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"It's ALIVE!!"..FrankenBoogie..

Discussion in 'Amps and Cabs [BG]' started by Rockbobmel, Mar 9, 2003.


  1. Rockbobmel

    Rockbobmel Supporting Member

    Holy Crap!!.. I did it. It LIVES!! I was at GC the other day and played through an Ampeg 8-10. It had that "in your kidneys" thing. After that I'm thinking of how I can make something sealed. I ain't kickin $1000 for the Ampeg. So I went inside my Mesa Powerhouse 1000 (115 & 4-10s) and took some dimensions. I had to make 2 pices with the notches for the inside bracing. I used rope calking so I can reverse it. So I sealed the upper and lower 2-10 compartments. I figured the 1-15 has about a 4.5 (22.75"x15"x15" cu ft ported compartment. Each 2-10 box is about 4.0 cu ft. "10"x 15"x22.75"). I stuffed the cap out of the 10s boxes with fiberglass and left the dacron stuff in the 15 compartment.
    ........It sounds tight like the Ampeg. (Not quite as punchy), but with a crisp deep bottom ans a lot of sustain. I'll tri it out tomorrow when the neighbors are away and crank it.............. The 15 is a Peavey BW and the 10s are Eden XL drivers.
     
  2. Rockbobmel

    Rockbobmel Supporting Member

    Nobody else been in the laboratory?
     
  3. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    You made a Fridge! Well done!

    How did you determine the porting? Or did you copy the Mesa cab? Or did you used Eden style porting on the 10's and Peavy style porting on the 15? The reason I ask is that you may damage your speakers when you do eventually get to "crank it".

    Oh and if you used and extra 4x10's instead of the 15, you would have that "punch" you're missing. Personally I like to a have a 15 in the mix.
     
  4. Rockbobmel

    Rockbobmel Supporting Member

    I guess I gotta hedda my self and was not clear. What I did was modify my Mesa 5410 cab by extending the interior partition so it sealed off the 10s completely. I did not build anything. Just made a couple of plywood pieces that fit the interior contours and calked them sealed. The 15 remains the same. So the 2 separate 2x10 compartments (above and below the 15) are sealed. The 15 is ported.
    BTW is it better to have a small box for sealed 10s v. a larger one? I heard you can stuff it full of stuffing. ......Where is Joris and Bruce Gavin??
     
  5. What about the speaker cone excursion and all? Isn't the cab designed and ported to work optimally with the supplied speakers?
     
  6. Rockbobmel

    Rockbobmel Supporting Member

    Prolly. I's got a 1-15 Black Widow and 4 Eden XL 10s. The supplied speakers (EVs) are on hold. One of the 10s need re cone. Maybe the 15. It is floppier than the PV. The old Mesa cabs came with a few different speaker brands. That and a few other sources lead me to believe that manufactures "engineer" their cabs by "dimensional convenience and trial" more than scientific. I'm not saying that speakers can't work better in some applications better than others. I would prolly be better off with a lighter duty 10 for the sealed compartments, but I got what I got. The thing sonds REALLY good. More focus and punch than before. I'll play out with it Friday "in the real world", and report back.
     
  7. So, if I understand you correctly, you modified a cabinet which had 1 15 and 4 10s working in the same space, and has now 2 pairs of 10s in a separate, sealed compartment using loosely fixed separation panels? Right?

    Mesa got two different types of speakers (a 15 and 4 10s) working in one space succesfully, and they deserve a lot of credit for this trial and error design process. Mesa also uses custom wound speakers, and I doubt they'll release the T/S specs on them, so all you can do is experiment (like Mesa did theirselves) and see if it sounds good. No speaker design theory is involved in this process.

    If you don't like the sound of this well-crafted cabinet, you might consider a different cab altogether.
     
  8. Rockbobmel

    Rockbobmel Supporting Member

    Thanks Joris,
    The partitions that I blocked are with 3/4 plywood cut to the iside contour and sealed with rope calking (That was hard), and screwinng securely. They are sealed. So, loosely, maybe compared to factory glue/screw. But I am confident it is sealed tight......When I got the cab, One EV10 was torn, so I borrowd 4-10s from an Eden D-410XLT that I have. (Expensive re-cone for EVs). The 15 was somewhat loose, so Again I borrowed a BlackWidow from another cab. I am holding off putting serious re-cone cash into the cab until I'm sure I am comitted to it. I indeed do like the cab. I am merely experimenting to try to "tweek" to see if I can stumble onto something. ..........Will it hurt the Edens, being in a sealed box instead of ported???
     
  9. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    That's the question on my lips as well. I'm concerned that you're gonna end up with more speakers in need of expensive reconing.

    If I was you, I'd have a look at the Eden cab and duplicate the porting. Or at least come up with something similar. You can always seal the ports if it turns out you don't like it later. But my gut feeling is that those Eden drivers will be happier in a ported cab as per their intended design.

    Sorry to be a kill joy. But that's just my opinion and it's based mostly on gut instinct.

    Anyone else?
     
  10. Rockbobby,

    So you replaced all speakers in the cab? No wonder why it sounds like crap!

    It can't be repeated enough:

    A cabinet is designed for one specific brand and type of speaker.

    The Powerhouse 1000 even uses TWO different speakers in the same work space, which complicates matter to the extreme (see my previous post)!

    Refit the original brand and type of speakers and the cab will sound the way Mesa meant it to sound.

    PS. what Pete said.
     
  11. Rockbobmel

    Rockbobmel Supporting Member

    Joris, who said it sounded lik crap? It sounds better than my Eden D-410XLT on top of my Sonic 1-18. Well, maybe equal. But it is punchier.AND more focused! The 10s cone movement is less (sealed ?). I think there is WAY too much credit for "made to spec drivers" "designed especially" for "our enclosures". I'll go on the firing line to say that I bet they laugh all the way to the bank. "Hey, these checques were DESIGNED for our account" "Let me use you CUSTOM deposit slip".."here let me sign it with my PROPRIETARY pen"
     
  12. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    We may have to turn this into a long term project with updates over time.

    Personally I believe there is a little bit of truth in Rock boby's theory but there's a point where his theory and physics colide. I'd be interested to see where that point is.
     
  13. Rockbobmel

    Rockbobmel Supporting Member

    What a beautiful word. Speaking of theory, check this out.... http//home.student.utwente.nl/e.j.j.ulfman (I don't know if this will link. You prolly have to type it. This IS engineering!! BTW, you could use ANY drivers in these.
     
  14. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    That website caused my computer to freak out twice. What was the jist of it?
     
  15. Rockbobmel

    Rockbobmel Supporting Member

    It's a homepage about John E. Karlson's speakers. Try a search on google for "Karlson Speakers" It should have a link. Maybe I copied it wrong. I just tried it and got it. This guy made these in the 50's. Some claim to get down to 26hz.!! You have to see these.
     
  16. Rockbobmel

    Rockbobmel Supporting Member

    Hey Pete, Well? What do you think?
     
  17. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    They reminded me of these speakers .

    These types of designs didn't really evolve because they introduced their own problems. The biggest one being size. Have a look at how much empty space in in the cabinets. The Bass reflex design may not be perfect but the reality is we usually have to lug our rigs in and out of cars, up and down stairways etc..... And in Hi-Fi applications, people don't always have massive lounge rooms. Yes bass reflex it makes the matching of driver and cab more critical than these designs, but the advangages out weigh that.

    I'm also dubious about claims like "works with any driver".
     
  18. Rockbobmel

    Rockbobmel Supporting Member

    I know what you mean, but I take "any driver" with a grain of salt. It is however a far cry and the extreme from "specific to the enclosure" hype. I remember hearing a band that the bass player had two Karlson 15s in the mid 70's. That sound has remained in my head. Like a clear, deep, punchy bell, if you will, in the bass world. BTW, I just won some plans for the K15s, I may just try to put one together. I think it is something like 32"H x 18" x 18". No bigger then a PV 1-15BX. I'll post when I get the plans..... Pete, did you ever go to www.londonpower.com ? Kevin Connor has a design called De-tuned cabs. (2 x Bigger than tuning size) ? I love this stuff>>
     
  19. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    I think that guitarists have made the word "De-tune" into a buzz word. By tuning the cab to "well below resonant frequency", there's a real scarifice in the overall sensitivity. He's overcome that by making the cabined HUGE - the size thing keeps comming up.

    My other hobby is live sound reinforcement. I love folded horn subs. And so do a lot of PA operators, but you never see em. Why? Coz they won't fit in the van.

    But as someone who plays through a fridge, size may not be a concern for you. In which case, tell me to shut up and I will :)
     
  20. Rockbobmel

    Rockbobmel Supporting Member

    No Pete, You make sense. You are talking business economics. Nothing wrong with that. In the 70's I had two "W" cabs that had 1 Gauss 12" driver. It was squshed into a 1" x 12" SLOT, then expanded through the "W". The size of the cab was 4'x 4'x4'. Oh, BTW, I remember these were cut in HALF. They were originally 8'x4x4.With 2-12s. It was laughable, I could'nt even move them. I hooked them up to my stereo.(stupid). When I was gigging I used an Acoustic 370/301 rig with a 2-15 EV loaded Traynor ext cab........ My current FrankenBoogie is 38"x24"x18". Hmmm there's those highly engineered dimensions again! You could almost make one of these out of a sheet of 4x8' plywood. But the thing weighs about 165lbs.