Results 1 to 6 of 6

Thread: 4345+- DIY

  1. #1
    Junior Member
    Join Date
    May 2007
    Location
    West Central Florida
    Posts
    6

    4345+- DIY

    FWIW,

    So I'm not one to post a whole lot as you can see from my post count. Been reading along for a few years. Even got my account deleted because I was a zero poster for so long.

    Been collecting parts for a few years from folks here on the forum, and thought I'd post what's become of them. Hoping in a few weeks to see what a 4345 (+ anyway, hopefully it's a plus) but the baffle is done as is the box.

    Liked the sound of the 2397 years ago so, and the 4345 makes sense and is regarded well here. So, This baffle which has taken me an incredible amount of time to learn how to use a router will be equipped with:

    2245
    2012
    2397 / 2445
    Someday probably a 2405, for UHF but don't have 'em now. Major milestone here getting the baffle done, as I'm much more comfortable with a soldering iron than a router. Also cheated on the ports so that I can adjust them....

    Probably Tri-Amp them being that I have the amps / crossover to do that, and I want to hear them soon, then will take on the project of a cc: crossover and drop back to bi-amp one day (like next winter). This really has been a slow project.


    Anyway, Nice to see the post count increment by one.

    Any thoughts on the logical name for this modified 4345 ?

    Mike
    Attached Images Attached Images  

  2. #2
    Senior Member macaroonie's Avatar
    Join Date
    Jan 2005
    Location
    near Glasgow Scotland
    Posts
    2,272

    Each step

    is a step closer to the end result. Looks like a neat project. Keep the pics coming please.

  3. #3
    Senior Member Baron030's Avatar
    Join Date
    Feb 2005
    Location
    Chicago, Illinois
    Posts
    431
    Hi Mike

    I can see from your posting that you are one of the few brave souls that decided to use the 2012 driver. The 2012 is not a very popular driver around here. And the only reason for this is that it does not have as flat a frequency response as some of the other 10" drivers within the JBL lineup. The 2012 has a rising frequency response, which does require some equalization for it will sound right. As you can see from the first chart pictured below, this driver has a large peak at about 1 KHz. Assuming that you will be crossing over to the 2397/2445 at some point near 1 KHz. then all the other higher frequency peaks are not going to be an issue, because the crossover network will kill them off. But, the 1 KHz peak will present a serious problem, unless some form of equalization is used with the 2012. Since, you are going to tri-amp your system. I can share with you a possible solution. After much trial and error and a lot of testing, I have found a LRC circuit that works really well with my 2012H drivers. Pictured below is a schematic and I have also included a parts list. As you can see from the second chart, the frequency response is a lot flatter with the LRC circuit. And from the LRC circuit's impedance chart, you can see that this circuit does not introduce any large insertion losses, except for where it is really needed. Since this circuit does have very high "Q" value, I would recommend that you use the parts listed and not make too many substitutions. The coil's "Q" value has a huge impact on how much attenuation occurs at the LRC circuit’s resonant frequency.

    Parts list (per channel):
    1 - 0.30 mH, 0.10 ohm DCR, Erse perfect layer air coil 14 AWG.
    1 - 82 uF Solen metallized polypropylene cap.
    1 - 0.01 uF Bypass Cap. (It’s wired in parallel with the 82uF cap.)
    4 - 40 ohm 10 watt resistors (wired in parallel = 10 ohms @ 40 watts)

    With some EQ, I know you like the 2012.

    Baron030
    Attached Images Attached Images     

  4. #4
    Super Moderator Hofmannhp's Avatar
    Join Date
    Dec 2003
    Location
    Central Germany
    Posts
    1,266

    Project name?

    Quote Originally Posted by StillUse4560s View Post
    ....
    Any thoughts on the logical name for this modified 4345 ?
    Mike
    Hi Mike,

    a very nice project.....hope to see some more pics.

    My idea for the model number is 4397, refering to the used horn.

    HP
    Please help us save more info about the vintage systems. Let us register your speakers and drivers.

  5. #5
    RIP 2009
    Join Date
    Feb 2004
    Location
    Rohnert Park, CA
    Posts
    3,785
    Quote Originally Posted by Hofmannhp View Post
    My idea for the model number is 4397, refering to the used horn.
    I was just going to suggest the same, but you beat me to it...

    John

  6. #6
    Super Moderator Hofmannhp's Avatar
    Join Date
    Dec 2003
    Location
    Central Germany
    Posts
    1,266

    model number

    Quote Originally Posted by johnaec View Post
    I was just going to suggest the same, but you beat me to it...

    John
    ok John... but now you have a new chance.....
    Do you have an idea for MY new compact monitors (see thread in DIY) ?

    HP
    Please help us save more info about the vintage systems. Let us register your speakers and drivers.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. The JBL 4345 Club
    By Ian Mackenzie in forum Lansing Product General Information
    Replies: 349
    Last Post: 05-01-2022, 07:31 PM
  2. Another driver in 4345.
    By matsj in forum Lansing Product DIY Forum
    Replies: 9
    Last Post: 07-25-2007, 02:30 PM
  3. 4345 References Thread
    By hjames in forum Lansing Product Technical Help
    Replies: 4
    Last Post: 06-24-2007, 07:34 PM
  4. 250 DIY BASS RENONANCE - HELP
    By gerard in forum Lansing Product DIY Forum
    Replies: 15
    Last Post: 11-17-2005, 06:07 PM
  5. 4425 DIY vs original
    By Guido in forum Lansing Product General Information
    Replies: 2
    Last Post: 02-24-2005, 04:44 AM

Posting Permissions

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