Do some calculations. r=sqrt( V / (c * RT60) ). Volume in m³, speed of sound, reverberation time. or

r = 0,054 * sqrt ( V / RT60)

A 30m² room with RT60 of 1s get's about 0,5m. Getting reverberation time down to 0,5s -> 0,7m

Now you would need to add the directivity index of the speaker ... which we don't know and changes over frequency. A perfect cardioid or figure of 8 would boost it to 1,2m - but that's pretty unrealistic. So you would be in the 0,8-0,9m range.

And now go into Studio building ... reverb time of 0,2s boosts to 1,1m and with directivity a little more. But that means a LOT of absorption area! Not hanging a few panels ...