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HemiMoparGuy198
08-20-2009, 01:10 PM
Hey All,

I have a set of JBL 2380A horns with 2445J drivers on the back. I need new diaphragms for the drivers. Do I really need to get the 16 ohm diaphragms or could I get the 8 ohm ones which would be better and require less power as they are less resistive? Any help is greatly appreciated.

TY in Advance,
Eric

SMKSoundPro
08-20-2009, 01:53 PM
I have a couple sets of same 2445 and 2380 siting here. I also have a brand new pair of unused D8R2445 phragms if you are interested.

The 8 ohmers are less resistive and really pack a wollop.

Scotty.

HemiMoparGuy198
08-20-2009, 07:29 PM
Will they work in my 2445's? If so how much are you wanting for them?

doodlebug
08-22-2009, 06:46 AM
I've used the same setup with good results in a home setting. I'd first ask why the 'phrams are blown before embarking on what to do about replacements. Can you tell us more about your installation?

Impedance decisions would seem to be driven by what a passive crossover would require in order to work properly.

Lastly, be aware that the 2380s are CD horns and will need to have the compensation applied by the crossover - passive or electronic - to provide proper dispersion and sound quality.

Might that be related to the blown 'phrams?

Cheers,

David

HemiMoparGuy198
08-22-2009, 08:58 AM
I've used the same setup with good results in a home setting. I'd first ask why the 'phrams are blown before embarking on what to do about replacements. Can you tell us more about your installation?

Impedance decisions would seem to be driven by what a passive crossover would require in order to work properly.

Lastly, be aware that the 2380s are CD horns and will need to have the compensation applied by the crossover - passive or electronic - to provide proper dispersion and sound quality.

Might that be related to the blown 'phrams?

Cheers,

David

What do you mean by CD horns? And yes, I've concluded that the diaphragms were blown due to the absence of any crossover. I bought them from a pawn shop and wasn't very knowledgeable about pro audio speakers at that point, I had only dealt with home and/or car audio speakers which typically most don't need crossovers...at least the ones I have messed with that were factory original didn't have any. Anyway, I did post another thread for the crossover issue.

http://www.audioheritage.org/vbulletin/showthread.php?p=262528#post262528

That thread details the setup I have much more than I did in this one. It also has a couple of my questions about crossovers, so if you can help out there as well I'd be greatly appreciative.

Thank You

doodlebug
08-22-2009, 09:42 AM
What I meant was Constant Directivity horns. For an inexpensive and flexible entry into the use of the drivers and the horns, I'd suggest an electronic crossover with the CD equalization built into the crossover. I use the Behringer CX-3400, which allows me to dial in the crossover points, phase, and delay characteristics.

You'll find them inexpensive and flexible but will need an extra amp, of course, with a woofer. Spend some time here and you'll also discover that a DC block cap is recommended in series with the compression horns when you use them in a bi-amped setup.

BTW, your experience with car installations would imply that the crossovers are typically built into the amps themselves. You still had some of the controls on them like crossover points. It is just that you now get to deal with the crossover in a separate box.

Hope that helps. There are folks here who are far more knowledgeable about this sort of stuff than I. Read and understand from them as they've been _very_ helpful to me in learning about the JBL pro stuff.

Cheers,

David

HemiMoparGuy198
08-22-2009, 09:42 AM
I suspect he meant Compression Driver Horns, as opposed to Bass Horns ...

Ah ha, see, I knew what he was talking about I just didn't piece together CD and compression driver

HemiMoparGuy198
08-22-2009, 09:49 AM
Ah ha, see, I knew what he was talking about I just didn't piece together CD and compression driver


Wow, I musta read it then responded 2 seconds after

HemiMoparGuy198
08-22-2009, 09:51 AM
I use the Behringer CX-3400, which allows me to dial in the crossover points, phase, and delay characteristics.

I have a Crate Pro Audio LS4-XO. Would that be a sufficient substitution?

http://www.musicresourcesusa.com/music_effects_resources/manual/crate%20pro%20audio/ls4-xo.pdf

grumpy
08-22-2009, 10:20 AM
yes. will need more amps though, as you noted early on... in the other thread.

doodlebug
08-22-2009, 10:24 AM
I have a Crate Pro Audio LS4-XO. Would that be a sufficient substitution?

This model has the CD equalization switch on both channels. See page 6 of your owner's manual for the details. According to it, 12db boost is provided for this model and is fixed. This might be a bit agressive for the 2380/2445J horn but I have experience only with the Behringer and the original 3152 passive crossover network. IIRC, the Behringer CX3400 runs about 1/2 of that boost at 6dB.

I can assure you, though, that you will get much better results with equalization to compensate for the horn's dispersion characteristics.

BTW, I assume you're planning for use in a residential setting. If this is intended for pro/high volume use, then you'll need to consider other aspects such as power handling, directiity, max room size, crowd noise, etc. This is not my area of expertise but you have others here that do this for a living.

Cheers,

David

grumpy
08-22-2009, 10:32 AM
David's right. Would be better to have adj. frequency and amplitude for
correctly EQ'ing that particular CD horn design.

I was reading between the lines, saw the word "sufficient",
and figured the goal was to get up and running on a shoestring budget.

Some external EQ or at least a 'treble' knob may help there.

HemiMoparGuy198
08-22-2009, 12:58 PM
Yeah, it is just a residential HT setup I am trying to set up. And yes, trying to do a shoestring budget as of now. Then upgrade to bigger/better amps, etc as I have the funding. I'm just tired of having these awesome speakers sitting on milk crates in the basement as to not get wet. I want them functioning, even if its not to their full potential at least for now.

But I welcome advice as to how to make it superior so I have the knowledge when the money comes is as well as the most economical way to make them function for now.

doodlebug
08-22-2009, 01:24 PM
OK, that helps. Here's your problem: If you want to use only 2 channels of amplification, you're looking at a passive crossover. Building one scratch-built to use the JBL horn/drivers will be heading for $200-300 the pair. Price out the JBL 3115 parts list at Parts Express to get an idea of what I'm talking about.

Since you've got the e-crossover already, why not just spring for a smaller amp to drive the horns via the e-crossover? At least you'll be able to sell it on Craigslist later if you choose another path or abandon the project. Why not snag a little 20wpc amp on CL, lash up the JBLs/crossover and be done with it for a while?

What do you have for low end drivers?

Just my thoughts......

Cheers,

David

HemiMoparGuy198
08-22-2009, 01:39 PM
OK, that helps. Here's your problem: If you want to use only 2 channels of amplification, you're looking at a passive crossover. Building one scratch-built to use the JBL horn/drivers will be heading for $200-300 the pair. Price out the JBL 3115 parts list at Parts Express to get an idea of what I'm talking about.

Since you've got the e-crossover already, why not just spring for a smaller amp to drive the horns via the e-crossover? At least you'll be able to sell it on Craigslist later if you choose another path or abandon the project. Why not snag a little 20wpc amp on CL, lash up the JBLs/crossover and be done with it for a while?

What do you have for low end drivers?

Just my thoughts......

Cheers,

David


Low end is JBL 4647, but I also don't have amp for those either, so I'd need to buy 2 amps. I was thinking Crown CE1000 for horns and CE2000 for woofers. But even on Ebay I'd have about $600 into those.

grumpy
08-22-2009, 02:46 PM
FWIW, translation: 4647=4507cab+2226H bass driver, maybe 2225H if older.

Have to read this off the back of the driver magnet assembly, not the box.

I'd personally suggest a higher xover than the 3115 provides with that
horn, and the -A suffix units have the CD compensation. The 3110 vs 3115
thing is just my preference and experience.

Worth a read of this thread:
http://www.audioheritage.org/vbulletin/showthread.php?t=7480

4673 was a JBL theater system (same components with 3115A).
Might have a google search on that system...

HemiMoparGuy198
08-23-2009, 07:27 AM
FWIW, translation: 4647=4507cab+2226H bass driver, maybe 2225H if older.

Have to read this off the back of the driver magnet assembly, not the box.

I'd personally suggest a higher xover than the 3115 provides with that
horn, and the -A suffix units have the CD compensation. The 3110 vs 3115
thing is just my preference and experience.

Worth a read of this thread:
http://www.audioheritage.org/vbulletin/showthread.php?t=7480

4673 was a JBL theater system (same components with 3115A).
Might have a google search on that system...


Sorry, I knew the component breakdown, but I guess I assumed people would know what they were. After looking at the 4673's mentioned on JBL Pro website, that is exactly what my speakers look like...like someone tried to make them into 4673, but like the cheapest most cobbled way possible using the smallest angle brackets available at any hardware store, and drywall screws.

TY for finding that the 4673 is a manufactured version of what I have. I wonder why whomever built these speakers to clone the 4673 left out the crossover. Of course it figures I got interested in this project again after running new wires to the drivers and soldering connections for a bi-amp setup, and then I find out that they are basically cloned 4673's, and now I know what crossover I need, so all that work was wasted cuz I gotta clip the connectors off so I can put the wire in the 3115A's I found online.

Hopefully I get these up and running soon as they seem to have been neglected/abused by the previous owner trying to cobble them together. They had like 18-20 Ga wire to the woofer and I kid you not phone wire to the horn. Not the white phone wire coming from your wall plate, but the wire that is most likely ran from the NID box outside to the phone jacks in your home. So I replaced the wiring and over-killed it. I had plenty what I think was 10 ga Monster Cable, which I'm sure woulda been plenty, but instead, since there were 2 wires inside a clear thick plastic sheath, I twisted them both together and soldered the ends to make basically 5 ga wire to the woofers. And then I had some 16 ga speaker wire laying around so I put that to the horns. Like I said, I know it's over-kill, cuz the 25 ft patch cables with 1/4" connectors I have are not nearly 5 ga, and the speakers will never handle enough power to need the 5 ga, but hey, I had it and will prolly never really use it for anything else, so why not?

Anyway, Thanks for all the info it gives me a few ideas/options. The suggestion of buying smaller amps NEVER occured to me for some reason. I wanted to buy the amps that would put out basically the max power handling of the components. Then the discovery of the fact that I have a cobbled clone which tells me exactly what I need to finish these speakers properly

doodlebug
08-23-2009, 08:11 AM
Depending on the size of your room, I'd invest in quality, low-wattage amps especially for the horns. We're not talking about a lot of power required to get it plenty loud. Also, the amp for the horns will need to be as quiet as possible. Get amps that have input controls so that you can adjust them and the crossover levels for the best gail throughout the system in order to minimize noise.

You have, essentially, what I now have for a system with the JBL bass units although I came across my stuff differently. I drive the bass cabs with a 100wpc SS amp and the horns with a Mac MC-225 (25wpc) tube amp through the electronic crossover. Or I can run the whole thing with a passive crossover with the Mac and it still gets plenty loud for my needs.

Enjoy!

Cheers,

David

HemiMoparGuy198
08-24-2009, 10:14 AM
Wow, you think 25x2 will run both beasts at a decent volume? Maybe I'll just try my Sony bookshelf unit at first that has 100x2. I know it's not a high quality amp, but I always thought it sounded pretty good...having never been able to hear anything much superior to it.

stage One Pro
12-22-2011, 04:38 PM
Hey All,

I have a set of JBL 2380A horns with 2445J drivers on the back. I need new diaphragms for the drivers. Do I really need to get the 16 ohm diaphragms or could I get the 8 ohm ones which would be better and require less power as they are less resistive? Any help is greatly appreciated.

TY in Advance,
Eric

Ty; I used the 2445j drivers with 2380a horns and they are great. It is better if you used the 16 ohm than the 8 ohm. 16ohm can handles more power and less burnout. To get the right diaphragms for your 2445j,call Richards at 1-800-787-5758 tell him I sent you. Part # is jbl2445j-16@$62.00 ea.

Steve
Stage one Productions

Lee in Montreal
12-22-2011, 05:22 PM
Ty; I used the 2445j drivers with 2380a horns and they are great. It is better if you used the 16 ohm than the 8 ohm. 16ohm can handles more power and less burnout. To get the right diaphragms for your 2445j,call Richards at 1-800-787-5758 tell him I sent you. Part # is jbl2445j-16@$62.00 ea.

Steve
Stage one Productions

$62.00 for a JBL diaphragm?

BTW Shouldn't a 16 ohms driver require more amp power than 8 ohms for the same output. ;)

grumpy
12-22-2011, 09:28 PM
More voltage, yes :)

Fort Knox
12-23-2011, 07:59 AM
Ty; It is better if you used the 16 ohm than the 8 ohm. 16ohm can handles more power and less burnout. To get the right diaphragms for your 2445j,call Richards at 1-800-787-5758 tell him I sent you. Part # is jbl2445j-16@$62.00 ea.

Steve
Stage one Productions

Be careful changing ohm values (unless your running sep. amp)

louped garouv
12-28-2011, 11:54 AM
$62.00 for a JBL diaphragm?


:blink:
maybe an aftermarket unit?
like here:
http://www.ebay.com/itm/Diaphragm-JBL-2446-2447-2450-2450-8-2451-H-8-ohm-/350511556287?pt=LH_DefaultDomain_0&hash=item519c1de6bf

I can't see that being a genuine part,
at that price I'd think the retailer would be taking a bath on every sale;
and folks would be lining up to get them....
:yes:

Lee in Montreal
12-28-2011, 12:17 PM
:blink:
I can't see that being a genuine part...

Me neither. But when a "pro" like StageOnePro mentionned the "right" part, I guess I expected a real JBL diaphragm. ;)

"To get the right diaphragms for your 2445j,call Richards at 1-800-787-5758 tell him I sent you. Part # is jbl2445j-16@$62.00 ea."

I guess, I will call Richard and let him know that his buddy sent me for an original JBL diaphragm for $62.00...

BTW "1-800 787-5758" is Sound Speaker Repair on ePrey.

54251

1audiohack
12-28-2011, 12:52 PM
The listing says it is "just like" an original JBL. Even at a glance the brass looking screws say non JBL.

edgewound
12-28-2011, 01:32 PM
Ty; I used the 2445j drivers with 2380a horns and they are great. It is better if you used the 16 ohm than the 8 ohm. 16ohm can handles more power and less burnout. To get the right diaphragms for your 2445j,call Richards at 1-800-787-5758 tell him I sent you. Part # is jbl2445j-16@$62.00 ea.

Steve
Stage one Productions

The "right" part for a JBL 2445J is JBL part number D16R2445 and it's not $62.00.

The "best" part for a JBL 2445J is JBL part number D16R2451SL...it's basically an Aquaplas coated D16R2445.

Lee in Montreal
12-28-2011, 01:46 PM
The "right" part for a JBL 2445J is JBL part number D16R2445 and it's not $62.00.

The "best" part for a JBL 2445J is JBL part number D16R2451SL...it's basically an Aquaplas coated D16R2445.

And it's only $185.00

54252

pos
12-28-2011, 02:34 PM
The "right" part for a JBL 2445J is JBL part number D16R2445 and it's not $62.00.

The "best" part for a JBL 2445J is JBL part number D16R2451SL...it's basically an Aquaplas coated D16R2445.
The "better" part would be a truextent BE4016 :D

Lee in Montreal
12-28-2011, 02:40 PM
The "better" part would be a truextent BE4016 :D

Sure. And twice the price?

edgewound
12-28-2011, 03:05 PM
The "better" part would be a truextent BE4016 :D

Probably better spent on the 2446 and later 4" voice coil drivers with the advanced "Coherent Wave" phase plug.

JeffW
12-28-2011, 03:12 PM
Sure. And twice the price?


Well, the -SL JBL 'phragm is 3X more expensive than Richard's $62 replacement.

We have to remember that it's not about how it sounds, it's how cheaply we can get there.

pos
12-28-2011, 03:28 PM
From my listening tests (after careful eq and in rapid A/B switches) between some of these diaphragms (Ti ribbed, Ti smooth SL, Be truextent), IMHO the SL is the best value for the money, but the Be is undoubtedly the best of the bunch