Which horn on JBL 4560?

[retro soulman]

Happy new year to everyone! Well im thinking of trying a new horn on my JBL 4560 instead of my 2390 horn/lens i use now. The problem is that any crossover point upper the 500hz make the speaker system to not sound correct. At 800hz the blend of the mid frequencies with the lows is not good and you can hear that. So i need a horn that goes down to 500hz . I got the 3115a , 3110a and 3152 crossovers (also some active ones). On woofers i got the 2220 , 2205, e145, k140 , and k130. On horns i got the 2355 (total crap), the 2380 (smooth down to 500hz with great blend with the lows but missing the detail of the 2390) , and the 2390 lenses that most of the time i use the 2309 horn only cause i really like its attach and uncolored sound. I was considering the 2397 smith horn but i know that its loading is limited to 800hz only :/. Any other ideas? Regards!

[retro soulman]

With the 2309

[Riley Casey]

The 2350 radial horn was often used with the 4560. Makes life pretty hard on the 2440 / 41 drivers often used with them but that's how it goes when using a speaker cabinet designed for 1950s movie theaters. Not sure I'd characterize the 2355 as total crap just not the right tool for the job of listening in a living room. Could say the same thing about the 4560.

[Eaulive]

I guess the 2380a is a good match with the 2220, but you'll need some kind of EQ to account for the decreasing HF response due to the CD design.

That being said, I'm no expert and my experience with horns is limited.

[retro soulman]

The 2350 radial horn was often used with the 4560. Makes life pretty hard on the 2440 / 41 drivers often used with them but that's how it goes when using a speaker cabinet designed for 1950s movie theaters. Not sure I'd characterize the 2355 as total crap just not the right tool for the job of listening in a living room. Could say the same thing about the 4560.

Indeed already searching some better JBL cabinets although i was searching this original pair of 4560 for almost a decate so i cant let them go that easy. I was considering the 2386 horns. Way less distortion from the mouth of the horn and horn loading down to 400hz but still the 2397 are stacked to my head. I wonder if anyone here got them for an opinion about them

[grumpy]

2360 w/ appropriate horn contour/EQ. Sounded awesome. EQ’d low end (a bit... I’m not a basshead or subs would have been necessary). Had 2226 w/spacers in the 4560s. I believe I had SL dias in 2446 bodies. Did not use a tweeter.

Takes a bit of willpower to not just keep turning it up. :bouncy:

Ultimately, it was too tempting and I value my hearing (and at the time, my kids were learning to use the stereo). Not particularly flat, but very entertaining and enticing.

[Riley Casey]

I hadn't really connected your forum nickname to your post before but if you really want a speaker system that sounds like a live sound system from a mid 1970s R&B concert in the USA your 4560 cabinet with a 2220 driver and a 2350 horn with a 2440 on top crossed over at 800 hz with a 12db per octave electronic crossover would be exactly what the crowd would have been listening to. :D


Indeed already searching some better JBL cabinets although i was searching this original pair of 4560 for almost a decate so i cant let them go that easy. I was considering the 2386 horns. Way less distortion from the mouth of the horn and horn loading down to 400hz but still the 2397 are stacked to my head. I wonder if anyone here got them for an opinion about them

[grumpy]

Haha, from like 50+ feet away (please).

[short_circutz2]

Depending on when the cabinets were manufactured, the top panel comes off where a 2345 or 2370 horn bolts right in. The 2370 is a hair too big to fit in the opening of the older cabinet version.

Check the 4662/3. 4663 has the 2405 added to extend the top end.

I have my 4560 cabs loaded with K140 and 2345 horns with 2470 drivers with ti 'phragms.

[retro soulman]

Depending on when the cabinets were manufactured, the top panel comes off where a 2345 or 2370 horn bolts right in. The 2370 is a hair too big to fit in the opening of the older cabinet version.

Check the 4662/3. 4663 has the 2405 added to extend the top end.

I have my 4560 cabs loaded with K140 and 2345 horns with 2470 drivers with ti 'phragms.


Both are 4560a version but indeed the one cabinets opening don't fit the 2370 horn and i was really wondering why! Lol
Still i prefer 2" horn drivers cause i like the lower crossover points. What a driver can reproduce at 500hz cant a paper cone reproduce in that accuracy.

[retro soulman]

2360 w/ appropriate horn contour/EQ. Sounded awesome. EQ’d low end (a bit... I’m not a basshead or subs would have been necessary). Had 2226 w/spacers in the 4560s. I believe I had SL dias in 2446 bodies. Did not use a tweeter.

Takes a bit of willpower to not just keep turning it up. :bouncy:

Ultimately, it was too tempting and I value my hearing (and at the time, my kids were learning to use the stereo). Not particularly flat, but very entertaining and enticing.

Had the 2360 horns. Never liked their sound when crossed under 1k hz.

[jbl4ever]

If you can try some 2382’s, I think you will like that better

[retro soulman]

If you can try some 2382’s, I think you will like that better

Oh that tight slot on the horn looks nasty! I bet it effects bad in sound :/

[RMC]

Hi retro soulman,

RE "The problem is that any crossover point upper the 500hz make the speaker system to not sound correct. At 800hz the blend of the mid frequencies with the lows is not good and you can hear that. So i need a horn that goes down to 500hz."

Following a troubleshooting pattern from simpler to more complex... and trying to make good with what you have.

Assuming the driver reversed polarity issue was taken care of for a 12 db/oct crossover?

On your pic a vent opening, for vented rear chamber, shows bare plywood inside on back panel. LF driver low mid reflections in cab due to lack of damping material?

Moreover have you tried with some other LF drivers you have? e.g. K130, K140

Before jumping to conclusion about the MF horn, since you have active crossovers, hopefully with 24 db/oct, have you tested it with this? Considering these cabs provide pretty high "shelving" type response in the low mid, problem experienced might also be one of too much LF/MF overlap around xo freq. A steeper xo might help cleaning the sound?

BTW the initial 4662: 4560 with K130, 2461, 2345 and 3110. Later 4662A: 4560, E140, 2425, 2370 and 3110A (later with 2426). This might give you some additional ideas. Regards,

Richard

[retro soulman]

Hi retro soulman,

RE "The problem is that any crossover point upper the 500hz make the speaker system to not sound correct. At 800hz the blend of the mid frequencies with the lows is not good and you can hear that. So i need a horn that goes down to 500hz."

Following a troubleshooting pattern from simpler to more complex... and trying to make good with what you have.

Assuming the driver reversed polarity issue was taken care of for a 12 db/oct crossover?

On your pic a vent opening, for vented rear chamber, shows bare plywood inside on back panel. LF driver low mid reflections in cab due to lack of damping material?

Moreover have you tried with some other LF drivers you have? e.g. K130, K140

Before jumping to conclusion about the MF horn, since you have active crossovers, hopefully with 24 db/oct, have you tested it with this? Considering these cabs provide pretty high "shelving" type response in the low mid, problem experienced might also be one of too much LF/MF overlap around xo freq. A steeper xo might help cleaning the sound?

BTW the initial 4662: 4560 with K130, 2461, 2345 and 3110. Later 4662A: 4560, E140, 2425, 2370 and 3110A (later with 2426). This might give you some additional ideas. Regards,



Richard


With the bss 24db slope crossover the "broblem" is more clear. With the smooth 12db slope is not that huge. I believe the problem with these cabinets is the large distance between the horn and the woofer. With the 4530 i had no prb at all at 800hz or even higher crossover points !

[RMC]

Hi Soulman,

RE: "I believe the problem with these cabinets is the large distance between the horn and the woofer."

I have something else which may be relevant to your sound problem.

From the picture you posted, and subject to the perspective (depth) a viewer may have, it appears to me the MF/HF drivers are somewhat behind on top of the cab.

According to J. Eargle (Handbook of Sound System Design, chapter: Dividing Networks/Components Matching, section: Physical Placement of HF and LF Elements), the horn should be mounted on top of cab with its mouth flush with the front of the enclosure.

"A good rule to follow is this: mount the HF horn so that its mouth is flush with the upper edge of the LF enclosure. Then, make the polarity test and determine which poling, if either, results in the greatest output. (...) Details of this are shown in Figure 7-6B. The advantages of keeping the HF horn mouth flush with the front of the LF enclosure are minimized interferences in the crossover region and smoother vertical polar response in the crossover range." (p. 129)

There are sketches explaining this, but I'm not at liberty to reproduce all that because of copyright issues.

However, a small text says: "HF horn flush with LF enclosure, Displacement about wavelength at crossover; therefore, wire HF driver for maximum output: both outputs in phase at crossover" (p. 128)

Hopefully the above may help with the issue. Regards,

Richard

[retro soulman]

Hi Soulman,

RE: "I believe the problem with these cabinets is the large distance between the horn and the woofer."

I have something else which may be relevant to your sound problem.

From the picture you posted, and subject to the perspective (depth) a viewer may have, it appears to me the MF/HF drivers are somewhat behind on top of the cab.

According to J. Eargle (Handbook of Sound System Design, chapter: Dividing Networks/Components Matching, section: Physical Placement of HF and LF Elements), the horn should be mounted on top of cab with its mouth flush with the front of the enclosure.

"A good rule to follow is this: mount the HF horn so that its mouth is flush with the upper edge of the LF enclosure. Then, make the polarity test and determine which poling, if either, results in the greatest output. (...) Details of this are shown in Figure 7-6B. The advantages of keeping the HF horn mouth flush with the front of the LF enclosure are minimized interferences in the crossover region and smoother vertical polar response in the crossover range." (p. 129)

There are sketches explaining this, but I'm not at liberty to reproduce all that because of copyright issues.

However, a small text says: "HF horn flush with LF enclosure, Displacement about wavelength at crossover; therefore, wire HF driver for maximum output: both outputs in phase at crossover" (p. 128)

Hopefully the above may help with the issue. Regards,

Richard

You mean the lf cabinet and horn "look" at the same direction?

[Riley Casey]

I suspect he means the vertical distance between the woofer and the horn. In front loaded speaker systems this distance would likely be less than one wavelength at 1khz. When listening at a distance of two or three meters this doesn't have a big effect on arrival times from two sources and thus doesn't cause significant comb filtering. Your speaker set up has a much larger vertical distance well over a wavelength at an 800 hz crossover. Less of an issue when listening at the 10-20 meters this speaker cabinet was designed for but pretty noticeable in a home environment.

Your
You mean the lf cabinet and horn "look" at the same direction?

[retro soulman]

I suspect he means the vertical distance between the woofer and the horn. In front loaded speaker systems this distance would likely be less than one wavelength at 1khz. When listening at a distance of two or three meters this doesn't have a big effect on arrival times from two sources and thus doesn't cause significant comb filtering. Your speaker set up has a much larger vertical distance well over a wavelength at an 800 hz crossover. Less of an issue when listening at the 10-20 meters this speaker cabinet was designed for but pretty noticeable in a home environment.

Your


Ok... i need better cabs and definitely not horn loaded ! Maybe a pair of 4507 would be way better

[Riley Casey]

One trick people experimented with back in the day ( before we gave up on 4560s altogether ) was to mount a horn in the 4560 horn with the HF driver acting as a sort of low budget phase plug for the 15" low driver. Can't say I ever heard one myself but I did hear a similar concentric bass horn box that sounded pretty good ( well maybe not bad would be more accurate ). It was not as big a driver as a 2440, the driver we normally used on top of 4560s but I don't remember what it was, perhaps a 2425 or an EV. The horn was not a large 500 hz capable horn but again I don't remember what was used. Might be fun to play with if you have a small enough horn. Certainly would make the phase at crossover more coherent having an over sized coax.


Ok... i need better cabs and definitely not horn loaded ! Maybe a pair of 4507 would be way better

[retro soulman]

One trick people experimented with back in the day ( before we gave up on 4560s altogether ) was to mount a horn in the 4560 horn with the HF driver acting as a sort of low budget phase plug for the 15" low driver. Can't say I ever heard one myself but I did hear a similar concentric bass horn box that sounded pretty good ( well maybe not bad would be more accurate ). It was not as big a driver as a 2440, the driver we normally used on top of 4560s but I don't remember what it was, perhaps a 2425 or an EV. The horn was not a large 500 hz capable horn but again I don't remember what was used. Might be fun to play with if you have a small enough horn. Certainly would make the phase at crossover more coherent having an over sized coax.

No small horns here! Lol . For now i add the 2380 horns with the 2440 drivers. Smooth sound but plastic also87980

[Riley Casey]

Nothing wrong with well designed plastic horns. It’s aluminum that makes a poor material for horns. The 2350 & 55s had to be coated with plaster to reduce the resonance but never really eliminated it.


No small horns here! Lol . For now i add the 2380 horns with the 2440 drivers. Smooth sound but plastic also87980

[Mike Caldwell]

Keep in mind the JBL 2390 lenses were designed to be used with a baffle behind the lenses, I didn't see anything like that in your pictures.

Cut a piece of plywood that's about 12 inches larger in all dimensions of the 2390 lens with the horn mounted in the center. You want to assemble it so the back of lens is directly resting on the plywood baffle.

[retro soulman]

Keep in mind the JBL 2390 lenses were designed to be used with a baffle behind the lenses, I didn't see anything like that in your pictures.Cut a piece of plywood that's about 12 inches larger in all dimensions of the 2390 lens with the horn mounted in the center. You want to assemble it so the back of lens is directly resting on the plywood baffle.87985

[Mike Caldwell]

87985

Your already there!

[retro soulman]

Your already there!

Yeap i had the baffles but still not the sound i like :/

[Cyclotronguy]

Not my cabinets. Actually if anyone has photo's of my 4560's it would be Ian in Australia.... but that is another story. They ended up in my wife's office with horns stuffed into the cabinets and a 4 inch riser under the cabinet that replaced the volume lost to the the horn.

Similar to this photo, lifted from the web. They actually worked better than they had any right too. And were eventually replaced with L-300's In some ways the 4560's altered thusly are better than the L-300's They certainly project "Live" or the illusion of live better than the L-300's

https://img.usaudiomart.com/uploads/large/688953-34f3b559-jbl_45604672_rare_mahogany_restored_2225h_23452461 3110a_alnico_titanium.jpg

[jbl4ever]

The 2345 horn fits in the above cutout well. If you use the 2425/26 you will have to take off the rubber magnet protector. Still have 4 pairs
88208