10 ohm vs. 4 ohm speaker
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
Originally Posted by BanGnGearS
"Ohm
The measure of resistance in a circuit to the flow of an electric current. The greater the ohm value the more difficult it is for current to flow through a given circuit. Conversely, a low ohm value represents a low resistance and the easy flow of current through a circuit.
Ohms are often used in reference to loudspeakers which have a certain level of resistance associated with them. A typical speaker may have an ohm rating (rating the speaker's resistance) of 4 to 8 ohms nominal impedance (impedance being resistance to current flow). Resistance in a speaker varies, however, from low ranges often as low as 2 or 3 ohms to high ranges as high as 30 or more ohms.
As speaker impedance decreases, more current flows and the amplifier is called upon to output more power to the speaker. When shopping for speakers and amplifiers, make sure the amplifier is able to output power properly into the speakers' impedance. Many receivers are not able to operate properly with speakers having impedance loads of less than 8 ohms. While most separate amplifiers can handle lower impedance loads down to 4 ohms or less, some speakers present impedances of 1 or 2 ohms at their minimum requiring particularly robust and powerful amplifiers designed for such loads. Generally, most any separate amplifier will be able to properly power almost any speaker (with the few exceptions being in most cases highly-exotic, very expensive speaker designs) while receivers should be mated with speakers having nominal impedances (average impedances) of around 8 ohms."
This article gives a pretty good description of what is happening. In other words as the resistance (OHMs) drops, the speaker is allowing more current to flow from the amp. Underpowered amps may not be able to supply the necessary current allowed by the speaker. I often use the analogy of a water hose: Given the same amount of water pressure (Power) to a small diameter hose (say 1/2 inch diameter) the flow of water (current) will come out pretty forcefully. Given the same amount of water pressure on a 4 inch diameter hose the flow of water comes out with much less force. The larger hose has created less resistance. To get the same force with less resistance you need to increase the pressure at the source. So a speaker with less resistance (lower OHMs) needs more power to operate correctly.
The measure of resistance in a circuit to the flow of an electric current. The greater the ohm value the more difficult it is for current to flow through a given circuit. Conversely, a low ohm value represents a low resistance and the easy flow of current through a circuit.
Ohms are often used in reference to loudspeakers which have a certain level of resistance associated with them. A typical speaker may have an ohm rating (rating the speaker's resistance) of 4 to 8 ohms nominal impedance (impedance being resistance to current flow). Resistance in a speaker varies, however, from low ranges often as low as 2 or 3 ohms to high ranges as high as 30 or more ohms.
As speaker impedance decreases, more current flows and the amplifier is called upon to output more power to the speaker. When shopping for speakers and amplifiers, make sure the amplifier is able to output power properly into the speakers' impedance. Many receivers are not able to operate properly with speakers having impedance loads of less than 8 ohms. While most separate amplifiers can handle lower impedance loads down to 4 ohms or less, some speakers present impedances of 1 or 2 ohms at their minimum requiring particularly robust and powerful amplifiers designed for such loads. Generally, most any separate amplifier will be able to properly power almost any speaker (with the few exceptions being in most cases highly-exotic, very expensive speaker designs) while receivers should be mated with speakers having nominal impedances (average impedances) of around 8 ohms."
This article gives a pretty good description of what is happening. In other words as the resistance (OHMs) drops, the speaker is allowing more current to flow from the amp. Underpowered amps may not be able to supply the necessary current allowed by the speaker. I often use the analogy of a water hose: Given the same amount of water pressure (Power) to a small diameter hose (say 1/2 inch diameter) the flow of water (current) will come out pretty forcefully. Given the same amount of water pressure on a 4 inch diameter hose the flow of water comes out with much less force. The larger hose has created less resistance. To get the same force with less resistance you need to increase the pressure at the source. So a speaker with less resistance (lower OHMs) needs more power to operate correctly.
If you have the 4 ohm speakers and want to use them; and your amp calls for 10 ohm speakers - put a healthy (maybe 5 Watt) 6 ohm resistor in series with each + side feed. The volume won't be as high as it would be if you used 10 ohm speakers, but you won't burn out your amp.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Here's the best advice. If your stock stereo wants 10 ohm speakers...provide them for it. If you replace teh stereo with a mroe modern stock replica, and it likes 4 ohm speakers, get 4 ohm. It's that simple. Rigging it to work with a speaker it wasn;t designed for is bad news.
