!!!!!!!


Sid Menon,
How are you set up in the room? Do you have any trapping in the corners at all?

Glenn

[Ethan Winer]

Originally Posted by Sid Menon

Here's the frequency graph for my room at my listening position.

Looks typical.

The test was done with an NT1000 microphone, which I believe is relatively flat.

I'm sure it's flat enough, but it's the wrong type of microphone. You really should use a small diaphragm omni. More here:

Comparison of Ten Measuring Microphones

Anyone have suggestions on how to improve this graph?

Bass traps, more bass traps, and yet more bass traps.

Seriously, that's the mantra around here because it's the truth.

--Ethan

[steveschizoid]

My ignorance knows no bounds. For some reason I thought room EQ wizard was meant to be used with the radio shack meter (I seem to remember a place in the settings dialog to let the software know that that is what you are using) I had no idea the convention was to point the element towards the ceiling. I've been pointing it in between my speakers at ear level, but, if the element is omni, why would the direction matter?

There was a point last week where I had put a bass trap in a floor trihedral corner (horizontally, below one hanging vertically to the ceiling) as an experiment. I then took a measurement and it actually made a 75 Hz null I am trying to eradicate worse! It was the middle of a long night I spent moving, hanging and rehanging bass traps, so don't ask me to describe precisely what happened, but I suppose there is an exception to every rule? Also Ethan, you've probably seen my posts about this room; it's an odd shaped room. See http://www.gearslutz.com/board/2875083-post18.html if you haven't and you're curious and want to take a crack at explaining the anomaly. I do intend to keep adding bass traps until it's optimized. I was recently in a fairly small room used for mastering that was totally plastered with Real Traps...I can only say that that project turned out exceedingly well.

[Sid Menon]

So in addition to the 4" thick 703 bass traps I built for the rear of the room, I should have 4" thick 703 traps in the front corners as well, on the corners of the wall behind the monitors?
Then start addressing wall/ceiling corners?
What about diffusion in the rear of the room?
I'll redo the test with a SD omni as well, but I did with some cardiod omnis and they seemed to return very similar charts, which the exception beign the high end. All mics showed a huge dip around 95 hz, 350, and then 800 hz. These seem consistent, and when doing the test tones I can actually hear these frequencies get much quieter.

[Glenn Kuras]

Originally Posted by Sid Menon

So in addition to the 4" thick 703 bass traps I built for the rear of the room, I should have 4" thick 703 traps in the front corners as well, on the corners of the wall behind the monitors?
Then start addressing wall/ceiling corners?
What about diffusion in the rear of the room?
I'll redo the test with a SD omni as well, but I did with some cardiod omnis and they seemed to return very similar charts, which the exception beign the high end. All mics showed a huge dip around 95 hz, 350, and then 800 hz. These seem consistent, and when doing the test tones I can actually hear these frequencies get much quieter.

Sounds good on retesting, but also I would like to know where you are set up in the room. Are you facing the short wall and sitting back about 38% of the room length?


Glenn

[Sid Menon]

I am facing the one of the short walls, and I am more like 30-33% back. My monitors are centered along the wall, and are 5' apart and about 5' from me.

[steveschizoid]

Originally Posted by Sid Menon

So in addition to the 4" thick 703 bass traps I built for the rear of the room, I should have 4" thick 703 traps in the front corners as well, on the corners of the wall behind the monitors?
Then start addressing wall/ceiling corners?

Probably so.
I saw a significant difference when I merely moved the trap in the wall/ceiling corner in front of my desk a few inches so it straddled the corner better.

I know nothing about R13; where do you get it, does it help? I was under the impression that you really need rockwool or OC 703 to have any impact at all below 200 Hz.

You will likely want to play with your monitor/listening position. Inches make a difference, and you may get lucky and find a good spot at less than 38%.