Hartke KILO Owner's Manual

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Contents

Hartke KILO Owner's Manual Manual pdf 16 page image

16Choosing the Correct Speaker CabinetsWhen choosing a speaker cabinet to use with your Hartke Kilo, there are many specifi-cations to consider (impedance, power handling, frequency response, etc). While mostspecs are pretty straight forward, many people have difficulty understanding imped-ance. Basically, impedance is the amount of current that will flow through a speakerat a certain voltage. It is measured in Ohms. The actual impedance of a speaker is notconstant across all frequencies. So, for convenience we use the term “nominal imped-ance”, which refers to the impedance that a speaker presents to an amplifier at a refer-ence frequency.A typical speaker has an impedance rating of 4, 8, or 16 Ohms. Generally, the lower theimpedance of a speaker, the more power will be developed by a given amplifier. Forexample, a 4 Ohm speaker will extract more power from your amplifier than an 8 Ohmspeaker. If you connect a speaker with an impedance lower than the rating of the am-plifier’s output, the amplifier can overheat and damage the power output section. It isimportant to learn how to connect multiple speaker cabinets safely without damagingthe speakers or the amplifier in this way.As a general rule, amplifier speaker output jacks and speaker cabinet input jacks areconsidered “parallel” connections, and will follow the rules described in this section.When speakers are connected in parallel, the impedance is reduced. The formula tocalculate the total impedance of your speaker system is:1/Rt = 1/R1 + 1/R2 + 1/R3 + … 1/Rn. Where “R” is the impedance of a speaker cabinet.If all speakers have the same impedance, the total impedance will be equal to theimpedance of a single speaker divided by the total number of speakers. For example, ifyou have two 4 Ohm speakers connected in parallel, the total impedance is 4 dividedby 2, or 2 Ohms. You must be careful when connecting speakers in parallel to anamplifier. The impedance can quickly fall below safe levels. This is especially true whenconnecting speakers in parallel to a bridged amplifier.The Hartke Kilo has two independent amplifiers capable of 500 watts, to which youcan connect speakers with a minimum impedance of 2 Ohms. The amplifiers can bebridged together to deliver 1000 watts of power to a minimum 4 Ohm speaker load.When choosing speakers, make sure that they can match or exceed the outputpower of the amplifier, or you can damage the speakers.16Ω + 16Ω = 8Ω8Ω + 16Ω = 5.3Ω8Ω + 8Ω = 4Ω8Ω + 16Ω + 16Ω = 4Ω16Ω + 16Ω + 16Ω + 16Ω = 4Ω4Ω + 8Ω = 2.7Ω4Ω + 4Ω = 2ΩTypical Impedance Calculations