Passive Radiators vs. Bass Drivers.......

[superdougiefreshness]

Hey everyone,
What the heck is a speaker designer thinking about when deciding to add Passive radiators ? And what the hell are they anyhow........? Now that is a great set of junk to ponder. In the mid 1980's I had a pair of floor standers that had one each of bass driver and passive radiator along with a midrange and tweeter so I think that makes them 3-ways or 4-ways ? I never really understood why this design was needed and certainly never understood why my speakers didn't have 2 each bass drivers instead of that radiator. What is the difference in both units and why are they even used ?
Point being the BIC America "Venturi DV64"
Design: Two-way, video-shielded tower with dual woofers and dual passive radiators.
Why this strange design and where the heck is the mid range sound coming from here ?
And lastly Where is there info to read on this stuff to help me clarify these items ?
Thanks and Later Guys

[markw]

A properly designed and integrated passive radiator in a closed system takes the place of a port in what otherwise would be yer basic ported bass reflex system.

It does not add to the driver count, just as a port does not add to the driver count.

[superdougiefreshness]

A properly designed and integrated passive radiator in a closed system takes the place of a port in what otherwise would be yer basic ported bass reflex system.

It does not add to the driver count, just as a port does not add to the driver count.

Believe it or not my old floor standers had one port each, also one bass driver and one wired in parallel with the bass driver - passive radiator each........strange combo now that I think back on it.
Any Idea what the designer of my old pair was thinking......???
LOL

Later

[markw]

Believe it or not my old floor standers had one port each, also one bass driver and one wired in parallel with the bass driver - passive radiator each........strange combo now that I think back on it.
Any Idea what the designer of my old pair was thinking......???
LOL

Later

Sounds to me like you had two bass drivers and no passive radiators. So, what's your point here?

[GMichael]

In my oppinion:

Full drivers cost more but work the best.
Passive radiators cost less than full drivers but work better than ports.
Ports are the cheapest way to extend the base but can be tricky to get right.

Passive radiators are a very nice opption.

[superdougiefreshness]

Sounds to me like you had two bass drivers and no passive radiators. So, what's your point here?

"My point being here.................... was to ask all my very important and exact questions as I did prior that this forum was designed for.


There are many of us still learning this hobby..........and many many many many more if we allow them to come forward. Lets offer the understanding that being an audio geek is a process of growing......over time and financial gain.......as well.....I need not ever have a point what so ever is my point......."shooting the
-%$#@" is all the point I will ever need in mine and our forum here.

All of your info helps looking back on those old heavy floor standers. We opened them up to add new tweeters after blowing the originals when we discovered the parallel wired bass units. You see the literature for the speakers mentioned passive radiators and we did not know why each of the 2 bass drivers were the same size and looked only slightly different in front and in back and of course were wired in parallel along with the ported enclosure. That indeed at that time brought many questions to all the people in my barracks who loved listening to my system and not a person around to answer all those questions. I am now informed as to what I was dealing with, just mentioning we had no INTERNET back in the mid 80's and I was isolated at a very small navy base when I purchased those huge things. Now reading about the BIC towers brought up all those old questions.
Thanks Greatly

[markw]

"My point being here.................... was to ask all my very important and exact questions as I did prior that this forum was designed for.


There are many of us still learning this hobby..........and many many many many more if we allow them to come forward. Lets offer the understanding that being an audio geek is a process of growing......over time and financial gain.......as well.....I need not ever have a point what so ever is my point......."shooting the
-%$#@" is all the point I will ever need in mine and our forum here.

All of your info helps looking back on those old heavy floor standers. We opened them up to add new tweeters after blowing the originals when we discovered the parallel wired bass units. You see the literature for the speakers mentioned passive radiators and we did not know why each of the 2 bass drivers were the same size and looked only slightly different in front and in back and of course were wired in parallel along with the ported enclosure. That indeed at that time brought many questions to all the people in my barracks who loved listening to my system and not a person around to answer all those questions. I am now informed as to what I was dealing with, just mentioning we had no INTERNET back in the mid 80's and I was isolated at a very small navy base when I purchased those huge things. Now reading about the BIC towers brought up all those old questions.
Thanks Greatly

Perhaps I should have pointed out the meaning of "passive" first. "Passive" means no power is applied and no wiring is needed, but I really thought you had that concept down pat.

[N. Abstentia]

[FONT=Century Gothic][COLOR=purple]Believe it or not my old floor standers had one port each, also one bass driver and one wired in parallel with the bass driver - passive radiator each..

Wait....you had passive radiators wired in parallel with your bass drivers?

That's kinda like having 2 tires and 2 bare rims on your car..it just don't compute. Methinks you didn't have passive radiators at all. Here's what the back of a passive radiator looks like:



Notice a few important things missing..such as a voice coil, magnet, and a wire terminal? Ahh..passive radiators are just that..passive. You can't have wired plugged into them.

[GMichael]

Notice a few important things missing..such as a voice coil, magnet, and a wire terminal? Ahh..passive radiators are just that..passive. You can't have wires plugged into them.

Sure you could. Just jam them in there with a stick. But they won't help much. The extra hole would make them even more passive. They would just lie there like a few girls I used to know.

[kexodusc]

Passive radiators are just another way to augment the bass extension capabilities of the speaker. A few nice things about Passive Radiators - they are cheaper than woofers with motors, they can help compensate for baffle step loss without having to sacrifice sensitivity, and they can eliminate large, complicated ports and port noise. Nothing wrong with Passive Radiators at all.