Terra Rysing Posted June 28, 2014 Report Posted June 28, 2014 I got a kenwood 6.5" component set which has a inline passive crossover going to the tweeters. When I measure the tweeter's impedance its 4.1 ohms. Then when connected with the passive its 0.5 ohms. WTF.
gckless Posted June 28, 2014 Report Posted June 28, 2014 Sounds normal, since you aren't measuring just the tweeter after it's connected. Where are you measuring after it's connected? "Clipping" is the biggest forum boner now. It's like witchcraft... it automatically explains just about everything people don't understand. My build log: http://www.stevemeadedesigns.com/board/topic/200295-gckless-2011-chevrolet-impala/ High resolution photos: Gilbert Kless Photography
Terra Rysing Posted June 28, 2014 Author Report Posted June 28, 2014 I have each pair wired to one channel and its at .5 ohms.
Krakin Posted June 28, 2014 Report Posted June 28, 2014 There are other components that could lower the overall resistance inside the crossover. I've never cared to measure mine, but I can on Tuesday when I get home. Krakin's Home Dipole Project http://www.stevemeadedesigns.com/board/topic/186153-krakins-dipole-project-new-reciever-in-rockford-science/#entry2772370 Krakin, are you some sort of mad scientist? I would have replied earlier, but I was measuring the output of my amp with a yardstick . . . What you hear is not the air pressure variation in itself but what has drawn your attention in the two streams of superimposed air pressure variations at your eardrums An acoustic event has dimensions of Time, Tone, Loudness and Space Everyone learns to render the 3-dimensional localization of sound based on the individual shape of their ears, thus no formula can achieve a definite effect for every listener.
Terra Rysing Posted June 28, 2014 Author Report Posted June 28, 2014 I first thought my tweeter protection was kicking in but the tweets and my 6.5's both quit playing. So I thought my amp may be going into protect, that's why I got out the ohm meter. I have them wired in parallel so I should have a 2 ohm load at my amp per each channel.
Stephen13 Posted June 28, 2014 Report Posted June 28, 2014 Impedance cannot be measured by an ordinary DMM or VOM. Impedance is an AC measurement that varies with frequency and is at it's highest at the resonant frequency of the driver. Resistance is a DC measurement. A 4Ω tweet connected in parallel with a 4Ω mid-woofer thru the passive X-over does not make a 2Ω load. Thanks to the X-over the tweet presents a 4Ω load to frequencies above the X-over point and the mid-woofer presents a 4Ω load to frequencies below the X-over point. Combined they make an overall 4Ω load. 2011 Chevy Silverado LT 5.3L 4x4 Ext.-cab "Enjoy yourself. It's later than you think."
audiofanaticz Posted June 28, 2014 Report Posted June 28, 2014 whoa, someone that understands that there is a difference between impedance and resistance and what that difference is!!!!!! PROPS!
Terra Rysing Posted June 28, 2014 Author Report Posted June 28, 2014 The kenwood component set does not have a crossover for the woofer it is just an inline for the tweet. Does that make a difference?
gr8handogoatness Posted June 28, 2014 Report Posted June 28, 2014 Impedance cannot be measured by an ordinary DMM or VOM. Impedance is an AC measurement that varies with frequency and is at it's highest at the resonant frequency of the driver. Resistance is a DC measurement. A 4Ω tweet connected in parallel with a 4Ω mid-woofer thru the passive X-over does not make a 2Ω load. Thanks to the X-over the tweet presents a 4Ω load to frequencies above the X-over point and the mid-woofer presents a 4Ω load to frequencies below the X-over point. Combined they make an overall 4Ω load. Dude nice. I didn't expect anyone to post this. This is correct. Impedance is not the same as DC resistance. Most likely what you were measuring was an inductor in the crossover.
Stephen13 Posted June 28, 2014 Report Posted June 28, 2014 No, the inductance of the woofer’s voice coil acts like a LPF at the speaker’s upper frequency response limit. You can see this in the manufacturer's frequency response curve. A typical 6.5” mid-woofer when run full-range will have a natural roll off in it’s upper response around 4kHz to 6kHz or so.If the lower limit of the tweet is say 2kHz you will have an area in the two response curves that overlap from 2kHz to around 4kHz. This small overlap area will have a lower impedance at or around 2Ω but the nominal impedance of the two combined drivers will still be 4Ω providing that both the tweet and mid are both 4Ω. 2011 Chevy Silverado LT 5.3L 4x4 Ext.-cab "Enjoy yourself. It's later than you think."
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