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I have a sub box in my wife's Bird with 2 subs in it. If they are wired in phase, they don't put out much sound. If you disconnect one of them, the sound at least doubles. If you hook one up out of phase, it gets a lttle louder still. Does this box need a port? Is there some other problem?
Thanks,
John
 

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lively said:
I have a sub box in my wife's Bird with 2 subs in it. If they are wired in phase, they don't put out much sound. If you disconnect one of them, the sound at least doubles. If you hook one up out of phase, it gets a lttle louder still. Does this box need a port? Is there some other problem?
Thanks,
John
I'm not a speaker expert, but i have done every car i own, except my current (got lazy). It sounds to me that your amp isn't getting enough power to support both subs. My friend has a huge box in his car (2 12'' subs) and he has the similar problems you are having. He told me the car itself isn't putting out enough power to support his sound system (Alternator is too weak).Whats really runny is his car actually reacts to the stereo being on and changes when it goes off. I never though electrical components could put such a strain on the engine. You'll need to boost the power somehow, this is where my knowledge ends since i have never had this problem wiring my systems.
 

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It sounds very much like they are not in phase. It may be that the labeling or red dot on the woofer basket identifying the positive terminal is incorrect. Sure fire test is to briefly connect a 9 volt battery to the terminals and see which way the woofer cone moves. 2nd possibility is that the amp is out of phase on one channel, probably intentionally. This is an old trick to reduce power supply fluctuations in the amplifier. Since most powerful bass is mono, running the channels out of phase dramatically smooths out the current draw on the rails. Naturally, connecting the woofers out of phase would be mandatory with such a scheme. Carver did it on the original POS cube. One channel, the black terminal was actually positive.
 

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The subs also could be wired incorrectly for resistance. Are the subs wired in series or parallel? The amp resistance also comes into play. Is your amp 2 channel or mono? If you have 2 channel is the amp bridged? There is so many scenarios. Give me the specs on each unit, like what is the stable resistance of the amp, how many channels on the amp, the ohm ratings of each sub. I can tell you how it should be wired from there. If you don't have that info, let me know model numbers of each..
 

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Discussion Starter #6
bob_50 said:
The subs also could be wired incorrectly for resistance. Are the subs wired in series or parallel? The amp resistance also comes into play. Is your amp 2 channel or mono? If you have 2 channel is the amp bridged? There is so many scenarios. Give me the specs on each unit, like what is the stable resistance of the amp, how many channels on the amp, the ohm ratings of each sub. I can tell you how it should be wired from there. If you don't have that info, let me know model numbers of each..
Thanks. Will try to post info later this evening.
 

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bob_50 said:
The subs also could be wired incorrectly for resistance. Are the subs wired in series or parallel? The amp resistance also comes into play. Is your amp 2 channel or mono? If you have 2 channel is the amp bridged? There is so many scenarios. Give me the specs on each unit, like what is the stable resistance of the amp, how many channels on the amp, the ohm ratings of each sub. I can tell you how it should be wired from there. If you don't have that info, let me know model numbers of each..

I would agree. It sounds as though they may be wired in a series not parallel on the same channel. If they are 4 Ohm speakers wired in series, they would present the amp with an 8 ohm load effectively halving the output of the amp. Be careful though if you wire them in parallel on 1 channel that will present the amp with a 2 ohm load. Too low for some amps. My best advice is to make sure the amp has 2 separate channels and wire one speaker to each channel. Also check the manual for any switches that my be on the amp for bridging or ohm balancing.

More info here:
http://www.usspeaker.com/speaker wiring-1.htm

http://www.installdr.com/TechDocs/999016.pdf
 
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