Is this true?
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Joined: Feb 2006
Posts: 16,860
In the same way a speaker has an input impedance (4ohms for example for an average speaker) an amplifier also has an input impedance, but it is more like 10,000 ohms or more.
If you know a little about ohms law or wiring speakers you know that two 4 ohm speakers wired in parallel will create a load of: (4*4)/(4+4)= 2 ohms. Well if you parallel a 4 ohm load with a 10,000 ohm load you get: (4*10000)/(4+10000) = 3.9984ohms which is essentially the same as before so your deck won't even notice the extra load.
If you know a little about ohms law or wiring speakers you know that two 4 ohm speakers wired in parallel will create a load of: (4*4)/(4+4)= 2 ohms. Well if you parallel a 4 ohm load with a 10,000 ohm load you get: (4*10000)/(4+10000) = 3.9984ohms which is essentially the same as before so your deck won't even notice the extra load.
50 Watt CAFz'r
Joined: Jan 2007
Posts: 221
In the same way a speaker has an input impedance (4ohms for example for an average speaker) an amplifier also has an input impedance, but it is more like 10,000 ohms or more.
If you know a little about ohms law or wiring speakers you know that two 4 ohm speakers wired in parallel will create a load of: (4*4)/(4+4)= 2 ohms. Well if you parallel a 4 ohm load with a 10,000 ohm load you get: (4*10000)/(4+10000) = 3.9984ohms which is essentially the same as before so your deck won't even notice the extra load.
If you know a little about ohms law or wiring speakers you know that two 4 ohm speakers wired in parallel will create a load of: (4*4)/(4+4)= 2 ohms. Well if you parallel a 4 ohm load with a 10,000 ohm load you get: (4*10000)/(4+10000) = 3.9984ohms which is essentially the same as before so your deck won't even notice the extra load.
I'm sure I understand where any confusion about LOCs is comming from..... and my last post dosen't really do justice to the situation....
what you should find inside an LOC is two small transformers and a couple resistors.... the transformers will have a primary winding that has basically zero DC resistance along with a ~10 ohm non inductive resistor with it in series, and a center tapped secondary...
The transformer is used to change the high level signal to a low level one, and the reistor is there to protect the deck and trasnformer windings at the moment the deck starts up and from DC offset.... (other wise the deck would see short)
This is probably where the confusion is comming from since measuring the DC resistance across the LOC's inputs would give a reading equal to the value of the resistor... it could be as low as 2ohms, but its probably more like 10ohms..... (anyone with some LOCs handy want to check?)
Anyway.. durring operation what we are interested in is the reflected impedance to the primary winding.... since the primary impedance to the secondary impedance is the square of the turns ratio if our LOC used 10:1 transformers an amplifier with a 10K ohm input impedance will actually present a 10 million ohm load to the deck........
something tells me that a 10000010 ohm load in parrallel with your stock speakers will be OK....
what you should find inside an LOC is two small transformers and a couple resistors.... the transformers will have a primary winding that has basically zero DC resistance along with a ~10 ohm non inductive resistor with it in series, and a center tapped secondary...
The transformer is used to change the high level signal to a low level one, and the reistor is there to protect the deck and trasnformer windings at the moment the deck starts up and from DC offset.... (other wise the deck would see short)
This is probably where the confusion is comming from since measuring the DC resistance across the LOC's inputs would give a reading equal to the value of the resistor... it could be as low as 2ohms, but its probably more like 10ohms..... (anyone with some LOCs handy want to check?)
Anyway.. durring operation what we are interested in is the reflected impedance to the primary winding.... since the primary impedance to the secondary impedance is the square of the turns ratio if our LOC used 10:1 transformers an amplifier with a 10K ohm input impedance will actually present a 10 million ohm load to the deck........
something tells me that a 10000010 ohm load in parrallel with your stock speakers will be OK....
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