I used near the speakers, beside them and on top of the speakers what i called Helmholtz diffusers, some tubes of different size and length with great success...
I used some tubes with one mouth open, others with one mouth or the two mouths filtered by some various thickness of fabric cloth or with smaller packs of tubes inside one mouth or the two mouths...
The SECRET is that these diffusers are used in a DISSYMMETRICAL way for the speaker A and the speaker B...
Why ?
Because i used the "precedence principle" or first wavefront principle of Haas which is a psycho-acoustical binaural effect that say the location of sounds in space is created in the brain by the differentials timing of the first wavefront coming to speaker A and Speaker B to Ear A and EAR B...
To increase and reinforce that effect i use, like a focusing "lense" for the soundwaves direct one and also some reflected one, a two panels foldable screen of wood( with many H. diffusers on it behind my head and listening position...
I used a complete room treatment and a big grid of H. resonators and diffusers, all that work in synergy...( ionizers too and a Schuman generators grid)
The effect of vibrations control with among others things dissymetrical compressive force applied under and on top of the damping load of the speakers, and added to that the effect by controls over the electrical noise floor of the house (my golden plate:shungite+copper+quartz+graphene) with the described acoustical and psycho-acoustical control above is astounding for a relatively good but basic audio system...
About the OP question, i dont know what will be the effect of these diffusers ALONE with your type of speakers ( mine are a two way box type with front porthole) because i used these diffusers near my speakers only after my system/room/house was already heavily controlled... This added improvement to all my others devices effect and embeddings controls..
You must listen and experiment.... DONT LISTEN TO ANYBODY... Read think listen and experiment... Only you know the sound coming through your ears...
No room /system is the same and the acoustic of small room for one head is more complex than Hall acoustic for a crowd by the way...Tuning a small room for one pair of ears and using reverberation time and acoustic specific content is difficult, you CANNOT USE an easy recipe to reach an optimal.. you must experiments and listen for the tuning.. Simple recipe are there to make easier the life of the sellers of acoustic panels...They work but dont make the maximal possible positive improvement...
I say all that for those lucky enough to be able to experiment in a dedicated audio room...
By the way my room is a LABORATORY not a living room or an esthetical model...
I only spoke to communicate to some the way to good sound: acoustic, and to motivate some to experiment...By the way all this cost me almost nothing except time...
My best to all in this dire time of ours......
Music is a therapeutic with power increased by sound control ...
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