Passive radiators can be useful in many types of speaker systems, but they really shine in certain specific applications:
- Small speakers where port noise may be an issue – The lack of turbulent air flow in passive radiators avoids port “chuffing” noise in compact designs[1][2].
- Small enclosures where port size is constrained – Passive radiators allow small boxes to reach lower tuning frequencies vs limited port sizes[1][3].
- High power/SPL applications – Passive radiators have greater excursion capabilities than ports, allowing higher output before distortion[2][4].
- Outdoor/marine use – Passive radiators are insensitive to environmental conditions compared to ports[3][5].
- Subwoofers – The resonant behavior of passive radiators complements low frequency reproduction[1][4].
- Multi-driver systems – Passive radiators can augment bass from full-range drivers in multi-way designs[2][6].
However, passive radiators may not be the best choice when:
- Maximum efficiency is required – Passive radiator systems are less efficient than properly tuned ports[2][3].
- Fast transient response is critical – The resonant behavior causes slightly slower bass decay than ports[3][5].
- Extremely low tuning is needed – Very large passive radiators would be required vs more practical large ports[1][3].
So in summary, passive radiators excel in compact enclosures and high output applications but may not suit systems optimized for efficiency and transient response. The design goals determine if they are appropriate.
Citations:
[1] https://www.avu.ca/audio/what-are-passive-radiators-in-speakers/
[2] https://en.wikipedia.org/wiki/Passive_radiator_(speaker)
[3] https://www.hifireport.com/passive-radiators-101-a-beginners-guide-to-audio-technology/
[4] https://youtube.com/watch?v=p2Fi7yNByfU&t=0
[5] https://blog.miscospeakers.com/benefits-of-a-passive-radiator-speaker-enclosure
[6] https://www.salksound.com/blogtopic.php?id=6