what do i do wrong?? (rew pics included)

[upstar]

Hi,
lately ive realised how much my room lies to me... ive done some tests.
what would you suggest??
Thanks

[Glenn Kuras]

Can you post the REW file? Something with your test is not right.

Also what are those panels behind the monitors? And how are they made? Room dimensions would also help with more pictures if you can.

[Smithcok]

Originally Posted by Glenn Kuras

Can you post the REW file? Something with your test is not right.

Also what are those panels behind the monitors? And how are they made? Room dimensions would also help with more pictures if you can.

Ditto - REW seems askew, and what are those panels?

[upstar]

room size is (lwh) 4.12 x 3.05 x 2.35
panels are diy: 1.2 x 0.6 mineral wool (10cm thick)
in the corners: plywood > gap > 5cm mineral wool
and thats the link to rew file:
Download 4.01.12.mdat from Sendspace.com - send big files the easy way

ive done the measurement with cardoid condenser mic set up in listening position. should i get the omni mic for measurements??

[DanDan]

Strange looking graphs. Something is wrong.
Do you have the Inverse checked like this?
Attachment 270186


Omni is better but by all means learn the ropes using your current mic.
I recommend not using any Cal or Loopback correction until you really know what those things are.
Also, as ever, single speaker for Full Range Frequency Response.
http://www.gearslutz.com/board/studi...er-v2-1-a.html

Resonant Bass Traps like that need to be critically damped. Too little damping and they will resonate, increasing decay.
DD

[Glenn Kuras]

Resonant Bass Traps like that need to be critically damped. Too little damping and they will resonate, increasing decay.

Just to add I would not recommend something like that behind the monitors in this case. Either make them broad band (remove plywood) and straddle the corner or make them tuned which those would be flat on the wall in the corner. Note that those have to be sealed to work properly.

[upstar]

thanks a lot for answers.
ill remove that plywood and ill use single speaker for measurements.
and ill keep reading then ill make new test and post it here

just a quick question about them corners (english is my secound language so just to check if i understand it) : `straddle the corner or make them tuned` im not sure what do you mean by that??? should i put panels on both walls in the corner?? in 90 degree?


thanks for your time

[upstar]

right... just to check ive removed those panels with plywood from the room. ive done measurement with one monitor only.
it doesnt look as bad now??

[Glenn Kuras]

Originally Posted by upstar

thanks a lot for answers.
ill remove that plywood and ill use single speaker for measurements.
and ill keep reading then ill make new test and post it here

just a quick question about them corners (english is my secound language so just to check if i understand it) : `straddle the corner or make them tuned` im not sure what do you mean by that??? should i put panels on both walls in the corner?? in 90 degree?


thanks for your time

With broad band bass traps (like you have) you want to straddle the corner.
See the following on broad band
How Bass Traps Work. Acoustic Panels and Bass Traps.

With a tuned trap it would go flat on the wall in the corner. Not sure how to explain a tuned trap to you but this is copy from a up coming product we are doing explains it in general terms.

The GIK Tuned trap takes low end control to new level with maximum targeted absorption using a membrane design with an air tight chamber. Think of them like a drum in reverse. When you strike a drum, it makes a sound based on the mass of the head and the size and depth of the drum body. In the GIK Tuned absorber, the sound strikes the ‘head’ and causes the membrane to move, absorbing the energy based on the mass of the membrane and the depth of the air tight cavity.

[Glenn Kuras]

Originally Posted by upstar

right... just to check ive removed those panels with plywood from the room. ive done measurement with one monitor only.
it doesnt look as bad now??

Only view it from 20hz to 500hz and also show the waterfall graph.

[upstar]

is that kind of bass traps any good??

[Glenn Kuras]

Not sure what that is but if it is foam then no I would not recommend it for low end control. What you want is thick panels (or fill the area like a soffit design) made from ridged fiberglass or mineral wool (broad band bass trapping).

[upstar]

thanks to both of you Glenn and Dan. i appriciate every single word

waterfall is from one monitor as well

my room sound strange now haha

[Glenn Kuras]

Originally Posted by upstar

thanks to both of you Glenn and Dan. i appriciate every single word

waterfall is from one monitor as well

my room sound strange now haha

room size is (lwh) 4.12 x 3.05 x 2.35
panels are diy: 1.2 x 0.6 mineral wool (10cm thick)
in the corners: plywood > gap > 5cm mineral wool

5cm for the panel is not nearly thick enough. Twice that is minimum and would go even thicker or just fill the whole area. Also you are going to want to fill more corner area to help with the decay times. After you have done that then I would start to think about something tuned to help frequency response (placement can be tricky) and decay times or just keep bass trapping corners with broad band (easiest but will further deaden the room).

[DanDan]

The Waterfall still looks really weird. The LF energy appears to be increasing with time. Make sure there is no feedback path from mic to speaker. You want to drive one speaker only and record on one channel only.

Enormous thick fibre traps will work very well. There are DIY options appearing though. Perforated Panel with Porous Absorber trap
DD

[upstar]

maybe ill show you more pictures of the room. maybe there is something that i should remove (like wardrobe) or maybe window is a problem?? should i place my desk on oposite side where the window is??

its so frustrating :(

[upstar]

i just dont uderstand it all... more i read more i get confused.
ive changed monitors placement. ive checked again with rew. this time with left monitor.
i just dont understand

[kasmira]

Originally Posted by upstar

i just dont uderstand it all... more i read more i get confused.
ive changed monitors placement. ive checked again with rew. this time with left monitor.
i just dont understand

That actually looks much better - what aren't you understanding?

[upstar]

it all changed because ive moved monitors 25cm to the middle??

[Glenn Kuras]

Originally Posted by upstar

it all changed because ive moved monitors 25cm to the middle??

You did have those monitors pretty close to the corner and that will excite things pretty bad. Who really knows though but the nice part is things do look better. Retest a few time (with the mic in the same spot) to make sure it is correct.

[Smithcok]

Originally Posted by upstar

it all changed because ive moved monitors 25cm to the middle??

Welcome to acoustics!

On a more serious note - the newest graph looks closer to reality (something was quite bugaboo with the "bass getting louder" graph). I'd suggest taking a picture of your test setup (mic placed where? speaker? etc.)

[kasmira]

Originally Posted by upstar

it all changed because ive moved monitors 25cm to the middle??

I meant the graph looks better, not the results.

Your speakers look like they are in the corners of the room, about 2 feet from the wall. This seems to be the absolute worse placement for speakers.

I'd suggest bring them in towards the center, and try even placing them up against the wall. The general consensus seems to be they should be spaced at least 2 meters away from the wall, and if not, then they should be right up against the wall. In between those positions is usually regarded as the worst spot, and corners are not good either. This can cause all sorts of peaks and nulls. (NOTE: THIS IS PROBABLY NOT COMPLETELY TRUE. Its just a general rule to "try" these other configurations and see which is best, and in my personal experience I've experienced the worst sounds within a meter of the wall)

Also, bass traps that thin will not do much of anything for the low end. I would suggest multiple 6 inch bass traps for this room - and yours are only 2"

Since you have a door in one of the corners, this might cause problems too.

I would firstly clean up your room! Then, flip your room set up. Bring the monitors in closer. Try them right next to the wall, try them away from the wall, and see what sounds best. I would stick two of your 10cm panels together to make 20 cm panels and straddle those in the corners. Put your other traps at your first reflection points. Not sure about how to fix the tests or why you're not able to use them, as I've never actually used the software.

Good luck

[DanDan]

25cm is a big move, try smaller increments. I have heard a well known acoustician say position is 70% of the game.
I think you understand OK, your little experiment has proved itself. Now believe!

DD

[upstar]

I think ive seen that interview. It was Bob Hodas saying 70% positioning, 25% treatment and 5% eq. I think ill spend few days to take everything out of the room and try different positioning. Then ill make some thicker bass traps and ill let you know what the results are.
Once again thanks a lot

Sent from my GT-I9000 using Gearslutz.com App

[DanDan]

You are welcome. I can't fully make out what those speakers are, but I suspect they would sound better in terms of stereo image, standing vertical, tweet over woof.
DD

[upstar]

Originally Posted by DanDan

You are welcome. I can't fully make out what those speakers are, but I suspect they would sound better in terms of stereo image, standing vertical, tweet over woof.
DD

Samson rubicon r5a . In manual it says that you can use them both ways. But my next purchase after sorting the room was suppose to be monitors. I make hip hop and rnb. Ive read in reviews that samsons ive got doesnt have good details in low end. Maybe adams or yamaha with 7-8" woofer. If its not to big for my size of room?? Or should i sort my room after ill get new monitors??

Sent from my GT-I9000 using Gearslutz.com App

[DanDan]

The usual room treatments work irrespective of the speakers.
As many as possible Big Bass Traps in corners. Broadband absorption to the Left and Right and Overhead.
Just think of lots, make it twice as thick, then buy four times what you have in mind. :-)
DD

[upstar]

hi, its me again.. ive read that its good to continue same thread if its about same thing to let others study the case.... so..

ive fliped my room already.. results are similar but ive spent some time to walk around the room with spl meter and i understand now how importent is to listen to the room, to learn the room and the basic acoustic rules.

now.. should i build huge broadband panels for bass traping or... shoud i fill the corners with triangle shape pieces and cover with fabric??

[Glenn Kuras]

now.. should i build huge broadband panels for bass traping or... shoud i fill the corners with triangle shape pieces and cover with fabric??

Filling the corner is always better as it will reach lower, but making panels around 6" thick is also nice as you get a spring action around 70 to 80hz. All and all both are proven to work. See the following test I did with panels. You can see a great deal of improvement at 70hz
Need advice on waterfall!

[upstar]

in that case maybe ideal will be to fill the corners on the front wall (the one with the window) and put 6" traps at the back (theres doors in one corner so it will have to be something mobile)????