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

[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.

[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.

[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.

[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.

[Blue Meanie]

SuperDougie...

Mind if I ask exactly which speakers you had back in the '80s?

Jeff

[superdougiefreshness]

SuperDougie...

Mind if I ask exactly which speakers you had back in the '80s?

Jeff

Hi Blue,
I am sorry I don't know the name of the speaker brand from back in the day, what I do remember is that the sound was very strong with deep bass when we played rock and soul records. But I can tell you that the system I bought with them was "1986" made by a company called Cybernet with a Turntable, Cassette Deck, Tuner and separate amp/switcher of some sort all made by Cybernet in a real heavy and nice stereo rack/stand and those huge heavy tower speakers that weighed about 60 lbs.ea. and stood up to my ribs........50"s tall.........10" woofer's.......and 12 Gauge monster speaker cables....they were totally kick dude........and we never could blow the bass out on those suckers, they took everything we could throw at them without any trouble at all.........I purposely at the time bought much bigger speakers then most people would have with that system so I could enjoy really big sound "young and crazy I was" Also I do know that the tweeter was some sort of metal and its sound was real nice. I still have the Cybernet turntable and it works great, as well as my NAD turntable from 1989.......I guess I am lucky I don't have to go out and buy new turntables and cartridges and all the other stuff. I have had my stuff in storage for years and now can us them.....................of course the rest of that system is gone except the TT.........sorry I got rid of it all now, those speakers would have done a great job in a garage or workshop up in the rafters.....LOL...I believe someone mentioned that the speakers where American and from California, probably out of business now?


Later.

p.s. and still no one here has mentioned what speaker I have as my Icon......?
any guesses out there......?....LOL

[Blue Meanie]

Thanks, Dougie! I've never heard of Cybernet. Doesn't mean much, as I've lead a sheltered life, LOL.

About your avatar: Is that a copper dome tweeter? Celestion? SL600 maybe? My memory could be faulty, though. But if I'm right, SWEET speaks!!!

Jeff

[superdougiefreshness]

Thanks, Dougie! I've never heard of Cybernet. Doesn't mean much, as I've lead a sheltered life, LOL.

About your avatar: Celestion?

Jeff

Blue,
You can't be as sheltered as you may think, especially if you knew my avatar....LOL Many contributors would never have known that speaker, which by the way is a true legend and a somewhat rare collectable........I wish I owned or had that model...they are beautiful.
Now if you know the model I would be very impressed indeed..........
I do not own the model that is my avatar but I do own a similar model, mine are SL6si circa 1989, I even have the original literature and sonic sound diagrams from the factory with all the inspection sign off cards for each speaker that have the inspectors initials and the date on them. I even have the business card of the sales man who sold them to my friend. But I'm not bragging or anything.......LOL. I will never get rid of my Celestion speakers never ever because they came from a dear departed friend and I like and enjoy the way they sound. They were my first true and real audio speakers. They will always be with me even if they just sit on the shelf in a closet until I use them again. They are beautiful and I consider them pieces of art.........for real.........Just the lovely cabinets and the extreme attention to detail.......they are almost 20 years old now, and people tell me the tweeter was a revolution in its time.
Well I would certainly keep a car with the same reputation ??? yes indeed.

Now back to my question: Do you know the model of my avatar ??? remember they are not the same as the one's I own.........LOL


Later
don't ya just love these little guys ? It's like that song "bang your Head". LOL

[Blue Meanie]

Hey Dougie! Read my previous reply again. I edited it to add my guess which model your avatar is while you must've been typing your reply. Damn, you must type as slowly as I do, LOL!

Jeff

[superdougiefreshness]

I was right, your not as sheltered as you had thought and yes my avatar is SL600 indeed...........How Sweet It Is. You know I have never listened to them and can not wait. I must admit I am impressed you know your stuff............
Impressed and thirsty I shall now have a nice strong drink.........or three.......

Later

[jim goulding]

You know, a viewer can click on your avatar and make a pretty informed guess as to what those speakers of yours are. Along with Blue, I had guessed that, too. Not the model exactly, only the make because of their resemblance to the last of the breed which was encased in a mid grey composite enclosure and regarded highly by many of that time. I expect many are actively in use, but, as you know, sometimes I don't know WTF I'm talking about. The publisher of an online audio review magazine, John Sunier- the magazine is Audiophile Audition- used them up until fairly recently in his surround system. There might be some information about them on his site. He mentioned them in an article about the thing that I do in the July issue.

Your comment above somewhere in bold typeface is appreciated here.

Keep it up, old bean.