I've been through this process about 4 times, with a few years between each iteration, and each time it is like I'm learning it all again.
A few years ago I bought Jim Smith's "Get Better Sound" which provides a detailed step by step speaker placement tuning approach, and I found it really helpful.
Unfortunately the book piskies have hidden my copy and I can't find it anywhere, so I'm going to try and repeat the process from memory, but with one difference: I plan to rely on video clips to supplement my audio memory for before and after comparisons.
My recollection of the process is this:
- Assume a reasonable starting point with zero toe-in and speakers all symmetric, level & vertical (I think my current speaker positions are probably not too far off)
- Use tape to mark on the floor a centre line from the centre between the speakers to the listening position with regular accurate perpendicular divisions every 10cm or so. Measure these accurately so that these can be used as references instead of time-consuming individual measurements between the speakers and walls (or other reference point)
- Start by using bass to tune the distance between speakers and listening position. Move the speakers backwards and forwards until bass is at its most tuneful. I recall finding a few false peaks, and the optimal position can take quite small movements (<1cm) to find.
- Once the optimal position for bass is found, move the speakers wider or narrower without changing the perpendicular distance to the listening position to tune the mid/high tones. As for bass position be prepared for false peaks and the optimal position is likely to be found within quite a small range.
- Finally for imaging, tune the toe in.
Music I've used include Fleetwood Mac "The Chain" for bass and Cowboy Junkies "Trinity Sessions" or Chieftains "Tears of Stone" for mid/high tones.
Any suggestions? Does this sound right? I think it generally takes me a few hours to do. much to the bafflement of my family.