| This article gives information on | | | | (often refered to by the manufacturers as |
| understanding loudspeaker impedance | | | | being 2 Ohms Stable. However this application |
| (resistance) which is measured in ohms, and | | | | is rarely encountered since it would need 4x |
| how to match loudspeakers to a suitable power | | | | 8 Ohm Speakers to be connected to each |
| amplifier. | | | | channel to acheive this. |
| | | | |
| The information is relevant to any music | | | | Working out Ohms:- |
| system, including in car entertainment, Home | | | | |
| Cinema Systems, Band pa rigs and Mobile | | | | Most Music, Hi-Fi, Disco & P.A loudspeakers |
| Discos | | | | are rated at 8 ohms, so connecting one 8 ohm |
| | | | speaker to one channel of the amplifier will |
| A Channel on an Amplifier refers to the | | | | present a load of 8 ohms to it. |
| individual module or circuit inside the | | | | |
| amplifier which takes in a signal mono low | | | | However most automotive loudspeakers are |
| level signal and boosts it to drive a | | | | rated at 4 ohms. |
| loudspeaker(s). | | | | |
| | | | Plugging in an additional 8 ohm loudspeaker |
| All Stereo amplifiers have two Channels, one | | | | into either the existing connected speaker or |
| channel handles the left hand signal and | | | | the second socket on the same channel of the |
| speaker, the other obviously does the same | | | | amplifier (if fitted) will equal 8 ohm + 8 |
| for the right. Other than some amplifiers | | | | ohm = 4 Ohms load to the amplifier. |
| sharing the same power supply, the internal | | | | |
| Left and right channels or circuit boards are | | | | To get 2 ohms you would need to connect:- |
| seperate, which means in the event of a | | | | |
| loudspeaker problem or component failure the | | | | 8 Ohms + 8 Ohms + 8 Ohms + 8 Ohms = a 2 Ohm |
| opposite channel should continue to work. | | | | Load, so to get your amplifiers 2 Ohm rating |
| | | | you need to connect (4x) 8 ohm speakers to |
| Some Amplifiers used in home entertainment or | | | | it. |
| Home Cinema systems have four or five output | | | | |
| channels. These essentially work just like | | | | Given the fact that each channel is identical |
| stereo (2 channel) amplifiers, but use | | | | and seperate, your Amplifier has the |
| additional outputs to drive front and rear | | | | capability of running 4 x 8 ohm speakers per |
| loudspeaker pairs, and either a subwoofer or | | | | channel! - a total of 8 speakers - which is |
| center channel for surround sound | | | | why I said to ignore 2 ohm ratings when |
| applications. | | | | buying an Amplifier and concentrate on the 4 |
| | | | or 8 ohm wattage ratings!. |
| Okay - the load which determines how much | | | | |
| power your amplifier provides to the speakers | | | | 2 Ohms of load on the Amplifier can also be |
| is dependant on the actual number of speakers | | | | acheived by connecting (2x) 4 Ohm loudspeaker |
| connected and their individual impedance. | | | | cabs to the same channel. |
| | | | |
| The load is called the impedence, and the | | | | In Hi-Fi Applications, it is also common to |
| level of impedence is measured in ohms. Most | | | | find 6 ohm and 4 ohm loudspeakers for sale in |
| hifi and low power PA amplifiers will only | | | | the marketplace. If your amplifier is rated |
| work to a minimum of 4 Ohms however some | | | | at 4 ohms minimum load, then it is wise to |
| professional PA or Disco amplifiers such as | | | | just connect a single speaker to each channel |
| Peavey, and QSC etc and some powerful car | | | | to avoid overload. |
| amplifiers will work into a 2 Ohms load | | | | |