Specifications

5.1-Channel Production Guidelines Production Environment
3-21
For future reference, if calibrating the subwoofer with an RTA, measure the level
with an SPL meter and note the meter reading for the proper calibration. Use this
measured value for quick checks of the system calibration in the future.
3.5 Signal Delay
In addition to setting the proper monitoring levels, it is important that the sound from
each speaker arrives at the listening position at the correct time.
In an ideal room setup, the five main speakers would be equidistant from the mixing
position. In this case, the listener would hear common sounds emanating from two or
more speakers at the same time. If the speakers are not and cannot be equidistant,
signal delay will be required to achieve the intended result. The speaker position
furthest from the listener determines which of the remaining speakers will require
signal delay. Relative delay times are derived from the difference in distance between
the furthest speaker and each individual speaker. The required delay time is
approximately 1 ms per foot or 3 ms per meter. With proper compensation, the entire
system should exhibit coincident signal arrival at the primary listening position.
To achieve this, the delay times of the Center and Surround channels may need to be
adjusted. Channel delay is determined by calculating the distances from each speaker
to the listener, as seen in Figure 3-6.