speaker ohmage
By the speakers "ohmage" do you mean the DC resistance of the voice coil? Also called the " Re or Rvec". Or do you mean the impedance (Z) or it's opposition to AC current flow?
The impedance, or also called nominal impedance is the number thats on the back of the speaker ie: 8 ohm, 4 ohm etc. It can't be measured with an Ohmmeter.
The DC resistance, or Rvec is measured with an ohmmeter. The Rvec is always lower than the nominal impedance that's on the back of the speaker
Hope this helps;
Doug
By the speakers "ohmage" do you mean the DC resistance of the voice coil? Also called the " Re or Rvec". Or do you mean the impedance (Z) or it's opposition to AC current flow?
The impedance, or also called nominal impedance is the number thats on the back of the speaker ie: 8 ohm, 4 ohm etc. It can't be measured with an Ohmmeter.
The DC resistance, or Rvec is measured with an ohmmeter. The Rvec is always lower than the nominal impedance that's on the back of the speaker
Hope this helps;
Doug
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Maybe it would be easier if you tell us exactly what the application is. Do you have a schematic of a crossover that you are trying to adapt to your own speaker at home, and you don't know the impedance of the speaker in the crossover schematic? Is that it?
If so, do me a favor. Is there an inductor in series and a capacitor in parallel with the driver in the schematic? Can you give me the values for the inductor and the capacitor? Also, tell me-is there a resistor in series with the driver in question?
If you have a scanner, posting the schematic would help. GIF is the best file type for posting here.
Maybe it would be easier if you tell us exactly what the application is. Do you have a schematic of a crossover that you are trying to adapt to your own speaker at home, and you don't know the impedance of the speaker in the crossover schematic? Is that it?
If so, do me a favor. Is there an inductor in series and a capacitor in parallel with the driver in the schematic? Can you give me the values for the inductor and the capacitor? Also, tell me-is there a resistor in series with the driver in question?
If you have a scanner, posting the schematic would help. GIF is the best file type for posting here.
If the schematics have driver info, you just look up the impedance of the driver.
Basically, you go by the values on the crossover, if it comes to that. Try to find the crossover frequency. If it is not listed, then apply two formulas to find it:
The ohms for a capacitor = 1/(2 pi F C) where F = Frequency and C = Capacitor value in Farads. That is 1,000,000 uF.
Inductor ohms = 2 pi F L where F = Frequency, L = inductor value in Henries. That is 1,000 mH.
An element in a crossover is either an inductor or capacitor.
A 6 dB crossover will have the inductor and capacitor having ohmage = the impedance of the speaker. A 12 dB crossover will have the inductor and the capacitor with ohmage 1.5 times the value of the speaker.
So, if the speaker has one element in front of it in series, it is a 6 dB crossover, most likely. If it has one element in series in front of it, and one in parallel, it is a 12 dB inductor.
An 8 ohms speaker will have an element with 8 ohms at the crossover frequency. It will have elements with12 ohms at the crossover frequency for a 12 dB crossover.
Similarly, a 4 ohms speaker will have an element in series that has 4 ohms at the crossover frequency. It will have 2 elements with ohmage of 6 in a 12 dB crossover.
What is the crossover frequency? Well, you 'll just have to find the ohmage of the elements in the crossover, and see where it makes sense. Choose a likely crossover point-like 2500 Hz for a 2 way speaker-and just keep calculating the ohms of your elements until you hit a frequency and speaker impedance that makes sense.
That is the formula. Not easy, but it can be done if it has to be.
Of course, just because a speaker is rated 8 ohms doesn't necessarily mean that you can drop any speaker rated 8 ohms into the crossover and have it work well. there is a decent chance that it will, but no guarantees.
Basically, you go by the values on the crossover, if it comes to that. Try to find the crossover frequency. If it is not listed, then apply two formulas to find it:
The ohms for a capacitor = 1/(2 pi F C) where F = Frequency and C = Capacitor value in Farads. That is 1,000,000 uF.
Inductor ohms = 2 pi F L where F = Frequency, L = inductor value in Henries. That is 1,000 mH.
An element in a crossover is either an inductor or capacitor.
A 6 dB crossover will have the inductor and capacitor having ohmage = the impedance of the speaker. A 12 dB crossover will have the inductor and the capacitor with ohmage 1.5 times the value of the speaker.
So, if the speaker has one element in front of it in series, it is a 6 dB crossover, most likely. If it has one element in series in front of it, and one in parallel, it is a 12 dB inductor.
An 8 ohms speaker will have an element with 8 ohms at the crossover frequency. It will have elements with12 ohms at the crossover frequency for a 12 dB crossover.
Similarly, a 4 ohms speaker will have an element in series that has 4 ohms at the crossover frequency. It will have 2 elements with ohmage of 6 in a 12 dB crossover.
What is the crossover frequency? Well, you 'll just have to find the ohmage of the elements in the crossover, and see where it makes sense. Choose a likely crossover point-like 2500 Hz for a 2 way speaker-and just keep calculating the ohms of your elements until you hit a frequency and speaker impedance that makes sense.
That is the formula. Not easy, but it can be done if it has to be.
Of course, just because a speaker is rated 8 ohms doesn't necessarily mean that you can drop any speaker rated 8 ohms into the crossover and have it work well. there is a decent chance that it will, but no guarantees.
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