Acoustics panels for small office room?

[hyvokar]

Hi,

planning to treat my office space a little bit. I have zero experience with room acoustics.

Got 350x280x250cm (LxWxH) room . Three thin walls (2x13mm gyproc sheets), the one with windows is thick brick wall.
60x180cm wardrobe is room height.
Two KEF LS50 speakers on my desktop, aimed to my sitting position (X), ~10-15cm from wall. 10" sub on the floor in the bottom right corner.


Now the questions:
Without prior knowledge, microphone and spending hours on measuring stuff, how likely I'm:
a) make things worse?
b) just waste my money?

Planning to use something like https://www.amazon.de/FENNEXT®-Absorber-Acoustic-Noticeably-Reduced/dp/B0BFBQZMTQ/ but may have to get something cheaper.
Budget ~300e/$

My initial plan is/was to make a nice looking figure out of hexagon shaped panels on the back wall (top side of the pic) to cover ~25% of the wall. Can the figure be somewhat centered, or should forget the figure and place the panels evenly?
Should I also consider treating the opposite wall (bottom in the pic) and ceiling?

Not expecting end result to be Sydney Opera House, but if I spend couple of hundred e/$, is a person with healthy hearing likely to notice any difference?

 

[Flaesh]

Without prior knowledge, microphone and spending hours

is a person with healthy hearing likely to notice any difference?

It depends)).
In very reverberant rooms almost any minor treatment produces positive results that are audible to most people. Or less effect in other cases. Is ~$4 mic like

and let's say one hour to install REW and whistle an acceptable cost for you?))

 

[hyvokar]

Thank you for your reply, Flaesh
Mic cost is not an issue, but planning to purchase Antimode x2d after room treatment.
Now I'd only need to know where to slap those acoustic panels

 

[Flaesh]

I'd rather know what's going on in the room first. And then I would buy and glue [something] on.
Considering room, gyproc walls and the location of the listener and speakers, things may not be too bad.
Without mic - does the room sound muddy, boomy, dull, hollow, honky, ringing, bright?..))

 

[hyvokar]

I do have a logitech usb mic and laptop available, but when I checked the first rew tutorial, it said that i'd need some loopback stuff. Looked like external sound card to me.

 

[hyvokar]

Not sure if it's help any, but if I clap my hands loudly, it takes ~1sec for sound to dissipate