weird sound on my rec room

[redmetal]

Hi guys, I have a problem with a recording room that i'm building, i clapped my hands and felt this weird sound and i would like to know if anyone had a similar problem.
I want to get rid of this sound so i wanted more opinions before doing something, in the sound clip , I'm standing on a thick curtain on the last claps (but covering all the floor with curtains isn't an option haha).
I'm not certain about the material of the floor, is some kind of tile but it feels like plastic, i'm thinking about putting hardwood flooring.

AS you may noticed english isnt my native language so there are some errors in the coherency .. if you know anything or need some info please ask.

the size of the room is like 22m2 ( near 7x3meters) and 2,8m high.
recorded with an audix adx51 at 1,5m high
one wall is covered with mineral wool covered with fabric, the others are plasterboard
the ceiling is covered with a sound absorber material.

My big doubt is if this sound is made from an acoustic thing(resonance ... reflections....) or a "physical" thing like something vibrating in the room (havent found anything....) or bad state of the ceiling

 

[Tadpui]

I can't really hear any ambient sounds on your recording on my current speakers (an aging 4.1 system in my office), but I'd almost guarantee that the mechanical sound that you're hearing is flutter echo. I had some pretty nasty ringing in my old studio room, and still a fair amount in my new studio. It's most likely the parallel hard surfaces in the upper heights of your room. The lower portions of rooms have furniture, amps, equipment...all sorts of stuff that tend to break up and scatter mid and hi frequencies and keep them from bouncing back and forth between parallel hard surfaces. But those upper reaches of a room tend to have very little "stuff" to disrupt the sound waves from bouncing back and forth and creating a strange metallic ringing after the room is excited by something like a hand clap.

So you have one wall completely covered with mineral wool? Hopefully that's the "back" wall relative to where your speakers are. That would create some odd stereo imaging if it were one of the "side" walls.

The standard advice (and it's standard because it's effective in most small rooms) is to do floor-to-ceiling broadband traps in all 4 corners, then broadband absorption at all of the first reflection points (walls and ceiling). Then assess your needs from there. Entire walls covered with absorption is out of my realm of experience (except for carpeted floors). I would consider some absorption in the upper wall/ceiling junctions to combat that flutter echo. Straddling the wall/ceiling junctions with bass traps would be a two-for-one deal to help flutter echo and help with low frequency absorption.

 

[gecko zzed]

I hear flutter echo as well. It is stronger in the first half of the sample.

 

[JimmyS1969]

Yep.

 

[redmetal]

Thank you guys!
and since putting the curtain on the floor the flutter echo went away almost entirely, can i assume that the echo is produced mainly between the floor and the ceiling? i was going to do broadband traps in the corners anyway... this will be only a recording room so no speakers here....

my plan was putting broadband absorption on all corners and then some absorption panels made of wood and mineral wool on the walls, then i would hang plywood from the ceiling with an angle so the floor and ceiling aren't so parallel anymore (and maybe cover this with some material like mineral wool or foam)

 

[mixsit]

..
then i would hang plywood from the ceiling with an angle so the floor and ceiling aren't so parallel anymore (and maybe cover this with some material like mineral wool or foam)

Or otherwise known as 'clouds to counter the hard floor.
And mineral wool or fiber glass is almost always cheaper per cubic' whichever meter than foam.

 

[redmetal]

though it is really necessary to cover the plywood with mineral wool or fiber glass? anyway, the broadband absorbers on the corners and the "clouds" will be my main thing to do

 

[mixsit]

There is the broad band trapping tackling the major room issues, and .. simpler (easier) mid and higher freq reflection control. (Seems you are trying to get into diffusion of reflections.
any way here's a whole bunch of real good reading and info for ya.
RealTraps - Home