Bass traps - foam cushiony items from Amazon ok?


I see foam style bass traps for about $25 that seem workable.  Maybe buy two just to test experience.  Are these good to buy?

and maybe than i can buy more pricier panels.  
jumia
Did you have enough to make a difference? Did you measure what peaks you wanted to tame.

They have to be tuned and with enough volume to effect the mode in that room.. A single or even 4 if 8 are needed still leave you without "ENOUGH" to treat the tones correctly..

It's a volume thing not a placement thing as "much as". Diffusion or absorption are different..  This works on canceling a certain peak or peaks.. The formulas are way over my head.. But I can read a mic sweep and see its effects on a given room.. Large will work, just fine smaller will not for BASS anyway..  Adjust the slot to change the frequency, pretty simple.  Just how much ugly can one put up with.. Starts looking like a Roman or Greek Temple.. Ahh that's the reasons for the columns.. LOL

Tuned the Temple..
Post removed 
I use pink fluffy 2’x2’x8’ superchunks in 3 possible corners of my room and the decay time is great, 20ms i think.....

start with trihedral corners

foam go good :0)