Hi all!
Just wanted to post some outdoor measurements on two JBL horns that seem rarely discussed here: the 2365 and the 2385 medium throw horns. Both are 60 x 40 horns (horizontal x vertical angle) and constant directivity (using a slot). The 2385 slot is quite wide and near the driver throat.
I have read on some forums that people consider these horns to be too directive, that they (people) don’t want their “head clamped in a vise.” I am skeptical of that, 60 degrees horizontal seems pretty good dispersion, it allows plenty of people on a couch, and does minimize wall reflections. I suppose if you want everybody in a room - from wall to wall - to have the same experience, maybe, but for several people located centrally, I think a medium throw horn is fine.
Measurements presented are with a JBL 2446H compression driver with original Titanium diaphragm (I think, I was gifted these drivers). Outdoors with a grass floor, 1m high, normal horizontal orientation (horn not pointing upwards), no hard reflective surfaces nearby. None of these measurements use EQ of any kind, SPL is smoothed 1/48.
The JBL 2446H driver on JBL 2385 horn at 1m is +/- 3 dB over the range 450 HZ to 8 kHz, which seems to be a fairly flat response. I used one driver (right channel) that had some diaphragm rubbing and distortion, the left driver had the diaphragm re-centered and is used for the distortion graph. I later re-centered the right driver diaphragm and a lot of distortion went away.
The first image is comparing SPL for both horns at 1m distance.
The second image is SPL at 3m.
The third measurement shows the distortion for the left 2446 driver at 1m distance.
The fourth shows the effect of a hard surface (floor, here an Alumalite sheet) on frequency response.
The last two images are taken indoors at 1m, right driver 2446H on 2385 horn, before and after diaphragm adjustment.
Comments welcome.
The 2365 horns are for sale BTW, too big for my listening space.
Jamie
Just wanted to post some outdoor measurements on two JBL horns that seem rarely discussed here: the 2365 and the 2385 medium throw horns. Both are 60 x 40 horns (horizontal x vertical angle) and constant directivity (using a slot). The 2385 slot is quite wide and near the driver throat.
I have read on some forums that people consider these horns to be too directive, that they (people) don’t want their “head clamped in a vise.” I am skeptical of that, 60 degrees horizontal seems pretty good dispersion, it allows plenty of people on a couch, and does minimize wall reflections. I suppose if you want everybody in a room - from wall to wall - to have the same experience, maybe, but for several people located centrally, I think a medium throw horn is fine.
Measurements presented are with a JBL 2446H compression driver with original Titanium diaphragm (I think, I was gifted these drivers). Outdoors with a grass floor, 1m high, normal horizontal orientation (horn not pointing upwards), no hard reflective surfaces nearby. None of these measurements use EQ of any kind, SPL is smoothed 1/48.
The JBL 2446H driver on JBL 2385 horn at 1m is +/- 3 dB over the range 450 HZ to 8 kHz, which seems to be a fairly flat response. I used one driver (right channel) that had some diaphragm rubbing and distortion, the left driver had the diaphragm re-centered and is used for the distortion graph. I later re-centered the right driver diaphragm and a lot of distortion went away.
The first image is comparing SPL for both horns at 1m distance.
The second image is SPL at 3m.
The third measurement shows the distortion for the left 2446 driver at 1m distance.
The fourth shows the effect of a hard surface (floor, here an Alumalite sheet) on frequency response.
The last two images are taken indoors at 1m, right driver 2446H on 2385 horn, before and after diaphragm adjustment.
Comments welcome.
The 2365 horns are for sale BTW, too big for my listening space.
Jamie
Attachments
Owned a 2365 for years. It has some drawbacks, but it`s also one of a few horns out there that really help depth by it`s big format.
Big, really lively and more realistic sound than most, if you take good care in the electronics behind it.
Do need tweeters and at least 3 meters listening distance.
Big, really lively and more realistic sound than most, if you take good care in the electronics behind it.
Do need tweeters and at least 3 meters listening distance.
Jamie,
I have preferred the more defined coverage of the JBL 60 degree over the 90 degree pattern horns, especially at the edge of the coverage pattern.
Interesting to see the much larger JBL 2365 horn is -3dB less sensitive in all but the region below 400Hz compared to the flat front Bi-Radial 2385, don't recall ever seeing the comparison before, it surprised me.
Also interesting to see the effect of diaphragm re-centering on distortion, many people don't even consider that, expecting the pins to do the alignment.
The effect of grass on eliminating much of the floor bounce comb-filtering gets my vote for a plush rug between the speakers and couch
Art
Are you sure about those numbers? Comparing the 2385 sheet with the 2365 here shows the sensitivity specs within 1 db, with the edge going to the big horn.
Sorry, I should have been more clear. I did not drive these with exactly the same level, though in hindsight I should have. I was mostly interested in the relative response over the frequency range, not the absolute response. For the first measurement above (at 1m), the 2385 horn was generating -28.0 dBFS according to REW, while the 2365 horn was generating -30.3 dBFS (i.e. quieter). Hence the lower SPL observed. It took a few hours to set up and measure, so not sure I'll repeat it anytime soon.
I have redone the measurements. Equal input level for all tests (receiver volume setting unchanged between tests, CD moved between horns while connected). Outdoors, 1m and 3m, 0.9m above a grass surface (2 inch grass and uneven surface). The 3m measurements seem to show some floor reflection off the grass, but not strong like the Alumalite hard floor (above). Each distance (1m and 3m) measured from the horn mouth. Note that the 2365 is over 50cm longer than the 2385, so the microphone is further from the CD with the 2365 horn.
Jamie
Jamie
I should note that I checked the levels using the REW "Check Levels" button (probably pink noise). No level adjustment between measurements. (No EQ of any sort either.)
At 1m from horn mouth:
2385 was 99.5 dB
2365 was 100.8 dB (1.3 dB louder)
At 3m from horn mouth:
2385 was 91.6 dB
2365 was 93.7 dB (2.1 dB louder)
Jamie
At 1m from horn mouth:
2385 was 99.5 dB
2365 was 100.8 dB (1.3 dB louder)
At 3m from horn mouth:
2385 was 91.6 dB
2365 was 93.7 dB (2.1 dB louder)
Jamie