275nd / S3100 compatibility

[Bernard Wolf]

Hi everyone - I have searched the forum but still do not have my question answered. I am wondering if a 275nd would be a drop in replacement for the 2426H thats in the S/3100 now. Of course I know it will fit , as the 3100 mkII uses the nd, but my real question is will the crossover need to be changed as well. On one of the posts I read someone mentions that the sensitivity might be higher on the 275nd and thus require a crossover change. Can anyone confirm this ?

Also, I do wonder if it would all be worth the effort. Will the nd sound that much better? The reason I ask all of this is that there is one 275nd up for sale at the moment and I am tempted to purchase it and wait for another.

Any input would be much appreciated.

Bernard

[pelly3s]

there really is only one way to find out if it will sound better and that is to do it

[Earl K]

Any input would be much appreciated.

Okay, you've asked for some input :

- I'd say, buy the 275nd and just drop it in ( if the price is right ) .
- I also think that you should build some new "DC-Biased" crossovers, utilyzing better parts than those which presently exist in your stock crossovers . Make them external .


- I have searched the forum but still do not have my question answered. I am wondering if a 275nd would be a drop in replacement for the 2426H thats in the S/3100 now.

- I'm not surprised you can't find anything definative here. My recollection is that no one here, has ever done this "one for one" swap .


Of course I know it will fit , as the 3100 mkII uses the nd, but my real question is will the crossover need to be changed as well.(?)


- I don't think anyone here can tell you that based on my above point .
- But, I would always assume that a crossover should be tweaked for a different component type.
ie; Logically, why buy another driver type , if it's not actually different sounding ?


On one of the posts I read someone mentions that the sensitivity might be higher on the 275nd and thus require a crossover change. Can anyone confirm this ?

- I can't confirm any sensitivity differences, but swapping out resistors for more appropriate values is simple enough .


Also, I do wonder if it would all be worth the effort. Will the nd sound that much better?

- I've wondered about that myself. I hold more stock in the fact that I can readily hear the differences between the various types of metals used for the domes . But I find that any audible difference caused by the magnet type is much harder/ if not impossible to pin down ( at least with compression drivers ) . I've heard a response difference in le14 woofers, seemingly caused by the magnets ( Alnico vs Ceramic ) / though I tend to think the differences I've experencied were more likely caused by partially discharged alnico magnets .

- If it was me ( & if I couldn't stand the suspense ), I would buy a pair of 275 replacement diaphragms ( plastic coated Titanium ) and install them into the stock 2426 drivers .

FWIW - I think a more interesting upgrade path would be to retrofit a pair of 1.5" exit ( 243x ) drivers onto those big ( 1" entry ) horns . Zilch has mentioned an existing JBL adapter ( I think ) .

ps ; Now that Zilch has a pair of similar 2346 horns ( along with the mentioned 3" diaphragmed drivers ) / help for this DIY modification just might appear along with some RTA measurements .


;)

[Zilch]

Yup, and some H2600's are on the way.

2346's are a "trip." Just discovered last night that phase relationships wander all over the place unless the woofer is properly aligned with that long neck.

I'm dubious about down-adapting 1.5" to 1", but I'll try it.... :D

[Zilch]

:no: 1.5-inchers...

Use a 1" exit cd with a titanium diaphragm that has a coating of aquaplas.That'd be 275ND replacement diaphragm in like 2425/6, no?

Others?

[Earl K]

:)

Yup, and some H2600's are on the way.

- I thought I previously read that N2600(s) are on the way. Anyway ,,,
- You obtained H2600(s) ? Okay , who are you blackmailing ? :D
- Well, if you get a pair of H2600 horns, it would sure be nice to get a close looky-see at the metal throat adapters. I think the metal throat splits into two parts .


2346's are a "trip." Just discovered last night that phase relationships wander all over the place unless the woofer is properly aligned with that long neck.

- Properly Aligned ? What does it physically work out to be ?


I'm dubious about down-adapting 1.5" to 1", but I'll try it.... :D

- Yeh, these adaptions/contraptions are always dubious / still the exercise will give one an idea of the LF loading capabilties of a horn/driver combo .

:D

[Zilch]

- Properly Aligned? What does it physically work out to be?What I know at this point is if you just stack 'em 2346's facing front on woofers (as in S3100) and get the two drivers in phase perpendicular, when you move the 30° onto real horn axis, you've got a big notch at 3110A 800 Hz crossover frequency. Inverting the HF driver phase makes it flat again, but screws it up perpendicular.

"WAIT! You just DID that, silly!"

Everest rotated the LF driver that 30° to put both drivers on parallel axes. I gotta free up some space here to work with different physical alignments to see what's up. Presumably H2600 will exhibit the same behavior. In any case, real time-alignment would appear to be, well, "challenging." :p

Regarding the 275ND crossover, clearly S3100 and S3100 MKII use different topologies, the latter using what I'm calling the "parametric" approach of cascaded notches. I'll have to model them both to see if the newer (12/00) MKII is really different, or merely "improved" over the earlier (11/95) 2426H version. That'll also answer the question of "drop-in" interchangeability of the two drivers. Both networks are 750 Hz, 12 dB/octave, looks like....


If you get a pair of H2600 horns, it would sure be nice to get a close looky-see at the metal throat adapters. I think the metal throat splits into two parts .?We'll see. Comes with, apparently:

319381-001 HORN S2600/S3100 (+useTHROAT 318793-001)

May afford opportunity to make a custom 1.5" throat for 243x drivers....

[Bernard Wolf]

man .. ... you guys leave me in the dust so fast isn't not even funny :blink:

will take me a day and a half to figure all of this out.... but thanks for the extra quick response.... should have put a stopwatch on it ;)

Bernard

[Zilch]

[It]will take me a day and a half to figure all of this out.... In short ... thus far, we don't know.

But we encourage you to try it and tell us.... :p

Check me, now:

A) S3100 has a deep notch at 2.5 kHz, whereas,
B) MKII has, ummm, "undulations." :)

[Zilch]

Unless that's the 7.5-Ohm 1mH inductor, in which case, it's:

[Zilch]

That'sa familiar curve, actually. :p

O.K., who's got an S3100 MKII we can tear into to get the DCR's of the inductors? :D

[Kinda doubt the network's gonna show up on eBay....]

[Earl K]

Unless that's the 7.5-Ohm 1mH inductor, in which case, it's:

- That 7 to 8 ohm range looks right for that LCR filters' inductor.

:p

ps : Say Zilch , do you have an impedance plot for the le85 ? or is it buried in the Q&D 4430 thread ?

[Bernard Wolf]

correct me if I am wrong, but is the 2426 not also aquaplas coated ? I can't find the service sheet that I once had for this, but if in fact the 2426 is coated then what is the big deal with the nd ? As Earl was saying, hearing the differences in magnet material may be a futile experience. As much as I would like to facilitate your wishes that I go ahead and try it and then report.. well, I am not quite that adventurous, or wealthy ..:(

Bernard

BTW, that 275 nd is up for auction on ebay right now.

[Zilch]

Call it 10 Ohms. :p

Fmin is 1214 Hz.

Dunno why I keep getting negative Le's on compression drivers here....

I'd do it for you on S2600 horn, but that it comes without throat adapter. :(

[Whatta buttlick!]

Time out while I raise holy HELL with them.... :biting:

[Lancer]

S3100 has a deep notch at 2.5 kHz

Unless that's the 7.5-Ohm 1mH inductor, in which case, it's:

You guys are getting it! Yes, don't leave out the DCR values for the coils.

- That 7 to 8 ohm range looks right for that LCR filters' inductor.

It's hard to say. You'd need a response curve of the driver/horn combo and then figure the DCR of the coil accordingly. I know some of the 1.0 mH coils were 6.8 ohms instead of 7.5 ohms.

[Zilch]

Mini-Everest?

Appears to be the same horn with the face hacked off.

[O.K., O.K., "truncated," then.... :p ]

[Zilch]

Correct me if I am wrong, but is the 2426 not also aquaplas coated? Nope, I don't believe 2426 diaphragm is aquaplas coated....

[Earl K]

Thanks Zilch !

- The H2600 has arrived ? That was fast ! :blink:

- Too bad about the throat adapter . :(

- It sure does look like a sawed-off 2346 . Isn't that interesting !


You'd need a response curve of the driver/horn combo and then figure the DCR of the coil accordingly.

Agreed :p

:D

[Bernard Wolf]

Nope, I don't believe 2426 diaphragm is aquaplas coated....

You are absolutely right - I just downloaded the instruction manual from JBL and it is only the bass driver that is coated.

Bernard

[Bernard Wolf]

Mini-Everest?
[O.K., O.K., "truncated," then.... :p ]

Well.. yes :blink:..... I thought everyone knew that ... thats why I was rather bothered by some recent postings about the Everest having a diffuse soundstage... I didn't say anything because I have not heard the Everest, but I can tell you that the 3100 has really great soundstaging qualities and I cannot imagine the Everest not being the same.

Bernard

[Bernard Wolf]

[QUOTE=Earl K]

- If it was me ( & if I couldn't stand the suspense ), I would buy a pair of 275 replacement diaphragms ( plastic coated Titanium ) and install them into the stock 2426 drivers .

/QUOTE]

Do you think that would be a drop in replacement then ? No need to tweek the x'over? Same sensitivity ? If that were the case it would be a simple way to go, assuming I can find the diaphrams that is.

Bernard

[Earl K]

Hi Bernard,

For The Sake of Clarity


Do you think that would be a drop in replacement then ?

- I'll only assume the 275nd diaphragm will physically "fit" into the 2426h magnet assembly .
- This "fitup" assumption is based on an older link to a web-page ( since deactivated ) that was posted by an ex-JBL intern/apprentice who built an MTM system using 10" drivers ( 127H-1 ) with a 2426 that was fitted with a 275nd diaphragm . Since he had "inside" ( JBL ) exposure to workable mods, I'm just following his lead .


No need to tweek the x'over?

- I would assume the ( N3100 ) crossover would need some tweaking . This hybrid driver combo will likely have a response curve ( just guessing ) that has less lower mid response and more HF response than a stock 2426h. ( See Ziches crossover studies )

- I would guess the hybrid will require a reworking of at least some values within the crossovers hipass section. Again, see Zilches excellent graphs of the two crossovers voltage drives for my reasoning .

- The hipass section of the "mkII network" was obviously reworked to accomodate for a differing of the responses between the two driver types


"Overall" Same sensitivity ?

- I doubt it . See the above and look at Zilches voltage drive graphs . Also, note that the rework of the S3100 to the S3100 mkII allowed for a 1 db net increase in "system" efficiency ( this info is from the technical cut sheets ). The values of the damping resistors in the LF were raised ( in the mkII ) effectively burning off a little less energy. I assume this coupled with the rework of the hipass section allowed for the newer ( higher ) system rating .


If that were the case it would be a simple way to go, assuming I can find the diaphrams that is.

- Nothing is ever simple with this stuff. :p

:)

ps ; Would I still try out this hybrid driver ? Yes , but then I'm always willing to tinker with stock networks .

[Bernard Wolf]

thanks ever-so-much Earl, much appreciated... although most of whats being recommended is out of my league. I think what I will do is try to get that single 275nd if the bidding does not go too high. From there I have a friend - not local unfortunately - who can help me to build a mkii network while I wait to find another nd. Sound like it will be a long term project, but I don't mind that. In the meantime I could at least find out if the nd diaphram will actually fit as a retrofit.. thats assuming I win that bid.

Will let you know what happens when the bidding stops ;)

Bernard

[Earl K]

Hey Zilch,


,,,,(+useTHROAT 318793-001)


- I'd do it for you on S2600 horn, but that it comes without throat adapter.
- [Whatta b_ttl_ck!]
- Time out while I raise holy HELL with them....

Say,, did you have a conflab with JBL about this missing H2600 throat ?

And ?

<. :)

[Zilch]

Hey Zilch, did you have a conflab with JBL about this missing H2600 throat ?Confab? Bwahahaha!

They won't answer my eMail OR my phone calls now.

Musta flagged me as "TROUBLE!"

I have two horns, now, no throats. :biting:

This is Harman consumer I'm dealing with. If it was JBL Pro parts, I'd have 'em by now.

Matthias is sending me drawings to make my own, if necessary.... :)

[Earl K]

This is Harman consumer I'm dealing with. If it was JBL Pro parts, I'd have 'em by now. Ohhh,


They won't answer my eMail OR my phone calls now.

Musta flagged me as "TROUBLE!"

Hmmmm, I really don't want to speculate .


I have two horns, now, no throats.

Yep, that's a drag !


Matthias is sending me drawings to make my own, if necessary....

- Yeh , that's a good idea . From my perspective, these loading throats are all quite interesting. They all seem to be an adaptation of early parabolic horns ( H. Olsons' designation for the more evolved Smith horn ).

- I could post pics of the Altec style CD entry throat if you need them. The Altecs are a little more straightforward ( a little more planar or conical in their entry which will effect the lower ranges loading )


:p

[Earl K]

Well,,,,, Bernard ???? :)

[Bernard Wolf]

Well,,,,, Bernard ???? :)

Well.. I won the bid at $182.50 ! Not too bad I figure. I am now negotiating with the seller on a new 275nd diaphram which he is also auctioning. I f I can manage that then I will have 2 diaphrams and a driver. hey, its a start. At least I will then be able to experiment with changing just the diaphrams. According to the seller they are interchangable, size wise. We will see. In the meantime I will of course be on the lookout for another 275nd driver. If you happen to see one lying around...:)

Bernard

[Earl K]

Well.. I won the bid

Nice ! ... Yeh, I consider that a fair price ( considering the build quality of the driver and the rumoured price of a new 275nd diaphragm ) .


I am now negotiating with the seller on a new 275nd diaphram which he is also auctioning.

Hope that negotiation works out for you ! :)

[Bernard Wolf]

So, I finally did get the other 275nd diaphram but have not had the courage to try and swap them out yet. I am presently trying to acquire some new bass driver Gaskets - one of mine is due - and as I need to take out the bass driver to get at the 2426 once I get these I will probably at least take a look at trying a swap. Will keep you informed although perhaps these questions have been answered with Zilchs' experimentations.... I have not had the time to follow all of those experiments !

Bernard

[Zilch]

Will keep you informed although perhaps these questions have been answered with Zilchs' experimentations.... I have not had the time to follow all of those experiments!Bottom line: Sound great, frequency response is different, tho; crossover tweaks required; haven't done it yet.

Used autoEQ to play them....

[4313B]

Will keep you informed although perhaps these questions have been answered with Zilchs' experimentations.... I have not had the time to follow all of those experiments !

BernardZilch's experiments have nothing to do with you. You will have to measure your horn/cd combos and affect network changes accordingly. No one can do it for you.

[Bernard Wolf]

Well that leaves me out as there is no way I can do it ! I will just keep praying for a second 275nd to show up and then have a new MKII x'over built for me by Solen here in Montreal. Any ideas who I should pray to ?? ;)

[4313B]

Ship your loudspeakers to Zilch or see if Earl will help you there.
Or is Earl in Toronto?

I'd be interested in knowing what Solen would charge you to build a pair of MK II networks.

So what do you have? A pair of 275Nd diaphragms that you want to put in 2425/2426 cores?

[Bernard Wolf]

Earl is in Toronto which is about 350 miles..

Shipping at about 300 lbs would be way over the top..

Solen would charge I don't know what for those x'overs.. I'm guessing maybe $500.00 or so ?? I do have an electrical engineer friend who I could prob talk into it.. He would normaly be of help here also but he lives in Boston.

What I have is 1 275nd and 1 275nd diaphram. The thought was to take out the one diaphram and with the other try them in the 2426 just to see/hear.. but that does not seem possible , for me anyways.. I waited 2-3 yrs for the first 275nd on ebay.. hope I don't have to wait as long for the second.

[Zilch]

Problem with MKII is knowing the inductor DCR's.

I could probably guess at them in Spice, smoothing out the notches:

http://audioheritage.org/vbulletin/showthread.php?p=67212&postcount=10

Another alternative: I could maybe tweak the N3100 crossovers I built with 275nd diaphragms in 2426H and send 'em to you to try. (The crossovers, not the drivers. ;) )

Or the tweaks to do your own, or have done.

What you're trying to accomplish is a custom design. That requires having, or having access to, some way of measuring the result.

'Course I advocate every serious user have an RTA, anyway, and learn how to use it.

[$250 at Guitar Center.... :) ]

[Bernard Wolf]

So did you actually manage to get the 275 dias to fit in the 2426 ? Just a drop in ? If that were a known, for me at least, then I would attempt to tweak the x'over. BTW, I have a spare N3100 x'over :D

Bernard

[4313B]

Earl is in Toronto which is about 350 miles..

Shipping at about 300 lbs would be way over the top..

Solen would charge I don't know what for those x'overs.. I'm guessing maybe $500.00 or so ?? I do have an electrical engineer friend who I could prob talk into it.. He would normaly be of help here also but he lives in Boston.

What I have is 1 275nd and 1 275nd diaphram. The thought was to take out the one diaphram and with the other try them in the 2426 just to see/hear.. but that does not seem possible , for me anyways.. I waited 2-3 yrs for the first 275nd on ebay.. hope I don't have to wait as long for the second.I would imagine it would be tough to find another one. Those systems they were used in aren't parted out too often. You might try contacting Harman Japan about getting a single 275Nd.

[Bernard Wolf]

Mr. Widget tried that for me through a friend of his in Japan.. no go. Apparently they are 'obsolete'.. which really kills me. I guess they will repair them though.

[4313B]

Yeah, obsolete here too. :screwy:
I'll check around Monday.

[Bernard Wolf]

Well I certainly appreciate that... not much doing here. They (JBL Montreal) can barely comprehend what I am talking about! But in any case, whatever.. it's not like the 2426H sounds terrible you know :D.

Thanks - Bernard

[Zilch]

So did you actually manage to get the 275 dias to fit in the 2426?Yes, but I should probably try to "optimize" the installation alignment. One's a little different from the other; I'd like to get them better matched.

Wish I had a pair of coated standard diaphragms for comparison. ;)


BTW, I have a spare N3100 x'over :DThat's even better. You can do your tweakin' on that one.... :thmbsup:

[Bernard Wolf]

Wish I had a pair of coated standard diaphragms for comparison. ;)

That's even better. You can do your tweakin' on that one.... :thmbsup:

What do you mean by "standard Diaphragms"? 275nd's or 2426H ?

As for tweaking, yes, if I knew what to tweak.... I was thinking more of like sending it to you :applaud:

[Zilch]

What do you mean by "standard Diaphragms"? 275nd's or 2426H?DxR2425, 8 and 16 Ohms.


As for tweaking, yes, if I knew what to tweak.... I was thinking more of like sending it to you :applaud:Yeah, that'll work. I'll PM you the address should you decide to do it.

Only problem is, I'll have have to actually DO something around here for a change.... :p

[Earl K]

Hi Bernard,

Good Thing you're a patient guy ! ;)

- Since I saw my name mentioned above, within the context of helping to solve your dilemma / I've had a simplified S3100mkII network ( hipass only ) up & running on a 2426/2344 combo ( that's about 4 1/2 weeks now ). "Simplified" equates to just wiring up the "0" postion of the 3-way pad. Now I've got to reclaim my work bench ( after some documentation ) .

- Bottom Line ;The mkII hipass network is a lot more sophisticated than your stock 3100 type and is in my opinion a worthwhile improvement for the investment.
- So yes ! you should get a pair of mkIIs' networks built to use with your aquaplased diaphragms ( even the stock 2426 drivers ).

- The mkII network is a powerfull, user friendly network ( for tweakers ) that can easily accomodate changes, such as those driven by placing an aquaplased diaphragm in a ferrite 2426 magnet or even using a different horn flare .
- For example; I reassigned the LCR notch filters to work with a stock 2426/2344 combo . This meant substituting more appropriate LC values ( to the notch filters as well as the main 2-pole elements ) to counteract the 2344 horns' midrange undulatons. All in all , a great learning experience for me ( the buried inductor under the conjugate resistor in the Lpad was a real eyeopener ).

- Next time I'm in Montreal ( likely late summer / & if you desire ) , I'll bring along some test equipment to properly align your 275nd diaphragms ( in the stock 2426 drivers / that'll mean stripping the 275nd driver of it's diaphragm for use elsewhere ).

- PM me if interested. This will all need to wait till mid-summer when my time frees up. It'll also require onsite tweaking to properly dial-in the three notchfilters. That'll mean working onsite at your place ( & between golfgames / which is usually my best reason to be in Montreal ) .

:)

[Bernard Wolf]

Hi Earl - thanks for keeping up with this thread :applaud:....

Yes, I have been patient and the reason is that my 3100's sound just great as they are and thus there is no burning desire to change them. I also am not really interested in any kind of experimentation.. little too old for that... but am certainly interested in wanting to do an upgrade ala the 275nd.

I am not so sure about outing the titanium diaphragm to replace it with the aquaplased one as I envision possible problems there. As Zilch noted above it might no be as easy as it sounds. Also, I would then end up with a modified 3100 rather than an 'official' MK II. I think I would rather wait untill I get another 275nd complete and then do the swap. I am however,very interested in what you have to say about using the MKii network with the 2426 though.

If I read you correctly I could build the network now, use it with the 2426 and then on that great day when I pick up the second 275nd, I'm in business. Would the MKii network require much modifying to work with the 2426?

Bernard

[Earl K]

I am not so sure about outing the titanium diaphragm to replace it with the aquaplased one as I envision possible problems there. As Zilch noted above it might no be as easy as it sounds. Also, I would then end up with a modified 3100 rather than an 'official' MK II. I think I would rather wait untill I get another 275nd complete and then do the swap. I am however,very interested in what you have to say about using the MKii network with the 2426 though.

- I can understand that / though / you may want to try a fitup of your 275nd diaphragm into a 2426 assembly at some time / just to get a feel for its' "different" sonic texture. .
- I suspect that Zilch has encountered a "QC" issue that's mostly the result of the application ( by hand ? ) of the aquaplas coating. My 2, 2450SL diaphragms are different enough from each other that they really require different amounts of HF compensation from my passive hipasses .
- ie; ( & because of this experience ) I don't consider these JBL-shipped, aquaplas diaphragms to be a "plug & play" remedy to much of anything. Their QC is about the same as buying a carton of stock D8R2425 diaphragms .


If I read you correctly I could build the network now, use it with the 2426 and then on that great day when I pick up the second 275nd, I'm in business. Would the MKii network require much modifying to work with the 2426?

- Sure, I'd recommend that you get a mkII network when you can and use it with your stock 2426 drivers. The voltage drives that Zilch produced ( above ) do indicate this newtork also gives more HF content ( it's a bit more tweeter like ).
I know this advice is in contrast to something I've said previously ( I can't find that post right now ) / but whatever it was that I was thinking at the time / I was wrong . The mkIIs' LCR notchfilters lineup well enough with some undulations in my 2344/2426 workup that I can see that they are more driver/horn specific than diaphragm specific .

- Here's a .gif that represents a blast from the past ( when the 275nd was available as a part ).


:)

[Bernard Wolf]

$605.00..... Ouch ! ... Guess the $200.00 or whatever it was I paid off of Ebay was a steal considering it looks to be 'brand new'. OK then, as soon as I can I will be off to Solen here in Montreal and see what they will charge me to build the networks. As my stock x'overs are external swapping them out will be a piece of cake. So, I guess what you are saying is that they will not require any mods to work with the 2426... very interesting.

If I manage to get everything up and running by the time you show up here in Montreal I would be more than happy to have you come and have a listen. Even if not, by all means drop by and hear the 3100 as is. Have you ever heard them? I'm very curious to hear what other JBLer's with experience have to say about the 3100. I have never really heard any other JBL other than mine and so have no real idea as to were they stack up in comparison.

Thanks - Bernard

[4313B]

- Here's a .gif that represents a blast from the past ( when the 275nd was available as a part ). Yeah, I'm not real sure why they were discontinued. They were nice. I believe this one was the last one JBL had available and it went to France to another forum member. There are a few others at JBL, two in reference systems and one sitting on the shelf with all the other compression drivers they've ever made. I asked if I could shoot a picture of those shelves and the PWT. The answer was no.

[Earl K]

Hi Bernard,

Thanks for the invite !


$605.00..... Ouch ! ... Guess the $200.00 or whatever it was I paid off of Ebay was a steal considering it looks to be 'brand new'.

- Yeh, I posted that pic for reference.


OK then, as soon as I can I will be off to Solen here in Montreal and see what they will charge me to build the networks. As my stock x'overs are external swapping them out will be a piece of cake.

- I think we'll all be interested at what Solens' pricing will be .



So, I guess what you are saying is that they will not require any mods to work with the 2426... very interesting.

Sorry : Actually, that's not really the case ( though a new plug & play may be close enough for R & R ).

Still :
- The LCR notches will still need to be tweaked to properly zone in on the peaks produced by your specific 2426 drivers. Additionally, because the DCR values of the coils in the mkII are unknown, the notches are likely going to end up deeper ( from a custom Solen build ) than they ought to be ( unless you transport a speaker over to Solen so that they measure the results as they go along ).
- Also, my own preference would be to redesign the padding network to simplify it, to make it conform with what I perceive to be , more typical Northridge network design practices ( I'm a liitle uncertain if this network is GTs' handiwork or someone elses / it looks to be someone elses through my wandering eyes ).
- Also, this mkII network may benifit from having a LCR impedance correction network added to it ( as is found in the original N3100 ). This means someone needs to build the mkII network / measure it's overall impedance with drivers in place / then decide if the LCR impedance correction is applicable .

:)

[Zilch]

There is the remote chance that one or more MKII networks are available off the shelf somewhere within the JBL consumer parts system.

Part numbers 333938-001 (HF) and -002 (LF).

I've had some luck in the past with this sort of pursuit. The hard part is getting someone knowledgeable of what's where on the phone....

From the depth of the notches shown in my simulation, knowing the DCR of the inductors is crucial to getting it right, and even then, they will likely have to be custom optimized for the different driver/diaphragm combinations.

Agreeing with Earl, it's unlikely Solen will be able to do it without samples, but I'd be interested in knowing what they estimate as the cost. Biased and bypassed, that network is at the high end of construction complexity in my experience....

[Zilch]

Indeed.

And other stuff, too....

[Earl K]

Orientation ; Zero Degrees to what ( horn edge & middle of slot ) ?

Also, what network is being used ?
:)

[Zilch]

Hi, Earl.

0&#176; is perpendicular to the horn face, and alignment is to the empirically determined (from impulse delay) acoustic center, which, best I can tell, is at the slot, NOT the driver voice coil or diaphragm.

Driver is offset 30&#176; to the outside rear (left in the pic) by the throat.

Mic's at 30&#176; in the pic, i.e., in line with the driver axis, orange curve, max SPL.

Filter is 18 dB/octave 1200 Hz FFBREQ in 5235.

Driver is BMS 4552nd-8.

Measuring distance is 44".

Unless I'm totally FUBAR here, the horn is amazing.

See CLIO Clinic for polar response measurement methodology:

http://audioheritage.org/vbulletin/showthread.php?p=112442#post112442

Sitting at the apex of an equilateral triangle formed with a speaker pair, you'd be hearing the orange curve (30&#176;), somewhat further back, the green (15&#176;).

Then, as you move to one side, the nearer speaker goes toward the red (lower SPL) while the farther one goes toward orange (highest SPL), compensating for the change in distance and locking the image in place.

The effect remains operative even closer than the equilateral case due to the differential rates of SPL change with geometry.

[Earl K]

Hi Zilch,

Thanks for the visuals / with explanation .

They certainly do underscore everything everyone has ever said about these horns and their stable imaging .



:)

[Zilch]

Yup.

They were my "Final Iteration" over in Q&D.

Looks like CLIO has answered the rhetorical question there:

http://audioheritage.org/vbulletin/showthread.php?p=92145#post92145


;)

[Mr. Widget]

Unless I'm totally FUBAR here, the horn is amazing.What makes you say that? ...not the FUBAR bit, but why do you come to the conclusion that this is an amazing horn? I suppose I'm asking, what are your criterion for an "amazing" horn?


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[Zilch]

Why do you come to the conclusion that this is an amazing horn? I suppose I'm asking, what are your criterion for an "amazing" horn?It's amazing in that it so effectively reverses the normal progressive decay of SPL at the requisite angles without introducing major anomalies in the FR.

There are some quirks up at 15 kHz, but those are minor in comparison to what I've found measuring other horns/waveguides. The TOTAL variability here is controlled within +/- ~2.5 dB, and the response at each different angle retains its integrity throughout most of the range.

This level of precision FR and SPL control would seem to contribute significantly to the successful image stabilization. The power response appears extraordinarily well controlled. They work.

Since I'm still set up here, I'll run 2344A for comparison. I trust we can most all agree upon that horn as a "standard"....

[Mr. Widget]

Since I'm still set up here, I'll run 2344A for comparison....I don't see the point in that... JBL has published quite a thorough exploration of their axial performance. To me this exercise reminds me of those Stereo Review "Bench Tests" of receivers back in the '70s where this one had more zeros than that... none of them sounded as good as an old tube Mac even though the Mac's measured performance was significantly inferior.

For me what makes an "amazing" horn is in the listening. When I listened to those horns at your place, I did not think of them as amazingly good. What they do is very interesting.... I certainly agree that they are absolutely intriguing. I suppose if the goal was simply to provide a very good polar plot, they are unusually good at that, however I'd guess from having listened to them at your place they must make a mess of the signal's phase since they didn't create a stereophonic image that was really convincing. They certainly can't compete with any of the better dome and cone based systems. Personally I thought they sounded quite odd actually. Rather than focusing on a slight bump in the response of this or that horn perhaps you should set up some double blind listening tests... I believe that our onboard monitoring equipment is ultimately more discriminating than what we can generate with a mic comparing this curve or that...

Sorry... I have kind of gone off topic here again, it was just that I didn't see those horns as "amazing"... assuming amazing means stellar performers. I am sure there are plenty of folks who are happy with them, but I'd rank them as someone's personal fav as opposed to a universal success story.


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[Bernard Wolf]

Well, I do have to put my 2 cents worth in.. unfortunaltely, since I do not think that either of you have heard a factory built setup I don't know how you can say anything difinitive about the 3100/2600 finished product.. The reason I say this is having owned Quad 57's, which by most peoples definition are much better than average at stereophonic imaging, I can difinitively say that the S/3100 throws are very, very convincing soundstage. Every bit as good as the 57's and in most ways better.
Come and listen any time. :)

Bernard

[Mr. Widget]

Well, I do have to put my 2 cents worth in.. unfortunaltely, since I do not think that either of you have heard a factory built setup I don't know how you can say anything difinitive about the 3100/2600 finished product.. The reason I say this is having owned Quad 57's, which by most peoples definition are much better than average at stereophonic imaging, I can difinitively say that the S/3100 throws are very, very convincing soundstage. Every bit as good as the 57's and in most ways better.
Come and listen any time. :)

BernardBernard,

I'd love to... no plans for heading north just yet though. I do think you bring up a good point about the S3100 as a system. I have never had the pleasure of hearing them. I would love to have the opportunity. I think it would be very interesting.

As for the Quads, I have heard them and I like them. I wasn't particularly impressed with their imaging though. For imaging I generally like two way mini-monitors... yep Zilch, two ways! For them to work they typically need a 5-6" woofer so that it performs well up to the tweeter which typically needs to be crossed over around 2.5KHz.

Back on the topic of this thread (however loosely) I did hear the horn from the S3100s imaging... it just wasn't what I consider convincing. Now I'll be the first to admit that the speakers whose imaging I really like have very poor dynamics and can sound really strained at realistic SPLs... there are several "audiophile" speakers that I have heard that do a great job imaging and are dynamic, but they typically cost more than my car.:(


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[Ian Mackenzie]

No too rooms are alike either.

At any rate as G.T stated in another thread it comes down to what you like Bernard, screw everyone else. :D .

[Mr. Widget]

At any rate as G.T stated in another thread it comes down to what you like Bernard, screw everyone else. :D .Absolutely! That's what was implied by this statement:
I am sure there are plenty of folks who are happy with them, but I'd rank them as someone's personal fav as opposed to a universal success story.I started the whole counterpoint simply so that someone reading about a particular "amazing" horn doesn't blindly run out and buy a pair expecting the ultimate high end only to discover that they don't share the enthusiasm.


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[Zilch]

Absolutely! That's what was implied by this statement:I started the whole counterpoint simply so that someone reading about a particular "amazing" horn doesn't blindly run out and buy a pair expecting the ultimate high end only to discover that they don't share the enthusiasm.It's pretty tough to buy them anymore, alas.

Where I'm coming from is I'm hooked on the asymmetric controlled directivity image effect, and thus investigating how it works and what's required to accomplish it. I do have some horns from another manufacturer, and easily see from measurements that they haven't anywhere near the control precision of these JBL's. I'll also measure the Everest horns for comparison.

I think it's regrettable that JBL never made this technology generally available and that they abandoned it after S2600/S3100. It moved phantom center a major step forward, largely unnoticed and under-appreciated.

Next time Mr. Widget gets by here, we'll have another listen. Since he last heard them, and largely in response to what we heard in that session, I've moved the filter frequency up from 800 Hz to 1200 Hz, and also retuned the LE14H-3 boxes they're mated with. We've all agreed the horns need to be installed in cabinets for optimal performance, as Bernard suggests. That may permit lowering the crossover back down to where JBL ran them....

[Bernard Wolf]

[
Sorry : Actually, that's not really the case ( though a new plug & play may be close enough for R & R ).

Still :
- The LCR notches will still need to be tweaked to properly zone in on the peaks produced by your specific 2426 drivers. Additionally, because the DCR values of the coils in the mkII are unknown, the notches are likely going to end up deeper ( from a custom Solen build ) than they ought to be ( unless you transport a speaker over to Solen so that they measure the results as they go along ).
- Also, my own preference would be to redesign the padding network to simplify it, to make it conform with what I perceive to be , more typical Northridge network design practices ( I'm a liitle uncertain if this network is GTs' handiwork or someone elses / it looks to be someone elses through my wandering eyes ).
- Also, this mkII network may benifit from having a LCR impedance correction network added to it ( as is found in the original N3100 ). This means someone needs to build the mkII network / measure it's overall impedance with drivers in place / then decide if the LCR impedance correction is applicable .

:)[/quote]

Very scary Earl... sorry to take so long getting back on this. Anyways, I have decided to leave well enough alone for the present as I am not really interested in experimenting right now. Besides which the 3100 sounds fabulous as is. I will just bide my time untill that second 275nd shows up. In the meantime, if you want to come over and take a listen while you are in Montreal that would be great. I have never heard any other JBL speakers and would be curious as to what your take on these would be.

PM me if you want to stop by and I will give you my coordinates.

Bernard

[Bernard Wolf]

Still :
- The LCR notches will still need to be tweaked to properly zone in on the peaks produced by your specific 2426 drivers. Additionally, because the DCR values of the coils in the mkII are unknown, the notches are likely going to end up deeper ( from a custom Solen build ) than they ought to be ( unless you transport a speaker over to Solen so that they measure the results as they go along ).
- Also, my own preference would be to redesign the padding network to simplify it, to make it conform with what I perceive to be , more typical Northridge network design practices ( I'm a liitle uncertain if this network is GTs' handiwork or someone elses / it looks to be someone elses through my wandering eyes ).
- Also, this mkII network may benifit from having a LCR impedance correction network added to it ( as is found in the original N3100 ). This means someone needs to build the mkII network / measure it's overall impedance with drivers in place / then decide if the LCR impedance correction is applicable .

:)
Sorry to take so long responding to this post.. been rather busy...

The notion of doing all of the above is way beyond my needs/interests at this point in time... kind of scarry too ! Actually, I am more than thrilled with the 3100 as it is and so I will just sit tight and wait untill that day in the not too distant future - hopefully - when I do find that second 275.

In the meantime Earl, if you are in the area and would like to hear the 3100's please drop me a PM and we will work it out.

Thaanks - Bernard

[MatthiasA]

hello

i bought 2 H2600 for my two DIY S2600's
brand new from Harman Germany
but ive no idea where i can buy the adapter?
is there any part available in the USA?

Greetings Matthias

[Guido]

And they don't have the Adapter available?

[Jan Daugaard]

What does http://www.rw-soundsystem.de/ say who sold the H2600 horns to you?

[Zilch]

The last throats I got came from Harman France. I'd be surprised if there were any in the USA, as it was Hell getting my last pair in December, 2005.

It's confusing. Since it's not shown on the drawing, a resonable buyer would assume it comes with the horn.

But, no. The part number is:

318793-001 Horn Throat S3100

Let us know if they have any.

[MatthiasA]

how much are the throats ?

i paid about 220 euros for one horn

i dont know that throats have another number...
yes you are right - theres no number of throats in the drawing
i thought it comes with the horn
for that price....

greetings matthias

[Zilch]

i thought it comes with the horn
for that price....Yes, I did too, and it looks in the parts listing system like it is supposed to come with, but nobody knows or cares about that, since there is also a referenced part number for the throat sold separately.

My first pair of those horns, I was able to make enough of a fuss about them being useless without throats to get them (the throats) for free. Second pair I had to pay $98 apiece for the throats, so the total is close to $600 list for a pair of the horns complete.

I've posted pics of the disassembled throat in these forums. It's smoothly contoured inside to make the transition, and a simple fabrication from plywood, for example, as I originally contemplated, won't suffice. However, they are two-piece and could easily be replicated, if necessary.

I'm surprised you got horns, actually. I've been told several times there are simply no more and none contemplated for production. A big hurdle with US Harman Parts is that those products (S2600 and S3100) were never sold in this country....

[MatthiasA]

Hello

RW Soundsystem answerd my Email.
Mr Kallis from RW said the Throat is out of stock in Europe at the moment
but he would send me an Email as soon as possible
if the adapter is available

....:bs: happend...

offer anybody of you one or two Adapters for me?

greetings Matthias

[Zilch]

Ask Guido to contact Harman Parts directly, Harman France, in particular.

He's pretty resourceful in obtaining JBL stuff....

[Mr. Widget]

Please check every possible option first, but if they prove to be no longer available, I could borrow one of Zilch's and cast some in a sonoglass like material I use.

I assume Zilch would help out in this...;)


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[Zilch]

I assume Zilch would help out in this...;)Well, sure.

It ain't as if nobody does stuff for ME here, you know.

[To what end remains unclear.... :p ]

[Jan Daugaard]

Hi Widget!

What is the sonoglass-like material you are using for horns and other loudspeaker parts? What does it cost and where is it available?

Jan D.

[Mr. Widget]

It is a mineral filled urethane resin. It is quite dense and has physical properties that seem very similar to that of the Sonoglass horns I have seen. Structurally is may not be as strong... but since horns are not typically stress tested, that shouldn't be an issue. It could be an issue for a thin walled PA horn that sees a lot of physical abuse. Come to think of it, I am not sure if JBL uses Sonoglass for any PA horns...?

The material I am using is from BJB and is called TC-1630. I pay about $70 for a gallon kit of the stuff... and shipping is expensive too.

http://www.bjbenterprises.com/index.php

http://www.bjbenterprises.com/pdf/TC-1630.pdf


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[Bernard Wolf]

Hi Mr. Widget,

Tell me,if you would be so kind, how you think this material might work out applied to the back of a H3100 for sound absorption. I presently have applied a layer of automotive type deadening material to the horn but can still feel the sound waves from the bass driver radiating into the horn.. I was planning on another thicker layer but this resin sounds interesting. Could it be built up in layers to an appreciable thickness and do you think it would adhere?

Thanks - Bernard

[Mr. Widget]

You would need to build a mold behind the horn and pour the material into that cavity... it would certainly add mass and lower the resonant frequency as well as require more energy to excite it. How rigid are those horns? I have seen them over at Zilch's, but I don't remember if they were very rigid or a bit more flexible... some of the JBL horns are rather flimsy. If they are not terribly rigid the BJB mineral filled material would likely be a big help.

If they are very rigid, I think I would apply many coats of a brush-on rubber material, or you could cast a thick layer of this hard rubber... it is similar to car tire rubber when cured.

http://www.devcon.com/devconfamilyproduct.cfm?familyid=148&catid=14

Alternatively you could use the techniques used with the Altec horns... damping compounds, tar etc.


Here are a couple of pics of one of my raw (not cleaned up and painted) cast horns and throat adapters. They weigh 60lbs each!


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[speakerdave]

They weigh 60lbs each!
Yes.

[Guido]

Very nice horns!

[Zilch]

Very nice horns!Yeah, it'd be nice if we could see the HORN part.... :p

[Mr. Widget]

Yeah, it'd be nice if we could see the HORN part.... :pThat didn't seem relevant to the conversation... hey Zilch I have a relevant question for you. How rigid are the mini-Everest horns? Are they as rigid as acrylic or more like polypropylene?


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[Zilch]

Rigid like acrylic. Half the thickness of 2344s or 2380s, same material, seems like. In S2600, they're isolated in a separate chamber. Not so with S3100....

[Bernard Wolf]

Rigid like acrylic. Half the thickness of 2344s or 2380s, same material, seems like. In S2600, they're isolated in a separate chamber. Not so with S3100....

they are quite ridgid and could probably take a lot of weight if one were to go this route.. very interesting. .. have been thinking about it and it might not be all that difficult to make a mold behind the horn. There is a distributer in Montreal for this material which makes it doubly interesting.. a winter project perhaps ?? sure do wish I could find that other 275nd though.. now that would be a great project !!

Bernard

[Bernard Wolf]

If they are very rigid, I think I would apply many coats of a brush-on rubber material, or you could cast a thick layer of this hard rubber... it is similar to car tire rubber when cured.

http://www.devcon.com/devconfamilyproduct.cfm?familyid=148&catid= (http://www.devcon.com/devconfamilyproduct.cfm?familyid=148&catid=14)


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Mr. Widget

Same question though.. would it adhere to the horn ?? Important consideration... also, isn't rubber rather transmisive ?

Bernard