January 4, 2016 - by Freddy Rose, PHRED instruments
I started this project with a budget of building a 2x12 speaker cabinet for under $500. The 2x12 speaker cabinet will be paired with a MosValve Tube Works RT-2100 amp that was purchased used for $250. The RT-2100 is a 1x12 hybrid amp, with a tube pre-amp stage and solid state power amp. It has two speaker outputs on the back, each capable of putting out 100 watts of power.
To get stated, I found an empty 2x12 speaker cabinet on eBay for $99 + shipping.
2x12 solid Pine, Raw wood Extension Guitar speaker Empty cabinet G2X12ST RW
From the item description:
This sale is for one, 2x12" raw solid pine, guitar speaker extension empty cabinet…made with 3/4" (18 mm) 11 ply front baffle, and raw unfinished solid Pine shell, rounded edges and sanded…the construction shows staples marks, for stain or paint finish, some filling and finishing job will be required, for other finishes like tolex or tweed, is ready to go! Made in the USA.
Dimension: 29.25"W x 11.25"D x 16"H. Weight 19 lbs, shipping weight is 44 lbs UPS.
Cabinet includes : strap handle on the top side, single 1/4" metal jack plate with original Switch craft connector on the back, 4 rubber feet on the bottom side, 16 each, #10 X 1" Phillips pan head wood screws for speaker mounting.
I requested a second input jack be added for a small additional charge, and that all the hardware be included, but not installed. Also, the eBay seller has the option of purchasing two speaker grills with plastic clamps and wood screws for an additional $15.
I chose to install Ted Weber’s Ceramic California 12 speakers, priced at $114 each. I chose the 8 ohm impedance to match the amp’s requirements, and an aluminum dome. I chose this speaker for its similarity to a JBL D120F, and have read many excellent reviews of this speaker, and Ted Weber’s speakers in general.
CERAMIC CALIFORNIA 12
From their website:
For Twins JBL D120F tone with ceramic punch. 12", 60oz ceramic magnet, 80 watt, 2" voice coil, curved cone. Loud, smooth, uncolored, available with paper, aluminum, or the large H screen dome for more warmth.
Aluminum: Very bright, almost piercing highs akin to vintage JBLs. Good for crystal cleans, but avoid for even slight distortion.
Recessed Metal Handles
Since I won’t be using the strap style handle included with the 2x12 speaker cabinet, I needed to get some recessed handles to mount on the sides. I found a pair on Amazon for $18. They do not include screws. You’ll need 20 screws. I used screw size #8 x ¾”. Cost for these screws was about $4 at Home Depot.
Speaker Cabinet Medium Sized Metal Pocket Handles H3025
From the item description:
Two Steel Recessed Pocket Handles. Black Metal Finish. Overall Measurement of 6 7/16" x 8 5/8". Cut Out Measurement of 4 1/2" x 6 3/4". 2 1/2" Mounting Depth. Requires Screws that are NOT Included.
Here’s a photo of all the hardware parts and speakers
Before installing any of the hardware, I put one coat of Watco Danish Oil on the cabinet. The oil finish is rubbed on with a cloth and seeps into the wood. It provides some level of protection and accentuates the wood grain. I chose the natural finish, but they have options with darker stains as well.
Installing the recessed handles
The next thing I had to do was cut-out a rectangle hole on both sides for the recessed handles. I wasn’t too concerned with this cut being perfect since it would be covered up by the flange of the handle. In this photo, you can also see the staples used on the cabinet. I chose to not cover them up.
Here’s what it looks like with the recessed handles in place, with the flange covering up the imperfect cut.
Installing the Speakers
The Weber Ceramic California 12 speakers fit nicely into the speaker baffle.
I used a power screwdriver to screw in the screws. Realizing that one false move would puncture a hole in the speaker, I tried to be as careful as possible. I would recommend some sort of protection for the speaker while securing the screws to the baffle. Perhaps another piece of wood that covers the speaker but allows access to the screw would be useful. Suffice is to say, no speakers were harmed in the process.
Here’s a photo from the back side. Notice the speaker terminals facing inward toward each other. This is done so there is less distance from the input jacks to the speakers. Additionally, if down the road I decide to run the speakers in parallel or series from a single input with a different amp, the wire lengths will be short and clean.
Speaker Grill Covers
Next up was to install the speaker grill covers. The grill rests nicely on top of the California 12 and the plastic clamps fit over the grill and the edge of the speaker. I decided to install the grill such that the crosshatch was parallel and perpendicular with the edges of the cabinet.
Here’s what it looks like with both of the speaker grill covers installed.
Installing the Recessed Handles
The recessed handles were installed after the speakers, although they could have been installed before. The reason I installed them afterwards was because I didn’t have the screws yet. I placed the handles just above vertical center on the cabinet with the larger opening at the top.
Installing the Input jacks
The input jacks that come with speaker connectors require soldering. Although you could just strip the wires, insert the wire into the connector and clamp it down without soldering, I chose to solder the wire, and also clamp it down for good measure.
Here’s what they look like soldered and clamped.
Installing the input jacks was simple. Use the provided screws to secure the input jacks to the back of the speaker cabinet.
Next, connect the speaker connectors to the speaker terminals. Notice that one of the speaker terminals is painted red. When you connect the speaker connectors, make sure that you connect the same color wire to the same speaker terminal on both speakers. I chose to pair the black wire with the red speaker terminal. If one of the speakers is connected with the wires switched, you’re speaker cabinet will be out of phase and you’ll probably notice that something sounds not quite right.
Installing the rubber feet
The final step was installing the rubber feet on the bottom using the screws provided. Nothing special here, just place them toward the corner ends. I was thinking to install caster wheels down the road, but for now, the rubber feet will work just fine.
It took about a full day of work from start to finish with a few breaks in between. This includes preparation, letting the Danish Oil sit for an hour, and clean up. How does it sound? Amazing. We’ll post some video and audio soon. But don’t wait, go out and build one!
Total weight of the cabinet is about 41 pounds.
Total cost: $360.50 + tax and shipping
2x12 Speaker Cabinet: $99
Speakers Grills: $15
Additional Input Jack: $4.50
Ted Weber Ceramic California 12: $114 each
Watco Danish Oil: $10
#8 screws: $4
Here are some additional photos of the speaker cabinet.