PA Midrange Help

[2$Bill]

All:

I am a PA used-to-be who is looking for additional thinking for a midrange speaker for a new system. Be it known that (1) I am not much of a woodworker and (2) I want to use stock on hand.

The low end will be a pair of JBL AS1015-STD (2226Hs) and the high end be a pair of 2446Js on 2382As horns - initial thinking of crossing over at 300 and 1200 Hz. My midrange choices are one E120 (12") or a pair of 2118s (8") in closed boxes. Bass Box calculations (as much as I am capable of understanding) are basically equal.

My concerns are that one E120 weighs more than a pair of 2118s, but the 2118s will need to be stacked horizontally as opposed to vertically (what I understand to be best).

Of course, I want whatever will work best and sound best with the least amount of woodworking. Input will be greatly appreciated.

[Mannermusic]

All:

I am a PA used-to-be who is looking for additional thinking for a midrange speaker for a new system. Be it known that (1) I am not much of a woodworker and (2) I want to use stock on hand.

The low end will be a pair of JBL AS1015-STD (2226Hs) and the high end be a pair of 2446Js on 2382As horns - initial thinking of crossing over at 300 and 1200 Hz. My midrange choices are one E120 (12") or a pair of 2118s (8") in closed boxes. Bass Box calculations (as much as I am capable of understanding) are basically equal.

My concerns are that one E120 weighs more than a pair of 2118s, but the 2118s will need to be stacked horizontally as opposed to vertically (what I understand to be best).

Of course, I want whatever will work best and sound best with the least amount of woodworking. Input will be greatly appreciated.

Not a PA guy but I use something similar for my home system except single drivers. I use a E110 but with a paper cap which I like a lot. Crossover 275/1200. I've experimented with the 2118 as well and found it also sounds "good" but is not as incisive, quick, transparent - "in your face" (I love in your face). Like they are standing there playing in the room - excellent for jazz. The 2118, by comparison, is more "pleasant," a lot of people would probably prefer it. Edges rounded slightly, not as ruthlessly transparent. Slightly "warm." But, for PA, I'd think you'd want the E120. I assume it's like the E110 only moreso; power capacity, efficiency, 4" voice coil. Sounds made for serious PA. Just one cat's thots! Good luck.

[4343]

Not a PA guy but I use something similar for my home system except single drivers. I use a E110 but with a paper cap which I like a lot. ....

That's what led to the 2223H, it's just a reconed E110, optimized for PA mid use. Slight rising response, which can be tamed with the right crossover. I used this one:

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/4344MkII%20ts.pdf

[Mike F]

Why do you feel the need for a mid? Both woofer and horn would gladly meet at the +/- 1Khz area.

[Hans Bleeker]

Why do you feel the need for a mid? Both woofer and horn would gladly meet at the +/- 1Khz area.

http://www.google.nl/search?q=jbl+4770a&hl=nl&tbo=u&tbm=isch&source=univ&sa=X&ei=FaTEUKqbJanP0QWRv4CoCw&ved=0CEUQsAQ&biw=1053&bih=636
There's a 46xx version too.
www.jblpro.com/pub/obsolete/Concert_Series.pdf (http://www.jblpro.com/pub/obsolete/Concert_Series.pdf)

I used to use those 4771's, they where great and would go SERIOUS loud, else I would suggest a 2206, in my opinion closest match sound wise to the 2226.

[subwoof]

I have a boatload of 2123H's from a pair of theater installs - PM for a price...also some of the newer Nd 2250H 8" as used in the line array. Very light, powerful, frame is squared off and these HAVE an integral shell for isolation so you don't have to make a doghouse...:)

I don't have any online source on the JBL site to tell me it's operating range but it should do 300 with little problem.

The 2118 is way way under powered compared to the 15 and/or 2" and the paper cones on those tend to "fold" or crease right at the first rib up from the dustcap - can't tell you how many I have seen that failed that way. The coil is only 2" and the heat buildup is an issue.

The E110 is a great speaker also but (A) it has an aluminum voice coil ( easier to open up under high power ) and an aluminum dustcap ( a bit harsh sometimes ) and the biggest reason: it is a sound "producer" - meant for electric instrumentation on stage.

The 2123H is a sound "reproducer" - meant for playback systems and used where the coloration of the musical instrument types is not recommended.

if you want another direction idea, I have a pair of MF/HF assemblies from a pair of 3115 install cabinets that are fully loaded and have crossovers... the 2119 / M209-8A was weatherized and the HF drivers are like new...

http://www.jblproservice.com/pdf/AS%20Series/CS3115.pdf

sub

[ivica]

..........

The E110 is a great speaker also but (A) it has an aluminum voice coil ( easier to open up under high power ) and an aluminum dustcap ( a bit harsh sometimes ) and the biggest reason: it is a sound "producer" - meant for electric instrumentation on stage.

The 2123H is a sound "reproducer" - meant for playback systems and used where the coloration of the musical instrument types is not recommended.

.........
sub

Hi SUBWOOF,

It would be nice if you have any idea where can be found The Distortion measurements for E110 in correlation with the applied power. Owing to its construction of the VC-length and Top-Plate thickness, I can imagine that for not too high power, such driver can be used as mid-bass for the home listening, for sure without AL-dust cup.

Regards
Ivica

[subwoof]

Most of the "distortion" can be attributed to the fact that the E110 voice coil will be driven out of the gap with little effort as compared to the 2123 which has a MUCH deeper coil. this over-emphasizes low volume use at the expense of large bursts which will be attenuated - perfect for guitar on stage but not PA / playback.

it's called Xmax

JBL does publish ( internally ) data sheets with those specs and *some* are in the tech library section on this site thanks to 4313B's effort but NOT all. I suggest you contact JBL and see if they can send one to you.

see this thread:

http://www.audioheritage.org/vbulletin/showthread.php?16962-Field-Guide-to-the-JBL-10-inch-Midbass-driver-2121-2122-2123

[ivica]

Most of the "distortion" can be attributed to the fact that the E110 voice coil will be driven out of the gap with little effort as compared to the 2123 which has a MUCH deeper coil. this over-emphasizes low volume use at the expense of large bursts which will be attenuated - perfect for guitar on stage but not PA / playback.

it's called Xmax

JBL does publish ( internally ) data sheets with those specs and *some* are in the tech library section on this site thanks to 4313B's effort but NOT all. I suggest you contact JBL and see if they can send one to you.

see this thread:

http://www.audioheritage.org/vbulletin/showthread.php?16962-Field-Guide-to-the-JBL-10-inch-Midbass-driver-2121-2122-2123
Hi SUBWOOF,

All the things you have mentioned are known to me, but owing to the fact that if E110 is used from over 300Hz, the cone movements are not too much, I can guess that less then 1mm Xmax, so owing to that and the coil size and large top-plate, I wonder that for about of up to 10W, which would be quite loud for home listening , may be the 2-nd and 3-rd distortions would not be too much. Unfortunately such data are not presented on any JBL official data, so if You, or any other know more abut, it would be interesting to be seen.
My friend who has 4345 with 2122 installed, has told me that when he has tried k110 INSTEAD OF 2122, it had seamed him almost the same.

Regards
Ivica

[Mannermusic]

Hi SUBWOOF,

All the things you have mentioned are known to me, but owing to the fact that if E110 is used from over 300Hz, the cone movements are not too much, I can guess that less then 1mm Xmax, so owing to that and the coil size and large top-plate, I wonder that for about of up to 10W, which would be quite loud for home listening , may be the 2-nd and 3-rd distortions would not be too much. Unfortunately such data are not presented on any JBL official data, so if You, or any other know more abut, it would be interesting to be seen.
My friend who has 4345 with 2122 installed, has told me that when he has tried k110 INSTEAD OF 2122, it had seamed him almost the same.

Regards
Ivica

Hi Ivica. Check out post #2 above. Thanks for the feedback on your friends 4345 experience. Verifies what I suspected.

P.S. The rig above produces 90+ db @ 1 watt in my listening room. Would seem futile to compare home requirements to pro audio requirements. Two different Universes.

[ivica]

Hi Ivica. Check out post #2 above. Thanks for the feedback on your friends 4345 experience. Verifies what I suspected.

P.S. The rig above produces 90+ db @ 1 watt in my listening room. Would seem futile to compare home requirements to pro audio requirements. Two different Universes.

Hi Mannermusic,

Looking at the:
http://www.audioheritage.org/vbulletin/showthread.php?16962-Field-Guide-to-the-JBL-10-inch-Midbass-driver-2121-2122-2123&p=319806&viewfull=1#post319806

I think that some HF-dumping has to be 'add' in the network in the E110 usage instead of appropriated one 2122/2123

Regards
Ivica

[Mannermusic]

Hi Mannermusic,

Looking at the:
http://www.audioheritage.org/vbulletin/showthread.php?16962-Field-Guide-to-the-JBL-10-inch-Midbass-driver-2121-2122-2123&p=319806&viewfull=1#post319806

I think that some HF-dumping has to be 'add' in the network in the E110 usage instead of appropriated one 2122/2123

Regards
Ivica

Agree!

[Baron030]

Hi 2$Bill
I have been meaning to respond to this thread for some time now. Some of the components that you are thinking of using for your PA project are actually in my home stereo system. So, I can offer some advice. If you really want to use crossover points of 300Hz to 1200Hz then a 12” driver may be the better way to go (2206H or 2262H). The 8” or 10” drivers that are being suggested will actually perform better with a slightly higher crossover point of 400Hz or above. In my own system, I use a 2012H driver, which is not at all popular around here because it does require equalization to get it to sound right. But, the 2012H driver is actually a very good driver. It’s very clean sounding and it can handle a lot of power. But, I can only recommend it, provided that you using a graphic equalizer or possibly use the following passive EQ network with a tri-amped system.

http://www.audioheritage.org/vbulletin/showthread.php?20823-4345-DIY (Post # 3)

And the main reason why I am suggesting the 2206H or 2262H driver is that it gives you the freedom of going with much lower crossover point, which would put more of the vocal range into the midrange driver. And fundamentally, the point of adding a midrange driver is to reduce intermodulation distortion and to reduce power compression within the 2226H woofers by re-directing some of the PA systems power into a midrange driver. And the higher power handling characteristics of a 2206H or 2262H would be a better choice than the E120, from a power compression point of view.

Without getting to far off the subject, the 2446/2382a combination does roll off pretty abruptly at 10 KHz. So, I would recommend that you add a UHF driver to your system.

Baron030:)

[2$Bill]

Thank you to all who have replied.

Most of my initial thinking came from viewing JBL product lines. The why of a midrange at all comes from JBL, in both consumer and pro lines, use of a cone midranges in so many systems. I always figured JBL knew more than me.

The 300 and 1200 Hz crossover points came from Drew Daniels' use of those frequencies for his crossover points with 2123s.

Obviously I have not made any decisions, so I am still open to continued discussion.

Again, thank you for everyone's experiences,

Bill

[2$Bill]

"Without getting to far off the subject, the 2446/2382a combination does roll off pretty abruptly at 10 KHz. So, I would recommend that you add a UHF driver to your system."

I also have a 2380A horn. From a non-engineer stand point, I have been weighing the +/-s of using the 2382A or the 2380A.

Thanks,

Bill

[Baron030]

The response curve that I measured with my own 2446H/2382a combination very closely matches the JBL published results found in their 2382a.pdf. So, even though the links below are for 2300 series horns equipped with 2445 drivers. The frequency response differences between a 2446 and a 2445 driver appear to be are pretty minor. In my own system, I set an active crossover point for the 2446H/2382a combination and a 2405 driver at about 7.5 KHz. Without a UHF driver, I don’t think you would like the sound of the 2382a horn unless you were to use an awful lot of active EQ.

http://www.jblpro.com/pages/pub/components/2380a.pdf
http://www.jblpro.com/pages/pub/components/2382a.pdf
http://www.jblpro.com/pages/pub/components/2385a.pdf

Baron030:)

[Mannermusic]

The response curve that I measured with my own 2446H/2382a combination very closely matches the JBL published results found in their 2382a.pdf. So, even though the links below are for 2300 series horns equipped with 2445 drivers. The frequency response differences between a 2446 and a 2445 driver appear to be are pretty minor. In my own system, I set an active crossover point for the 2446H/2382a combination and a 2405 driver at about 7.5 KHz. Without a UHF driver, I don’t think you would like the sound of the 2382a horn unless you were to use an awful lot of active EQ.

http://www.jblpro.com/pages/pub/components/2380a.pdf
http://www.jblpro.com/pages/pub/components/2382a.pdf
http://www.jblpro.com/pages/pub/components/2385a.pdf

Baron030:)

Hi Baron - How's the weather on the other side of the lake? It's apparently spring here - the local Sand Hill Cranes have returned for the summer (not kidding)! Anyway, definitely agree with you on the 2382A for hi fi. Spent a lot of time with EQ, crossover ptes, slopes, active, passive, you name it. It's not a hi fi horn in my estimation - sounds kind of flat, dead. Miss the high frequency compression that is part of the old JBL exponential horns. It's a trade-off. The 2382A, especially, is intended for maximum dispersion - likely a major reason D.D. used them in the Disney rig. Realistic simulation of Saturn V launch, not hi fi. But, depends on what Bill is looking for - we haven't heard back. He was indicating PA so it might be just the ticket for his app. Have a good holiday! Mike

[Baron030]

Hi Mannermusic
Well, I can’t say how my 2382a horns stack up against other JBL horns.
I just don’t have any experience to go on.
You see I went straight from a 030 system to a system inspired by Drew Daniel’s “Ancient Audiophile’s Quest for the Ultimate Home System” project.
Unfortunately, I don’t have the room for the four 2242 sub-woofers to really complete the project.
So, I had to just make do with the small 15” four-way satellite speakers. :rotfl:

Bill, I would think that for a PA a longer reach would be better.
So, the 2380 or 2385 might give more gain before microphone feedback kicks in, and for reproducing sibilance it pretty hard to beat a ring radiator.
And if the budget will not allow for classic JBL UHF drivers, then maybe the new JBL Selenium ST400 might work.:dont-know:

Baron030:)

[Mannermusic]

With you, on the money. And, if you ever decide (or get a contract for) simulating a Saturn V launch, you can always add the subs!:D In the meantime, there is enough info here to keep Bill busy for a couple years.

[Baron030]

Hi 2$Bill

Getting back to the subject of a PA midrange driver, you might be tempted to mount the midrange in a small box and then stack it to one side of the high frequency horn. From firsthand experience, I would not recommend it. The on axis frequency response is not affected, but moving off-axis there are some really bad sounding phase cancelations and the frequency response gets really choppy. So, the midrange driver really does need to be centered vertically under the high frequency horn for best results.

Baron030:)

[subwoof]

A couple of custom club cabinets I built back in the 80's required a pretty low vertical profile and as mentioned, side by side MF/HF did cause some issues.

I would use the 2380 horn and would cut out a section of the lower curve/flange and it would be replaced by the top panel of the 10" mid's chamber - a little bondo and paint and it actually looked nice. Alas I didn't take any pics of them but JBL did a similar cutaway around the same time with the 2344 in their concert series 4828 wedges ( still have a pair ) .

With the pile of 2380's and 2123's sitting in the storage room I just might recreate a batch this summer...need to flex the tablesaw after a long dormancy...:)

Of course being past that age, would need to add a 2404 into the assembly.