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JBL E-140 content/ ongoing DIY 215 project

Discussion in 'Amps and Cabs [BG]' started by Chris 'Wighat' Jordan, Sep 25, 2013.

  1. I've started a couple of threads about my Ampeg V4B and DIY 215 project but I'm switching tracks on the cab now, so here goes another.

    Modeled and built a box around the MCM 2983 driver. Got the tuning right, and it sounded OK, but I wasn't happy with the mids and certainly not with the efficiency.

    New design parameters:

    215, don't care about size or weight (within reason)

    5-string friendly with some action below 40Hz, preferably usable down to 31 Hz

    Old-school tone and appearance to go with the V4B

    Enough efficiency to make this cab/head combo a viable alternative to my SVT/410 rig

    Almost danced a jig when I came across the spec's to the (discontinued, I know) E-140! Fs of 32 Hz, 100dB sensitivity and (unfortunately) a whopping 10.5 cu ft Vas. Aluminum dust cap and, according to many, among the best-sounding speakers for bass guitar.

    So, if I tune a 6 cu ft chamber for each driver at 35Hz, I'll get a -10 dB point of 31 Hz. I don't think my V4B is going to be getting much over 150 watts (correct me if I'm wrong). Excursion is safe up to that figure.

    Anybody got any comments, criticisms, etc?
  2. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    That all sounds highly optomistic ... Good luck with it though.
  3. Stumbo

    Stumbo Wherever you go, there you are. Supporting Member Commercial User

    Feb 11, 2008
    Song Surgeon slow downer. https://tinyurl.com/y5dcuqjg
    PM JBl guru JohnK_10.
  4. I would be pleased to hear why.
  5. jnewmark

    jnewmark Just wanna play the groove. Supporting Member

    Aug 31, 2006
    Stax 1966
    Third St. Cigar Records staff musician.
    Go for it ! here's my LDS built 215 with JBL's.

    Attached Files:

    • 215.
      File size:
      6 KB
  6. will33


    May 22, 2006
    A more manageable 4 cu.ft. box with those same JBL's will give you a much more practical, and just as good sounding a rig, seeing as your V4B doesn't have anywhere near enough juice to push 31hz audibly in comparison with the rest of the bandwidth and its output transformer would limit it's ability to do so, even if you added another zero on the end of its watt rating.

    In other words, the boxes would sound just as good, if not more so, and you'd actually be able to fit them in your car.....meaning you could take them places and play them for other people to hear. :D
    Count Bassie likes this.
  7. will33


    May 22, 2006
    I'm saying something approaching 4 cu.ft per driver, not for both. If I mis-understood that, ignore what I said earlier and continue on with what you're doing....sorry.
  8. There isn't any inherent reason my amp can't do the 30's. Got plenty beefy transformers and I've done quite a few listening tests by both sine wave and bass. Anyway, cab design is one of the few factors I can control. Fat strings help, too.
  9. will33


    May 22, 2006
    It may be a hifi design with big transformer and fat strings, but it still doesn't have the juice to push 30hz "loud enough to matter" in comparison to the rest of the bandwidth.

    Yes, you need some response that deep, and it may have it, but you don't need response even with the rest of the bandwidth down there, which is a good thing, because it would severly limit how loud you could go with the rest of the bandwidth.

    It's a V4 and JBL's....pretty hard to make sound bad. I'm just advising against fridge size boxes with one speaker each when something more manageble would sound just as good. 100 watts, no matter how badass those particular 100 watts are, isn't going to put out 30hz that can be heard audibly in a typical bar/club full of bodies...at least not at any level that matters.
  10. One problem you might have is SPL. The E140 is rated for 200W and they might not get loud enough for you in the extreme low end.

    Good luck with it. I will be interested to know how it turns out.
  11. For sure. I'm thinking one fairly large-ish 215 that will be a standard bass cab with a touch of low extension.
  12. JBL's Enclosure Guide recommends an 8.0 cu ft enclosure for a pair of E140's. Tuned to 40 hz, (4) 4.0 inch ducts at 5.0 inches long.
  13. will33


    May 22, 2006
    OK....4 cu.ft. per driver then.
  14. will33


    May 22, 2006
    Really, 4 cu.ft. per driver is a sort of sweetspot for a deep, ballsy 15" bass rig one can still take places/do something with. Sure, you can go bigger, and get "hifi" sort of range.....in something that is low power handling for live use and turns into a bigger PITA to haul around than sub bins are....to very little benefit, and possibly some detriment, for the listening public in a typical, direct radiator alignment.

    It just works. You can shrink it some and lose very little, at least at first.

    Or you can embiggen <---(I love that word) quite a lot, gain very little and lose more.

    Caveat: for use in projecting live sound, bass musical stringed instruments.....nothing to do with high fidelity, pre-recorded music playback listening or electronic blip-n-bleep so-called "music" kids make on laptop computers.
  15. taurus1


    Sep 13, 2006
    Vancouver B.C.
    I have a couple E-140's in an old Acoustic cab, I like it.
    I've always wanted a 2x15 cab the same dimensions as my Marshall 4x12, so I can stack it and have it match, purely aesthetics.
    that would have to be a pretty deep 4x12ish size cab to get 8 sq. feet I'm thinking.
    anyone have a rough idea?
  16. will33


    May 22, 2006
    26" x 26" external face times whatever depth to reach 8 cu.ft. allowing panel thickness, etc.?

    If done right, you'd hear little if any difference between there and 7.33 cu.ft.
  17. The Marshall is about a 26x26 inch cabinet so the 2x15 cabinet will have to be about 2 feet deep to have a volume of 8 ft[SUP]3[/SUP].
  18. What are the stats on that badboy?
  19. This rig will certainly not be hi-fi!

    Again, just want a little lower capability out of this cab and I don't mind it being fully fridge-sized. I understand that the larger enclosure and lower tuning will diminish the power handling somewhat but I don't need it to handle that much -I'm keeping my eye on excursion. Also, these drivers are said to be very conservatively rated.

    I can't think of any other negatives to this design, will33, but hearing them is why I posted, so thank you.
  20. Do you already own the drivers? If not I would take a serious look at the greenboy Dually loaded with the 15PR400's. Or if you are building your own cab take a look at JohnK's starliner with the same drivers. In either case you can have the cab finished how ever you want.

    I love my Ampeg amp with my DuallyT.

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