[LAU] OT Design of audio space

Friends Not Linux specific. I am involved in the design of one, and renovation of another, space for performing amplified music.  I have been looking for advice on acoustic design.  In both cases there is nothing I can do about the basic external shape but in both cases I have a lot of control over the internal lining design. Acoustic isolation is important, and I can find advice on that (plenty) on the web.  But what I cannot find is advice on how to make it sound good inside. The b3est advice I have had was a throwaway comment about avoiding right angles, and it seems logical to me to avoid parrallel walls that can support a standing wave and be susceptible to resonance. But beyond that I am a bit at sea.  Is there any place on the web that documents best practice for some one in this position? Worik -- If not me then who? If not now then when? If not here then where? So, here I stand, I can do no other root(a)worik.org 021-1680650, (03) 4821804 Aotearoa (New Zealand)