Choosing between the Dolphin M400 vs Dolphin Sigma means comparing two of Maytronics’ most advanced robotic pool cleaners. Both designed for in-ground pools up to 50 feet, they bring exceptional performance, automation, and cleaning technology. However, while the M400 is a part of the M-series and emphasizes navigation precision and multi-layer filtration, the Sigma is one of the few models to offer triple-motor power and gyroscopic control, pushing the limits of robotic cleaning.
In this detailed comparison, we examine how the Dolphin M400 and Dolphin Sigma perform across all essential criteria, from design and cleaning efficiency to filtration and smart control.
Contents
Differences Between Dolphin M400 vs Dolphin Sigma
Design Comparison
Both the Dolphin M400 and Dolphin Sigma are built for large residential pools, featuring sturdy construction and robust engineering. The Dolphin M400 weighs 25 pounds and uses PowerStream mobility—a water-jet propulsion system that increases wall grip and stability during vertical climbs. This makes the M400 particularly reliable in deep pools or those with steep inclines. Its top-load multi-layer filter basket is easy to access and clean, with compartments that separate fine particles from larger debris.
The Dolphin Sigma, at 24.6 pounds, is equally substantial but shifts the design focus to gyroscopic control and triple motor drive. This allows for a more dynamic navigation system that responds quickly to orientation changes and complex pool shapes. Like the M400, it features a top-load filter system, but its ultra-fine cartridges are more specialized and optimized for sand, silt, and fine debris rather than large organic waste.
Both models include a 60-foot tangle-free swivel cable, allowing smooth operation in pools of all shapes without cable twisting.
Winner: Dolphin Sigma
With advanced gyroscopic navigation, triple-motor propulsion, and precision cornering, the Sigma leads in intelligent structural design and movement fluidity.
Cleaning Performance Comparison
The Dolphin M400 uses dual active brushes that rotate faster than the drive system, effectively scrubbing algae and biofilm from the pool floor, walls, and waterline. The PowerStream technology provides stable wall climbing and optimized cleaning tracks. Combined with a suction rate of 4,500 gallons per hour, the M400 excels in consistent, thorough coverage and aggressive surface scrubbing. Its multi-layer filter basket is especially versatile, capturing both fine debris and large leaves in one cycle. Runtime can be set to either 2 or 2.5 hours, offering flexibility depending on pool size or condition.
The Dolphin Sigma also features dual active brushes and the same 4,500 GPH suction capability. However, what sets it apart is the triple motor system, which gives each side of the robot independent propulsion for enhanced agility. The Sigma includes gyroscopic navigation, allowing it to make precise turns, track contours more efficiently, and avoid redundant pathing. Its ultra-fine filter cartridges are highly effective at removing micro-particles, though they fill quickly in leaf-heavy pools.
Both models clean the waterline, with the Sigma relying on its gyroscopic intelligence and the M400 leaning on PowerStream propulsion for vertical navigation.
Winner: Dolphin Sigma
With triple motors and gyroscopic steering, the Sigma demonstrates more refined cleaning logic and dynamic maneuvering, ideal for complex pool layouts or heavy fine debris.
Feature Comparison
The Dolphin M400 is fully compatible with the MyDolphin™ Plus App, allowing remote scheduling, cycle selection, and real-time control. It also offers firmware updates and performance tracking. The M400’s PowerStream mobility system is semi-intelligent and enhances wall navigation, though it does not generate 3D maps or positional awareness.
The Dolphin Sigma supports the same MyDolphin™ Plus App, but couples it with AI-based navigation, thanks to its integrated gyroscope. This means the Sigma better adapts to pool contours, optimizes its route with fewer overlaps, and cleans in tighter, more deliberate paths. The triple motors add torque and independent wheel speed control, allowing it to pivot with precision and handle deep ends or complex geometries more intuitively.
Winner: Dolphin Sigma
While both models are smart-connected, the Sigma’s combination of gyroscope, AI pathing, and triple motors provide more advanced and adaptive features for hands-off precision cleaning.
Quick Rundown Of Dolphin M400
Quick Rundown Of Dolphin Sigma
Conclusion
Choose the Dolphin M400 if you want a durable, reliable robotic cleaner with aggressive scrubbing, dual filtration layers, and strong vertical wall performance backed by PowerStream navigation. It’s ideal for those who want powerful results, flexible cleaning cycles, and consistent all-around coverage with minimal manual involvement.
Choose the Dolphin Sigma if you need cutting-edge smart navigation, tighter cleaning patterns, and enhanced mobility through triple motors and gyroscopic control. It’s the better option for unusually shaped pools or those frequently plagued by fine particulate matter.
Overall Winner: Dolphin Sigma
With its intelligent navigation, superior agility, and triple motor design, the Dolphin Sigma stands out as the more advanced, precise, and future-ready robotic pool cleaner—ideal for homeowners seeking peak cleaning automation and efficiency.