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JBL E140-8

Started a build yesterday for bass cab to go with the aquired Ampeg V-4B. Wanted something vintage and always admired JBL stuff. Can't afford what people want for the D140's, so it was a K or E. K's can also bring a premium price as it's an Alnico unit as well, which led me to a really nice original E140.
Frequency response:

Impedance and T/S parameters:

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Comments

  • These are commonly used in a 4cf@40Hz box, so I ran the numbers and seems to be fine with that.
    The width of the amp is 27" , I wanted it up as far as possible, so I ended up with 30" high and 12" deep. I leaned the baffle back a few degrees for a little dispersion aid. With the baffle set back I ended up around 4.3 cubes. Should come close to the 4 once ports, driver, and bracing happens.


    dynamo
  • I build them with a removable back because it makes covering easier, avoiding big bunch of seams. Used 1/2" ply for the cleats, sides, top, and bottom.
    Got the back cut and the baffle made/mounted today. I used 3/4" for those. Added another 3/4" thick ring behind the driver opening for mounting hardware. Freak weather break is nice👍🏼



    Added some 1/2" strips to the front edge to beef it up a bit, looks better. The pieces are a little proud, thought I had a top bearing flush bit, but I didn't, have to go pick one up. Hope to get all the round overs done before the weather turns crappy again.

    hifisideSteve_Leeugly_wooferNicholas_23PWRRYDdynamo4thtry
  • Yeeesssss , black tolex ? Maybe knock down a few of those corners ?

  • LOL NM , spoke too soon. Yeah very cool !

    6thplanet
  • Yeah, right now I'm at black tolex and some sorta red/oxblood color grill cloth.
    Might as well drop a link to the Ampeg project. Lots of ups and downs.
    https://www.talkbass.com/threads/nad-ampeg-v-4b-project.1583026/

  • edited January 2023

    Baltic Birch? Looks nice/ void free. 9 ply and 5 ply?

     John H, btw forum has decided I don't get emails
  • Got hooked up by my buddy. He's in the veneer business and scored a pallet of off cuts and rejects.

    SCORE!

    Silver1omotajanesjhollanderkenrhodesSteve_LeePWRRYDugly_wooferdynamo4thtryR-Carpenter
  • That's a great score! Prices for nice plywood like that is ridiculous these days.

    Steve_Lee
  • For some reason, I recall JBL drivers being labeled with reverse polarity, so that might be something you should verify.

    6thplanetdynamo
  • So after reading through your build thread , are you in need of some 6L6 tubes? I think I have a pair someplace after replacing them with some Electro Harmonix 6L6's. I think they are of the Fender groove tube flavor...

    6thplanet
  • Ben, you'd be correct. It has red and black terminals, and I hooked it up red to red. As you can see on the impulse graph it's reverse.

    Nicolas, I appreciate that, but it's supposed to have 7027A's. I'm gonna go back with those. Although the 6L6 is a proven tube in this amp, the specs on the Svetlana's in it say max 500V, the 7027A's are 600V. I measured 536V at idle.

    dynamo
  • Got a baffle to back brace made, threw some speed holes in for some really fast bass and all.😛
    Then knocked out the handle openings. Had a gift card from Lowe's, so ordered up the top bearing flush bit.

    Steve_Lee4thtry
  • Skeletonized brace, you must have had a day off.

    6thplanetSteve_Lee
     John H, btw forum has decided I don't get emails
  • sovtek branded , rebranded by Fender

    6thplanetR-Carpenter
  • All the routing is done and sanded. Got the input terminal cup done, too. Ran out of gasket material, so when that shows up I can assemble enough to check cab tuning

    4thtrySteve_LeeBryan@MACBilletugly_woofertajanesNicholas_23dynamo
  • Put it all together to see where the tuning ended up. It ended up at 30Hz with the two 3" aeroports as short as they'd go. I removed the inner flare and it responded with 40Hz. So I took the flares to the band saw and epoxied them together to yield an overall length of 3.5".

    Hooked it up to the Hartke, because I had to hear it, ehh!! Holy crap! This speaker is pretty bitchin🤘🏼. I was not let down one bit on the JBL magic. I get it, I totally get it, and this is just an E series. Can't wait to hear it with the Ampeg.🔥

    Steve_LeehifisidePWRRYDugly_wooferNicholas_23Bryan@MACSilver1omoBilletdynamo
  • I assume you shortened the port tubes to raise the box tuning frequency, yes?

  • Impressive work and speed of construction with such fine woodworking detail.

  • Everything Eric builds is awsome. He's no hack that's for sure.

    6thplanetBillet
  • Completely true! Nice job as usual Eric.

    6thplanet
  • Great build! Amazing how that "old tech" driver can sound so great.

    I also like the camshaft lamp!

    6thplanet
  • Is that a Losi?

    6thplanet
  • @Tom_S said:

    >

    I also like the camshaft lamp!

    Wow! Totally missed seeing that. Agreed, that is badass!

    Steve_Lee
  • You need to see the drawer pulls on his bench. =)

    6thplanet
  • Thanks guys!! Should look even more bitchin when the tolex goes on.
    Yes, my old losi XX4. Retired. Got the bug again after renting a buggy at an indoor off-road track that's like 10min from me. To many expensive hobbies, y'all know the deal. Heck I still have my old JRX2 ProSE !😛

    hifiside
  • Better pic of the lamp. I made it probably 20 years ago? I'm working on another lamp using an old JBL speaker.

    I made the cone light up, still have to make the rest.

    Drawer pulls🤘🏼

    tajaneshifisideSteve_Leeugly_wooferkenrhodesSilver1omoTurn2dynamo
  • LOL on the door pulls , F'in fantastic and also , glorious !!

    6thplanet
  • @6thplanet said:
    Thanks guys!! Should look even more bitchin when the tolex goes on.
    Yes, my old losi XX4. Retired. Got the bug again after renting a buggy at an indoor off-road track that's like 10min from me. To many expensive hobbies, y'all know the deal. Heck I still have my old JRX2 ProSE !😛

    RCs are fun no matter how old you are! We never got big into racing, but our youngest worked at a hobby shop that held races almost every weekend. We did a lot of crawling with our Axial scalers. Trashed a few steering servos with those trucks!

    6thplanet
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