What is a passive radiator in a sub and what does it do for me?

[gcmarshall]

I am looking at a sub that has a 10" woofer and a 10" passive radiator. Just when I thought I understood subs....what is the passive radiator and what does it do for me? Is it considered desirable? For example, http://www.bostonacoustics.com/home_product.aspx?category_id=6&product_id=110

thanks.

 

[j_garcia]

The passive radiator is exactly what it says - a passive driver that radiates sound in conjunction with the active driver. It serves a similar function as a port in a vented speaker design, though the sub remains a sealed design. It makes the active driver "think" it is in a larger enclosure, allowing the use of a slightly smaller enclosure.

 

[gcmarshall]

j_garcia:

thank you. is a passive radiator design generally considered a good thing or is it a matter of taste?

 

[j_garcia]

In the grand scheme of things, I think passive radiator subs are pretty good. Not quite as good as a dual driver sealed design, but a bit cleaner than vented if done right. From my reading though, passive radiator designs can be a bit tough to get right. For a well designed sub, vented, sealed or passive radiator, the end result should be the same - good sound...I don't know if that answers your question or not though