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Tweed fearful 12/6 with integrated head. Thanks TB!

Discussion in 'Amps and Cabs [BG]' started by Meep, Dec 15, 2018.


  1. Meep

    Meep

    Oct 13, 2018
    There are a number of threads already on fearful builds, but as a TB newbie, I appreciated all of them, and wanted to "give back" by sharing my take on it. All of the threads here have been so helpful for amp and speaker choices I've made, thank you!

    I'm a more recent bass player, coming from keys and horn. Not gigging right now, I've had time to learn bass, which, maybe should have been my instrument from the beginning. I've always been mesmerized by the sound, the expression, and the pocket, and once I picked one up I've been hooked.

    Having PA build experience, I started with two DIY 1x10 neo's with a TCE BH250. They are well suited to indoor practice and easy portability. The 10's are tuned to ~50hz so they go plenty low but tap out (obviously) if pushed at any kind of volume. I love the tuning and the fullness while also capturing J-bass growl. If nothing else, I really like the character of their sound, but when the [convenient] "need" arose for a second amp, I didn't want to lose the character of the tens but knew that something with more output was needed. The low tuning (51hz in this case) of those tens is so unassuming and full, but it limits their output. I’ll post on them later.

    I spent months reading different threads and designs. fearful, fearless, BFM. In the end, the Fearful tuning on paper is very close to how I voiced the 10s, so that's what I chose.

    I did not do anything special; I'm probably just average at cab construction, and I don't do it often any more. There a couple of 12/6s out there with fingered joinery in furniture grade wood that I wouldn't dare ever taking out of the living room, let alone the places I used to play. Beautiful! But, I'm limited to hand tools, and no such thing as a saw with a guide, so there's always more slop in my cuts than I'd like. I use screws and glue instead of fine joinery or biscuits; it's just what I have.

    There are a couple of additions in my build. First, I decided to integrate an amp in a doghouse on top. zzounds offered a blemished RH 450 at a reduced price. It was very reduced, but appropriate as this amp was well blemished. Two knobs cracked and falling off, scuffing on the case, but I ran it for a few hours and it worked great and I like the TCE sound. The BH550 and 800 I originally sought are back-ordered for 3-4 months and increasing. Second, the doghouse makes it just tall enough to tip back onto wheels without using a dolly. So this cab will include tilt-back wheels.

    I struggled up to the last minute deciding between the standard 12/6 and the 12/6 cube. The cube lends itself perfectly to a full 19" rack space on top, which could be more versatile over the long haul. In the end, I went against the cube based on aesthetics and weight - the skinnier 12/6 looks better in the room, and the extra width, especially with extra lumber for the doghouse, plus whatever ended up in there, would weigh more on a cube. My back isn't getting any younger.

    I decided to finish it in tweed, because tweed is cool and that's where I'm at in my life. While the 1x10s use tolex and metal grills, they look metallic and cold in my living room. And, I've built a bunch of black cabinets with black grills and just wanted something different. If the tweed works out with the 12/6, I may redo the 10s to match.

    Regular Home Depot "sandply" 1/2" plywood was chosen for the wood, as it always seems a consistent and honest ply. I stayed with the standard dimensions for all the cuts and was very pleased with the fearful plans. It was a lot quicker using his drawings than working up my own and then cutting braces to match fit. As someone with a little design and DIY experience, it's a great set of plans to go from.

    The amp cubby sits on top, and it's like a mini-rack, with two wooden rails to eventually screw the amp tray in to. The amp tray is cut to fit the amp as tightly (too tightly once covered) as possible. The amp is snugged in to it's "face hole" and zip-tied down. The rear feet of the amp fit into holes to add security; the front feet are removed. The zip ties ride grooves in the tray. The whole thing fits up top and screws in. A hidden wire feeds to the amp's speakon port from the speaker, and a plate is on the rear of the cabinet if there was ever a need to daisy chain to a 2nd.

    Tweed is a wonderful material but is not as forgiving as tolex. I lost a few hours of my life to youtube vidoes on tweed application. A few tips. I'm never using spray glues again. The normal stuff weakened badly in 6 months on my tolex-covered 1x10s. This time I used the high strength stuff, and it's just ok, but it's not right for tweed. You have to put a lot on to prevent bubbles, but then tweed quickly soaks it up and causes splotching if there's more than it needs. Thankfully, tweed looks mostly ok with splotching, but the whole thing was a compromise. Of course, the sprays dry fast, which, on the other hand, made the covering quick and fun. In the end however, corners are already coming up and require regluing. Already annoyed with that, wood glue was attempted for applying the tweed to the amp tray. I just slathered it over the wood and laid the fabric over it. Zero splotching, and it is not budging at all. This is how I think I'll handle the next tweed job. I used thinned poly with a little wood stain mixed in, and then just straight poly, to finish it. Tweed picks up every stain and dustball in the room before coating. Oh, and spray glue MELTS spray paint instantly, which made a mess since I'd pre-painted the ports black before applying tweed. There are some permanent stains in the port tweed as a reminder. I'm also suspicious that the thinned poly dissolved some of the spray glue holding down the tweed. Bottom line: 1. white wood glue to adhere, 2. poly to finish, 3. and pre-plan black paint boundary since white glue won't stick to it.

    Crossover. I'm sticking with the CBG design, and I like what he's done there. It's a little unorthodox, or outside of the boundaries of Crossovers 101, but I like the approach and simplicity. I departed from the iron core low frequency inductor because of personal principals - no iron cores in XOs, and certainly no iron cores in the low-pass stages. I'm assuming GB found the iron core suitable and nobody complains about them, except for one thread one the edge of the internet where a store-bought iron core LP filter created havoc in a fearful build, but I just can't do it when the air core is $10 more. Assuming his iron core choice was right, the air core should not change the character of the Fearful build. The air core I bought was 15ga from parts express. If I remember, I'll post some frequency response measurements.

    I've never been a cloth grill guy, but tweed calls for it, so this grill is cloth. Black metal would be my other choice, but then character falls a little to favor durability, and there's a weight penalty. The cloth is surprisingly sturdy, so we'll give it a chance. It certainly looks right in this application. This stuff from Parts Express is far sturdier than the soft stretchy stuff that Radio Shack used to sell.

    Since the cabinet tuning is already right for the drivers used, I only put a little bit of absorbent material in the box for reflections. I found an old, dilapidated bedroom pillow that was pathetically thin and lame, and screwed it into the case. I've found that if a cabinet is built right, the stuffing needed is minimal. The grill is press-fit. When the grill material is pressed against the tweed, it's got a good grip, so care was taken to cut a grill board "just right" to hold it pinched in firmly.

    The final product is surprising. It is very lightweight - startlingly light for its size. The tilt back wheels would be easier to use with a long handle, but extendables aren't sealed and require additional cabinetry for their own compartment, hence more weight and size. I dig the unique look.

    If I could it again, about the only thing I'd change is the glue used for the tweed. since starting this writeup I did go back and re-cover the two 1x10s using smeared titebond wood glue, and the results were spot-on.

    It’s not broken in yet but I have enjoyed playing through it. It’s a little more buttery sounding than the 2 10s but with slightly less growl. It’s got deep lungs and feels like there’s plenty of oomph in reserve. I’d say there’s a very very slight edge or accuracy lost from the 10’s, but it also has a little more “hammer of Thor” that the tens lack. Again, it’s not broken in yet, but in my mind, anywhere more power is needed, you’d go through the PA. Very pleased with it overall!

    Pics follow. Thanks TB for the dialogue on these builds - it really helped me decide what I wanted to do.

    Meep
     
    Stumbo, GuitarJay and rogypop like this.
  2. Meep

    Meep

    Oct 13, 2018
    pics! IMG_8514.JPG IMG_8543.JPG IMG_8549.JPG IMG_E8782.JPG IMG_E8780.JPG IMG_E8788.JPG IMG_8547.JPG IMG_E8785.JPG
     

    Attached Files:

  3. Blues Bass 2

    Blues Bass 2 Supporting Member

    Oct 3, 2001
    Davenport Iowa
    That looks awesome ! Great job !
     
  4. Jim Carr

    Jim Carr Dr. Jim Gold Supporting Member

    Jan 21, 2006
    Denton, TX or Kailua, HI
    fEARful Kool-Aid dispensing liberal academic card-carrying union member Musicians Local 72-147
    Cool!
     
  5. That is really neat. And the retro vibe is cool. I’ve thought of this several times and wondered why more of these aren’t built. A combo like this made from the 15/6/1 cab could do a high percentage of my gigs. Adding another 12/6 under your combo would be a great addition if the firepower was needed.
    Enjoy your new rig. As I’m sure you will.
     
    Meep likes this.
  6. Meep

    Meep

    Oct 13, 2018
    Thank you! I’m super-pleased with it. I tried running it loud for a bit the other day and I gave in before it did. I’ll see if I can post some frequency measurements on it after I’ve played it a few more times.
     
  7. basscooker

    basscooker Commercial User

    Apr 11, 2010
    cincy ky
    Owner, ChopShopAmps
    How does the amp ventilate?
     
  8. Meep

    Meep

    Oct 13, 2018
    It’s open in the back and the amp has space all around it. It doesn’t have a fan, or not one I can find, and barely gets warm at all. I have two of these TCE amps, the other is a bh250, and neither seem to ever get warm.

    M
     
    basscooker likes this.
  9. two fingers

    two fingers Opinionated blowhard. But not mad about it. Gold Supporting Member

    Feb 7, 2005
    Eastern NC USA
    Cool build! Looks great!
     
    Meep likes this.
  10. pfschim

    pfschim Just a Skeleton with a Jazz bass Supporting Member

    Apr 26, 2006
    SF Bay Area
    cool build :thumbsup:
    I have a soft spot for high quality combo's for sure. I moved away from them when I pulled my beloved Walkabout from its 1x12 cab a few years ago, but I really like the format.

    How does the TC sound with the ff 12/6 ?
    I used to have a 450. I did not bond with it very well, but it sure had some cool features.
     
    Meep likes this.
  11. Meep

    Meep

    Oct 13, 2018
    Here are some frequency response plots. I’m just using iPhone tools for these. This is using the CBG crossover BUT with an air core inductor on the low-pass instead of the spec’d iron core inductor.

    Pic 1: on axis
    44C2A545-4E21-4DE3-B9F9-5194F05F7105.

    Pic 2: off axis
    BDEF2C4E-7E4D-4B71-B435-893E5E4B2BF7.

    Pic 3: mic buried in the mid
    977FE5C4-4313-429E-BB32-F615E142DF3F.

    Pic 4: mic buried in the LF
    CB3CEC42-5DF3-4112-84F7-5B0B0B7AA3DB.

    These were taken in my two car garage with fully exposed insulation in the ceiling. My back yard has traffic noise which would interfere. The garage isn’t bad for approximate measurements. The speaker was off the floor at chest height to reduce reflections from the floor. The on-axis plot is slightly middy but it’s not bad at all. I never looked to see if the drivers are matched for efficiency but it looks like the mid maybe a couple dB hotter than the LF. Off axis, you can’t really ask for much better, though a hifi PA build might notch that bump around 1800-4000Hz. Mids roll in around 600 and out around 5k. Really nice numbers for a 3-way, depending on the HF element. If I were to do this with a HF, I’d really want a constant directivity horn that had a wider dispersion to reduce the narrow beaming I think the stock horn would provide, but then the cab shape has to be reworked, but that reduces his goal of portability. To me it’s interesting to see that the low end roll off begins somewhere around 65-70Hz. Its a little smoother than my other DIY cabs which are tuned around 51. This cab is better, in other words. On those I roll the lows down on the EQ because E-A become too prominent. I still do on this one, but only half as much to suit taste. I gotta say, this is a really good design, and if I were to only improve one thing, it would be to add a compensation network to the XO to drop the mids by 3db. BUT, doing so also alters the voice of the cab, which would take it towards PA but not necessarily help it as a bass cab. As a bass cab, it’s so subjective. Some might prefer the boost. I don’t mind it at all. Maybe instead I’d want to tame that 2k bump a little. Either way, for now, I’m just going to enjoy it.
     
    Last edited: Dec 22, 2018
    dabis likes this.
  12. If that unit sounds half as good as it looks it’ll be a winner. Very well done!! :D
     
    Meep likes this.
  13. Meep

    Meep

    Oct 13, 2018
    Pfschim,

    I’m ok with the RH450. My only other amp is a bh250. The 450 seems to have a lot of variability but it’s not as easy to dial on the fly. I prefer the BH series because it’s all “right there,” without tweaking features not on the main dials. That and, the knobs and jack on the BH mounts to metal, I think. The RH mounts to plastic, it looks like. The BH supports tone prints, though only one can be used at a time so you’re at the mercy of their prints. With the RH you can’t do prints but the only two efx I use are comp and their tube emulation. To that end, I AB’d their emulation against a presonus tube pre: the presonus has a slightly sweeter sound, but you’ve got to have everything set just right to stay in the sweet spot. The emulation has a broader sweet spot. I’m still learning to play, and will have to get a lot better before such small differences would mean much.

    BassmanPaul: thank you!!!
     
  14. Interceptor

    Interceptor

    Mar 29, 2005
    Madison, WI
    That is very pretty.

    I ran a 12/6 with a Thunderfunk for six years worth of gigging. If I was to build it again, I would have built the head in like you did. Nice work!
     
    Meep likes this.

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