The new Fluance Powered Bookshelf Speakers look nearly identical. The Ai series of Powered Speakers share many design features and are suitable to the same applications however they do differ in a few key ways.
Audio Input Options
The Ai41 and Ai61 share nearly all the same input options (RCA, Bluetooth 5 and optical toslink) however the Ai61 include a USB Type-C input. This allows for a USB connection to a computer rather than using the analog RCA input to connect to a PC. You can still use the Ai41 for a computer setup however you would have to connect it through RCA with an RCA to aux cable, optical cable (if your computer supports that input) or connect via Bluetooth.
Another difference between the two models are the amplifier power. Both utilize an integrated ultra-low noise class D amplifier to produce a powerful signal without degrading its signal-to-noise ratio. The Ai41 have a 90 Watt continuous average output (2x45W RMS) amplifier while the Ai61 have a 120 Watt continuous average output option (2x60W RMS) amplifier.
With the difference in size and components in the two speakers there are a few implications for the performance specifications of each speaker pair. Most notably there is a difference in the frequency response in each set of speakers. The Ai41 have a frequency response of 35Hz-20kHz (DSP Enhanced), while the Ai61 measures at 32Hz-20kHz (DSP Enhanced). That difference means that the Ai61 produce more low-end bass frequencies than the Ai41.