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Up firing PJB Double Four

Discussion in 'Amps, Mics & Pickups [DB]' started by madbanjoman, Nov 19, 2017.

  1. madbanjoman


    Feb 23, 2011
    6AAF2D5E-22F4-4082-9AD5-D2717652EC64. image. After reading about the new Upshot speaker cabinet from AI in another thread, I got to thinking of trying this out with my PJB Double Four. At first I used a couple of books to put a little space between the passive rear speaker and the floor without blocking it. I liked what I was hearing. The sound was more focused and I wasn’t reaching for my HPF pre to tame the lows. I happened to have a spare set of 1/2 thick amp feet, so I installed them on the back of the amp. While I love this amp, prior to making this change I felt wasn’t loud enough for my outdoor street gigs. Now I have been using it exclusively completely happy with the volume and sound.

    I wanted to pass this on to any PJB Double Four owners as possible modification.

    Of course I have added pics for proof

    You can hear it in action with my EUB in this youtube video.

  2. Earl

    Earl Supporting Member

    I have also tried this with my double four and it works well in some rooms, in others though the bass radiator facing the floor can make it too boomy.
  3. If I may ask, how did you do it precisely? Did you just use the stock bolts?
    Last edited: Mar 7, 2018
  4. madbanjoman


    Feb 23, 2011
    I used wood screws and drilled a guide hole first to attach the feet.
  5. Okay, thank you! There seem to be two versions of the double four. Older ones don't have screws on the back. Newer ones do have them. So does mine.
    D4 back.


    I checked the screws and they seem to be reasonably long. Perhaps I have to use something longer but I try to make it work with the stock ones.
  6. madbanjoman


    Feb 23, 2011
    Much better to use the screws you have than drill holes

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