More than one type of 2416?
Quote:
Originally Posted by
subwoof
post a pic of the bad dia so I can see the exact version - I have some of the older 2416H in the used pile. most of the 4425's I have run across have these, not the later 2416H-1
Get a case of bradour in my pocket and I'll send you one..:)
*cheers*
Great, yet another variable..:D I`ll take a look, get a shot of it tomorrow. What are the differences?
In the mean time, I`ll get a shipping quote for the Brador.
serial number sticky (not)
Many versions / production runs of the 4425 had serial numbers that were just little white stickers stuck onto the input terminal cup - pretty cheap. And nowhere inside the cabinet are ther references to it.
Seems that these were blasted out in high volumes and not stamping the nice aluminum foilcal meant less work...sigh...
BTW the earlier models used the standard 5 way binding posts and the woofer ( 2214H ) had them also.
Later versions used the recessed / angled dual banana posts and the woofer was the 2214H-1 which had the polorized spade connectors.
I have 3 sets of these in various states of use / repair and each is slightly different. Swapping woofers is a PITA with the terminal diff...grrr...
sub
Radian vs JBL; 2415H; 2416H-2416H-1; 2417H
Quote:
Originally Posted by
Lee in Montreal
Just adding to the discussion that Radian is one of the very few suppliers of replacement diaphragms for JBl drivers that offers data comparing their product with an original JBL diaphragm. Priced between an original JBL part and a waste-o-money Chinese knock-off, Radian diaphragms make sense for those who don't seek the exact JBL sound. ;)
http://radianaudio.com//components/c.../1245_1225.pdf
I agree with you on the Radians and the cheap chinese knockoffs! See my post re: actual PWT measurements of 2425 driver with Factory-installed JBL diaphragms, Radian dias. and a cheap chinese knockoff:
http://www.audioheritage.org/vbullet...ht=#post325397
Regarding the three variants of JBL drivers and replacement drivers, subwoof has it right. Edgewound and subwoof enlightened me a few years ago (thanks, guys! :wave:) about the "Salt and Pepper shaker" phase plug being from a 2415H driver after I posted pics of pair for sale on ebay asking what they were.
While on the subject, don't be tempted to "upgrade" to the 2417 diaphragm. The 2416 diaphragm is lighter (thinner),has a very tiny diamond pattern stamped into the surround, a different back cap, and about 5 dB more output at 15KHz than previous models (according to the JBL SR Series II catalog).
However, the 2417H phase plug is not as high as the previous models and the 2417 diaphragm will contact the 2415/2416 phase plug before the diaphragm mounting flange seats on the magnet.
The 2415/2416/Radian/aftermarket diaphragms will "fit" the 2417, but I can't imagine them sounding very good due the much greater air space between the diaphragm and the 2417 phase plug.
I proved this while trying to positively identify a 2417 driver I had acquired but, like all of these, has no model number markings on the driver itself. I had a blown 2425 diaphragm (no cover) that I dropped onti the 2417 and pressed down on the diaphragm to check phase plug clearance. It seems to be enormous! got out a 2416H driver and put the 2425 diaphragm on it to check phase plug clearance, and it was close- as it should be. I then took a 2417 diaphragm and gently lowered it onto the 2416 driver until it teetered on the phase plug. That was enough to convince me that I indeed had a 2417 driver and ordered a new JBL diaphragm for it.
Prior to this the only known clue to ID a 2417 was a slightly rounded outer edge to the magnet top plate stamping, but that apparently does not hold true.. I bought one on ebay that was purported to be a 2417, but looked exactly like the 2416's sharply defined top plate edge. I was suspicious. Now I know the only way to positively ID a 2416 or 2417H driver is to fit test a 2417 or an unusable 2425 diaphragm , or measure the phase plug height if you have the means to accurately do so.
Lastly, I recently purchased a NOS JBL 2415H diaphragm, and the major differences I can spot are that the voice coil winding appears to be of copper instead of aluminum, and the DC resistance is much different-4.4 ohms on the 2415 dia and 2.9-3.1 ohms on my 2416 dias.
All of the JBL diaphragm variants I have (2415H, 2416H, and 2416H-1) do have the pin hole vent in the cap. The Radian cover and sealing gasket sold to use with their 1225 dia on 2415/16 drivers does not have a vent hole. However, their surround is perforated, which allows for pressure equalization. The sealed back cap also prevents the woofer from modulating the diaphragm at high level low frequencies.
Read through the sister thread I linked above for more details.
Perhaps a moderator should combine these threads?
2425 diaphragm compatability; 2418H yet another different beast
Quote:
Originally Posted by
Earl K
Good info there Rudy , about the 2417 being a different beast all-together . I didn't know that . Thanks !I had also wondered whether or not my 2425 diaphragms would properly fit the (2) 2415 magnetic assemblies that I have here / & now I know that they should . :thmbsup::)
Yeah, just order backcap kits from Radian and run the JBL 2425 or Radian 1225 diaphragm in it. I'll be doing that myself shortly.
I've no personal experience with th 2415H "salt shaker phase plug" driver, but I think it is safe to say that the phase plug profile and compatibility is there, considering the JBL 2415 replacement diaphragm supersedes to a 2416H-1 diaphragm. For that matter, I think it is possible that the filter network may not care either, since the impedance curve may not be much different between the 2415 copper coil and the 2416 aluminum coil. It would be interesting to see/compare impedance plots of the two diaphragms and the networks from a very early 4425 and a late-model 4425.
The 2418, used in MR9xx, several EON's, and maybe a couple others, is yet another beast with an entirely different diaphragm and a separate back cap.The diaphragm is so cheesy-looking and flimsy to the touch that I never took it any more seriously than I do a 2412H... I'm not even sure it is titanium, so I never have fooled around with one. My personal feeling about the 2418H is that it is an example of upper management profit motives trumping product design and manufacturing quality.