What are watts?

Watts

Watts are a measurement of electrical power that determines how much energy is used or produced each second. When it comes to speakers, wattage tells you how much power an amplifier can transmit and how much a speaker can handle before distorting or sustaining damage.

Think of it like a car engine, just because an engine has a high horsepower rating doesn’t mean the car will be faster if the rest of the components aren’t efficient. The same goes for speakers, high wattage doesn’t automatically mean high volume.

Peak vs. RMS power

Manufacturers often provide different wattage ratings, the most common being RMS (Root Mean Square) and Peak Power.

• RMS Power measures the continuous power a speaker can safely handle over time. It’s typically about 70% of the peak power rating.
• Peak Power, sometimes called Max Power, refers to the highest power level a speaker can briefly manage before distortion or damage occurs.

While peak power may seem impressive, RMS is the better indicator of a speaker’s actual capability.

Does wattage still matter in modern sound systems?

In the past, when most PA systems were separate passive speaker cabinets driven by external amplifiers, peak power and RMS were essential for matching amp power and speaker capacity. These measurements helped ensure that an amplifier had enough headroom to drive the speaker safely without clipping and that the speakers could handle the amplifier’s signal volume.

While this principle still applies to passive PA systems, it’s not as crucial for modern active speakers, where the amplifiers and speaker drivers are already matched by the manufacturer.

Many modern PA speakers use Class D amplification, DSP processing, and contemporary design features that contribute to higher output efficiency, essentially rendering RMS ratings less important. However, many manufacturers still include them in the specs as a rough guide to how the speaker will perform.

To get a more accurate idea of how loud a speaker will be, you should consider factors like elevation, output angle and arc, and Sound Pressure Level (SPL).

Wattage doesn’t equal loudness!

It’s a common myth that higher wattage means a louder speaker. Wattage alone doesn’t determine volume, loudness is actually measured in decibels (dB).

Decibels (dB)

Decibels measure loudness on a logarithmic scale. Every 10dB increase sounds roughly twice as loud to the human ear. For example:

• 70dB is about as loud as a vacuum cleaner.
• 80dB feels twice as loud and is comparable to a police siren at close range.

Speakers are typically tested for decibel output at a distance of one metre from the sound source.

Sound Pressure Level (SPL)

SPL – or sensitivity – measures a speaker’s efficiency and is recorded as dB per watt at a one-metre distance. A speaker with a higher sensitivity rating will produce more volume with less power.

For example:

• A low-wattage speaker with high sensitivity can sound louder than a high-wattage speaker with poor efficiency.
• A 3dB increase in SPL means a speaker is roughly twice as loud at the same power input.

This is why a well-designed, low-wattage speaker can sometimes be louder than a high-wattage one in real-world situations.

Does speaker size affect volume?

Speaker size mainly impacts bass response, not overall loudness. Bigger speakers typically have larger drivers and woofers, allowing them to move more air and produce deeper, more powerful low frequencies. That’s why floor-standing and PA speakers tend to have better bass than compact monitors or portable speakers.

However, size alone doesn’t dictate loudness or sound projection. A small, highly efficient speaker with a powerful amplifier can sometimes be louder than a larger speaker with poor efficiency.

For instance, a 15-inch woofer might not project sound as effectively as a 12-inch woofer with higher sensitivity and better power handling.

Other factors that affect loudness

As you’ve probably guessed by now, there are lots of variables to ensure you have a good quality sound for your whole audience. In this section, we will briefly explore four more factors to consider when choosing a PA system and setting it up in the venue or space.

Speaker placement

When setting up speakers, it’s important to factor in height, angle, and arc. The arc and elevation of your speaker’s output are crucial when it comes to how sound is distributed throughout the room, and speaker placement can significantly affect loudness for people in different areas.

Placing speakers against a wall or in a corner can boost bass, while placing them too close to soft furnishings can absorb sound and reduce clarity. For PA systems, speakers should be elevated to project sound evenly across a room.

In stereo setups, keeping speakers at ear level and ensuring proper spacing improves sound distribution. Poor placement can make even a high-wattage speaker sound weak, so consider height, distance, and room layout when setting up.

Event space acoustics and size

The way sound behaves in a room impacts loudness and clarity. Hard surfaces like tiles and glass reflect sound, making a room sound louder but also more echoey. Soft materials like carpets and curtains absorb sound, reducing volume but improving clarity.

In large or open spaces, sound disperses more, requiring speakers with higher sensitivity and power. If a room has poor acoustics, using acoustic panels or adjusting speaker positioning can help balance the sound.

Crowd density

In a room full of people, sound can get swallowed up easily by the crowd, furniture, and any other obstacles. You should take into consideration how many people are going to be in the event space. If you have a narrow but long space, you may want to incorporate delay speakers that project sound to people at the back of the room.

Instruments, sound source, and processing

If you’re plugging in a full band (drums, bass, guitar, keyboards, vocals), you’ll need higher-output speakers, possibly with a subwoofer for extra bass. You will also want to position your speakers so the audience watching can perceive the sound originating from the stage. Also, EQ adjustments can enhance clarity and cut unwanted frequencies, providing an even better sonic picture for your audience.

How to choose the right speaker for your venue

Choosing the right speaker depends on the size of your space, the type of event, and the sound coverage needed. Here’s a breakdown of suitable speakers for different venues:

House party or small gathering

For a small party at home, you’ll likely want a compact PA system, which will fit in with your furniture. You may want a couple of inputs for extra mics or instruments.

Here are some recommended PA systems for home use:

• SubZero P8 Portable PA Speaker with Bluetooth & Wireless Mic – This is a small, easy-to-use PA speaker, that also includes a wireless mic
• SubZero MP8 Multi-Position Battery Powered DSP PA System – This is a compact and lightweight PA that is good for small parties or busking

Pub or small bar

In a small bar or pub environment, you’ll probably want to keep your setup compact enough to store away and easy enough to carry and transport. You’ll need something that is a little bit more powerful than a standard compact PA. I would suggest something that can comfortably output around 90dB to give you enough volume for a noisy social environment.

Here are a couple of PA systems that are suitable for small bars and pubs:

• Yamaha Stagepas 400BT Portable PA System – This is a nice, simple PA system with a few inputs for multiple instruments and mics and an FX unit
• HK Audio Polar 8 Column PA System – A simple all-in-one-column PA with DSP features, Bluetooth connectivity, and multiple inputs

Club or large indoor space

In a club environment, you’ll want a full PA system. To protect people’s ears, keep the music below 100dB but have a good spread of sound around the room. If you have a larger space, you may want to consider having a couple of delay speakers that cover the back of the room too.

This setup is ideal for a larger indoor venue:

• Electro-Voice ELX200-15P 15” Active PA Speaker Bundle with Stands and Cables – A bundle of up to four high-quality speakers and the accessories to go with them
• Electro-Voice ELX200-18SP 18” Active PA Subwoofer – A decent size subwoofer that will pack a punch in any club environment

Garden party or outdoor event

For events outside, you will want something compact, easy to set up, and able to disperse sound over a wide range.

Here are some suitable options for outdoor events:

• dB Technologies ES 1002 Column PA System – A simple yet effective solution for any outdoor party with a powerful 130dB SPL
• HK Audio Polar 12 Column PA System – Another fantastic column PA that delivers clarity and packs a punch

Festival or large outdoor event

For large crowds, high SPL PA speakers with subwoofers are necessary, providing wide sound coverage that ensures the music reaches the entire audience. You’ll need multiple units, with added subwoofers and delay speakers, depending on the size of the space.

Here are some PA systems perfect for festivals:

• Bose F1 Model 812 Flexible Array Loudspeaker System with F1 Subwoofer – A flexible array setup from renowned manufacturer Bose
• SubZero HiCAST LA12 Flown PA System – Compact line array setup based on professional designs

FAQs

How many watts is a good speaker?

There is no amount of wattage that makes a speaker good or not, you should look for speaker sensitivity or SPL to gauge how efficient it is. Speaker sensitivity (SPL) determines loudness, not just power. A 1500W speaker with 125dB max SPL will be weaker than a 1200W speaker with 130dB SPL. Choose a speaker based on the volume you need and its efficiency at delivering that output.

Do higher-wattage speakers sound better?

Higher wattage speakers don’t necessarily sound better than lower-wattage speakers. Wattage only indicates power handling, not audio quality. Factors like speaker design, sensitivity (SPL), and component quality play a bigger role. A well-designed low-watt speaker can outperform a high-watt one in clarity, detail, and overall performance.

Is a 100w speaker loud?

A 100w speaker is not necessarily loud, it depends on the design and the efficiency of the speaker itself. You also need to check to see if the watt rating is RMS or Peak. A low-efficiency 100W speaker may sound weak, while a high-SPL, well-designed one can be significantly louder and more impactful in real-world use.

Final thoughts

When choosing a PA system, speaker wattage is just one piece of the puzzle. To find the right speaker, compare SPL ratings, efficiency, and design features to ensure clear, powerful sound suited to your space. Also, consider accessories like stands and placement techniques to maximise performance.

If you’re still unsure, you can always refer back to this guide when picking your next speaker setup, and if you want to learn more about PA and live sound, check out similar articles by us:

What is a PA System? Here’s Everything You Need to Know 

What Is a Subwoofer and Why Do You Need One?

How to Find the Right Sound System for Your Church or Place of Worship