Phase problem. Help!!
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TECH Regular
Joined: May 2005
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Phase problem. Help!! Ok, I just got the milhouse box from Subthump, and noticed with some songs that have higher mid-bass, the subwoofer (JL Audio 12W3v2) and main speakers (Kenwood components in front, 2-ways in rear) sound like they are out of phase. This is with the subwoofer hooked up normally (+ to +, - to -). Disconnect the sub, I hear midbass from the speakers as it should. Reverse polarity with the sub firing into the well, the phase problem seems to be gone. Little loss on the bottom end (not enough to care), sounds fine. But, if I flip the box up to make room for the t-tops, the system sounds better if I switch the polarity back to normal. Any ideas on why this is happening? Is it my subwoofer or my main speakers that are reversed polarity? How can I tell? Thanks.
TECH Senior Member
Joined: Apr 2004
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From: Texas
One way to tell is to take a SMALL battery and touch the leads going to the speaker (+ to +, - to -). If the speaker moves outward then that is correct. Make sure that both subs move out on the positive pulse. Some cars with some subs create dead spots, expecially if the ports are ported on different areas in the car.
Thread Starter
TECH Regular
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I only have one 12" sub. I have plenty of deep bass, but when the mid-bass notes kick in, it sounds like the sub is working against the main speakers. This is with everything + to +, - to -. I reverse the polarity on the sub, it sounds normal, like the sub is working with the main speakers. Then, with the box flipped up (firing into the glass) and sub reverse polarity, the midbass problem comes back. The sub and main speakers then sound better with the sub + to +, - to -.
Just trying to figure out what I need to swap polarity with. The sub or the other speakers. Also, will using the wrong polarity on the sub damage it? Thanks.
Just trying to figure out what I need to swap polarity with. The sub or the other speakers. Also, will using the wrong polarity on the sub damage it? Thanks.
Launching!
Joined: Mar 2005
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From: H-Town
As long as everything is phased the same, you won't blow anything just from having the + wire on the - terminal. Also, having them all the same means you won't have the problem you're having right now. I'll give you props - lots of people wouldn't even notice a difference. What I'd do at this point is ensure that there are no phase switches or buttons on the amp(s) that are messing you up. Then, make absolute certain that everything is wired the way it should be. Somewhere, you've got something outta phase, and that's why you're experiencing what you are. Sounds to me like at least the rears (possibly fronts as well) are outta phase.
Thread Starter
TECH Regular
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I checked all the wires, everything is hooked up properly (+ to +, - to -). Subwoofer also + to +, - to -. Like I said, seems to vary when I flip the box up vs. down.
This is with the subwoofer preout phase set at normal.
This is with the subwoofer preout phase set at normal.
Last edited by Jeff 97 Formula; May 23, 2005 at 10:01 PM.
Staging Lane
Joined: May 2005
Posts: 57
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From: Moses Lake, WA
Originally Posted by Jeff 97 Formula
Does it matter that I have everything crossovered at 80hz? (LPF for subwoofer, HPF for all main speakers)? Thanks.
