How to determine polarity of speakers

[Rod]

I suspect that the 3-way Alpine SPX speakers that I had installed are
not all in phase. Normally, to test polarity, I'd hook a 9volt battery
up to the speaker wires normally going into the amp. Each speaker
should either pop out or pull in, but all should do the same thing,
assuming positive and negative are hooked up correctly.

HOWEVER, these 3way speakers have not one but two crossovers that like
to absorb the 9v and prevent the speakers from moving.

How else can I test the polarity? Do I simply need to add more 9volts
into the equation, and if so, how many, and how many would it take to
accidentally fry my crossovers?

Thanks!

[MZ]

> I suspect that the 3-way Alpine SPX speakers that I had installed are
> not all in phase. Normally, to test polarity, I'd hook a 9volt battery
> up to the speaker wires normally going into the amp. Each speaker
> should either pop out or pull in, but all should do the same thing,
> assuming positive and negative are hooked up correctly.
>
> HOWEVER, these 3way speakers have not one but two crossovers that like
> to absorb the 9v and prevent the speakers from moving.
>
> How else can I test the polarity? Do I simply need to add more 9volts
> into the equation, and if so, how many, and how many would it take to
> accidentally fry my crossovers?

There are high pass crossovers in series with the woofers too?

Another way to do it would be to listen to the bass response, reverse the
leads of one speaker, and listen to the bass response again. Usually, but
not always, the bass response will be substantially higher when the two
speakers are in phase with each other.

A third way to do it would work if you have a simple voltage meter -
preferably an analog meter (I tend to say that a lot), but it usually works
with a digital meter as well. If you have access to the speaker wires
somewhere, either at the back of the radio or the amplifier (depending on
what it's hooked up to), you can measure the sign of the induced voltage
when you press the speaker cone. In other words, push the cone in (not so
far that you damage something) reasonably fast - the faster, the higher
voltage you'll measure - and have a friend watch the meter. Pushing it in
should make the needle either go positive or negative, and letting it out
should make it go in the opposite direction. Make sure it matches for both
speakers.

[joe.ker]

"Rod" > wrote in message
...
>I suspect that the 3-way Alpine SPX speakers that I had installed are
> not all in phase. Normally, to test polarity, I'd hook a 9volt battery
> up to the speaker wires normally going into the amp. Each speaker
> should either pop out or pull in, but all should do the same thing,
> assuming positive and negative are hooked up correctly.
>
> HOWEVER, these 3way speakers have not one but two crossovers that like
> to absorb the 9v and prevent the speakers from moving.
>
> How else can I test the polarity? Do I simply need to add more 9volts
> into the equation, and if so, how many, and how many would it take to
> accidentally fry my crossovers?
>
> Thanks!

How is the amp hooked up to the head unit? What brand head unit is it?
I suspect you have the amp hooked to a factory radio and the input may be
out of phase.
The Alpine xovers should have different size connectors for + & - so it
should be hard to hook them up out of phase to an amp.
The easiest way to test if there out of phase is to fade the head unit to
just those speakers. then balance the head unit from left to right.
if the bass increases when you are all the way left or all right and
decreases when balance is in center, then the speakers are out of phase.

[Chad Wahls]

"Rod" > wrote in message
...
>I suspect that the 3-way Alpine SPX speakers that I had installed are
> not all in phase. Normally, to test polarity, I'd hook a 9volt battery
> up to the speaker wires normally going into the amp. Each speaker
> should either pop out or pull in, but all should do the same thing,
> assuming positive and negative are hooked up correctly.
>
> HOWEVER, these 3way speakers have not one but two crossovers that like
> to absorb the 9v and prevent the speakers from moving.
>
> How else can I test the polarity? Do I simply need to add more 9volts
> into the equation, and if so, how many, and how many would it take to
> accidentally fry my crossovers?
>
> Thanks!

That crossover has a cap in series with the woofer!?

Chad

[GregS]

In article >, "Chad Wahls" > wrote:
>
>"Rod" > wrote in message
...
>>I suspect that the 3-way Alpine SPX speakers that I had installed are
>> not all in phase. Normally, to test polarity, I'd hook a 9volt battery
>> up to the speaker wires normally going into the amp. Each speaker
>> should either pop out or pull in, but all should do the same thing,
>> assuming positive and negative are hooked up correctly.
>>
>> HOWEVER, these 3way speakers have not one but two crossovers that like
>> to absorb the 9v and prevent the speakers from moving.
>>
>> How else can I test the polarity? Do I simply need to add more 9volts
>> into the equation, and if so, how many, and how many would it take to
>> accidentally fry my crossovers?
>>
>> Thanks!
>
>That crossover has a cap in series with the woofer!?
>
>Chad

Not sure what the tester can't do. I have had to use high magnification
at times to watch tweeter move, but it works.
Some 9 volt batteries are cheaply made, not having welded connections,
but but end connections between cells. The internal resistance of these is poor to
bad. A 1.5 volt cell is all that required.
Even when you can't see the speaker, polarity testing is easy by
comparing two or more drivers sound.


greg

[Vivek]

Great insight!

--
The best is yet to come
V

"MZ" > wrote in message
...
> A third way to do it would work if you have a simple voltage meter -
> preferably an analog meter (I tend to say that a lot), but it usually
works
> with a digital meter as well. If you have access to the speaker wires
> somewhere, either at the back of the radio or the amplifier (depending on
> what it's hooked up to), you can measure the sign of the induced voltage
> when you press the speaker cone. In other words, push the cone in (not so
> far that you damage something) reasonably fast - the faster, the higher
> voltage you'll measure - and have a friend watch the meter. Pushing it in
> should make the needle either go positive or negative, and letting it out
> should make it go in the opposite direction. Make sure it matches for
both
> speakers.

[Rod]

Thanks for the input, all.

I have listened to special bass test tones that go in and out of
phase, but that only demonstrates if left and right speakers are in or
out of phase. It's useless for judging if a pair of woofers in just
the left side or just the side are in/out phase. The only way is to
use your ears, or my RTA.

Speaking of which, my RTA indicates the right set of 3-way speakers
has 15db higher bass response around the 75-150hz region than the left
set. And the left set actually has a nasty 15hz dip centered around
90hz that I can NOT remove using internal or external EQ's in my
system. That indicates an out of phase woofer set to me.

I found the following item on Monster Cable's site:

http://www.monstercable.com/productPage.asp?pin=534

This would be an invaluable tool for home audiophiles and especially
good car audio shops (which is why none around here have one!). But
it's $150.00, which is a steep price to pay just to prove my shop
****ed up my install. Anyone use this device, and if so, is it worth
it? Supposedly it can even check TWEETER phasing, which i've never
been able to pull off with batteries or listening.

Hell, I can't even find a car audio shop that has an RTA!!! What has
this pathetic world come to?!?!??! "Duhhhh... can you put some big
beats into my Cadillac??? Duhhhhh"