help me in room treatment

[luigichelli]

Hello guys, i need some serious help in fixing the acoustic of this room...

the walls are woody, with rockwool+gap (around 15cm) between them and the concrete wall behind.
above the drop ceiling there's rockwool too.

here you can see a photo (sorry for the quality, made with a phone)



i made some tests with fuzzmeasure:

the microphone was calibrated @ 0dBFS = 96 dBSPL, and the sweep done @ -12dBFS = 84dBSPL
Microphone: Schoeps mk2
Loudspeakers: ATC SCM16a
Recording done in the listening position, with monitors spaced 2m and both 1m away from the back wall.
Lacking a sub-woofer i ran the tests from 80Hz to 20kHz.




as you can see from the plots i got some troubles with the low freqs (~127Hz, ~205Hz etc...)
and a very very bad ring of all the mid and hi-mid range (the max is @ around 1.4kHz)


The question is what should i do to fix that room? unfortunately i don't have much time to build some traps and diffusors, so i'm considering buying commercial produts here in europe...
my budget is quite tight and i shoud stay under 1500€
any advice of what should i buy?

thanks a lot for you help!!
Luigi.

[Glenn Kuras]

A few things.

1)Start with having your seating facing the short wall with your setting at 38% of the room length. You will then want to move forward or back to get the best response.
2)Treat all corners with bass trapping
3)Thick absorption on the back wall.
4)Thinner panels for the early reflection points.(What Are Early Reflection Points. SPOTLIGHT:Bob Ebeling - Revolution Studio)

See the following for placement help.
GIK Acoustics: Room Setup

[luigichelli]

Thanks for your help Glenn!
i made some tests @38% but i can't improve the response so much..
this is a pic with the new position (38%) in red, versus the old in blue.



I'm definitively intrested in buying some traps and first reflections panels, but i'm afraid that it will not affect the midrange reverberation that the wooden walls are causing...

what do you think?

[bpape]

First, try turning off smoothing and just run the plot up to about 500Hz so we can see more of what's going on.

The previous peak that now is a null most likely can be tamed by the seating position being somewhere between those 2 positions. Usually, it ends up being between 33 and 38% but not always.

Other than that, you're realistically not all that bad. You're within +/-5 in room other than a couple of bad actors.

Bryan

[Raider]

The above guys are experts but, fix the bass problem first as they alluded.
Bass trap all corners; THEN analyze and fix the rest of the freq range.

[luigichelli]

Originally Posted by bpape

First, try turning off smoothing and just run the plot up to about 500Hz so we can see more of what's going on.

The previous peak that now is a null most likely can be tamed by the seating position being somewhere between those 2 positions. Usually, it ends up being between 33 and 38% but not always.

Other than that, you're realistically not all that bad. You're within +/-5 in room other than a couple of bad actors.

Bryan

new test without smoothing, 0.5 Hz resolution



i ran more tests from different positions but i can't find a "best". All graphs shows more or less the same problems, i figured that i can only fill the 300hz dip moving the listening area towards the 46% (green line)



...a question to the gik's guys.... yours diffusors must be shipped from usa or can be packaged with other traps from europe?

thanks again,
Luigi.

[Glenn Kuras]

...a question to the gik's guys.... yours diffusors must be shipped from usa or can be packaged with other traps from europe?

They have to be shipped from the US. We can ship them to the plant in the UK but you would end up paying more in shipping as it would have to ship twice.