Author Topic: C300z - phase inverted?  (Read 1258 times)

lightguy48

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C300z - phase inverted?
« on: June 19, 2014, 02:01:06 AM »
Just curious if anyone has ever run a phase test on these cabinets.

When I tested mine, compared against a Yorkville and a Peavey cabinet my speaker 'pinger' always tests it as being out of phase compared to other speakers.

I'm thinking I should just swap the wires on all of the speaker leads internal to the cabinet.

Greg C.

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Re: C300z - phase inverted?
« Reply #1 on: June 23, 2014, 07:53:14 PM »
Just curious if anyone has ever run a phase test on these cabinets.

When I tested mine, compared against a Yorkville and a Peavey cabinet my speaker 'pinger' always tests it as being out of phase compared to other speakers.

I'm thinking I should just swap the wires on all of the speaker leads internal to the cabinet.

What polarity tester are you using? Do have a pair or just a single c300? When testing polarity of a full range cabinet, you have to be careful since all drivers are going at once and you can get false readings. The only way to be certain the the entire cabinet/both drivers have reversed polarity is to test each driver one at a time. So you'll need to open up the cabinet and disconnect the horn and test just the woofer. Then disconnect just the woofer and test the horn. If they're both on at the same time, the output of one driver might overpower the other even if you have the polarity checkers mic aimed at the driver you're trying to check.
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lightguy48

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Re: C300z - phase inverted?
« Reply #2 on: June 28, 2014, 09:50:21 PM »
Well I performed an old fashioned test with a AA battery comparing to several speakers that tested 'in phase' and they all tested the same, + to the + pushed the woofer out, so I'm not sure why my AudioTools Speaker Polarity tester is showing inverted.

I'm going to have to send them an email and see what they say.

Greg C.

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Re: C300z - phase inverted?
« Reply #3 on: June 28, 2014, 11:37:43 PM »
Well I performed an old fashioned test with a AA battery comparing to several speakers that tested 'in phase' and they all tested the same, + to the + pushed the woofer out, so I'm not sure why my AudioTools Speaker Polarity tester is showing inverted.

I'm going to have to send them an email and see what they say.

What about the horns? It could be the one box has inverted polarity just on the horn (which will cause a frequency "suck out"  from cancellation in the crossover area). The visual battery test won't work for that. If you contact the app guys, they're probably just going to tell you that polarity testing on 2 drivers at the same time will give sketchy results.

P.S. phase is not the correct term when referring to polarity.
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lightguy48

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Re: C300z - phase inverted?
« Reply #4 on: June 30, 2014, 03:08:18 AM »
Except why would my Yorkville's and some old Crate cabinets all show the polarity was correct?

Just odd....


Greg C.

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Re: C300z - phase inverted?
« Reply #5 on: July 15, 2014, 05:48:13 PM »
Except why would my Yorkville's and some old Crate cabinets all show the polarity was correct?

Just odd....

Every cabinet design is different. Driver spacing and horn design will affect how the overlapping frequencies interact in terms of phase which can trick the close up mic used by the polarity tester. I'll just say again that the only way to get truly reliable polarity testing is to test one bandpass at a time with the adjacent one(s) turned off.
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