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tony359
02-08-2006, 12:29 PM
Hi everyone

Since this is my first post, let me introduce: my name is Antonio and I'm writing from Italy so pls excuse me for syntax! http://audioheritage.org/vbulletin/images/smilies/smile.gif

I discovered this interesting forum few days ago, I work as projectionist in theaters since many years and I love JBL sound of course!

During these years I had the opportunity to convert my home's garage in an home theater. I bought a theater's sound system for that! http://audioheritage.org/vbulletin/images/smilies/biggrin.gif

I have three 4648A-8 for LF and 2450J (16 Ohm) as drivers with 2360 horns.
8340 for surrounds, JBL MPX amplifiers, Behringer crossovers and equalizers.

http://www.jblpro.com/pages/components/cmp_drvs.htm#2450HJ
http://www.jblpro.com/pages/cinema/lfsub.htm#4648A-8
http://www.jblpro.com/pages/electronics/mpxamps.htm

I still have to choose the sub, I'll open another thead on this argument, but the choice is between triple chamber 4688 or 4645B.http://audioheritage.org/vbulletin/images/smilies/bouncy.gif

http://www.jblpro.com/pub/obsolete/4688.pdf
http://www.jblpro.com/pub/obsolete/4645b.pdf

The room is still under construction but I made some quick tests and I'm very happy with the system! For space problems I would like to replace the 2360 horns with something smaller, perhaps the 2380. I'd like to better understand the difference between the different horns and have a suggestion from you for "home" use.
I'm unable to fully understand what really change between "Large" and "small" horns: they're both available with the same directivity angles, which are the main differences?

Thanks for all of you help and suggestions!

Antonio

http://www.cinematech.it/Public/data/Antonio%20Marcheselli/200627134549_DSC01925Large.JPG

norealtalent
02-08-2006, 12:35 PM
Hello Antonio and welcome,

I have a pair of 2360 horns and I love them almost as much as my 2397's. They are wonderful. :bouncy:

tony359
02-08-2006, 12:53 PM
Hi noreal :)

2360 should be the same model you can see in my picture, isn't it?

I made only few tests but the quality of sound was much more of expected.

And what about the 2380?


Bye
A

hapy._.face
02-08-2006, 01:11 PM
Sweet! Movies must be interactive with what you have there! Nice. I can't tell you about the horns- but I will say: add more foam to your room. I see you did the ceiling and a few more panels in the back- but I would put something along the corners. Very cool, though!! :D

tony359
02-08-2006, 01:39 PM
Many Thank happy face! :D

Sure, the setup is not completed.

The foam you see is not fiberglass, it polyester wool, not as powerful as rockwool but I choose it because I do not want to have a full dead room. I put the speakers before filling the empty spaces because I want to check the results before.

My idea is to complete the blank spaces with very dense 4cm rockwool and pyramidal foam at angles.

What do you think?

Bye
A

hapy._.face
02-08-2006, 01:44 PM
Many Thank happy face! :D

Sure, the setup is not completed.

The foam you see is not fiberglass, it polyester wool, not as powerful as rockwool but I choose it because I do not want to have a full dead room. I put the speakers before filling the empty spaces because I want to check the results before.

My idea is to complete the blank spaces with very dense 4cm rockwool and pyramidal foam at angles.

What do you think?

Bye
A

Sounds like a great plan. I think you'll have excellent results. Smart, too. That stuff isn't cheap and it looks like you are putting the best stuff where it matters most. Don't forget to throw some rugs down on the floor! Regards
:cheers:

tony359
02-08-2006, 02:00 PM
Sounds like a great plan. I think you'll have excellent results. Smart, too. That stuff isn't cheap and it looks like you are putting the best stuff where it matters most. Don't forget to throw some rugs down on the floor! Regards
:cheers:
The speakers are used and since I work in cinema I had these for a good price... However you're right, they're not cheap! :)
Thanks again for your appreciations!

Sure for the rugs, I have to put something to insulate termically before.

Bye!
A

tony359
02-09-2006, 03:35 PM
Anyone that at least can help me better understanding the differences between the horns models?

Bye
A

norealtalent
02-09-2006, 03:47 PM
Yes Antonio, those look like 2360's to me.

You can research anything JBL Pro here

http://www.jblproservice.com/navigation/pdf_nav_parts%20lists.html

There is and endless supply of info and links here. That should keep you busy for a couple decades.:bouncy:

tony359
02-09-2006, 04:11 PM
I mean if someone can help me understanding all the data I can find on a pdf!

What I should keep in mind choosing my horns?
For example, in the "compact" ones there are 90x40 or 120x40: which is better for home use? I would say that the larger one (120x40) are less sensitive and less directional and can be better for a little room. As you can see all of my surface are dampened with wool.

Or I can just take any compact model with no problem at all for a little space?

Bye
A

yggdrasil
02-09-2006, 04:52 PM
I would go for wider dispersion. As far as I know the narrower dispersion is for longer throw.


You should try to listen to the new horns before you make a decision.

tony359
02-09-2006, 05:06 PM
I would go for wider dispersion. As far as I know the narrower dispersion is for longer throw.


You should try to listen to the new horns before you make a decision.

I think that I can have the chance to test the new horns.
About the throw, they're all very overestimated for my room. I think that a wider dispersion can smooth the sound, does it make sense?

If I correctly understand the larger horns has only more vertical dispersion. I'm not interested on this; or should I?

I'd like to keep the large horns (the ones in the photo) for left and right channels and change only the center channel.
Do you believe it is a smart action? All channels will be equalized and are in bi-amped connection so it is not a problem matching the sound.

I'm having problems placing a screen because the center channel is too high. But I'd love to have the bigger horns standing at the side of the screen!!! :)

What do you think?

Bye
A

norealtalent
02-09-2006, 05:09 PM
I've had the good fortune of playing with a lot of horns. IMO The 2 greatest are 2360 and 2397. If you want a small horn to exterminate the rodents, get a 2307 or better yet a 2311. If you want that glorious sound the 2360 gives you but don't want a towering behemoth in the corner, get a pair of 2397's. Once you've had either of them, you can never go back. If you must use a very small horn, try the H91/2312 and use an L94 lense. Actually, McCauley made one thats even better but the model # is top secret until I find 3 more for myself. They work awesome in an L220 instead of that LE5-? thing. I also like the wider horizontal dispersion patterns. I want my whole room filled with sweetness, not just one spot. All just my opinion, based solely on my experience. :bouncy:

hapy._.face
02-09-2006, 05:29 PM
Ditto what "norealtalent" says. I don't know all horns (most suck)- but I know what a 2397 is capable of and it's beyond words. :p

Steve Gonzales
02-09-2006, 06:09 PM
I'll throw in with the 2397 camp here, they definately have that somthing special. I've only had 1" 2421's attached to them and they have that 'you are there' sound. Give them a try and you won't be disappointed.

Robh3606
02-09-2006, 06:10 PM
"I'm unable to fully understand what really change between "Large" and "small" horns: they're both available with the same directivity angles, which are the main differences?"

Hello Antonio

That would be cut off frequency. The larger the horn the lower it can be used. So sure you can have horns with the same and similar directivity angles but they won't cover the same frequency range. If you can keep all 3 of those beauties across the front go for it!

Rob:)

Zilch
02-09-2006, 09:46 PM
It ain't about "throw."

http://www.jblpro.com/pub/cinema/cinedsgn.pdf

Harkness
02-10-2006, 02:38 AM
another endorsement of the 2397 from here..

great stereo imaging across the room (wide sweet spot), and they work very well in close range. amazing smooth sound, and very little vertical dispersion, so floor and ceiling reflections become less an issue. also slightly less effecient, so require less attenuation (not an issue if you're bi-amping though).

extend the top with some 2405's and you have it. depending on your mid horn roll the 2405's in somewhere in the 12kHz to 14kHz area. i use a simple first order capacitor high-pass on mine and the transition is very smooth indeed.

tony359
02-10-2006, 03:17 AM
Thank you for the suggestions.

I dont' think that the 2397 will be available in the cinema market right know. I'll try to have one for testing.

In the meantime I think I'll have to go with more "stardard" ones like 2380 or similar. What is your opinion on 2380?
Checking the pdfs seems that the smoother frequency response is with 90x40, the 120x40 one seems worst from this point of view. Then, of course, the listening test would be final.

But I'll keep in mind the 2397 number! :)

Isn't the HF responce of the 2397 a bit limited in the highest frequencies?

If the 2360 weren't so deep... :(

Bye
A

pangea
02-10-2006, 04:36 AM
Do you need a wide "sweet spot"? If you do, I'd go along with the suggestions above, but if you don't, I could suggest a very good, much smaller "Tractrix" horn, if the x-over will be 800Hz or higher. (The Selenium HL 14-50) Unless of course you only want JBL horns. :D

I have also used the single capacitor thingy on the 2405/2402 for many years, with great result, BUT recently I did disconnect my 2402's and EQ'd my 2441 with 2445 diaphragms to compensate the highs and I got an even better focus on the sound stage and more details, simply by removing that extra x-over point.

BR
Roland

Steve Schell
02-10-2006, 09:47 AM
Hi Antonio,

Just to throw some confusion into the pot, my recommendations will be a little different.

If there has been a single trend over the years that has limited the performance of horn systems, it has been the desire to shrink them to small proportions and fit everything into a box. We then end up with horn systems that are shrill, peaky and annoying. To explore what horns are capable of, we have to let them be the sizes they need to be to do their jobs well.

You say that you want smaller horns for space reasons. Why is this? Do you have something that needs to sit on your bass cabinets other than your high frequency horns? If it is just the imposing looks of the 2360s that you want to get away from, just consider that Big is Beautiful when it comes to horns.

My advice would be to stay with the 2360s rather than use the 2397s. My flame suit is on here, but I think you would find in a head to head test that the 2397 would sound pinched, nasal and really small compared to the 2360. The mouth area of the 2397 is only a tiny fraction of that of the 2360, for one thing. Mouth size really matters when it comes to midrange horns.

In terms of directivity, a narrower pattern usually works best in a smaller room, as long as the pattern is wide enough to serve the listeners. Excessive dispersion just sprays the walls, ceiling and floor with sound and causes disruptive reflections. I encourage you to damp your room quite heavily, and especially to soak up the first reflection from the side walls.

Steve Gonzales
02-10-2006, 09:49 AM
another endorsement of the 2397 from here..

great stereo imaging across the room (wide sweet spot), and they work very well in close range. amazing smooth sound, and very little vertical dispersion, so floor and ceiling reflections become less an issue. also slightly less effecient, so require less attenuation (not an issue if you're bi-amping though).

extend the top with some 2405's and you have it. depending on your mid horn roll the 2405's in somewhere in the 12kHz to 14kHz area. i use a simple first order capacitor high-pass on mine and the transition is very smooth indeed.

I wonder if you've tried a lower mid to high crossover point?. The 375 drops like a rock about 9-10khz on these horns, I believe. I would try an N8000. I want to say that if you are satisfied with the way your system sounds now, keep it that way.

Harkness
02-10-2006, 11:55 AM
I wonder if you've tried a lower mid to high crossover point?. The 375 drops like a rock about 9-10khz on these horns, I believe. I would try an N8000. I want to say that if you are satisfied with the way your system sounds now, keep it that way.
hey steve,
i appreciate your comments.

i experimented with listening to a number of capacitor values before settling on the (it does seem high) point i did. yes, the 375 does fall off steeply above 10k, but i found that there was also a rise from 5-9kHz with the 2397. i wanted to avoid the 2405 adding any more to that area as much as possible. bringing my 2405 with the -3 point at 14 meant that it's only down a few dB more at 9-10k. i found it blended with the 375 in a way that didn't contribute too much to the area i didn't want to add to, but took over where the 375 gives up and added the air i was missing without it.

however, i never had an opportunity to try them with the N8000. when i was first setting up my JBL system i tried bidding on some on ebay (this was about 4-5 years ago) but i was always being outbid, so i kind of let the idea slide. i'd still be interested to hear how that would sound. it's entirely possible i'd like it better.

though i must say, i am not dissatisfied with the sound i get with my system. :)

Harkness
02-10-2006, 12:04 PM
Hi Antonio,

Just to throw some confusion into the pot, my recommendations will be a little different.

If there has been a single trend over the years that has limited the performance of horn systems, it has been the desire to shrink them to small proportions and fit everything into a box. We then end up with horn systems that are shrill, peaky and annoying. To explore what horns are capable of, we have to let them be the sizes they need to be to do their jobs well.

You say that you want smaller horns for space reasons. Why is this? Do you have something that needs to sit on your bass cabinets other than your high frequency horns? If it is just the imposing looks of the 2360s that you want to get away from, just consider that Big is Beautiful when it comes to horns.

My advice would be to stay with the 2360s rather than use the 2397s. My flame suit is on here, but I think you would find in a head to head test that the 2397 would sound pinched, nasal and really small compared to the 2360. The mouth area of the 2397 is only a tiny fraction of that of the 2360, for one thing. Mouth size really matters when it comes to midrange horns.

In terms of directivity, a narrower pattern usually works best in a smaller room, as long as the pattern is wide enough to serve the listeners. Excessive dispersion just sprays the walls, ceiling and floor with sound and causes disruptive reflections. I encourage you to damp your room quite heavily, and especially to soak up the first reflection from the side walls.

i think there are some good points here.. i have never had the chance to hear those 2360's, but they look good :)

regarding dispersion.. i find it's easier to try different acoustical absorbtion treatments on walls compared to ceiling and floor, so that is why i would (in theory) prefer a horn with more limited vertical dispersion, and accept wide horizontal dispersion. it also makes the stereo field pretty much as wide as the room.

if those 2360 really sound much better than 2397's (i am willing to believe it's possible) then keep those ones for sure. they look like they have a fairly wide dispersion pattern for a room that size, so no problem there. and you've already taken steps to absorb ceiling reflections, so you're on your way there too..

big is beautiful in the world of horns (and speakers in general).

toddalin
02-10-2006, 01:03 PM
The N8000 is just two 1.5 mfd caps, two 0.3 mH coils (~0.25 ohm dcr), two 20 ohm 5-watt resistors, and an 8-ohm L-pad. Schematic is on-line. Only cost you a few dollars to see if you would like it.;)


hey steve,
i appreciate your comments.

i experimented with listening to a number of capacitor values before settling on the (it does seem high) point i did. yes, the 375 does fall off steeply above 10k, but i found that there was also a rise from 5-9kHz with the 2397. i wanted to avoid the 2405 adding any more to that area as much as possible. bringing my 2405 with the -3 point at 14 meant that it's only down a few dB more at 9-10k. i found it blended with the 375 in a way that didn't contribute too much to the area i didn't want to add to, but took over where the 375 gives up and added the air i was missing without it.

however, i never had an opportunity to try them with the N8000. when i was first setting up my JBL system i tried bidding on some on ebay (this was about 4-5 years ago) but i was always being outbid, so i kind of let the idea slide. i'd still be interested to hear how that would sound. it's entirely possible i'd like it better.

though i must say, i am not dissatisfied with the sound i get with my system. :)

Zeno
02-10-2006, 01:31 PM
Hello and thank you for accept me in this Forum:).
I`am just join to that what Steve Schell is writing. The very nice effect of the 2360`s is that you sit absolutley in the sound. The reason are the very low mids with punchy charakter which a smaller horn can physically not transmit. In addition, when you use the BMS 4590 coax driver (sorry, but JBL is not manufacturing such a driver yet) than you need no tweeter anymore.
PS: For this location I`would turn the horns 90 degrees! This comes because you can arrange the position of the audience in the way that they will get direct HF signal on the most places. Sorry if my explanation is confusing.

Zilch
02-10-2006, 01:44 PM
If I'm hearing Tony correctly, he wants to keep his 2360's for the fronts, and needs an alternative for the center due to space constraints. 2380A is a logical choice, as the specs and lineage compare favorably. It is also short.

Mr. Widget has documented the 2397 here, including the frequency response. The manual I linked to above documents the relevant parameters for theaters as developed by JBL. I'd look the Synthesis and Project Array for further guidance in scaled-down installations, but it's clear the same guidelines apply: controlled directivity, constant power response, coverage, EQ. Unilke music, the ambience is in the cinema program; it must be reproduced correctly.

If I had Tony's gear, I'd work it for all it's worth. It's the right stuff. 2397 would comprise a significant departure from that. If 2360's too big, I'd be looking at 235x as first alternate.

I believe Giskard does HT installations. Perhaps he can be coaxed to share his experience here....

tony359
02-10-2006, 02:29 PM
First of all thank you for all of your suggestions.

No, I'm not trying to have smaller horns because I don't like the larger one. I LOVE the larger 2360. BUT my room is not so big and since I'd like to put the speaker behind a perforated screen, I can sacrifice 45cm, but not 75cm. The smaller 2380 are as deep as the LF cabinet. The larger 2360 doesn't.

I'll try to maintain the 2360 ones, but eventually I'll had to change it.

The 235x are suited for 1.5", my driver (2450) is 2". Can be adapted to 235x horns?

Zeno
What do you mean with 90°? Please keep in mind that the photo I posted is absolutely NOT definitive!

Zilch
I'm sorry, my slang is not so evoluted... :) What do you mean with "If I had Tony's gear, I'd work it for all it's worth"? :)

Bye
A

Zilch
02-10-2006, 03:25 PM
The 235x are suited for 1.5", my driver (2450) is 2". Can be adapted to 235x horns?Not very well, probably. The correct drivers would be the best choice.


I'm sorry, my slang is not so evoluted... :) What do you mean with "If I had Tony's gear, I'd work it for all it's worth"?I'd do whatever is necessary to make it fit and work. It is very good equimpent ("Gear"). I wish I had it to work with.... :)

tony359
02-10-2006, 03:35 PM
I'd do whatever is necessary to make it fit and work. It is very good equimpent ("Gear"). I wish I had it to work with....

Don't worry, I didn't buy that equipment and work for 2 years on my room to have only "decent" results... :)

As I told to a fiend of mine, with an electronic crossover, two equalizers, biamplification and that kind of equipment the fun starts NOW! (I have an old CRT VPR too...)

I think I'll never stop thinkering on that! ;)

But at the moment the 2380 are the alternative, I'll try it and I'll decide.

Bye
A

norealtalent
02-10-2006, 05:30 PM
I do not wish to argue the validity of anyone else's experiences. I have strong agreements with most all the inputs given here. That said, I've had 2380's, they will not even begin to compare with the realities experienced with the 2360's. Steve said it right, a small horn cannot do what a big horn can. The 2397 is not a 2360 either. They both have their own character, as well as the 2380. Use the smaller horns where you have to and use the bigger horns where you can. A good sounding little horn is better than no horn at all. In other words,"Keep the paper to a minimum." :bouncy:

tony359
02-10-2006, 05:49 PM
That's important for me.

Ok, I'll try the 2380 keeping in mind all your opinions. I hope to have room for 2360 for the center channel.

Bye
A

herki the cat
02-26-2010, 03:41 AM
[quote=Zilch;91763]It ain't about "throw."
http://www.jblpro.com/pub/cinema/cinedsgn.pdf (http://www.jblpro.com/pub/cinema/cinedsgn.pdf)
[quote/]

Peruse & study this link <http://www.jblpro.com/pub/cinema/cinedsgn.pdf (http://www.jblpro.com/pub/cinema/cinedsgn.pdf)>

which describes the Comprehensive 39 page "CINEMA SOUND SYSTEM MANUAL" of JBL's "THX" state-of-the-art, Multiplex Cinema Sound Systems & Venue-acoustics installation: "essentially identical" to the Skywalker Lucas Theater & (post ops mixing facilities) in Cal, where the "Awesome 'Avatar film" is currently screening.__"Avatar" has received many accolades for "superb" sound quality.

In this Manual, Three JBL THX Sound Systems are featured, aka: (the JBL 3000 series, the 4000 series, & the 5000 series - covering three Audio Power Capability levels featuring "Three Channel Stage Speaker systems, each containing various 15 inch woofers plus the 18 inch JBL sub woofers in addition to a total of twelve "Surround Transducers' placed around on four walls of typical THX theaters."

The Phrase above, stating: "JBL THX, essentially identical to the Skywalker Lucas Theater & (post ops mixing facilities)" simply relates to the fact that "JBL's THX state-of-the-art Multiplex Cinema Sound Systems employ as many as 16 pairs, of conventional copper wire for the basic three channel stage speakers, plus the 18 inch sub woofers," plus another six pairs of wires for six-pairs of "surround sound transducers, all of which ultimately connect all the JBL system stage speakers to the audio power amplifier voice-coil output terminals in the progection booth."

Skywalker's Lucas Theater uses 100% of the sophisticated "Musical Interface Technology Inc., MIT" Speaker Cables, and interconnects, plus MIT's awesome "Trade Mark-Z Bar" Power Conditioner in both the Film Sound Recording Environment & monitoring in the Post OP Sound-Mixing Stage to guage the composit dry film sound as it ultimately will combine with the exhitor's theater acoustics.

This is the correct way to use these expensive cables, budget permiting, because you do retrieve the Movie-Auditorium Reverberation in viewing the finished movie in the theaters.

Considering the massive audio power required for six, or more opional 18 inch sub woofers & six of the 15 inch low-frequency drivers in a 5,000 series system, these long runs of copper wire pairs, potentially up to 500 feet long, with less than 0.5 db loss requiring AWG #3 wire do form a very expensive entity. You could say "It is JBL'S business to employ conventional wire to connect their Speakers.

Consider this: You can place the Philadelphia Orchestra in the cow pasture, and all you will hear is "Mashed Potato Sandwich." But in the Philadelphia Academy of Music, the sound is simply Gorgeous.

Note, when you go into a well equipped audio salon to audition speaker cables, the dealers always use demo records which they know were recorded correctly, for example, "The Weavers at Carnegie Hall" & many of "Wilma Cozar Fine's" treasures, & EMI's Beatles "Sargent Pepper" etc, and all the RCA "Living Stereo Red Seals recorded with three 1950's "U-47" microphones in the now "extinct" Chicago Symphony Hall Auditorium which rivaled Carnegie Hall's superb venue acoustics, not to mention the Boston Symphony Hall used extensively by RCA records.

Keep in mind that professional speaker cables are not for every body because a clean audio system will nearly always present a thread-bare, lean sound akin to a "Mashed Potato Sandwich." There is no place to hide. Most of your records do not have the full body of necessary recorded reverberation which was not available in the recording facility where most of your records were produced.

These conventional things sound OK when your electronics chain has a fat body of grungy sound the listener perceives as detail including the impure muddy mid bass. A good example was the poor under-damped beloved "AR-3 speaker with the tissy tweeter hissing behind the fat-sounding bass, which was skillfuly and Fradulantly demontraqted in the huge highly reverberating New York City Railway waiting room in the early 1950's.

Ce tout, Cheers,- herki the cat