With the 3Sixty gathering a little bit of popularity lately, I thought I would post up this little bit of info about the time alignment. When I was in Perth last, a few of us had a fair go at the TIme Alignment with the 3Sixty- measuring distances and whatnot but seemingly unable to achieve a truely great soundstage. It was good, but not great.
It seem's that there is more to it, than measuring the distances and plugging in the values for each driver. The following is reproduced from the RF Knowledge Base.
QUOTE
The human ear uses several methods to determine the location of sound, one of which is the difference in time from when the sound reaches the left ear compared to the right. In order for a sound to be perceived as being directly in front of the listener, the sound must arrive at each ear at the same time.
In a car, the listener is usually closer to an individual speaker. The sound from this speaker arrives at the listener earlier than the sound from the further speaker. This is perceived as the sound originating from the closer speaker. 3Sixty allows you to delay the speakers that are close to you such that all audio arrives at the listener at the same time. The below diagram illustrates how typical Kick Panel, Dash Location and Door Location installations vary speaker path lengths.
Let's look at a simple 2-speaker installation in the Door Location. The LEFT speaker 20" away from your ears and the RIGHT speaker 44" away. In an ideal world, both speakers would be the exact distance from you, therefore the sound they produce arrive at your ears at the SAME TIME. Since it is impossible to speed up the sound originating from your speakers, you have to work with the one that is furthest away as a reference (in our example, it will take the RIGHT speaker longer for its sound to reach your ear.)
So we have decided that the RIGHT speaker (at 44") is your reference. Regardless if the 3Sixty indicates "distance" or "time" is irrelevant. We said earlier that you want both speakers to be the same distance from you. This means the LEFT speaker needs to be extended 24" (44" - 20" = 24") or 2 feet. Now both LEFT and RIGHT speakers appear to be 44” away. This is a good start, but ultimately it is personal preference. You may find that you have to delay the LEFT speaker by 2'4". The procedure outlined above is simply a starting point.
In a car, the listener is usually closer to an individual speaker. The sound from this speaker arrives at the listener earlier than the sound from the further speaker. This is perceived as the sound originating from the closer speaker. 3Sixty allows you to delay the speakers that are close to you such that all audio arrives at the listener at the same time. The below diagram illustrates how typical Kick Panel, Dash Location and Door Location installations vary speaker path lengths.
Let's look at a simple 2-speaker installation in the Door Location. The LEFT speaker 20" away from your ears and the RIGHT speaker 44" away. In an ideal world, both speakers would be the exact distance from you, therefore the sound they produce arrive at your ears at the SAME TIME. Since it is impossible to speed up the sound originating from your speakers, you have to work with the one that is furthest away as a reference (in our example, it will take the RIGHT speaker longer for its sound to reach your ear.)
So we have decided that the RIGHT speaker (at 44") is your reference. Regardless if the 3Sixty indicates "distance" or "time" is irrelevant. We said earlier that you want both speakers to be the same distance from you. This means the LEFT speaker needs to be extended 24" (44" - 20" = 24") or 2 feet. Now both LEFT and RIGHT speakers appear to be 44” away. This is a good start, but ultimately it is personal preference. You may find that you have to delay the LEFT speaker by 2'4". The procedure outlined above is simply a starting point.
