275nd / S3100 compatibility

[Zilch]

Mini-Everest?

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

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

[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 !

- 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

[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.... ]

Well.. yes ..... 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.



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.

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 )

[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