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Greenboy fEARful 12/6/1 Cube – A D.I.Y. Bass Cab Adventure

Gear Reviews

Greenboy fEARful 12/6/1 Cube – A D.I.Y. Bass Cab Adventure

A D.I.Y. bass cab adventure in building my own Greenboy fEARful 12/6/1 Cube…

Greenboy Overall


I needed a compact, light weight, good sounding bass cabinet for some cool gigs where my 8×10 Fridge wasn’t welcome. After a good deal of research, I came across some discussions on Talkbass about a guy called “Greenboy” who lives in a remote cabin in Montana who had designed some kick-ass full range bass cabinets that readily reach down to a low F# and are lightweight to boot. The real kicker is that Greenboy, Dave Green, is also generous – he has made the Greenboy™ fEARful designs available, free of charge, to any home builder for personal use only. All of Greenboy’s fEARful designs use Eminence Kappalite 3012LF or 3015LF high excursion woofers paired with a midrange driver and an optional high frequency driver.

Greenboy fEARful -other

Choosing the Design

Greenboy fEARful - Crossover Schematic - Alpha 6The more I read, the more I became intrigued with the idea of possibly building one for myself, but which one? To answer this question, I went to the source: Designer Dave Green’s website: This website provided access to the fEARful™ design plans, links to authorized builders of Greenboy™ Audio products, lots of additional information and a link to the Greenboy/ fEARful™ users and builders forum. (Note: you may have to sign up and log-in to view)

Greenboy fEARful cabinet drawing 5

I found the users and builders forum to be extremely useful and entertaining as I studied the various designs and read the posts provided by other builders on their DIY experiences. Many of the builders have posted detailed descriptions and photographs of their builds as well as posting their own questions and comments. After much review, I decided on the 12/6/1 cube which utilizes the 3012LF woofer, Alpha 6 midrange and ASD 1001 compression driver – all Eminence products. In order to simplify the process, I purchased a kit from Leland Crooks at Speaker Hardware that included all the drivers, crossover components and other parts necessary for construction. Speaker Hardware even offers a Flat Pack that includes all the lumber pre-cut, but I opted to purchase the plywood locally and cut my own. I also purchased Duratex paint, internal dampening foam and speaker grilles from Speaker Hardware at an additional cost.

The Build

I purchased some 1/2 inch Baltic birch plywood from a local supplier and made the cuts spelled out in the cutting diagram and parts list by Greenboy.

Here’s a photo of all the wood cuts:

Greenboy fEARful -1

I then started gluing and clamping the cabinet together. Greenboy is a big proponent of using PL Premium polyurethane construction adhesive to fasten everything together. In short, this stuff is amazing – it gives an incredibly strong bond and will fill any minor imperfections between the bonding surfaces. Big Hint: use gloves with this stuff – it will stick quite well to skin too!

Greenboy fEARful -3

After the cabinet was constructed, I painted it flat black with a can of spray paint and over coated it with Duratex – a super durable coating that is specifically designed for speaker cabinets. I just rolled the stuff on with the provided textured foam roller. I am not a skilled painter and I think it came out looking great – this stuff is pretty easy to use.

Greenboy fEARful -4

The next step was cutting up the foam and gluing it in using spray adhesive

Greenboy fEARful -5

It was now time to wire it all up. I opted to use pre-printed circuit boards provided by Speaker Hardware, where I just put the electronic components in the correct locations on the circuit board and soldered them in place. I also wired up the various drivers to the crossovers and to the speaker jack plate.

Greenboy fEARful -6

And here is the final product:

Greenboy fEARful -7


In Use

The cube weighs in at about 48 pounds and is small enough in dimensions that I can easily carry it with one hand. This makes it a real joy to load into a gig. It is also, without a doubt, the most versatile bass cabinet I have ever owned. At indoor gigs I can easily keep up with live drums, two fairly loud guitars, a keyboard and a full PA system – this is pretty impressive for a single 12 inch woofer paired with a 6 inch midrange driver.

There is so much presence in the midrange driver that I often have the HF compression driver turned off. Turning on the HF driver turns the 12/6/1 cube into a miniature F.OH. system.   Just for grins, I hooked it up to a powered mixing board and fed it some music from my iPhone – it sounded just like any good PA would, faithfully reproducing the full spectrum of the instrumentation for a well balanced sound. Recognizing that these Greenboy™ designed enclosures are full spectrum cabinets is important when one first starts using one for bass. I find the midrange and even upper mid’s to be more forward on the 12/6/1 Cube, in comparison to my other cabinets, and I therefore adjust my amplifier EQ accordingly.

In Retrospect

I really enjoyed the process of building my own speaker cabinet. I have completed other DIY projects and they haven’t always given me this sense of fulfillment.   I attribute my contentment to the following:

1. The Greenboy™ products are very well thought-out, meticulously documented designs using high quality components.

2. The owner and builders forum provides guidance, support and a sense of community. During my build, I had mistakenly glued in one of the internal braces in the wrong orientation. The folks on the forum were very thoughtful and kind in pointing this out and they offered a few different, very practical suggestions to remedy the problem.

3. The end product really sounds good.

As far as cost goes, I invested about $500.00 in the wood, components, paint, etc. and a few weeks worth of time total. It is not the cheapest way to go, but I feel I got a huge bang for the buck. The retail cost of a similar product is considerably higher.

If, after reading this brief account of my latest DIY adventure, you are fired up to break out the saws and screw drivers – be careful and have fun! If you feel the DIY route is not for you, but that you are interested in Greenboy™ designs – take heart, there are a few options for you. There is a list of authorized builders on the Greenboy website for both Greenboy’s fEARful and FEARLESS products.

In Closing

I would like to thank Dave Green (Greenboy) for his talent, time and generosity in making these designs available free-of-charge to the bass community. I would also like to give some brief shout-outs to Leland Crooks, of  Speaker Hardware, for making sure I got all the right parts and Joseph Hawley, of JHawk Customs and Greenboy Audio – for taking the time at NAMM to introduce me to the Greenboy™ product line of fEARful and FEARLESS products. You can learn more about the speaker components listed in the article at


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