what are OHM?

Answer 1

Ohm's Law defines the relationships between (P) power, (E) voltage, (I) current, and (R) resistance. One ohm is the resistance value through which one volt will maintain a current of one ampere.


( I ) Current is what flows on a wire or conductor like water flowing down a river. Current flows from negative to positive on the surface of a conductor. Current is measured in (A) amperes or amps.

( E ) Voltage is the difference in electrical potential between two points in a circuit. It's the push or pressure behind current flow through a circuit, and is measured in (V) volts.

( R ) Resistance determines how much current will flow through a component. Resistors are used to control voltage and current levels. A very high resistance allows a small amount of current to flow. A very low resistance allows a large amount of current to flow. Resistance is measured in ohms.

( P ) Power is the amount of current times the voltage level at a given point measured in wattage or watts.

Answer 2

OHM is the unit for measuring the resistance in a circuit or component. In a stereo the output and speakers are rated in OHMS and should be matched. In other words if the unit has 4 Ohm outputs you must use speakers which are rated 4 Ohms. If you don't match the speakers to the outputs the efficiency of the unit will decrease, it will cause distortion and could result in damage to the speakers, the stereo or both.

Answer 3

In audio, the load (ohm = resistance = impedance) presented on the amp is what determines the output power of an amp in it's power range.

For example, this could be the specs for an amp:

400 watts RMS @ 4 ohm
800 watts RMS @ 2 ohm
1600 watts RMS @ 1 ohm

Just because an amp may be stable at 1 ohm, it doesn't mean it's best to load it it at that. It's always better to load an amp at higher impedance than lower as a higher impedance will cause the amp to run cooler, sound better and last longer.

If, for instance, you wanted 500 watts RMS for a system, it would be better to find an amp that's 500 watts RMS @ 4 ohm than 500 watts RMS @ 1 ohm as the THD (total harmonic distortion) increases the lower the impedances.

The selection of certain types of subs would allow you to run two subs with a 4 ohm load like so http://i81.photobucket.com/albums/j230/sparky3489/PARALLEL-SERIES.jpg

These are called DVC (dual voice coil) subs with two coils each. If each coil is 4 ohms, the rusulting impedance will be 4 ohms. Each sub would then need to handle 250 watts RMS as each sub will get half of the 500 watt RMS power output.

or

Two 2 ohm SVC (single voice coil, not usually denoted this way) subs wired like so http://i81.photobucket.com/albums/j230/sparky3489/SERIES.jpg would also present a 4 ohm load.

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Answer 4

ohms means resistance so the lower the ohms the louder the spaekers but the lower the ohm the more chances the speaker will blow if not that ohm capitable but ohm stands for resistance