+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 15 of 26

Thread: 4320 update w/2405

  1. #1
    Junior Member
    Join Date
    Jul 2003
    Location
    Paris, France
    Posts
    19

    4320 update w/2405

    Hello,
    Alongside my much beloved 4310, I just bought a pair of 4320 (belonged to the late John Entwistle !) and I'm thinking of adding a 2405 slot tweeter to enhance high frequency response. I'm looking for information and advice on the overall procedure --installation, connection, which crossover model, stuff not to overlook or forget, etc. Thanks in advance.
    David

  2. #2
    Your Memory Lives On RIP Tom Loizeaux's Avatar
    Join Date
    Apr 2003
    Location
    Baltimore, MD USA
    Posts
    669
    Sounds like a good idea. I did the same thing to my pair of old 4320s.

    You'll need a pair of 2405s (or 077s) of course, and a pair of 3106 crossovers.
    My 4320s came with two cut-outs in the rear panel. If yours did also, then installing the 3106s is easy. I assume you have 3110 crossovers in these already. ? If so, you take the wires from he 3110's high freq. outs and run them to the 3106's inputs. Then take the 3106's low outs and run them to the compression driver and run the 3106's high outs to the 2405. Wiring them to be in correct phase is a little tricky. More on that later.
    Most 4320s came with a cut-out that holds the 2405. It is located low and off-center, but if that's OK with you (it was with JBL) then the only mod you'll need to make is to drill new holes to line up with the four in the 2405's frame.
    If you get these ready to install and you have further questions, please ask.
    I think you'll be very pleased with these 4320s after the slots are in them.
    Check my photo and you'll see one of my 4320s with the 2405 installed centered above the compression driver lens.

    Tom

  3. #3
    Junior Member
    Join Date
    Jul 2003
    Location
    Paris, France
    Posts
    19
    Thanks Tom.
    I will sound like the ultimate badger, but how to you access the innards of the 4320 to install the 2405? --my guess is one has to take the LF speaker away, but I'd rather not make a blunder with a LF speaker that probably weighs a ton. There's a cutaway for a 2nd crossover indeed, it's currently closed by a woodpanel.
    A couple more questions:
    1. Is there only one flavour of 2405, impendance wise?
    2. What's the tricky part regarding the wiring of the 2405?
    Thanks !
    David

  4. #4
    Your Memory Lives On RIP Tom Loizeaux's Avatar
    Join Date
    Apr 2003
    Location
    Baltimore, MD USA
    Posts
    669
    Yes, accessing the inside of the 4320 requires removing the woofer. If you're new at this, be carefull that you don't damage the cone or surround. I sit in front on the cabinet while on the floor and remove all but the bottom screw, since my 4320s don't use JBL clamps, and then slowly remove the bottom screw while pressing my foot on the front rim at the bottom. Once the last screw clears, the speaker can be pulled from the cabinet. Unclip the wires to it and put it aside in a safe place.
    Shine a light inside and a lot will be revealed. As you remove drivers or crossovers draw a diagram of which color wires go to exactly which contacts.
    The cover panel can be removed as well as the cover on the tweeter hole.
    As far as I know, there is only one impedance version of the 2405. Though it meters near 8 ohms, it is really closer to 16 ohms in it's operating range.
    When you get your 2405s and 3106 crossovers - we can talk you through wiring these up to maintain correct polarity and phase.
    Keep us posted.

    Tom

  5. #5
    Junior Member
    Join Date
    Jul 2003
    Location
    Paris, France
    Posts
    19
    Thanks Tom, that's exactly the kind of "real life" advice I needed. I ran a search on 2405 and found this long thread on polarity. Interesting (scary?) ! Now to find a couple of 2405 and the crossover.

  6. #6
    Senior Member Doctor_Electron's Avatar
    Join Date
    May 2003
    Location
    California Central Coast, USA
    Posts
    144
    Or...if you can obtain the 0.16 mH inductors, you could copy the third-order high-pass portion of the #3107 network (used in the 4350). Its input connections ("common" and "high Freq") could be connected in parallel to the existing network's input connectors. Use 100V minimum voltage rated, non-polarized film caps. Remember...the built-in resistance of the inductor affects the network section's "Q", and therefore the steepness of the filter's slopes. For example, the 1.8 mH inductors associated with the 2440 drivers have a DC resistance of about 3.5 ohms each, far more than you would expect. This value is critical to the filter's function!
    3107:
    http://www.jblproservice.com/pdf/Net...%20Network.pdf

  7. #7
    Moderator / Treasurer/Marketplace Czar boputnam's Avatar
    Join Date
    Apr 2003
    Location
    northern california
    Posts
    6,896
    Originally posted by dkorn
    ...how to you access the innards of the 4320 to install the 2405? --my guess is one has to take the LF speaker away...?

    A couple more questions:
    1. Is there only one flavour of 2405, impendance wise?
    2. What's the tricky part regarding the wiring of the 2405?
    Hey...

    Tom has given some outstanding guidance there - lucky he's been through this exact upgrade!

    I've two points:

    1) When removing the LF (i.e., woofer) I always lay the cabinet on it's back. Period. Even the monstrous 4345's. Period. Too easy to lose grip of the LF, and risk not worth it. You risk damage to the baffle, and who knows how the LF would come to rest! Also, you may need to carefully ease a putty knife beneath the LF frame in a couple places around the frame to loose it from the baffle. Once free, lay a towel on the baffle face where you can rest the motor while you disconnect the leads. Set LF aside, face down (hold by frame back - watch for leads) and then restand cabinet for work if you need to access the rear.

    2) The 2405 comes in both 8-ohm and 16-ohm iterations. The "vintage" 2405's are 16-ohm. The newer and still sold are 8-ohm, look a bit different in the motor area, but take the same baffle-cut as the "vintage". I prepared and posted a composite image of the two 2405 iterations elsewhere on this Forum, on Page 3 here: 4345 Monitor Plans - Link I've not had the chance to compare A/B 8-ohm vs 16-ohm in same-same, and should know better than to speculate, wildly... Check this out: 3105 Network - Link from the inimitable Giskard, as usual. Looks to me like you're going to want to stick with the 16-ohm, vintage iteration, but there I go again...

    You might use the Search function for the 3107 network - Mr. Widget had some very intersting comments in the 2404 vs. 2405 Thread - Link

    Oh, yea, on wiring: Just hook 'em up the way their supposed to be, Red lead to Red UHF terminal. The 3106 has the 2405 running JBL Standard (negative): 3106 Network - Link

    So, how'd you come on Entwistle's 4320's, anyway?

    Make sure you post some pics and keep us current on progress!
    Last edited by boputnam; 09-07-2003 at 11:53 AM.
    bo

    "Indeed, not!!"

  8. #8
    Obsolete
    Join Date
    Apr 2003
    Location
    NLA
    Posts
    14,286

    077 & 2405

    Maybe this will help -
    Attached Images Attached Images  

  9. #9
    Moderator / Treasurer/Marketplace Czar boputnam's Avatar
    Join Date
    Apr 2003
    Location
    northern california
    Posts
    6,896

    Re: 077 & 2405

    Originally posted by Giskard
    Maybe this will help -
    Or confuse...

    So, they don't even sell an 8R diaphram for the 2405H (the nominal 8-ohm copy)... ??
    bo

    "Indeed, not!!"

  10. #10
    Junior Member
    Join Date
    Jul 2003
    Location
    Paris, France
    Posts
    19
    So, how'd you come on Entwistle's 4320's, anyway?
    When he passed away, a pro audio broker in the UK bought tons and tons of stuff, that was sitting in no less than 3 warehouses --as you can guess, besides being JBL endorsees, the Who were also linked to a lot of manufacturers.
    So, said broker had to buy everything, and then had to move the stuff fast ! Those 4320 were part of those "priced to go" pieces. I just happened to check the broker's webpage at the right time, and I thought I'd give them a try --I already own a pair of 4310s that I love. Having said that, he had put an ad previously on rec.audio.pro, so it wasn't really a secret.
    Also, about the 4320s, I noticed the four small vents in the back of the enclosure were filled. And, Entwistle had a switch fitted on both speakers to shut off the HF.

    So, in short, should I keep my monies for the real vintage 2405, or will the 8-Ohms do? Ebay has mosty newer ones. I can wait, though.

  11. #11
    Moderator / Treasurer/Marketplace Czar boputnam's Avatar
    Join Date
    Apr 2003
    Location
    northern california
    Posts
    6,896
    Originally posted by dkorn
    I just happened to check the broker's webpage at the right time, and I thought I'd give them a try. Having said that, he had put an ad previously on rec.audio.pro, so it wasn't really a secret.

    Also, about the 4320s, I noticed the four small vents in the back of the enclosure were filled. And, Entwistle had a switch fitted on both speakers to shut off the HF.

    So, in short, should I keep my monies for the real vintage 2405, or will the 8-Ohms do? Ebay has mosty newer ones. I can wait, though.
    Hey...

    Interesting stuff - thanks. Futzing around in the shop today I had some more thoughts, but first:

    Can you tell us more about the broker, and that "rec.audio.pro" - we might have further uses for them!

    On those ports being "filled - I don't know the 4320 and whether this is de rigeur or not. The HF off-switch, however has me suspecting Entwistle had these rigged to either emphasize his bass lines on recording playback, or maybe he actually played through them in his listening room (without having to drag out the road gear). Interesting...

    On the vintage vs newer 2405, I had thought that 3105 Thread suggested the 16-ohm version gave a smoother xover; then Giskard posted the diaphragm replacement parts list, suggesting JBL only sell the 16-ohm version. I'm waiting for some more clarity on that - you could pm him...

    But, back to the other thought: Not to take anything away from Tom's great suggestions, but I wondered the pros and cons of just going for a 4332-33 set-up (Lansing Heritage 4332-4333 - Link ). That would enable you to biamp, and if not that, would keep the passive crossover to one (3133) instead of two in series. As I say, I don't know if there's any benefits to this, except the 4332-33 are outstanding.

    Here's a Link for the 3133 Network - Link (passive, three-way) and the 3133A Network - Link for the biamp option (then you'd need an external active xover like the 552 M series brochure - Link)

    Last edited by boputnam; 09-07-2003 at 03:34 PM.
    bo

    "Indeed, not!!"

  12. #12
    Junior Member
    Join Date
    Jul 2003
    Location
    Paris, France
    Posts
    19
    With all the help I'm getting here, I feel I must give back ! That broker is called Funky Junk, they have offices in Paris, London, Milan and Stockholm. Website at www.proaudioeurope.com .
    I'm a little confused with all these options now... I sort-of would prefer to keep the 4320s closest to their original state rather than turning them into a project. Adding a 2405 seems OK to me in that respect--after all the cutout is there, so it's not really a "mod". I may sound silly, I know.

  13. #13
    Moderator / Treasurer/Marketplace Czar boputnam's Avatar
    Join Date
    Apr 2003
    Location
    northern california
    Posts
    6,896
    Originally posted by dkorn
    I sort-of would prefer to keep the 4320s closest to their original state rather than turning them into a project. Adding a 2405 seems OK to me in that respect--after all the cutout is there, so it's not really a "mod". I may sound silly, I know.
    Not at all.

    Most here prefer Vintage gear to stay "as built". But, since you recognize the benefit of improving the UHF response by adding a 2405 (exactly as JBL did... ), you already are altering the original. You are de facto creating a 4332-33, only with a different LF (the 2215B vs 2231). I was just expanding the question here to address what the "preferred" option might be in considering the crossover, too.

    Macht Nichts.
    bo

    "Indeed, not!!"

  14. #14
    Senior Member Dave G's Avatar
    Join Date
    Apr 2003
    Location
    England
    Posts
    111

    Thumbs up 4320

    Hello dkthorn

    Thats makes 2 known pairs of speakers of this vintage and type in the UK.

    I can help with info and beware of who you deal with for parts and advice as I was ripped off by 'experts' in this country.

    I have a C50SM which is the same box with 375 mid and 075 bullet. The vents should be in the front in the form of ports no rear venting on these?
    Last edited by Dave G; 09-08-2003 at 01:25 PM.

  15. #15
    Senior Member Dave G's Avatar
    Join Date
    Apr 2003
    Location
    England
    Posts
    111

    pic

    Need to get these set properly!
    Attached Images Attached Images  
    Last edited by Dave G; 09-07-2003 at 05:01 PM.

+ Reply to Thread

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. C50 and 4320
    By Zilch in forum Lansing Product Technical Help
    Replies: 19
    Last Post: 01-14-2005, 01:40 PM
  2. Help with 4320
    By dkorn in forum Lansing Product Technical Help
    Replies: 21
    Last Post: 05-19-2004, 03:34 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts