Its started out as a curiousness on what these are. found it in a pile of office demolition e-waste. looked interesting.
so like any IT guy, I searched online.
jblpro.com
Found that each speaker have 8 x 2inch drivers in a line array and they attenuates the signal to each driver in a specific way (ref: JBL web page: to accomplish consistent vertical coverage without the narrow vertical beaming and out-of-coverage lobing that are typical of straight form-factor passive column speakers.)
interesting.
ok, now what?, I assumed it would need 70v/100v amps to drive them, since they are the defacto standard in installation series speakers. that is , IF it works.
However, I brought them home in the hope that I could dismantle them and see whats inside and learn a trick or 2 , salvage for a DIY line array. (Always secretly wanted a line array, even though I have massive horn speakers in my system)
cleaned them up . removed paint, stickers...
a pleasant surprise: turns out its got couple of selection button on its side (which was covered by a black sticker)
1. Tap select: can select between 70v, 100v, or ....8 Ohms
2. equalization: select between Music / Speech
You Guessed my next move, Selected 8 Ohms, and Music
Hooked them up to my desktop tube amp, and fired them up. next surprise, they work. just like that. except, no bottom end.
Looked at the JBL spec sheet, its rated 80Hz - 20kHz. that explains why there is no bottom end.
Had a FB market place find of a Jensen dual driver Sub hiding under my table for a long time. this was also a rescue job Sub. cheap as chips when I got it. (had to strip it, peel off the paint and vinyl and repaint them, rewire them, change couple of caps etc) it was looking like my crapped out back yard. now it got matt black paint ( and the back yard got new lawn as well )
Routed the tube amp output through the Jensen Sub. (Low-pass / High-pass filter) and then to the JBL CBT.
I now have a desktop system thats very hard to beat.
Its sooooo clear, I could play it real low for background music, or crank them up.
even at very low volumes delicate drum hi-hat works tingles you. no wonder these are used extensively for places of worships etc. everything is clear.
Surprisingly the low power tube amp seems to drive them quite ok, at least in a 5m X 5m room, its more than enough.
so far its sitting on my work desk in my man cave.
This is so good, I am already thinking abt mounting them somewhere in the room, and Measure / correct it using DSP / Peq and see where it goes, I do have couple of other amps if needed if I find DSP correction is not working out on the tube amp.
so like any IT guy, I searched online.
JBL Professional CBT 50LA-1
Constant Beamwidth Technology™ Line Array Column Loudspeaker with Eight 50 mm (2 in) Drivers. Wit...
jblpro.com
Found that each speaker have 8 x 2inch drivers in a line array and they attenuates the signal to each driver in a specific way (ref: JBL web page: to accomplish consistent vertical coverage without the narrow vertical beaming and out-of-coverage lobing that are typical of straight form-factor passive column speakers.)
interesting.
ok, now what?, I assumed it would need 70v/100v amps to drive them, since they are the defacto standard in installation series speakers. that is , IF it works.
However, I brought them home in the hope that I could dismantle them and see whats inside and learn a trick or 2 , salvage for a DIY line array. (Always secretly wanted a line array, even though I have massive horn speakers in my system)
cleaned them up . removed paint, stickers...
a pleasant surprise: turns out its got couple of selection button on its side (which was covered by a black sticker)
1. Tap select: can select between 70v, 100v, or ....8 Ohms
2. equalization: select between Music / Speech
You Guessed my next move, Selected 8 Ohms, and Music
Hooked them up to my desktop tube amp, and fired them up. next surprise, they work. just like that. except, no bottom end.
Looked at the JBL spec sheet, its rated 80Hz - 20kHz. that explains why there is no bottom end.
Had a FB market place find of a Jensen dual driver Sub hiding under my table for a long time. this was also a rescue job Sub. cheap as chips when I got it. (had to strip it, peel off the paint and vinyl and repaint them, rewire them, change couple of caps etc) it was looking like my crapped out back yard. now it got matt black paint ( and the back yard got new lawn as well )
Routed the tube amp output through the Jensen Sub. (Low-pass / High-pass filter) and then to the JBL CBT.
I now have a desktop system thats very hard to beat.
Its sooooo clear, I could play it real low for background music, or crank them up.
even at very low volumes delicate drum hi-hat works tingles you. no wonder these are used extensively for places of worships etc. everything is clear.
Surprisingly the low power tube amp seems to drive them quite ok, at least in a 5m X 5m room, its more than enough.
so far its sitting on my work desk in my man cave.
This is so good, I am already thinking abt mounting them somewhere in the room, and Measure / correct it using DSP / Peq and see where it goes, I do have couple of other amps if needed if I find DSP correction is not working out on the tube amp.
