Unconventional use of JBL compression driver

[ginetto61]

Hello to Everyone !

I have a curiosity
Searching for info on JBL compression driver I found a message mentioning Stan Ricker, a mastering specialist
It seems he uses as a monitoring system JBL compression drivers backwards with the rear cover off in a line array :blink:
I would like to get opinions on this unconventional use of compression drivers
Is there any advantage in this technique ?

Thank you very much indeed
Kind regards, :D
gino

[ginetto61]

Hello, I have found something more on the subject

http://www.cardas.com/content.php?area=insights&content_id=16&pagestring=Record+Mastering,+an+interview+with+Sta n+Ricker+Part+3

They talk about an impressive "monitoring system without enclosures"
But no much more unfortunately
I understand that without horns the drivers' efficiency drops in a quite remarkable way
But what about the sound ?
I am trying to convince a friend of mine to perform some experiment
Not easy I am afraid, he calls me crazy :o:
Good evening :D
gino

[4313B]

It seems he uses as a monitoring system JBL compression drivers backwards with the rear cover off in a line array :blink:

1988 CASCADE (http://www.lansingheritage.org/html/jbl/specs/home-speakers/1988-cascade.htm)

[MikeBrewster77]

Be cautious about what links you open if you do a Google search for "JBL Cascade" :barf:

[ginetto61]

1988 CASCADE (http://www.lansingheritage.org/html/jbl/specs/home-speakers/1988-cascade.htm)

Very very interesting indeed. Thank you sincerely for the link
It is not much the line array placement of drivers that intrigues me, but the use of compression drivers backwards without bottom cover (maybe connected with inverted phase ... do not know)
After all compression drivers are ultra performance domes ...
Very very intriguing
Kind regards,
gino

[4313B]

It is not much the line array placement of drivers that intrigues me, but the use of compression drivers backwards without bottom cover (maybe connected with inverted phase ... do not know)

1989 XPL SERIES (http://www.lansingheritage.org/html/jbl/specs/home-speakers/1989-xpl.htm)

[ginetto61]

Thanks a lot for the kind information
So no news under the sun ...
Sometimes I think that the risk of reinventing the wheel is for real
nevertheless I like very much these old JBL series of speakers
Kind regards,
gino

[Horn Savant]

1980's MIX magazine featured recording studio in Denmark that did this w/ large JBL compression drivers run as dome midrange (cover removed).

It inspired me to try it using Altec 288's at the time .

[Steve Schell]

One several occasions I have resorted to using a screwdriver as a chisel or pry bar. This can work in a pinch, though there are disadvantages. Likewise I have found that using a compression driver as a direct radiator can work, though not very well IME.

First of all there is a drastic loss of sensitivity, probably 15 to 20dB. Both the compression loading and horn loading are lost. The driver, intended to see this loading, has extremely limited excursion capability. Distortion will rise drastically if the designed excursion is exceeded, and diaphragm suspension failure may run close behind. I think that unless one is simply making do with what is on hand, it would be better to use a purpose-built direct radiator.

Mostly I have heard of folks like Alan Sides using small format compression drivers as direct radiator tweeters. I can see how this could work if there is enough crossover protection, though with higher distortion and limited output capability. What one would have would be a large and expensive dome tweeter, a device we normally run screaming from when we move to horns!

[MickeyFinn]

Be cautious about what links you open if you do a Google search for "JBL Cascade" :barf:

Indeed! Too funny...

[ginetto61]

Thank you very much for your very helpful replies
It was basically a curiosity reading of that high end monitoring system
I understand that is much better to use the drivers in the traditional way
And a different use can even damage the units
Kind regards,
gino