How to Get the Best Sound from Small Speakers: Nuvoton NAU83G60 with Klippel Controlled Sound
- 1 day ago
- 8 min read
Introduction – The Small Speaker Problem Has Never Really Been Solved
Every engineer who has worked on a compact audio product knows the feeling. The mechanical design team has determined that the speaker driver must fit within a 45mm diameter and 8mm depth. The industrial design team has decided the enclosure is 12mm thick. And the product brief still requires the device to sound impressive.
This is the small speaker problem, and it shows up across a surprisingly wide range of products: portable and desktop wireless speakers, tablets, all-in-one PCs, soundbars, automotive door panels, and smart home devices. The physics are unforgiving. A small driver in a shallow or compact enclosure has limited linear excursion, a constrained bass response, and less thermal headroom. Push it hard and it distorts. Protect it conservatively and it sounds flat and lifeless.
The industry's conventional answer has been multi-band dynamic range compression (DRC), basically a system of two or three fixed frequency bands with protection thresholds set during product development. The engineer tunes the thresholds, accepts the compromises, and ships the product. So, instead of the usual balancing trick of optimising two or three bands of DRC that you get with most amplifiers, the NAU83G60 does the hard work for you! With the Klippel approach dynamic bands automatically change with the speaker and the signal, making it theoretically impossible for the system to ever sound bad.
The Nuvoton NAU83G60 is a stereo 2x30W smart Class-D amplifier with an integrated Advanced Audio DSP running the Klippel Controlled Sound (KCS) algorithm (a nonlinear adaptive system) that replaces the static tuning compromise with a continuous, physically-modelled approach to speaker control. For engineers designing products where space is tight and audio quality still matters, it represents a genuinely different set of possibilities.
How the Nuvoton NAU83G60 Addresses Small Speaker Limitations
The NAU83G60 is built around the premise that the amplifier should work with the physics of the connected driver, not simply limit around them. Its feature set reflects this across every layer of the signal chain.
Klippel Controlled Sound: Replacing Compromise with a Physical Model
The core of the NAU83G60 is the integrated KCS algorithm, developed in collaboration with Klippel GmbH - the Dresden-based specialists in loudspeaker measurement and control. KCS is a nonlinear adaptive speaker control system that uses voltage and current sensing at the speaker terminals as continuous feedback. From these measurements it identifies the real-time electromechanical parameters of the connected driver and maintains a continuously updated physical model of its behaviour.
This matters for small speaker design for three specific reasons.
First, distortion compensation. The model is used to calculate what harmonic and intermodulation distortion the driver would generate given the current signal and state. A distortion compensation filter – effectively a digital twin of the driver's nonlinear behaviour – pre-corrects the signal before amplification. Small drivers are inherently more nonlinear at high excursion, so this compensation has a proportionally larger benefit in compact designs than it does in larger systems.
Second, active voice coil alignment. DC compensation holds the voice coil at its ideal rest position continuously. In a small driver, excursion is already limited; any offset from the optimal rest position reduces the usable linear range further. By actively correcting this, KCS recovers excursion headroom that a conventional amplifier leaves on the table, directly translating to more bass output from the same physical hardware.
Third, and most distinctively: the DRC bands are not fixed. Where conventional protection systems apply static thresholds across two or three frequency bands – set once during design and never updated – KCS updates its effective protection bands and thresholds continuously, based on the current signal content and the real-time state of the modelled driver. This means the system is always applying exactly the right amount of protection, no more and no less. It never sacrifices output quality unnecessarily, and it never under-protects. For small speakers operating near their limits, this is the difference between a product that consistently sounds as good as its hardware allows, and one that sounds as good as its worst-case tuning assumptions allow.
Powerful Stereo Class-D Amplifier Stage
The power stage delivers 30W per channel into a 4 ohm load at under 10% THD+N from a 24V supply, or 60W in PBTL (parallel bridge-tied load) mode into a 2 ohm load. At typical listening levels, e.g. 1W into 8 ohms, THD+N is just 0.05%. Operating voltage spans 5V to 24V, covering battery-powered portable products through to mains-connected designs.
Integrated Audio DSP and Signal Processing
The on-chip DSP provides 2x15-band parametric equalisers, a crossover and audio mixer for ultrasonic bypass mode, and up/down sampling conversion. For active noise control applications, the signal path is designed specifically for low latency, and a linearised echo cancellation reference signal is available. This reference has speaker-induced distortion removed, which improves wake-word detection and speakerphone performance which is important for tablet and smart speaker designs where the speaker and microphone share close proximity.
Audio Interface and Power Management
The NAU83G60 supports I2S, PCM, and TDM audio interfaces at up to 8 channels and 192kHz sampling. Control is via high-speed I2C at up to 1Mbps. Battery-oriented features include automatic level control (ALC), under-voltage lockout prevention (UVLOP), and battery limiter control; all relevant for portable products where power management is as important as audio performance.
Detailed Specifications – NAU83G60
Parameter | Specification |
Output Power (Stereo) | 2 x 30W @ 4Ω, <10% THD+N, 24V |
Output Power (Mono PBTL) | 60W @ 2Ω, <10% THD+N, 24V |
THD+N (Typical) | 0.05% @ 8Ω, 1W |
Operating Voltage (VBAT) | 5V to 24V |
Audio Interface | I2S / PCM / TDM (up to 8 ch, 192kHz) |
Control Interface | High-Speed I2C (up to 1Mbps) |
DSP | Advanced Audio DSP, low-latency |
Parametric EQ | 2 x 15-band PEQ |
Speaker Algorithm | KCS (Klippel Controlled Sound) |
Protection | Mechanical (displacement), thermal (voice coil), output power and voltage limiter |
KCS Features | Distortion compensation, adaptive alignment, active DC compensation, real-time diagnostics |
ANC Support | Low-latency signal path, linearised echo cancellation reference |
Battery Management | ALC, UVLOP, battery limiter control |
Typical Applications | Automotive/ANC, TV/soundbar, notebook/PC/AiO, wireless/smart/active speakers, tablets |
Industry Applications and Use Cases
Wireless and Portable Speakers
This is the application where getting the best sound out of small speakers is most acute, and where the NAU83G60's advantages are going to deliver results you can literally hear for yourself. Portable Bluetooth speakers face simultaneous pressure on driver size, enclosure volume, and acoustic performance – precisely the conditions where conventional DRC tuning produces the most audible compromises. KCS extracts the maximum acoustic performance the driver's physics will genuinely allow, and the adaptive alignment ensures that performance is maintained consistently as the product ages and as temperature changes during use. An engineer can also take a more deliberate approach to driver selection: knowing that KCS will compensate for the driver's nonlinearities removes some of the acoustic risk from specifying a smaller or lower-cost component.
Tablets and Thin Embedded Displays
Tablets represent one of the most constrained audio environments in consumer electronics. The speaker must be thin, the enclosure is essentially non-existent, and the driver is typically operating well into its nonlinear range at anything above moderate volume. The NAU83G60 is directly relevant here: the distortion compensation reduces the harshness that thin tablet speakers typically exhibit at volume, while the voice coil alignment and adaptive protection allow higher output than a conservative fixed limiter would permit. The ANC-related features – low-latency signal path and linearised echo cancellation reference – are also relevant for tablet voice applications where speaker proximity to the microphone array creates acoustic feedback challenges.
Soundbars and TV Audio
Soundbar design presents a familiar version of the same constraint: bass response from a shallow enclosure. The adaptive speaker alignment in KCS continuously models and corrects the low-frequency response of the driver, providing measurably extended bass compared with passive crossover and fixed protection approaches. A soundbar manufacturer can deliver equivalent perceived bass from a physically smaller driver, or noticeably better bass from the same hardware, without increasing the risk of driver damage during high-amplitude transients.
Automotive Audio and Active Noise Control
Door-mounted automotive speakers share many of the same constraints as portable consumer speakers: limited enclosure volume, variable temperature, and long service life requirements. KCS adapts automatically to temperature and ageing effects on the driver's mechanical parameters, which is well aligned with the automotive requirement for consistent performance across a wide environmental range. For ANC specifically, the combination of a low-latency DSP path and a distortion-compensated echo cancellation reference improves cancellation depth at the amplitudes where in-cabin noise is most disruptive.
Notebooks and All-in-One PCs
Ultra-thin notebooks are an increasingly prominent application. At high volume settings, thin notebook speakers are almost always operating beyond their comfortable range. Conventional protection rolls off the output or introduces pumping artefacts; KCS manages the excursion and thermal state in real time, allowing more output power than a fixed limiter would safely permit while simultaneously cleaning up the harmonic distortion that makes laptop audio sound compressed and fatiguing at volume.
Conclusion: A Different Approach to a Familiar Problem - how to get the best sound from small speakers
The Nuvoton NAU83G60 does not simply improve on the conventional smart amplifier. It changes the fundamental approach: from static, tuned-at-design-time protection to a continuous, physically-modelled system that adapts in real time to the driver, the signal, and the environment.
For engineers working on products where audio performance must be extracted from small, thin, or physically constrained hardware, that distinction is commercially meaningful. It means less dependence on conservative tuning assumptions, more consistent performance across production variance and product lifetime, and a genuinely higher acoustic ceiling than fixed DRC architectures will allow.
Hear the NAU83G60 in action Yourself
The NAU83G60 will be demonstrated live at Embedded World 2026 - Hall 4 / 106. To request samples, arrange a technical discussion, or to book a meeting at the show, please contact the Ineltek team.
FAQ - Can you really get great sound from a small speaker?
Q. Why do small speakers distort more, and how does the NAU83G60 address this?
A. Small drivers are physically more nonlinear at high excursion because their suspension and motor geometry operate closer to their limits during normal use. Conventional amplifiers apply fixed protection thresholds but do not compensate for the distortion these nonlinearities generate. The NAU83G60's KCS algorithm uses a continuously updated physical model of the driver to pre-correct the signal before amplification, reducing harmonic and intermodulation distortion at the source rather than simply limiting the output that causes it.
Q. How does the NAU83G60 get the best sound from small speakers?
A. The integrated KCS algorithm builds a continuous real-time physical model of the connected driver using voltage and current measurements at the speaker terminals. This enables distortion compensation before amplification, active voice coil alignment for maximum bass excursion, and protection thresholds that update dynamically with the driver's actual state rather than being fixed at worst-case design-time values – delivering always-optimal performance from whatever speaker hardware the design allows.
Q. How does KCS deliver more bass from a small driver without damaging it?
A. Active DC compensation holds the voice coil at its optimal rest position at all times, maximising the available linear excursion range. Adaptive speaker alignment then continuously models and corrects the low-frequency response for changes in driver stiffness due to temperature and ageing. The driver is therefore always operating with its full available excursion and most accurate low-frequency response, within safe limits set by the real-time model rather than conservative static thresholds.
Q. Is the NAU83G60 suitable for tablets and ultra-thin embedded designs?
A. Yes. Tablets are among the most constrained audio environments in consumer electronics – the driver is thin, the enclosure is minimal, and the speaker operates in its nonlinear range at moderate volume. Distortion compensation reduces the harshness this typically produces, while voice coil alignment and dynamic protection allow higher output than a conservative fixed limiter would permit. The low-latency signal path and linearised echo cancellation reference are additionally useful where speaker and microphone share close proximity.
Q. Does KCS replace the need for careful speaker selection and acoustic design?
A. No – KCS extracts the best possible performance from whatever driver and enclosure the design allows; it does not substitute for acoustic engineering. It does, however, change the risk calculation around driver selection. Knowing the amplifier compensates for driver nonlinearities in real time means engineers can specify a smaller or lower-cost component with greater confidence, without tuning conservatively around worst-case assumptions.
Q. What audio interfaces does the NAU83G60 support?
A. The NAU83G60 supports I2S, PCM, and TDM audio interfaces at up to 8 channels and 192kHz sampling frequency, with high-speed I2C control at up to 1Mbps.
