PDA

View Full Version : JBL 2435HPL's



Steve Gonzales
04-11-2005, 01:13 AM
Hello,
I won some brand new JBL 2435HPL's today!. I want some suggestions for a horn that will be suitable for an 800hz crossover point. I've looked at the JBL Pro site and it shows a "wave guide" horn. I am thinking about modifiying an H92/2312 to fit the 1.5" throat exit. Idea's anyone?. I looked at the tech sheets on this driver and am drooling over the possibilities as one of the finest midrange drivers on the planet. I realize that this is an underkill use for an overkill driver but, I couldn't HELP MYSELF! I am going to use them in my L220's with the L94 lens for starters and see what THAT sounds like. I sold my 375's and put the money into these amongst other neat toys (JBL). I have NO idea how to calculate the flair of a horn to work with a compression driver and I do hope someone out there is willing to help. I will say THANK YOU now. Talk to ya later, Steve G :D

subwoof
04-11-2005, 05:42 AM
Hey there...I modified some 2307's for a 1.5 driver ( also have a pair of 2435's ) and here is the description. The pix are long gone from my website so I need to look for them though.

Getting 800 Hz is going to be a real problem due to horn length. The JBL horn 2332 ( as used in the DMS1 monitor ) is the best choice ( although it's a 1K horn ) and it's footprint will closely match the L94's in that cabinet.

I also have a couple of ASC24 crossovers that were designed for the pro 14/1.5 combo ( array series ) and would bi-amp those cabinets well with some small corrective EQ ( the driver + cone are a little different )

Then it will look + sound like the $20,000 japanese models and you can sell the cats eye tweets and retire...

http://audioheritage.csdco.com/vbulletin/showthread.php?t=2171&highlight=2313

sub

Earl K
04-11-2005, 06:06 AM
Hi Steve

A couple of things ;

(1) 800 hz Crossover Point :

First & Foremost ; You'll need to determine if the 2435 actually supports the 800 hz crossover point. The extremely tight fitting backcap may prevent proper production & propogation of these lower frequencies. I'm under the impression that typically the 2435 and its siblings are all used above 1000hz. I might be wrong though . You might see if you can get Zilch or Widget interested in assisting in the determination of this question. ( ie. the lower limit for these new 3" diaphragmed drivers) They have the necessary measuring tools.

(2) Horn ;

(i) I guess you could convert a 2312 to accept a 1.5" exit driver . You'd do this by sawing through the throat at the point where it is 1.5" in diameter ( and then building a new mounting flange ). For this horn to even partially load 800 hz, it needs to have a throat length that is equal to at least 1/2 of the length of the 800 hz waveform. That equates out to a distance of @ 8.5" necessary depth, ( measuring from bell exit back to drivers phaseplug ) .

(ii) Another option (the one I would try first ) is to simply take a 2307 horn and reverse-fit the 1.5" to 1" adapter onto it. There's no reason I can think of why not to do this, given that you are adding a tweeter overtop of this setup. JBL sells a 1 to 1.5" adapter. It's part number can be found somewhere in Ziches Q & D 4430 thread ( multipaged tome ).



:cheers:

Steve Gonzales
04-11-2005, 06:46 AM
Earl, I was thinking of taking a 1.5" to 2" adapter and having the 2" end flange turned down to approx. 3/16" under OD and notched back 3/16" , then taking a 2312 and cutting it at the point where it reaches 2" and have that end milled out the negative of the adapter end. Just off the top of my head, I believe that this would give me the length that I need to support the 800hz crossover. I'll have a look at the other 2435 threads and see if it can safely play down that far. Thank you for answering the wave length question for me, I did'nt know that formula. Thanks to subwoof too. I remember seeing the original pictures of that horn mod.

Ian Mackenzie
04-11-2005, 07:20 AM
Why not look at some of the JBL PTwave guides, cheap and made to measure and Zilch has been exploring applications and crossovers.

Far more recent technology and tested by JBL with such drivers as I recall.

Suggest you hook up with Zilch and copy in on the Intel.

Ian:idea:

herve M
04-11-2005, 09:01 AM
"I'm under the impression that typically the 2435 and its siblings are all used above 1000hz. "
No problem for 3 in. diaphragm compression driver!! JBL use 2430 in 4622 (700hz for passive network, 500hz in active crossover). In 4350 , 1200hz for 2440:D


"The JBL horn 2332 ( as used in the DMS1 monitor ) is the best choice ( although it's a 1K horn ) "

Yes, I use 2430/2332 with DMS1 curve by DSC280 active crossover. Fantastic !!

HerveM

Earl K
04-11-2005, 09:48 AM
No problem for 3 in. diaphragm compression driver!! JBL use 2430 in 4622 (700hz for passive network, 500hz in active crossover).

- Thanks Herve ! You made me download the cut-sheets & take a quick gander .
- Anyone else interested can download this JBL info on the 4622 here. (http://www.jblpro.com/cinema/2way_SA.htm)


According to that sheet ( & for the included 2430h driver in that model ) :

- Passive Xover point is set at 750hz .
- Electronic Xover point can be as low as 630hz, as implied by the info sheet.

NOTE :
- I'd still be somewhat wary of the wholesale application of this info to the 2431H & 2435H models without additional testing or some more application notes from JBL .


< :cheers:

Zilch
04-11-2005, 10:02 AM
Posts by Giskard in the "Q&D 4430's" thread suggest that the back cap of 2435's must be replaced in order for them to play down to 800 Hz, which they will do nicely. I have no clue yet as to the part number or source for the deeper back caps. That's Project May territory....

If you won those 2435's on eBay from the seller currently listing them in the $500 range with misinformation about their retail price in the listing, be aware that the pair I bought from them will likely be going back to JBL for repair after we complete testing them, as my 2431's (one of THEM suspect, as well) have better frequency response.

We're still waiting for receipt of additional 2431's before we test all of the drivers together. The spec sheets for 2431 and 2435 are not available outside JBL, apparently, so we have to develop this information ourselves. :(

To use them on PT Waveguides, which are constant directivity, you'd likely be abandoning the L94 lens. I'm not familiar with the 2332, but several forum members have used them in their projects. The L220 Tech Sheet shows the effect of the L94 lens on LE5.

I'd have serious reservations about reducing an exit diameter with an adapter. Maybe go the other way and adapt up to the 2" stubby H93 horn instead? You really need some test gear. There's no way to reasonably accomplish anything by random action with this stuff, I have learned, and anything you DO accomplish is suspect otherwise....

4313B
04-11-2005, 10:06 AM
The L220 Tech Sheet shows the effect of the L94 lens on LE5....That's Zilch's cue to me to get crackin' :rotfl:

Zilch
04-11-2005, 10:12 AM
;)

Mr. Widget
04-11-2005, 10:44 AM
If you won those 2435's on eBay from the seller currently listing them in the $500 range with misinformation about their retail price in the listing, be aware that the pair I bought will likely be going back to JBL for repair after we complete testing them, as my 2431's (one of THEM suspect, as well) have better frequency response.


Better Response? Do you mean flatter in the mid band as Steve would be using these in modified L220s with the Cat Eye, or do you mean more extension up top as needed for your two-ways?

The PT waveguides would certainly physically fit the L220 mod project, I am concerned that the ones that Zilch has tried have all been a bit anemic at the low end. Will any of them go below 800Hz for a solid 800Hz crossover?

As for bigger back caps I think they would need to be custom fabricated. As far as I know the only ones made by/for JBL are the 435Be/435AL back caps... I doubt these are available. It shouldn't be too difficult to make some from PVC pipe and a bit of plastic sheet stock.

Widget

Mr. Widget
04-11-2005, 10:55 AM
Earl, I was thinking of taking a 1.5" to 2" adapter and having the 2" end flange turned down to approx. 3/16" under OD and notched back 3/16" , then taking a 2312 and cutting it at the point where it reaches 2" and have that end milled out the negative of the adapter end. Just off the top of my head, I believe that this would give me the length that I need to support the 800hz crossover.

I do think you would be pleasantly surprised if you try other horn designs... but rather than going to the trouble and expense of the above machining why not bolt a 2330 (1.5-2" adapter) to a 2311 (2" version of the 2312)?


Widget

Zilch
04-11-2005, 11:07 AM
Better Response? Do you mean flatter in the mid band as Steve would be using these in modified L220s with the Cat Eye, or do you mean more extension up top as needed for your two-ways?I was lookin' at extended HF, of course, which they're supposed to have over the 2431's, but now I forget the test conditions. I'll hook 'em up again here and see what the RTA says, maybe tonight, on PT waveguides.

In a week or so, we may be able to do something more precise. :)

Earl K
04-11-2005, 11:16 AM
Earl, I was thinking of taking a 1.5" to 2" adapter and having the 2" end flange turned down to approx. 3/16" under OD and notched back 3/16" , then taking a 2312 and cutting it at the point where it reaches 2" and have that end milled out the negative of the adapter end.

- Frankly , I just wouldn't bother cutting metal ( like your 2312s and any available 1.5" to 2" adapters .

- The 2307 is 8.5" deep on its' own . That throat length alone supports the 1/2 wave criteria for 800 hz ( though the mouth circumference does not ). The addition of a 1.5" to 1" adapter adds a little bit more LF loading. The addition of the serpentine-fins from the H94 effectively increases the length of the 2307 horn plus also increases the overall mouth circumference. So, if the stock 2435 has linear-loading down to 800 hz then the 2307/L94 will support it at those frequencies . But it's up to the 2435h to do its' part.
( Take a look at the available 4622 pics to get an idea of just how "oversize" a horn needs to be when a driver is restricted in it's ability to "do its' part" in the lower reaches. )

- Regarding JBLs' newer Waveguides :

(i) My advice ; buy one (or borrow) and take a listen to it . IME : JBL has traded-off quite a bit of lower-midband loading for the realized increases in HF extension.. This is what the SR market wanted & this is what it got. Changing that loading changes the dynamic curve of the combo and its' propagation authority in the midband area ( I'm not saying for good or bad - the older 2426H had maybe too much torque below 1K for "easy" HiFi reproduction ). What I am saying, is that when a system tweeter is a given - be careful about what technological compromises you are prepared to buy into . "New" does not necessarily equate to "slam-dunk" better when integrating these newer parts into an older system such as yours.

:cheers:

PS :
- I see the Widget has weighed in with the 2311/2330 combo / it might work . I'll need to test the 2308/2311/2330 combo ( on a Europeon 3" diaphragmed driver ) . Just be aware - the hole pattern for the 2330/(or its' Selenium equivalent) doesn't matchup to JBLs' newer 3" diaphragm drivers .
- I see Widget & myself appear to be in agreement , ( re; his remarks about "anemic midband performance" ).

Zilch
04-11-2005, 11:33 AM
Do you agree that an L94 lens would not be appropriately applied in front of a constant directivity horn?

Earl K
04-11-2005, 11:44 AM
Do you agree that an L94 lens would not be appropriately applied in front of a constant directivity horn?

Yes I agree.

- JBLs' series of lens already does the HF spread within the horizontal plane ( somewhat like a CD horn does ). One wouldn't want to double up the 6db per octave ? lowpass that these things impose .

FWIW :

- JBLs' original series of drivers when mated to these throats had a bit more HF builtin ( not UHF ) before it was flattened out by the horizontal redistribution the lens imposed .

- A 2440 on a 2311 has quite a bit more measurable HF for the 2308 ( up to 9.5K ) to "flatten & distribute" when compared against the 2441/2311 combo.


:cheers:

Ian Mackenzie
04-11-2005, 12:15 PM
Its been a long time since a studied wave guide and horn theory BUT I distinctly recall Dr Edgar and others advising against using a horn down to its wave length (or what ever) cut off and preferably 1 1/2 ~ 2 x for best performance. That might be acceptable for PA work but not HiFi.

Ian

Earl K
04-11-2005, 12:28 PM
Its been a long time since a studied wave guide and horn theory BUT I distinctly recall Dr Edgar and others advising against using a horn down to its wave length (or what ever) cut off and preferably 1 1/2 ~ 2 x for best performance. That might be acceptable for PA work but not HiFi.

- Yeh that makes sonic sense excepting that part about PA vs HiFi - since power handling is quite compromised ( due to diaphragm unloading ) at the lower limits of a horns' loading capabilities ..

- That old rule of thumb that you are referring to certainly has its' applications. OTOH; In HiFi - RL impedance equalizers can be used to mitigate some of the deletrious effects caused by (classically defined) improper horn loading . JBLs' passive circuit designers are masters at seemingly bending these iconoclastic "rules" . :rotfl:

:cheers:

speakerdave
04-11-2005, 06:14 PM
I don't think we can assume that 2435 (Be) and 2430 (Al) will play down to the same crossover point because the moving mass is probably different and will not have the same resonance point in the same volume. The Be 435 that is used down to 800 Hz in the 9800 has the larger back cavity, and I believe that is the reason.

David

Mr. Widget
04-11-2005, 08:51 PM
Hello,
I won some brand new JBL 2435HPL's today!. I want some suggestions for a horn that will be suitable for an 800hz crossover point....
I suppose that the horn needs to work within the scale of the L220 also? If not there are several possibilities. If you are after great sound first and fitting it into the L220 second, I'd look at the Edgar salad bowls or perhaps even Johnny's thread on 1" Smith horns... You could certainly make a 1.5" version.

Widget

Zilch
04-11-2005, 10:14 PM
24 dB filter at 500 Hz only:

Zilch
04-11-2005, 10:36 PM
Giskard's earlier post on this subject:

http://audioheritage.org/vbulletin/showthread.php?t=3838&page=13&p=44426

Steve Gonzales
04-12-2005, 04:16 AM
I spyed these waveguides, they look more to my liking, I wonder if they could be lengthened to go down to 800hz. As you can see, I want the darn things to work in the L220's behind the L94, and you already KNOW I don't care if it sticks out the back!. According to another spec sheet, the 2435HPL is crossed at 1k in the Vertec array's they are installed in.

Earl K
04-12-2005, 06:24 AM
Hi Zilch

- Nice RTA pics of the 2435 on your waveguides.

- FWIW ; I don't see anything that would lead me to believe those 2, 2435(s) are "off-spec" . Given the vertical scale you are using they are really quite linear between 1K and 8K . The @ 10 db per octave roll-off after 8K might be dissappointing - but even that slope is quite consistant between both units.

- I agree that the 2435 on your waveguides / with your crossover set to a 500 hz hipass / doesn't support much of anything below 1000hz.

- Now the question is really, why ? Here are a few suggestions for testing to narrow down the variables ;

(a) The 2435 needs to be tested on a horn that handily supports at least 600 hz to give the driver half a chance of loading the lower frequencies ( given the tight backcaps ) .

(b) The waveguides should also be tested/calibrated with a driver that is known to have significant reproduction down to 500 or 600 hz . That'll help determine where those waveguides' loading limits are .

(c) And last but not least ;

- The choice of a 500 hz hipass point for your pink noise test .

- This part of the test needs to be calibrated so that it's not a contributing variable . So :

(i) Plug a pink noise source into your electronic crossover .
(ii) Plug the hipass output of the utilyzed channel directly into one of the input chnls on your Behringer RTA/EQ .
(iii) Select this chnl as the "input source" while that EQ is in the RTA mode .
(iv) Get a working level of some observable pink noise .
(v) Assuming your crossover is variable in frequency , turn the frequency select knob to lower the frequency until 800 hz is about only .25 db lower than a similar measurement taken 1 octave above it . This is the point where the selected hipass point is starting to show a visable effect. ( ie some slope is manifesting itself ).

- I just did a calibration ( on a Behringer 2300 ) and found that a 250 hz point was about the highest acceptable point to test for 800 hz loading . Choosing any crossover point higher, was noticably attenuating 800 hz within the "stop-band" ( as seen on the RTAs' line input ) .


All the above variables can be contributing factors in the roll-off below 1000 hz. Each can "skew" conclusions about the 2435s ability to handle lower frequencies than 1000hz .


:cheers:

Alex Lancaster
04-12-2005, 07:31 AM
:) Ive never seen 2435's, except on photos, is it possible to make a spacer to increase the back chamber volume?

Robh3606
04-12-2005, 09:58 AM
You are going to have a difficult time finding a horn to fit it the same space as the H94 that supports an 800Hz crossover point. They are only 5X10 maybe a bit larger. To support and 800Hz crossover point the horn has to load a good bit lower. As Earl points out the 2307 supports the wave length at 800Hz. That is 1.2K horn. You would be better off cutting a 2312 if you decide to go that way. I also would not do a reverse adaptor. Have it 1.5 at the flange the way the driver was designed to work. It makes no sense except to do it right or you won't get the benefits of your investment. Take a look at any of the 1k horns like the 2344 and the new PT with the same 100X100 coverage and they are almost the same size 12X12. There is no free lunch and size is going to limit your choices unless you drop it on top of are willing to do some extensize mods to the cabinets.


Rob:)

4313B
04-12-2005, 10:09 AM
You'll need a complete network redesign as well. That part should actually be the most fun. :)

I'll leave "letting the cat out of the bag" with respect to the L220/L222 to others if they so choose. For better or for worse, I think things are going to start getting a wee bit more "diplomatic" around here though. :p

Mr. Widget
04-12-2005, 10:17 AM
Well said Rob... unfortunately true 800Hz capable horns are not small. Look at the H9800 from the K2-S9800. It is 8" by 17" and is about as compact as is really possible. The 2312 is a compromise design that is really an anomaly. It does work, using the baffle to make it's mouth appear larger and is probably the only horn that will work with your aesthetic design. The new waveguides that Zilch and others have been looking at will fit in your cabinet depth wise, certainly wouldn't benefit from the lens and probably won't fit your baffle area... they also won't blend as well with the LE14A.

I know this is heresy coming from a horn advocate, but how about losing the horn and lens and using the large dome midrange from the XPL series? I bet it would be a dramatic improvement over the stock cone mid with lens setup. I am suggesting this not knowing the range that the dome works in or it's sensitivity, but Rob could chime in... he is very familiar with it.

Widget

Zilch
04-12-2005, 10:21 AM
I'll leave "letting the cat out of the bag" with respect to the L220/L222 to others if they so choose. What, that they're generally regarded as a "horror?"

Aready posted that. ;)

[They make nice subs, tho....]

Earl K
04-12-2005, 10:23 AM
Alex

Ive never seen 2435's, except on photos, is it possible to make a spacer to increase the back chamber volume?

- It might be possible , though I don't have any of those drivers to check out that concept .
- I seem to remember someone saying that the backcap seemed to tightly house the diaphragm as if it was a one piece unit ( somewhat like the 2416 ) . Though maybe I hallucinated all that. :spin:


I think things are going to start getting a wee bit more "diplomatic" around here though.
- Any more diplomatic than it presently is and this place will turn into a shrine.
:p

Zilch
04-12-2005, 10:30 AM
:) Ive never seen 2435's, except on photos, is it possible to make a spacer to increase the back chamber volume?Nope. The terminals are integral to the back cap, and plug onto the diaphragm.

Just puttin' a big hole in the rear was mentioned earlier as an option. Don't think I'd be doin' that, tho.

The best answer would be to get the deeper back caps....

4313B
04-12-2005, 10:38 AM
I know this is heresy coming from a horn advocate, but how about losing the horn and lens and using the large dome midrange from the XPL series?I like your thinking Mr. Widget. ;) I'd look at doing the 046Ti too since it is a match and it "beats" the 076 in every way but LOUD.


The best answer would be to get the deeper back caps....I've tried... things are changing... it used to be easy to get stuff like that...

Zilch
04-12-2005, 10:39 AM
... unfortunately true 800Hz capable horns are not small. Here's the model cited earlier using 2430. It's 15" X 30":

Mr. Widget
04-12-2005, 10:48 AM
Alex


- It might be possible , though I don't have any of those drivers to check out that concept .
- I seem to remember someone saying that the backcap seemed to tightly house the diaphragm as if it was a one piece unit ( somewhat like the 2416 ) . Though maybe I hallucinated all that. :spin:


In the early stages of Project May we were told that if we wanted to use the 2435 down to 800Hz we would need to increase the rear chamber as JBL had to for the 435Be. It would not be difficult to do. As I posted earlier on this thread. It could easily be accomplished with a bit of PVC tube and plastic sheet stock.

To me the bigger issue is the design requirement. Steve wants to use a 1.5" driver with a horn and use the lens from the L220. I have some Meyer horns that are for 1.4" drivers and they are "modified radial" horns (the Meyer dog bone). They are very compact 7" by 13.5"... still too big for this project and they are only good to 1500Hz. (yes they will work down below that, but for optimum performance...)

Widget

Earl K
04-12-2005, 10:51 AM
Say Zilch


Nope. The terminals are integral to the back cap, and plug onto the diaphragm.

- What holds the diaphragm in place ?
- ( Bolts ? / Press Fit from the Back-Cap ? / ??? )

:)

4313B
04-12-2005, 10:52 AM
(yes they will work down below that, but for optimum performance...)Yeah but keep the system in perspective Mr. Widget... anything is probably worth trying...

Mr. Widget
04-12-2005, 10:54 AM
Nope. The terminals are integral to the back cap, and plug onto the diaphragm.

Just puttin' a big hole in the rear was mentioned earlier as an option. Don't think I'd be doin' that, tho.

The best answer would be to get the deeper back caps....

The deeper back caps are not JBL Pro... they are for the 435Be and 435AL... JBL Consumer. Highly unlikely you will be able to get them. That said, Steve was able to connect with a "Man from Harman" and secure some JBL Consumer Blue... maybe he could ask politely and get a pair of caps....?????

I would drill it out and add the can myself. Waiting for Harman isn't my idea of a party.

Widget

Zilch
04-12-2005, 10:58 AM
- What holds the diaphragm in place ?
- ( Bolts ? / Press Fit from the Back-Cap ? / ??? )Screws to the front assembly per conventional CD diaphragm mounting, if I recall. Only opened them once for a little peek. ;)

Purple coated diaphragms, probably Be. I'll get a pic.

Wanna try 2426 on them waveguides while it's still set up, too, to see how low they play under these test conditions....

Earl K
04-12-2005, 11:20 AM
Thanks Zilch !

- I figure you might all get a larf from taking a peek at one of my test horns .

- The pics should explain all .

- Yes, it loads quite low .

- These were made about a month ago . I think they were actually meant for the Klipsh "home-improvement" thread. Oh Well :p

- BTW ; the recommended crossover point for this driver is around 1000hz.
( & It also has a tight back-cap )

Zilch
04-12-2005, 11:35 AM
Actually, rear cap mounting screws hold "field replaceable" diaphragm assembly in:

4313B
04-12-2005, 11:38 AM
OMG! What are you doing! You just let out all the Argon gas from that back can! Now you have to take it to JBL so they can put the gas back in in their special clean room! :banghead: :crying:

spkrman57
04-12-2005, 11:50 AM
Me being more a vintage gear man, it is interesting to see the newer stuff JBL has for compression drivers.

Ron

Steve Gonzales
04-12-2005, 12:05 PM
"I know this is heresy coming from a horn advocate, but how about losing the horn and lens and using the large dome midrange from the XPL series? I bet it would be a dramatic improvement over the stock cone mid with lens setup. I am suggesting this not knowing the range that the dome works in or it's sensitivity, but Rob could chime in... he is very familiar with it."

No thanks, I've already got a mint pair of 2420's on the 2312's so if I cannot find a solution to the 2435 question, I'm still thrilled with what I have now. I am just not partial to domes/cones, it's my personal taste. I'll figure something out, no doubt.

Cool to see the innerds there Zilchster, thanks. Thanks Mr. Earl K!, you never dissappoint! :p

Zilch
04-12-2005, 12:11 PM
OMG! What are you doing! You just let out all the Argon gas from that back can! Not to worry. I refilled it with methane.... :D

Here's 2426 on PTH horns, same conditions as above (a) and 24 dB HP lowered to 300 Hz. (b).

2426 plays 500 Hz better than this on a proper horn, no? If so, looks like 800 Hz is the lower limit of the PTH waveguide using JBL 1" throat adapter.

Comparing the curves for 2435HPL under the (a) conditions, 800 Hz is a push for them, as well. 2426 plays better there....

4313B
04-12-2005, 12:12 PM
Not to worry. I refilled it with methane.... :D Excellent!

Carry on! :rotfl:

Steve Gonzales
04-12-2005, 12:18 PM
Has anyone tested that waveguide in the picture I posted? part#'s?

Robh3606
04-12-2005, 12:22 PM
"I know this is heresy coming from a horn advocate, but how about losing the horn and lens and using the large dome midrange from the XPL series? I bet it would be a dramatic improvement over the stock cone mid with lens setup. I am suggesting this not knowing the range that the dome works in or it's sensitivity, but Rob could chime in... he is very familiar with it."

Hey Widget

The 093ti and 046ti are one sweet combo. Running them next to the 4344's they give the top end a run for the money. They are remarkably clean and clear and the 046's goes up a bit higher. They also load the room differently and image better. The top end on the 4344 has a sweet spot and the vertical is limited by both the H94 and the 077's. The XPL' s are more like the 2344 where they you don't here the tonal mix change as much off axis. Certainly can't match the SPL's but I was driving them with Uri's 1200 amp hard enough to have his clipping light flash with the XPL's and no strain no hardness. Can't imagine another set of domes doing that, I was amazed they could absorb that kind of power.

Hello Giskard
Someone needs to build a pair of XPL 250's. I think you should do it:bouncy: . You already have the LE-14H's. I would love to hear how those sound.

Rob:)

4313B
04-12-2005, 12:25 PM
"Can't imagine another set of domes doing that, I was amazed they could absorb that kind of power."

Yes, they're kind of like power sponges.

"Someone needs to build a pair of XPL 250's. I think you should do ithttp://audioheritage.csdco.com/vbulletin/images/smilies/bouncy.gif . You already have the LE-14H's. I would love to hear how those sound."

Actually I have all the parts. I just need to build the charge-coupled filters for them.

Current project is a pair of Performance Series subs using the SUB1500's.

Earl K
04-12-2005, 12:26 PM
2426 plays 500 Hz better than this on a proper horn, no?

- Yes, I believe so.


If so, looks like 800 Hz is the lower limit of the PTH waveguide.

That seems about right .

:p

Lawrence HF
04-12-2005, 12:31 PM
That RCA MI 9594 and a 2482 is my midrange for center channel.

Earl K
04-12-2005, 12:43 PM
Has anyone tested that waveguide in the picture I posted? part#'s?
Steve,
- That part is from the Vertec Line Array series . If I remember correctly the vertical dispersion on that throat piece is designed to be maintained at 10 ( from 1K to 15K ) .

- I don't think you want such a limited vertical dispersion. The L94 works in the horizontal not the vertical .

- You need to stick with horn throats that the L94 was designed to work with. Or if you are going to stray from that path and still want to use the L94 / then don't wander very far from the round mouth and similar flare constant in the horn.

- One of Widgets other suggestions of getting a pair of wooden Edgar horns has merit. If committed to the L94 then I would morph that custom work into getting a set of simple exponential 2312 throat made in wood / custom turned on a lathe / for the 1.5" entry . Keeping the same depth as a 2312 but going to a wider entrance ( 1.5" ) means the flare constant has been changed. My instincts tell me if the mouth size is kept the same ( as the 2312 ) then the loss in HF boost will be very slight .



:)

Earl K
04-12-2005, 12:52 PM
That RCA MI 9594 and a 2482 is my midrange for center channel.

Really ? Wow ! You must have a lot of available depth to play with . These things will throw midrange into the next county .

- What components are above & below that 2482 ?

- How do you adapt the 2482 to the MI 9191 throat section ? ( which is 1.4" )


:cheers:

Oldmics
04-12-2005, 12:59 PM
" Waiting for Harman isn't my idea of a party."

Been there-Done that !!!!!!!!!!!!!!!!!:tribe:

Lawrence HF
04-12-2005, 01:10 PM
Between the horn and driver is MI 9591, the flange hole I think was 2", if it was not, I may have reamed it a bit, don't remember. The distance between 2 of the 2482 mounting holes a bit wider than flange holes, which are open on outer ends. Used some washers, fits tight, only 2 bolts into 2482, driver exit and horn entrance look perfect. It's a B to move. Gauss 5831 woofer, have others I could try, including JBL, may end up with 2 woofers, bass reflex 13 cu/ft. I think U once tried to look up G 5831 can't find anything on it. Sent U other info on rest.

Steve Gonzales
04-12-2005, 01:20 PM
If there is something that is a real weak point for me concerning speakers, it is the nuts and bolts of how they react in a given enlosure or on a horn ,etc. I have never been exposed to it, but I want to learn. One confusing point is the open mouth waveguide that is pictured in one of Zilch's posts. It appears to be "wide open", yet, it can support a much lower crossover point than I am looking to use (650hz?). How does a compression driver and horn work together?. What are the basic rules in regards to how the horn interacts with the compression driver at the point that they meet. What is (in better detail) "the loading". I assume that this has to do with throat pressure. Is this the consideration in regards to the information I've read in posts to why a 2" exit driver is preferred over a 1" when mated to a 2397?. Humor me for a moment; picture an Altec 311 old school horn. What if you where to build a horn that was patterned after 1 of the segments/ sections?. What ratios are to be considered in regards to flare rates. Is there a formula/rule of thumb?. I would want a rectangular mouth that was approx. 5"h x 10"w. and wouldn't care if it was over a foot in length. How do I calculate the dimensions? Maybe that is not a good idea. Anything you can explain in laymens terms is appreciated, I don't have the jargon down-yet-. Thanks, Steve G

Earl K
04-12-2005, 01:54 PM
Steve,

- I'm going to look around for some websites that can explain the basics in horn design. I don't have the time to muster up anything even half-assed coherent for the unlearned.

- Horns are really easy to make / unfortunately they are equally as hard to make good sounding.
- In your shoes ; I'd buy not build .

- Personally, I'd also stick with the round mouth and let the L94 do the rest.

- Each single cell Altec was usually speced at around 18 x 18. You'd want double that or even 45 by 45 . That somewhat describes the 2309 ? horn found behind the serpentine lens .

- WHG just posted a link to some Horn Sites for MatthiasA. Here's that thread. (http://audioheritage.csdco.com/vbulletin/showthread.php?t=5441) / one of the links has some horn calculators. Take a look around there and see what you can find out about horn design that you might find useful .

- The guys who really like to talk about horn design reside over at the High Efficiency Forum (http://www.AudioAsylum.com/forums/HUG/bbs.html) of the AudioAsylum web site . I'd suggest registering there and asking horn design related questions there.

:cheers:

4313B
04-12-2005, 01:58 PM
- The guys who really like to talk about horn design reside over at the High Efficiency Forum (http://www.audioasylum.com/forums/HUG/bbs.html)of the AudioAsylum web site . I'd suggest registering there and asking horn design related questions there.

:cheers:Definitely! They live and breath it day in and day out.

yggdrasil
04-12-2005, 03:46 PM
Horn sites:

http://melhuish.org/audio/horn.html
http://www3.ocn.ne.jp/~hanbei/eng-links.html
http://www.quarter-wave.com/

What I have read is that Tractrix or Smith horns are amongst the better designs for home use.

I have built Smith horns now, next will be a pair of Tractrixes. If you'd like I could try turn a pair of round Tractrixes for you. When putting the parameters into the calculator you find in the first link you'll find that they are rather small with e.g. a cutoff frequency of of 500/550Hz. PM me if interested.

Guido
04-13-2005, 01:22 PM
OMG! What are you doing! You just let out all the Argon gas from that back can! Now you have to take it to JBL so they can put the gas back in in their special clean room! :banghead: :crying:

Use a deep breath at a heavy hangover morning for refill :D