The DSP(digital signal processing) will impart a signal delay usually measured in milliseconds. A common delay would be 5 milliseconds. The speed of sound is (roughly) one foot per millisecond. So a 5 millisecond delay will cause your receiver to set the distance setting about 5 feet more than the physical distances involved. R = V/I – this is what a speakers impedance calculator would ensure you do. The Speaker Impedance Calculation Law. There are generally 2 ways to connect speakers; parallel and series. R = R1 + R2 (Serial connection) 1/R = 1/R1 + 1/R2 (Parallel connection) Speakers connected in series requires the impedance to be added. There are two basic ways to carry an electrical audio signal. The first one is unbalanced.The signal is carried on a two-conductor cable. Unbalanced signal connectors have two pins, such as the RCA (also called Phono and Cinch, commonly used by home hi-fi equipment) and the unbalanced 1/4' (used in musical instruments and semi-professional audio).
When configuring a sound system how do you properly set the delays?
The ultimate goal when setting up delay speakers is for the listener to not even notice the delay speakers are there. Yes, as silly as it sounds it’s true. A properly configured delay will give the illusion that the sound is still coming from the source and not the delay itself. There are several ways to go about a proper setup for your delays. Believe it or not you can actually configure a delay very precisely with a tape measure and not expensive test equipment. Just remember one very simple rule, sound travels 1130 feet per second (at sea level with 70% relative humidity at 72 degrees). In other words sound will travel 1.13 feet every millisecond. So if your delay speaker is 35 feet away from you primary speakers a delay of 31 milliseconds would be right on the money. Of course there are several sophisticated and expensive electronics to do the same thing. They use a calibrated microphone to compare the arrival times of a reference signal from the main speakers and the delay speakers as it arrives at the microphone. This difference in arrival times is obviously your delay time.
However there is also a phenomenon known as the HAAS effect which is too in depth to discuss in one post but what’s important to know is how it relates to settings delay times. In the study of psychoacoustics it is found that often times delaying the “delays” even further behind the arrival time of the primary speakers actually enforces the perception that the sound is originating solely from the primary speakers. This is because the secondary arrival is suppressed due to “involuntary sensory inhibition” which correlates to the human ear’s ability to localize sounds.