How Many Watts Should a Good Speaker Have?

by Andrew Bishop

Measuring and comparing a PA speakers performance can be difficult and many are misled by wattage figures that are merely numbers without any letters. Always ask for the RMS rating.

What Does RMS mean for speakers?

RMS stands for "Route Means Square". The RMS rating is the industry standard of professional speaker and transducer manufacturers. The true RMS is the measurement that a speaker will consistently deliver over many hours during playback.

A good full range RMS rating for a DJ or band playing to an audience of 200 people inside is 300w on the left speakers and 300w on the right. This will be a point source speaker system which are speakers cabinets on the floor or stage or on stands.

Don't be fooled by exaggerated ratings; remember:

300w RMS = 600w Program Power = 1,200w Peak Power. 

A 300w RMS speaker will delivery 1,200w of power but only for a nanosecond in a track such as initial cymbal crashes.

Top Tip - Always buy, measure and specify speakers using the SPL rating (Sound Pressure Level). The SPL reading is the genuine output of the speaker taking into full consideration of the internal components such as the LF woofer and HF driver combined with the intelligent cabinet design, porting, baffles, material and volume.

To learn more about SPL visit - How to measure speaker volume - RMS or SPL – BishopSound

How Can You Tell if Speakers Are Full Range?

Most full range speakers are 2-way which means they have a low frequency (LF) woofer or driver and a high frequency (HF) driver in a horn. These configurations are often hidden with a protective speaker grill. LF drivers are normally 8", 10", 12", 15" in a full range PA speaker cabinet. Full range speakers give a very full clear sound. Add a subwoofer speaker for more bass.

What is a horn tweeter speaker?

A tweeter is the name given to the high frequency driver because, allegedly, it delivers similar frequencies to some bird song. The best way to deliver high frequencies (1kHz - 20kHz) is with a compression driver with titanium dome. Try to avoid a Piezo tweeter as they are very cheap and deliver harsh often bitter high frequencies that are hard on the ear.

Do you you need a speaker processor?

When you are adding dedicated subwoofers to your full range passive speaker cabinets its time to split the mid high frequencies from the sub bass frequencies. The cut off point is normally around 98 - 105Hz which means the sub takes care of everything around 100Hz and less making the full ranges speakers more refined, clear and efficient.

The speaker processor often called the speaker management processor or crossover tells the amplifiers which frequency to send to which passive speaker. The resulting full range sound brings clarity and punch to you PA system and prolongs the life of the internal components.

Passive speaker systems sound far superior to active systems. Some of the major benefits are they give more control and you never have to run mains cables next to signal cables.

Remember Active or Powered speakers are fairly new on the PA speaker scene and are always a compromise. How do you tell if a speaker is active or passive? Simply, at a glance you will see a mains cable, IEC (kettle lead socket) or blue PowerCon socket on the back.

For unbiased advice on speakers and the chance to ask any question relating to PA speakers never hesitate to use BishopSound livechat and our engineers will answer promptly.