vindeville Posted April 2, 2014 Share Posted April 2, 2014 Does selecting different taps on an autoformer in a "universal type network" effect midrange driver polarity, or does this stay constant regardless of tap selection? I would like to better understand this. are the combinations using the 0 tap more optimal in any way? has anyone done any testing in this regard? Quote Link to comment Share on other sites More sharing options...
mustang guy Posted April 2, 2014 Share Posted April 2, 2014 I'm having trouble wondering why you would expect a polarity change. Are you talking about dot convention? An autoformer is a single winding for impedance raising and lowering. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 2, 2014 Share Posted April 2, 2014 does this stay constant regardless of tap selection Yes. Quote Link to comment Share on other sites More sharing options...
vindeville Posted April 2, 2014 Author Share Posted April 2, 2014 I worded my question poorly I guess, what I am wondering is if the taps effect phase relationship in the network in some way causing the midrange to go out of phase with the other drivers. Do some tap combinations sound or measure better than others in anyones experience. Quote Link to comment Share on other sites More sharing options...
djk Posted April 2, 2014 Share Posted April 2, 2014 "I worded my question poorly I guess, what I am wondering is if the taps effect phase relationship in the network in some way causing the midrange to go out of phase with the other drivers." No. " Do some tap combinations sound or measure better than others in anyones experience." Yes, but it is specific to the actual drivers used, and the room. Quote Link to comment Share on other sites More sharing options...
babadono Posted April 9, 2014 Share Posted April 9, 2014 Does selecting different taps on an autoformer in a "universal type network" effect midrange driver polarity, or does this stay constant regardless of tap selection? I would like to better understand this. are the combinations using the 0 tap more optimal in any way? has anyone done any testing in this regard? Yeah I too want to make sure I understand this. Depending on which lead from the midrange driver goes to which tap it is possible to invert the phase of the signal to the driver, is it not? Quote Link to comment Share on other sites More sharing options...
djk Posted April 10, 2014 Share Posted April 10, 2014 Are you serious? Of course if you hook the wiress up backwards it reverses the phase. Quote Link to comment Share on other sites More sharing options...
jcmusic Posted April 11, 2014 Share Posted April 11, 2014 LOL!!! You guys are real funny sometimes, in short the autoformer is used to attenuate the mid driver. The phasing stays the same unless you connect the wires backwards!!! Quote Link to comment Share on other sites More sharing options...
mustang guy Posted April 11, 2014 Share Posted April 11, 2014 LOL!!! You guys are real funny sometimes, in short the autoformer is used to attenuate the mid driver. The phasing stays the same unless you connect the wires backwards!!! Just remember, phase and polarity are different things. Phase can shift slightly, polarity is 180 degrees or 0 degrees. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted April 11, 2014 Share Posted April 11, 2014 In ALK's "white" paper for his ESNs he states "The phase of the squawker needs to be determined by trial". He mentions a dip of 6db when wired one way, and reversing the wires corrected it. On all the ESNs I have built and used, including what I am using today, the squawker had to be reverse phased in order to get the max output. It's a simple test to figure it out. I have no idea about the universal network though. Quote Link to comment Share on other sites More sharing options...
babadono Posted April 11, 2014 Share Posted April 11, 2014 Are you serious? Of course if you hook the wiress up backwards it reverses the phase. Yep I'm serious and I'll bet my question and your terse answer helped the OP. Quote Link to comment Share on other sites More sharing options...
mboxler Posted April 11, 2014 Share Posted April 11, 2014 Interesting read on the ESN. I may give that at try. Regarding the Universal network. The crossover to the Mid driver is 2nd order Butterworth, which results in a 180 degree phase shift. The outputs to the Mid drivers are reversed to correct this. The autoformer is part of this filter, but has no affect on phase. Quote Link to comment Share on other sites More sharing options...
jcmusic Posted April 12, 2014 Share Posted April 12, 2014 LOL!!! You guys are real funny sometimes, in short the autoformer is used to attenuate the mid driver. The phasing stays the same unless you connect the wires backwards!!!Just remember, phase and polarity are different things. Phase can shift slightly, polarity is 180 degrees or 0 degrees. Sorry I should have said polarity. Quote Link to comment Share on other sites More sharing options...
jcmusic Posted April 12, 2014 Share Posted April 12, 2014 Interesting read on the ESN. I may give that at try. Regarding the Universal network. The crossover to the Mid driver is 2nd order Butterworth, which results in a 180 degree phase shift. The outputs to the Mid drivers are reversed to correct this. The autoformer is part of this filter, but has no affect on phase. Is there some way of knowing this for sure? Quote Link to comment Share on other sites More sharing options...
WMcD Posted April 12, 2014 Share Posted April 12, 2014 It is a difficult thing to answer. Generally we are talking about the phase relation of the actual acoustic output of the two drivers at the crossover point. All roll-off and roll-up amplitudes are accompanied by phase changes. The overall slopes in acoustic outputs (and phase) are caused by the crossover and the natural roll-off and roll-up of the drivers and the horns themselves. In phase issues, you also have to consider the effect of relative delay in the length of horns or just plain old offset of the driver voice coils. The combination of these factors is why it is very difficult to predict the extent to which acoustic outputs of the drivers will have some phase difference and how much. I built a two way horn system and there was a dip at the crossover point when the overall wiring was wired in phase (it did use an auto transformer). Reversing the mid solved it. The effect of the autotransformer tap depend on how the crossover is designed. Changing the tap changes the electrical impedance presented to components upstream such as the cap which feeds the autotransformer. Therefore the crossover point will change and therefore the magnitude and phase of the signal at the original crossover point. WMcD Quote Link to comment Share on other sites More sharing options...
Deang Posted April 12, 2014 Share Posted April 12, 2014 http://eaw.com/docs/6_Technical_Information/StudyHall_and_TechNotes/Polarity_and_Phase.pdf 1 Quote Link to comment Share on other sites More sharing options...
Axz Hout Posted April 12, 2014 Share Posted April 12, 2014 x Quote Link to comment Share on other sites More sharing options...
beeker Posted April 12, 2014 Share Posted April 12, 2014 Thats more info than anyone would had bargained for. I was joshed a couple times there. It was straight got a twist kept twisted and twisting again with eyes shut then untwisted exactly 4 times the second untwist eyes open and then was ready to go..maybe 5 times then 6 then ready 3 Quote Link to comment Share on other sites More sharing options...
Marvel Posted April 12, 2014 Share Posted April 12, 2014 (edited) This is the same document in a more user friendly language Weird, how did they mess with the font like that? Crazy! Edited April 12, 2014 by Marvel Quote Link to comment Share on other sites More sharing options...
Deang Posted April 12, 2014 Share Posted April 12, 2014 They both look the same using my iPad. Quote Link to comment Share on other sites More sharing options...
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