Clarification on Watts-Speakers-Amps-Mixers

Discussion in 'Consoles / Control Surfaces' started by Kuroneku, Mar 6, 2015.

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  1. Kuroneku

    Kuroneku Active Member

    Mar 19, 2013
    Hello people
    The reason why I am creating this Thread is because there is a lot of confusion going on I believe, and I am not a professional on this Subject matter myself. So I'm hoping that somebody can break it down.

    Let's say if I have a Speaker with an output of a 1000 Watt. Then I would need, preferably, an Amp/Mixer that will give me an output of let's say 1500 Watt. Would that be accurate? We don't want to strain the Amp, correct?
    I read about a rule that says that the Amp should have at least 50% more Watt than the speaker.

    What if I have a Speaker that has a built-in amp, in that case I don't need a Mixer that has a built-in Amp, correct?

    For instance, I have an Alto 800 Watt 12 Inch speaker, and I love this speaker. I went ahead and bought a Mackie ProFx8, because I liked the value, the effects, and the amount of inputs etc.

    I don't have anything to worry about, or do I?

  2. DonnyThompson

    DonnyThompson Distinguished Member

    Nov 25, 2012
    Akron/Cleveland, OH
    Home Page:
    Not necessarily.

    First of all, amps don't kill speakers... people do. LOL. 9 times out of 10, it's an operator error that causes the amp to overdrive/clip, which in turn damages the loudspeaker.

    There are three main things that can cook a speaker.

    1. using too much power that exceeds the thermal rating of the speaker
    2. using too much power at too low of a frequency
    3. using too little power, where the amp can clip easily, which results in the amp sending maximum phase-forward power to the speaker before the speaker has a chance to cycle. This causes heat, which results in #1.

    If you have active speakers - - these are speakers with amplifiers built-in, then it's best to use the integrated amp with them because it's been matched and rated to work with that particular speaker.
    Many active speakers don't even have an input that allows them to be used with an external amp.
    For those that do, you need to be cautious - to make sure that the speaker is rated to "take" the external amplifier, in wattage, ohms, etc.

    There are other reasons that speakers can die... older speakers that have worn out over time, that may have been put through punishments of the road, or poor storage (moisture or humidity - or lack of) ; so the age of the speakers can be a factor.

    But generally, it's usually one of the three reasons listed above.

    kmetal and Kuroneku like this.
  3. Boswell

    Boswell Moderator Distinguished Member

    Apr 19, 2006
    Home Page:
    Loudspeakers don't have output powers, they have a maximum input power. So a speaker rated at 1000W r.m.s. continuous can be used with any amplifier, but, as Donny mentioned, you need to take certain things into account.

    (a) using a very low powered amplifier: it's going to sound pretty bad, but you are unlikely to do any harm to the speaker
    (b) using a reasonable but underpowered (e.g. <500W) amplifier: this can cause speaker damage due to the temptation to overdrive the amplifier producing high-powered distortion harmonics
    (c) using a matching power (1000 - 1500 W) amplifier: the preferred option, as long as you keep control of the overall volume
    (d) using a high-powered amplifer (>2000W): likely to cause speaker damage through excessive heating or transient excursion
    kmetal likes this.
  4. bouldersound

    bouldersound Real guitars are for old people. Well-Known Member

    Jan 23, 2010
    Boulder, Colorado
    Home Page:
    If you're trying to get more SPL than your speakers can produce you're likely to burn them up with just about any amp not way below their rating.

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