Passive Radiators

[JonF]

I'm new to the Klipsch community.  Looking at buying my first set of speakers, a used Forte I.  Can someone please explain the purpose of the passive radiators.  Also these are original in good condition with original phenolic tweeters.  They are version I with the round crossover covers. What components should i expect to replace to improve the sound and prolong the speakers' life.  Thanks.  Jon

 

[Schu]

Extension...

[Mike_S]

The radiators give you more bass extension. It's like half sealed box, and half port, but really neither. It works. 

Most likely you will need to refresh the crossovers. Crites has a kit for under $50, takes about 1-2hrs.

[John Chi-town]

As others mentioned bass extension.  The speakers should be placed about 8-10 inches away from the wall.  The passive radiator works off the wall.  Too far out and you cancel the passive.  Congrats on your upcoming purchase.  I am a Klipsch owner for 33 years, owned the forte II for 29 years, and forte IV owner the last few years.  You are making a great choice, any forte series is hard to beat, and INMHO the best overall value in the Heritage line.  Spend some time with them before any updates.  Placement is everything with the forte.  

[MMurg]

Both ported and passive radiator speakers are considered "bass reflex" speaker systems, i.e., ones that utilize the sound pressure otherwise trapped in the enclosure to increase the bass efficiency and deepen the bass extension.

https://en.wikipedia.org/wiki/Bass_reflex

 

https://en.wikipedia.org/wiki/Passive_radiator_(speaker)

 

[boom3]

The other advantage to "passive" radiators is that unlike ports, they don't let higher frequency components in the woofer passband come out, which often introduces distortion in conventional ported boxes. I built a pair of 2-ways a few years back and chose a PR because the crossover point is 1K and I didn't want the higher frequencies of the woofer to get mangled by a port.

 

Some people believe that a conventionally ported woofer has better transient response than a system with a PR. I'm not sure about that, but I'm quite happy with the PR system just mentioned. My primary system has four Cornwall IIs which of course are ported boxes.