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JBL 2360A Horns on KPT-904's?


mustang guy

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Has anybody tested these? I am looking for some tops to my kpt-904's, and these seem readily available. They are similar to the K402 in output and coverage. They accept a 2" driver, and there are some great options out there for that.

 

Here are the JBL 2360A specs:

 

Specifications:
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Horizontal Coverage Angle Degrees (-6 dB): 90° ( +5°, -20°)
Vertical Coverage Angle Degrees ( -6 dB): 50° (+20°, -22°)
Average Range: 500 Hz  16 kHz
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Directivity Factor (Q): 14 (+14, -7)
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Directivity Index (DI): 11.5 dB (+3,  3 dB) 
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Usable Low Frequency Limit: 300 Hz
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Minimum Recommended Crossover Frequency (using 2427, 2445, 2450): 500 Hz
Minimum Recommended Crossover Frequency (using 2485): 350 Hz
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Axial Pressure Sensitivity: Measured on axis in the far field with 1 watt input (2.83 V rms, 8 ohms; 4.0 V rms, 16 ohms) and referred to a 1 meter distance calculated by inverse square law. Listed sound pressure level (SPL re 20 mPa) represents an average from 630 Hz to 4 kHz using the JBL 2446, 2450, or 2485 driver.
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1 Watt/ 1 Meter Axial Sensitivity: 113 dB SPL
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Construction:
Horn Bell: Molded reinforced urethane resin
Horn Throat: Aluminum, sand cast (nominal 7.5 mm [5/16 in] wall thickness).
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Overall Dimensions: (with throat attached)
Mouth Height: 795 mm (31 5/16 in)
Mouth Width: 795 mm (31 5/16 in)
Length: 815 mm (3 27/64 in)
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Net Weight: 12.2 kg (27 lb)
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I was thinking the same thing when you posted those 3 904's for sale, It just seems wrong to put the JBL's on top of the Klipsch lf.  Though you got to do what you got to do.  I have heard with the right driver the JBL's are the next best thing to the K-402. I have considered buying a pair myself, and still giving a try. I would like to compare a horn that large to the EV's I have.   One thing I think may be an issue( which probably wouldn't take much to fix) is the depth of the speaker, as they are pretty deep.  Good luck with what you are trying to achieve.  Following to see what unravels. 

Edited by duder1982
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I would completely bi-amp them. Already have the electronic crossover....

Your ready then...I would not hesitate. Iv heard my share of each in quite a few setups although not exactly as your presenting....I know for sure I would take it a little at a time and get the job done. I bet you just melt once dialed in completely.

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"Is there any information on this? "

Analysis of Nonlinearities in Compression Drivers and Horns

This paper shows the main cause of distortion in compression drivers is the air nonlinearity that occurs in the horn and not in the transducer

 

Costs $20 to read the PDF at the JAES (don't waste your money).

 

 

"Is it at certain frequencies only?"

 

Yes, high frequencies.

 

ALL horns with narrow diffraction slots have this issue.

 

When I first heard this I thought I had a bad driver/amp/crossover, but that sound is from the narrow slot in the horns. I have heard this in all brands that are built like this, the narrower the slot is, the worse it sounds.

 

I first heard it with PA, and was thus able to recognize it when hearing it in movie theaters (sounds like 'quacking', 'frying bacon' etc).

 

How loud?

 

Just holding various horns to your mouth and then speaking through them in a normal voice will show you the differences in the horns.
 

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"Is there any information on this? "

Analysis of Nonlinearities in Compression Drivers and Horns

This paper shows the main cause of distortion in compression drivers is the air nonlinearity that occurs in the horn and not in the transducer

 

Costs $20 to read the PDF at the JAES (don't waste your money).

 

 

"Is it at certain frequencies only?"

 

Yes, high frequencies.

 

ALL horns with narrow diffraction slots have this issue.

 

When I first heard this I thought I had a bad driver/amp/crossover, but that sound is from the narrow slot in the horns. I have heard this in all brands that are built like this, the narrower the slot is, the worse it sounds.

 

I first heard it with PA, and was thus able to recognize it when hearing it in movie theaters (sounds like 'quacking', 'frying bacon' etc).

 

How loud?

 

Just holding various horns to your mouth and then speaking through them in a normal voice will show you the differences in the horns.

 

You can get around this by using them at lower volumes and/or using them as a midrange in a 3-way. Boosting HF on titanium drivers with their resonances also add some "bad stuff" to the mix. Using their natural rolloff without shelving boost gets around it pretty well. The K-402 is still a superior horn shape since it has no slot.

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I want to add something to this mix. The JBL is one of the ugliest horns I have ever seen. From reviews, the materials and construction are substandard. I can't get over how It looks like you are staring at a horse's a$$ when you look at them head on.

 

JBL+2360A,+Bi-radial+horn+for+2+inch+drihorse-s-ass-2483689.jpg

Edited by mustang guy
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The problems the horn's sonics are partly mitigated if you use a crossover frequency above 700-800Hz. The harshness seem worse when you cross at 500Hz

Yes indeed. I had mine in a 4-way setup before I got a K-402. I used a pair of Peavey MB-1's from 180-700 Hz. then went 700 Hz. on up 6 Khz. with the JBL "elephant butt cheek" horn. A lot depends on the driver used and the PEQ settings if you want better performance from 500-700 Hz.

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"Using their natural rolloff without shelving boost gets around it pretty well. "   Dream on.

 

LOL.

I used mine with a very limited bandwidth at extremely low power (80-85 db at sweet spot), so it was a reality in my application.

Edited by ClaudeJ1
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The low power is the key, but the narrow slots still sound 'less good' than horns without these diffraction slots.

Indeed you are correct. But the 2360 is still better than so many other horns on the market when it's virtues are maximized and it's anomalies minimized. JBL did get an Academy Award for it, so it and it was used in lots of theaters 20 years ago. It has always been matched to a direct radiator bottom, presumably because JBL 15's can play up to the 700 Hz. range easily.

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"JBL did get an Academy Award for it,"

 

And I had to leave the theater during 'The Mambo Kings', the 'frying' and 'quacking' noises were so bad (and the level was only about 85dB).

 

http://www.imdb.com/title/tt0104802/?ref_=fn_al_tt_1

 

Mainly a problem with trumpet notes (in the movie), but a very real problem with vocals in a PA (and I don't run it all that loud, say 105dB at the FOH position).

 

Listening at my home with normal spoken word (about 70dB) you can hear how un-natual the horns with slots sound.

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