Tannoy Proto-J Reference Manual page 11

The 2 millisecond reflection window really affects the character of the sound at the mix position,
drastically altering the response of the speaker in the critical audio bands of 500 Hz and above. The
10 millisecond reflection window does some more subtle things to the speaker's response, because
the ear/brain reads reflections arriving within 10 milliseconds of the direct sound as being part of the
speaker's response, these reflections can pull the stereo image around in different directions at dif-
ferent frequencies. Enough theory, now to the lab.
Here's where we have fun with science. Take the microphone stand and place it at the mix position.
Attach one end of the string to the top of the mic stand, and stretch the string out to the front of one
of the monitors. This is the direct sound path from the speaker to your mix position. To locate all the
surfaces that will contribute reflections within that magic 2 millisecond window, add 24" (600 mm) to
the string you have stretched out. Take a small piece of gaffer tape and attach the string to the baffle
(NOT the drivers!). Now, every surface you can touch with any part of that string can contribute a
reflection to your mix position.
The STRING analyser
This same concern about reflecting surfaces applies to all nearby widgets such as computer moni-
tors, outboard gear, coffee cups, rolls of tape, the producer's wooden leg and all the other usual
paraphernalia found in a studio environment. Cleaning up this short sound path between the speak-
er and your listening position is like using a cotton bud on your ear.
You can repeat the process with an extra 10' (3000mm) of string to see which surfaces will influence
the timbre and imaging of your mix. This exercise is not just about finding places to stick fuzzy or
foamy absorbers to, the last thing you want to do is make your room completely dead. What this
process will show you is which surfaces you should try to angle to redirect reflections away from
your mix position. If there are surfaces that you cannot move or shift, you can apply a small amount
of absorbent material to specific surfaces, rather than covering the entire room in absorbers.
You may want to consider a speaker placement other than the console meter bridge, perhaps on an
elevated mounting arm attached to the wall, or on a midfield monitor stand, just behind the console.
These positions can help clean up that 2 millisecond window. Keep your ears open for other prob-
lem reflections, like between the sloped connector panel on the back of the console and the baffle of
the speaker, which will find its way back to the mix position a bit too late to be useful. The string trick
works just fine for locating these reflecting surfaces.
It's important that you listen to the effect of speaker placement on the sound character of your
speakers, and understand what those changes are going to do to your mix. To make the point here's
are some more things to consider: