Subwoofer Phase

**IDOXLR8** · 10-27-2006, 12:02 PM

Please Explain Subwoofer Phase. This is a post I read.........

It synchronizes the in-and-out movement of your sub's woofer with the woofers in the rest of your system so that when the subwoofer cone is "pushing" air out, the other woofer diaphragms are also moving outward. If your subwoofer is on the same plane as your front speakers then set the subwoofer phase switch to 0. If your subwoofer is located anywhere else then try the phase switch in both positions and set it to the position that produces the strongest bass at your listening position. Given the vagaries of bass standing waves that result in all rooms, you may notice no difference at all, in which case set the switch to 0.

Now all that being said, what it mean to have all your speakers on the same plane? AL.

**fwaggle** · 10-27-2006, 12:54 PM

if one of your speakers is "pushing" air (cone extending) as another is "pulling" (ie cone retracting), they can in certain conditions cancel each other out, or have a host of other problems. sometimes having things 180 degrees out of phase (the equivalent of having the wires ("polarity", but term used loosely) reversed) can help matters, i've seen people do this with rear-facing subs, i also do it with my dash speakers - they fire at the windshield, and the sound bouncing off the windshield actually sounds better when they're reversed.

i'm pretty sure having them on the same plane means that the sub would be pushing air into the main listening "chamber" (ie, the cabin) on cone extension at the same time the other speakers would be. if your sub is in your trunk, this is unlikely to be true. with a sub though, it's really a trial and error thing - i for one know i'm not smart enough to mathematically figure out the phase of subwoofers (the wavelengths at sub-bass frequencies are massive) so whenever i'm putting one in i experiment with the phase and see what sounds best.

hope that long winded post helps.

**durwood** · 10-27-2006, 01:08 PM

Think of it in geometry terms. A plane is a flat surface. If your sub is mounted to the same flat surface with the rest of your speakers then everything is on the same "plane". In a car this is almost never true. Your sub is in the trunk and your other speakers are in the door for example. These are no where even near being mounted on a flat surface.

Just flip the switch in either direction and which ever gives you the most bass then leave the switch in that postion.

**Epon** · 10-27-2006, 03:37 PM

Well, no, you don't want to invert your phase and have your sub bumpin the inside of the box...

**IDOXLR8** · 10-27-2006, 07:18 PM

Originally Posted by Epon

Well, no, you don't want to invert your phase and have your sub bumpin the inside of the box...

You "Stang" Rocks!!! I saw you install Real Nice!!! AL.

**IDOXLR8** · 10-27-2006, 07:22 PM

Originally Posted by durwood

Think of it in geometry terms. A plane is a flat surface. If your sub is mounted to the same flat surface with the rest of your speakers then everything is on the same "plane". In a car this is almost never true. Your sub is in the trunk and your other speakers are in the door for example. These are no where even near being mounted on a flat surface.

Just flip the switch in either direction and which ever gives you the most bass then leave the switch in that postion.

I guess I have a little trouble undertanding this unless you are using multiple sources. AL.

**durwood** · 10-28-2006, 12:34 AM

Originally Posted by Epon

Well, no, you don't want to invert your phase and have your sub bumpin the inside of the box...

It does this anyway. A speaker moves in BOTH directions

Switching the phase 180 degrees inverts the signal. Its a timing thing. You can do the same thing just by reversing the negative and positive speaker leads.