Lockdown Combo Hack with Port and Ohm adventure

Discussion in 'Amps and Cabs [BG]' started by BassMan99, Aug 9, 2020.


  1. I came across a Crate BX100 combo for 40. Thought I would try to make a decent 1x15 cab out of it. Amps and Cabs my favorite forum here and DIY's probably my favorite thing to read here. I dont have the skills and tools some of you do but the first one came out pretty good. And it contained a surprise. I will post a few more pics.


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    Attached Files:

  2. The 1st Crate combo was crazy heavy. I would guess 80 plus lbs. Well when I got it home and opened it up it had a like new Eminence Kappa 15C in it. Nice . This with my GK 700RB 442565E9-7B6B-4915-A343-8D6352AEBC85.jpeg

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  3. For the heck of it I used the top of the Combo for a case for the amp. Works ok for a backup.

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  4. So another Crate Combo came up for $20. lol so what the heck. This one was in worse shape and a blown speaker. It as a BX80. The box was constructed differently. A touch smaller I think and it had a removeable baffle. At first I did not like it as well as the first. But this one worked out to be a sealed 15. I came across a great deal on an eminence Beta 15a. Sealed cab recommended for this driver. So I ended with one 15" ported cab at 4ohms, and 15" sealed 8 ohm cab. And I have been messing around with using one or the other or both!

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  5. Apologize about the pics. Its new for me. Here is the Speaker series parallel box I built. This is how I use both a 4 and 8 ohm cab. This has been interesting - comparing each cab on its own and together series parallel.

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  6. myrios

    myrios

    Apr 30, 2003
    Maybe a side question here: i want to convert my BX100 to a cabinet to use with my switchable 4/8/16 ohm amp head. There are two wires going from the amp compartment to the speaker compartment and it will be easy to add jacks, but that’s assuming those wires go straight to the speaker with a 4 ohm load. But the diagram in the manual shows the external speaker jack wired “in series” to the speaker... so I’m not 100% confident about what else is wired inside the speaker compartment that I should be thinking about...
     
  7. walterw

    walterw Supportive Fender Commercial User

    Feb 20, 2009
    alpha-music.com
    what does this mean?

    you have two boxes, they can be put together in series (12Ω with most of the power going to the 8Ω box) or parallel (2.7Ω with most of the power going to the 4Ω box).

    "series/parallel" is not a thing with just two speakers
     
  8. Just saw these replies. The BX100 I have had only one set of speaker wires that went directly to the speaker. They also have a second speaker out - I believe wired in series - on the front of the amp. That must be what you are seeing on the diagram. You can shave a lot of weight off that cab by cutting off the top where the amp is and also I cut off the wood lip at the front of the cab. Go for it.
     
  9. I have seen series/parallel used to describe this - I think. Maybe just serial is the best description. My multimeter says the two cabs - one 4 and one 8 ohm- are 11 ohms when run together with the series box. I can post the wiring diagram for anyone that wants it.
    There are a lot of variable going on here with the two different speakers at 4 and 8 ohm. The 4 ohm Kappa 15c can take more power than the beta 15a. Not sure about the efficiency of them. together they dont seem very unbalanced to me. I am running the 8 ohm on top so it is closer to my ear.
    I am still messing around with different combinations. I have noticed the difference in loudness with the different ohm loads on the amps. There is for sure a difference in amp loudness and feel at 4 ohms, 8 ohms and 11.
     
    Last edited: Sep 9, 2020
  10. Here is a wiring diagram for the series parallel box. i have made a bunch of these for friends etc. MUST use a NON conductive box.
    patbox_series_amp.gif
     
  11. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    How’s that a series-parallel box when it’s only series speaker connections?

    Series connection of very dissimilar speakers is not good from a performance perspective.
     
  12. walterw

    walterw Supportive Fender Commercial User

    Feb 20, 2009
    alpha-music.com
    Yep, that’s very much a series box.

    “Series/parallel” is something entirely different, requiring at least three elements. It’s how they wire four 8Ω speakers in one cab to have the whole cab be 8Ω
     
  13. it is series. my apologies.
     
  14. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
    Jun 15, 2021

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