The closest alternatives on specs, description and the systems they turn up in, with the specs they share set side by side.
The High frequency Be upgrade's sensitivity is 99 dB against the Ceramic with Be Center's 98 dB and its low-frequency extension 30 Hz against 20 Hz. Both share impedance (4Ω) and high-frequency extension (30 kHz).
The Proprietary Tweeter Array's sensitivity is 95 dB against the Ceramic with Be Center's 98 dB and its impedance 8Ω against 4Ω. Both share low-frequency extension (20 Hz) and high-frequency extension (30 kHz).
The Full system Be upgrade's sensitivity is 99 dB against the Ceramic with Be Center's 98 dB and its low-frequency extension 30 Hz against 20 Hz. Both share impedance (4Ω) and high-frequency extension (30 kHz).
The Vestia N°4's impedance is 8Ω against the Ceramic with Be Center's 4Ω, its sensitivity 92 dB against 98 dB, and its low-frequency extension 40 Hz against 20 Hz. Both share high-frequency extension (30 kHz).