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First DIY Cab Work - Combo / Extension Cab - Faital / EA Content

Discussion in 'Amps and Cabs [BG]' started by MWBass, Jul 19, 2012.

  1. MWBass


    Jun 19, 2005
    Belford, NJ
    So, I am 99% of the way done with my first DIY cab building project. It came out amazing. I am very excited.

    I have to say thanks to some TB'rs advice and guidance in my first attempt.

    I actually have to head out for a few hours, but I wanted to post some pics before I left.

    On with the project...
  2. MWBass


    Jun 19, 2005
    Belford, NJ
    So, I had a specific goal in mind...

    The usual take, from what I have seen is either compromise a bit on size and weight and build a one cab does it all type thing. These cabs currently, like the Thunderchilds, and the Fearfuls are unbelievable, not too big, in the 30 to 40 pound range, just awesome.

    The other take is having a smaller cab / combo, that can cover practice and smaller gigs, with an extension cab that will boost the power draw on the head and usually double the drivers so you get a nice 6ish db boost. I have seen this with guys using a single neo 112 GK and something like an MB500, then grabbing a second for larger gigs. Another killer sounding rig...

    My Goal...

    My take was that I wanted to kind of push the seond idea above to an extreme. Make a very tiny combo, for low low level apartment practices and writing sessions, that could blow up into a full blown stage rig with a larger extension cab.

    I accomplished this using a total of 4 Faital Prp 8" pr200's.

    The combo has a single 8, with an EA Micro built into it. The micro is outside rear loaded into the combo, a la phil jones cub style. I knew the head would be running at 2 ohms in stage setting, so I wanted to leave all vents open to free air with as much circulation as if it were just sitting on top of the cab. This cab uses smaller, only single end flanged ports. It is great for what I intended as a practice / writing tool. I cannot report on this combo, because the 4th faital driver will not be hear until Saturday. so, the combo has no "meat" in it right now.

    Now, to accomplish this big jump from a tiny combo to a full blown stage rig, I decided to built a 3 by 8" 2.67 ohm extension cab. This cab also utilizes 2 3" Precision Ports. Between the quadrupling of drivers, from 1 up to 4, and the added db from the precision ports (which I can comment on as definitely noticeable) minus the fact that the power didn't exactly quadruple, we are looking at a boost in the 12 - 15db range. I consider that a stage worth jump...
  3. MWBass


    Jun 19, 2005
    Belford, NJ
    OK so,

    The Combo -

    EA Micro - 300w @ 8 ohms , 550w @2 ohms

    Cab - 11.75" by 13.5" by 13.5"
    14 lbs., w/out driver ... So, probably 19.5 lbs.
    1200 cubic inches (post subtraction of braces, driver, port volume and combo head notch out.)
    Tuned to 50 hz (well in comp it was 50.4, but this allowed me use stock ports)
    The cab ( in the computer) shows a -3db point at 50hz, with a -2db shelf from about
    high 50's up to the 80's, the a smooth rounded roll into the higher frequency.
    I believe the driver rolls off in the 5k range.

    Pics - (Sorry about the quality)




    The Extension Cab

    Cab - 28.5" by 13.5" by 13.5"
    35.5 lbs. (on bathroom scale)
    3600 cubic inches (post all subtractions above)
    Tuned to 50 hz. as well.
    Showed identical graph to above.

    Pics - (Sorry about the quality)




  4. smeet

    smeet Supporting Member

    Nov 27, 2006
    Woodland Hills, CA
    That looks amazing! Can you get a really strong clean low end at high volumes out of that?
  5. MWBass


    Jun 19, 2005
    Belford, NJ
    Alright last post from me for now (I have been quilty of having many conversations on TB with myself)...

    Total cost (Minus mistakes... multiple extra pieces of plywood, multiple screws, latches, etc.) - $1500 including the Head.

    I have to give props to the following companies...




    and definitely USSpeaker.

    All of the companies were phenomenal to deal with. To give you an idea, I ordered 3 faital drivers from USSpeaker on a Sunday night, they called me Monday morning early and said that they would be at my house on tuesday, and they were. Just plain awesome.

    Meanwhile, the one faital I ordered on Ebay for minimal savings is still in transit... 3 weeks later.

    It says something about trying to save a dollar.

    Ok, i'm done.
  6. MWBass


    Jun 19, 2005
    Belford, NJ
    Well, I have only been able to test the 3 by 8 cab, but what I can say is that the cab is as loud as my my GB Neox212, super clean ( and the drivers haven't even broke in yet) and the bass is tight, almost subwoofer style booms, those precision ports are no joke. I was worried about using 8's and not having enough low end, but now I cannot wait to pick up FDeck's hi pass filter. The "boom" note, if you know what I am talking about, is somewhere in the low G to A range. When I play the note fingerstyle it sounds like a car subwoofer. I am not gonna say it is the ballsyest I have ever heard, but it is way more substantial than I expected or need.
  7. troy mcclure

    troy mcclure Supporting Member

    Mar 5, 2007
    Central Florida
    That is def cool, hope it sounds as good as it looks.
  8. newbold


    Sep 21, 2008
    I'm VERY impressed.

    Looks great, fantastic idea. Way to go.
  9. Frank Tuesday

    Frank Tuesday

    Jul 11, 2008
    Austin, TX
    Nice work. Any chance you're interested on sharing your plans for the cabs?
  10. MWBass


    Jun 19, 2005
    Belford, NJ
    Thanks everyone, I appreciate it.

    Troy - As I said before, so far the 3x8 sounds great at the house, but I can only truly judge when I get out on the stage.
    Its taking me a little bit to get used to the tweeterless design. The negative is a little bit of that top end sweetness is not there. The plus side is that all of the notes, low to high seem to jump out with similar volume and girth. This is also a characteristic inherent in the EA Micro, so its kind of double time with this setup. The other plus is that typical tweeter constant hiss in the backround is not there. The lightest of hiss coming from an 8" driver. I like that a lot. Well see.

    Well, I have three thoughts on this.

    1. I am by no means a cabinet designer, this is my first attempt with my minimal knowledge and winISD understanding. Basically I fiddle around with box volumes and tunings until I liked the graphs. Then I made the slightest of modifications so that I could use stockish ports. (Stock on the single flared in the combo, and the precision ports had no center tube insert, just flared end coupled to flared end. It changed my tuning by .4 hz, so I was cool with that.) There is no tweeter, no crossover, just a basic bare bones box, with tons of bracing and batting, because I feared aweful resonances.

    2. I have no desire to have anyone go out and build my boxes, my way. Guys like Mike Arnopol, Greenboy, Duke L., Roger B... these are the guys that know the real deal. They make cabinets and designs based on their expertise. I just experimented with this in the confines of my own home.

    3. I have no design drawings, I did this whole build on the fly. I spent hours coming up with how I wanted to lay it out, but when it came to measurements, I only had external measurements and modified the little things in the shop. I am a math teacher so calculations were just done right there. They say "measure twice, cut once", well, spent about $40 or $50 extra on wood because I wung it. I never recommend this. In the end, all was well.

    What I can say is, if you want to do your own cabs, like these, use the data above. Break out a pad and paper, design a box that has 1200 cubic inches pre driver... this is post bracing, driver volume and port volume, and cut the port for 50 hz tuning. Then your hearing what I'm hearing. If you want something more straight forward, talk to guys like over at Barry Audio. They may give you a crazy 8, or 88 unloaded so that you can dress the box as you wish. Just my 2 cents, or 12 cents...
  11. looks amazing dude ! Great job !
  12. Mike Arnopol

    Mike Arnopol Inactive Supporting Member Commercial User

    Jan 4, 2005
    Owner of MAS Soundworks
    Beautiful job---love the Tolex!
  13. 3rdcurve

    3rdcurve Supporting Member

    Dec 26, 2008
    Sullivan, MO
    Very nice!
  14. will33


    May 22, 2006
    That's pretty, man. Nice work.

    I did a little modeling with those 8's not too long ago to help a guy out with them.....pretty impressive.
  15. MWBass


    Jun 19, 2005
    Belford, NJ
    Thanks guys, appreciate the comments.
  16. MWBass


    Jun 19, 2005
    Belford, NJ
    Well, it's been a while, but I had some more work to do.

    When I finally finished the combo, the small 1.625" ports were chuffing, and the bass response was very poor from the cab. I also decided through some experimenting with an old Genz Benz tweeter / crossover,that I wanted to add the tweeter to the setup.

    So, I rebuilt the combo cab. Ended up about 1.5" taller then before. But with some unique designing, I was able to get one of the 3" precision ports at appropriate length into the cab. Also, added in the tweeter with an attenuators and a simple first order crossover.

    Well, the last step day was to get rid of the buzzing from the EA Micros metal chassis. The combo now has gobs of bass and the tweeter sounds smooth and terrific.

    So, rebuilt the combo, added a precision port, added a tweeter with attenuators, changed some hardware, and handle positions, touched up some lose tolex seams, and " de-buzzed the amp chassis. We are rocking now. Sounds like a million bucks.

    Oh yeah, also built a matching floorboard in the western tolex, just because I had to.

    So, new shots. Enjoy...

    Stack front


    Stack Back


    Stack With Combo Kick- Back


    Combo Head


    Combo Bottom With Kick-Leg & Angled Precision Port


    Floorboard 1


    Floorboard 2


    Floorboard 3


    And a family photo for good measure. Cool thing is, besides the EA Micro, and the floor pedals, I built it all!

  17. MWBass


    Jun 19, 2005
    Belford, NJ
    And as per usual, sorry for the **** photographs.

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