The power rating of a speaker is one of the most important factors you need to consider if you are planning to buy new speakers soon. This is often listed together with the other specifications of the device.
Unfortunately, many people are often unaware or even misunderstand the power specification. What they don’t realize is that it is crucial if you want to put together a good quality sound system.
When matching your speakers with amplifiers, learning more about these speaker power ratings is a must. What is nominal power in speakers, then, and how does it affect your choice of equipment?
Speaker Nominal Power Rating Defined
The “RMS” (root-mean-square) or nominal power rating refers to the amount of power that can be applied under normal circumstances to a speaker. One of the main factors that will determine the power rating of a particular speaker is its voice coil’s size.
Speakers with high-power ratings feature a large voice coil that allows the dissipation of more heat, thus allowing the application of more power to the speaker. This power rating is used to match the RMS capacity to the RMS output of an amplifier.
For instance, if your speakers have been rated to handle 50 watts RMS for each, make sure you choose an amplifier that delivers around 50 watts RMS to every speaker.
Speaker “Peak” Power Rating Defined
Another important power rating you should consider is the Peak or Max rating. This refers to the maximum amount of power applicable for shorter periods without causing any damage. When the peak power rating gets exceeded for a long period, it may pose the risk of deforming or overheating the voice coil.
It is important to avoid using this power rating to match speakers with amplifiers. This is only for informational purposes. Never match the RMS power rating of the speaker to the Max/Peak power output of an amplifier.
For instance, if the speakers have been rated to handle 50 watts RMS each then you choose an amplifier that delivers 125 watts RMS for each speaker, which means that you will be applying more power than what the speaker can handle. It can make the voice coil burn literally and even possibly short out which can render it inoperable.
Nominal Power vs. Peak Power Values
Once again, the peak or maximum power and the RMS or nominal power values are significant numbers you need to check. The specification should ideally make it clear, but it won’t most of the time.
For instance, if the 130-watts maximum power is nominal, the speaker can comfortably handle the peak power signal from an amplifier of approximately 300 watts.
But if the 130-watts value is the peak value or also known as the peak music power, it will be able to handle an average power of 70 watts.
This only goes to show that peak and nominal power values are two things that are completely different from each other. You must compare like with like if you need to match an amplifier’s power to a certain set of speakers.
It is important to always try to compare two peak values or two nominal values. Never be fooled into matching the nominal output for an amplifier to the speaker’s peak output.
If it doesn’t state if it is a peak or nominal value, it is safe to assume that it is the peak value since some manufacturers prefer giving the highest figure because it often sounds much better.
What are Maximum Power Ratings?
The maximum figure is more common, which refers to the power level that a speaker can handle before it starts to clip or distort. Ideally, you never go beyond this number.
You also need to remember that most of the numbers you will see in the specifications are usually a bit conservative. The truth is that you could go over these figures for shorter periods without experiencing any issues.
It means that if the specification of a speaker indicates 130 watts as its maximum power, you have to avoid hooking it to an amplifier with a rating of 1,000 watts output.
It is because it possibly will not take that much to get the amplifier to send beyond 130 watts and end up potentially damaging the speaker.
For this reason, provided that you take extra care when it comes to volume control, you will be able to pair any speaker set with any amplifier irrespective of its power. It will be much safer if you match the two of them a little bitter.
What are Minimum Power Ratings?
You might see the minimum value for the power every time you look at the specifications of a speaker. It refers to the minimum level of power required for driving the speaker to produce any useful sound or noise. This means that your amplifier needs to deliver at least this particular amount of power.
It shouldn’t be an issue at all and there is also no need for you to worry that much about these numbers, except if you plan to do something more extreme such as driving speakers with a rating of 500 watts with an amplifier rated with 10 watts.
Impedance and Power Specifications
Impedance and power specifications are two more areas that often confuse a lot of people. All the power ratings you see must be given to a specific load or impedance.
It means that if the amplifier rating offers 100 watts of nominal power into 8-ohm speakers, the nominal power it offers will be different when you attach speakers with 6 ohms.
Once again, you should only compare like with like all the time. When the power specifications of an amplifier are rated at 8 ohms, the power specs of the speaker must also be measured at 8 ohms once you compare them.
The Bottom Line
Learning the nominal power in speakers will not only ensure that you will enjoy wonderful sounds but at the same time, will also protect your equipment and keep them safe from unwanted damage.