Shopping for a Bluetooth speaker can feel overwhelming when you're confronted with a barrage of technical specifications. What does "20W RMS" actually mean? Is a frequency response of "60Hz-20kHz" good or bad? And why should you care about Bluetooth codecs? Understanding these specifications is crucial for making an informed purchase that matches your audio expectations and lifestyle needs.
In this comprehensive guide, we'll demystify the most common speaker specifications you'll encounter when shopping for portable audio equipment in Australia. By the end, you'll be equipped to separate marketing hype from meaningful performance indicators.
Power Output: Understanding Watts
Power output, measured in watts (W), is perhaps the most commonly cited specification and also one of the most misunderstood. Many shoppers assume that higher wattage automatically means louder, better sound. The reality is more nuanced.
Peak vs. RMS Power
Manufacturers may list power as "peak" or "RMS" (Root Mean Square). Peak power represents the maximum output a speaker can produce in short bursts, while RMS indicates the sustained power level the speaker can maintain without distortion. RMS is the more useful measurement for understanding real-world performance.
5-10W RMS: Suitable for personal listening, small rooms, or desktop use. 15-30W RMS: Good for medium-sized rooms, small gatherings. 40W+ RMS: Capable of filling large spaces and outdoor environments.
It's important to understand that doubling the wattage doesn't double the perceived volume. Due to how human hearing works, you'd need approximately ten times the power to perceive sound as "twice as loud." A quality 20W speaker can often outperform a poorly designed 40W speaker in both clarity and perceived loudness.
Frequency Response
Frequency response tells you the range of audio frequencies a speaker can reproduce, measured in Hertz (Hz). Human hearing typically spans from 20Hz (deep bass) to 20,000Hz or 20kHz (high treble). A speaker's frequency response is usually written as a range, such as "60Hz - 20kHz."
What the Numbers Mean
- Low frequencies (20-250Hz): Bass and sub-bass tones. Lower numbers mean deeper bass capability.
- Mid frequencies (250Hz-4kHz): Where vocals and most instruments reside.
- High frequencies (4kHz-20kHz): Treble, including cymbals, high vocals, and acoustic detail.
For portable speakers, a frequency response starting at 60-80Hz is common and acceptable. Speakers claiming response down to 20Hz should be viewed skeptically unless they're larger units with substantial drivers or subwoofers.
Beware of frequency response claims without a corresponding decibel tolerance (e.g., "±3dB"). Without this, the stated range may be technically achievable but practically inaudible at the extremes.
Driver Size and Configuration
Drivers are the components that actually produce sound by converting electrical signals into air movement. Driver size, measured in millimetres or inches, affects what frequencies the speaker can reproduce effectively.
- Tweeters (typically 20-40mm): Handle high frequencies, providing clarity and detail.
- Full-range drivers (40-100mm): Attempt to cover the entire frequency spectrum.
- Woofers (100mm+): Focus on bass frequencies.
- Passive radiators: Not powered drivers, but they help extend bass response in compact enclosures.
Many portable speakers use a single full-range driver or a pair of them for stereo separation. Premium models may include dedicated tweeters for improved high-frequency detail. The relationship between driver size, enclosure design, and amplification is what ultimately determines sound quality—not any single specification in isolation.
Bluetooth Specifications
Bluetooth Version
Bluetooth technology continues to evolve. Higher version numbers generally offer improved range, connection stability, and power efficiency:
- Bluetooth 4.2: Adequate but older. Range of about 10 metres.
- Bluetooth 5.0: Improved range (up to 40 metres in ideal conditions), better stability, and lower power consumption.
- Bluetooth 5.1/5.2/5.3: Incremental improvements in direction finding, power efficiency, and audio quality features.
Audio Codecs
Codecs determine how audio is compressed and transmitted via Bluetooth. Common codecs include:
- SBC: The universal baseline codec. Adequate quality but not exceptional.
- AAC: Better quality, works well with Apple devices.
- aptX/aptX HD: Higher quality audio with lower latency. Common in premium Android devices.
- LDAC: Sony's high-resolution audio codec offering the best Bluetooth audio quality.
- RMS wattage is more meaningful than peak power ratings
- Frequency response is important but verify with ±dB tolerance
- Driver configuration matters more than size alone
- Bluetooth 5.0 or higher offers the best connection experience
- Codec support determines maximum audio quality potential
Battery Life Claims
Battery life specifications are typically measured at 50% volume in controlled conditions. Real-world usage often differs significantly. When comparing battery life claims:
- Expect 20-30% less battery life at higher volumes
- Wireless features like multi-speaker pairing consume additional power
- Cold temperatures reduce battery performance
- Battery capacity naturally degrades over time
Making Sense of It All
While specifications provide useful reference points, they shouldn't be the sole basis for your purchasing decision. A speaker's overall sound signature—how warm, bright, or balanced it sounds—comes from the complex interplay of multiple factors that specifications alone cannot capture.
Use specifications to narrow your options to speakers that meet your basic requirements for power, portability, and features. Then, whenever possible, listen to your shortlisted speakers in person or seek out trusted reviews that describe the actual listening experience. Specifications are the starting point of your research, not the finish line.