PDA

View Full Version : Who says JBL doesn’t make affordable high performance horn systems???



Tweak48
12-10-2005, 04:42 PM
The JBL 4670D (http://www.jblpro.com/pages/cinema/4000.htm) from their cinema series is a large format system that happens to make a dynamite hi-fi system if you have the room to let them breathe. My dad wanted to update the speakers in his cabin which consists mostly of a large 40X25 room with high ceilings. He felt that the LF and HF extension from the old Stephens speakers you see below were just not up to the job. Finding new diaphragms, reconing, regaussing the magnets, and rebuilding the crossovers was just more than he wanted to deal with at his age, so I said “put ‘em on eBay and buy new ones.” After some 18 hours on eBay, some cat from Korea asked me how much I would want to end the auction; I hesitated for a minute and said $4000, and he said “sold!” He paid for crating and for BAX Global to pick them up and away they went.

Anyway, I got a hold of a local cinema contractor and ordered a pair (a separate franchise from JBL Pro; the sound reinforcement and musical instrument guys can’t get these). The price: a very reasonable $3000 including shipping.

With 100 db sensitivity, these things absolutely sing with his 35 watt Marantz triode amps. Dynamics are thunderous. HF extension is very nice, perhaps a little more laid back than my 4425’s or L-300s. Transients from gut strings on an classical gutiar are both powerful and delicate, This is my first experience with a 500hz horn, and for the first time I appreciate what those Altec 511 guys are talking about. Talk about liquid mids! I did not have enough time to evaluate them in the 75 watt pentode mode, they might have been even more impressive. To top it off , my dad had room to add some small bookcases with the left over space in the soffuts, as you can see from the photo below. I still have to work out some speaker grills however.

Why more HT contractors aren’t using these in custom home installations, is beyond me. I'm sure those Project Array 1400's are very nice speakers, but they're probably more than $3000 delivered.

http://audioheritage.org/vbulletin/attachment.php?attachmentid=9409&stc=1


http://audioheritage.org/vbulletin/attachment.php?attachmentid=11525&stc=1

http://audioheritage.org/vbulletin/attachment.php?attachmentid=11526&stc=1

johnaec
12-10-2005, 07:19 PM
Do those have a built-in crossover? JBL says 800hz crossover is recommended - the 2380A drops like a rock below 800 hz, and is a good 10dB down at 500 hz with the 2446.

I've got 2380A's with 2446 drivers crossed over at 800 hz and really like it, (single 2206H for LF now - soon to be 2226H, for PA use).

John

Tweak48
12-10-2005, 09:30 PM
Yes, crossovers are included with this system. The link I posted must be a misprint. Both the 4670D and 4675C use the 2446 at 500 hz per the attached full line cinema brochure and from the owners manual.

http://audioheritage.org/vbulletin/attachment.php?attachmentid=11528&stc=1

Zilch
12-11-2005, 12:14 AM
http://www.jblproservice.com/pdf/Theatre%20Series/4638TH.pdf

JonathanKeehn
12-11-2005, 04:19 PM
Great choice! You've picked a system that will put to shame about 99% of the so-called high-end systems out there, and for a very reasonable price. This what affordable high-end audio is now all about.

mikebake
12-11-2005, 05:09 PM
So what is correct here? 500hz?

Anyway, neat solution for the big room. Some would decry "not hi-fi" enough, but certainly a satisfying system. Way to go.

Zilch
12-11-2005, 06:14 PM
So what is correct here? 500hz?Crossover's 500 Hz according to the tech sheet. 18 dB/octave, looks like.

Johnaec just dropped of a 2446J mounted to a 2380A for testing here. We installed a new D16R2450 diaphragm in it.

I'll have some results soon's I get it appropriately mounted on an engine hoist.... :p