QuestionQUESTION: i have a 300 watt rms (@2ohms) mono amp and im planning on buying a kicker 12' solar barac sub that's 600 watts rms, can my amp be able to power this sub nice running @2ohms even though its got twice the rms on the amp or should i be concerned if the amp could take it? (mind the fact that this is an mtx thunder series amp)
ANSWER: I need to know more about the speaker you are using to give an intelligent answer. If it is a dual voice coil (most kickers are) then you must tell me how it is wired; series or parallel.
But, the answer, if the impedances are matched, is NO. The amp rating and the speaker ratings do not have to be matched. If the amplifier has greater output than the speaker is rated for then you must be careful with the volume control and avoid overdriving it into distortion. If you overpower it you can certainly damage it. My experience with kicker driver is that when you are over driving you can tell obviously by the distortion and stress in the sound coming out.
And,not related, but there is no such thing as rms power. I know everybody uses it but it is still wrong. Voltage and current come in rms values, but power does not. When an rms voltage is applied to a speaker voice coil it consumes average power, not rms power. Just a comment from an engineer who reads textbooks!
Let me know if there is more to your question.
C
---------- FOLLOW-UP ----------
QUESTION: the sub is dvc and its preloaded from factory in box for 2ohm operation, i guess where i was trying to get at was if the amp could bump this sub hard enough being rated much lower than sub or if getting a sub near the amps level of power handling would make a difference in the sound performance. basically i'm wondering if the amp is able to drive the sub near its optimal performance. and thanks for clarifying about the rms thing, i didn't even know.
AnswerThank you.
Yes, I understood your question clearly. For us audio purists we always want lots of amplifier power. Here is the thinking; we don't want the amplifier to start crapping out before or near the peak rating of the speaker power. Rather, we want to drive the speaker up to it limits with the cleanest power possible; hence if the amplifier is coasting then we will get the maximum performance out of the speaker. But there are other considerations which I offer for your consideration:
ONE: Speaker power rating methods are very nebulous as opposed to amplifier power which is very objective and precise. There is no universally accepted method for testing loudspeakers. Actual power ratings have several components to their testing as outlined below.
TWO: Further, loudspeakers handle power in different ways. At very low frequencies it is excursion limited; that is over-drive is from hitting it too hard at low frequencies and breaking the suspension components such as the spider and surrounds or bending the bottom of the voice coil form. At higher frequencies it is a heat related matter. Since the voice coil is somewhat inductive the impedance rises with frequency and the amount of power input is less and therefore the heat factor. Much of the power handling is a function of the electromechanical design of the magnet, plates, pole-piece, voice coil form, basket and spider elements.
THREE: The long-term build up of heat is another factor; if you are playing continuously music which is highly synthesized and has a very high heat value it is harder on the voice coil than pure music such as classical or even pop that is properly mixed. The peak to average acoustic or music power is very high in most most music, but synthesized music is like playing pure sine-waves and the peak to average power is very low.
Therefore, the power rating of loudspeakers is a number chosen by the manufacturer which is hoped to be safe. It is an average of various considerations tested and assumed by the manufacturer - and then adjusted for marketing reasons by the marketing department!
You should be careful in playing your system and when you hear clatter or clapping or any distortion of any kind you know you are driving it too hard and you should back off.
Now, a final comment. Under powered amplifiers are just as dangerous as over powering. Here is why. Let us assume a speaker is rated at 500 watts input but the driving amplifier is only rated at 400 watts. That means you can drive the amplifier to full power and not worry. Right? Wrong. Why? Because if the amplifier is over driven to a flat top square wave the high power transients and harmonic structure of the highly distorted output from the amplifier can cause rapid burn out of the speaker. This is especially true with tweeters. It is not as much of a problem with subwoofers, but still, you should not be underpowered in a quality system.
Hope this all makes sense to you.
C
