3TD-X | css-audio

Assembly Instructions

What You'll Need

At a minimum:

Screw Driver
Hammer or Mallet
Soldering Iron
Wire Cutters/Strippers
Wood Glue
Tape or Glue for the Port

You might also find beneficial:

Clamps
Electric Drill

Grill Assembly

This video explains how to put together the grills.

Flat Pack Enclosure Assembly

Verify all cabinet parts were received. (see Fig. 1 and Fig. 2)
Clear dust from corners of all panels. Any debris in the joints will prevent you from getting a tight, flush surface when gluing up the cabinet. (see Fig. 3)
Assemble cabinet WITHOUT glue to ensure all panels fit together. Please note that the two solid panels to separate the midrange chamber are similar sizes. We recommend marking these before assembly. The slightly longer panel goes toward the top of the cabinet (see Fig. 4).
1. NOTE: due to regional and seasonal humidity differences, some sanding may be required to insert braces into appropriate slots.
Disassemble cabinet and place panels on a clean surface, arranged for easy assembly. Take note of the recommended order of assembly in the pictures (see Fig. 5-7). Make sure the front baffle is placed with the tweeter flange recess on the outside and that the midrange chamber is facing the midrange and tweeter. The side with the brace cutout should be on the back of the cabinet (see Fig.
(OPTIONAL) Before assembly, you may drill pilot holes for mounting the crossover board using the board as a template. Use caution not to drill through the panel. The TM Circuit Board should be mounted on the side panel of the woofer enclosure, below the midrange sub-enclosure, just behind the top woofer. The Woofer Circuit Board should be placed on the side panel behind the second to top woofer (see Fig. 8). This step is not necessary, but will make installation of the board easier once your cabinet is fully assembled. Screws can be pressed into the MDF cabinets without drilling if desired.
Apply wood glue to one side panel dados and rabbets first. Install the braces and midrange chamber panels. Next, add tops and bottoms, adding glue to the rabbets for the front and back. Finally, add glue to remaining side panel and install. After the cabinet is fully assembled and the glue fully cured, sand cabinet flat. The front and back panels are designed with a 1 mm overhang intentionally to make for easier flush sanding. Fill any larger gaps with wood filler or Bondo and sand all surfaces flat again (see Fig. 9).
Finish as desired using veneer, vinyl, paint, etc. (see CSS blog post for ideas).

Fig. 1 - Panel Layout

Fig. 2 - Panel Layout

Fig. 3 - Vacuum Dados

Fig. 4 - Dry Fitting

Fig. 5 - Assembly, Step 1

Fig. 6 - Assembly, Step 2

Fig. 7 - Assembly, Step 3

Fig. 8 - Crossover Board Pre-Drilling

Fig. 9 - Bondo on Gaps

Crossover Assembly

Verify all crossover parts were received (see Fig. 10)
Place each component in its labeled location on the SmartNode board by putting the lead wires through the holes for the associated board location. Orientation does not matter as long as you can reach the through-holes.
1. Note: Pull inductor wires up through its center hole and back down if needed to prevent crushing the lead against the body of the inductor. This will prevent a potential short when cinching down the zip-ties.
Secure the components to the board with the supplied zip ties (see Fig. 11).
On the backside of the board, twist leads together that share common letters (e.g. A to A, or B to B to B) using supplied hookup wire where necessary to jumper between nodes. Ensure that no bare wires are touching unintentionally (see Fig. 12).
1. NOTE: Crossing bare wires from non-matching letters can degrade sound quality and damage the drivers or your amplifier. If you need to run across another wire, ensure you use the insulated hookup wire supplied in your kit.
2. NOTE: Inductors have an insulating coating on them. You cannot connect directly to the red colored portions of the inductor wire or you will cause an open circuit. You should connect to the pre-tinned leads (silver portion) to ensure proper connection.
Cut 12 lengths of wire for the pair of speakers as described below.
1. Qty 4 - 18” lengths to span from each of the woofers to the Woofer Circuit Board (+W-)
2. Qty 6 - 24” lengths to span from:
  1. 2x for binding posts to Woofer Circuit Board (+IN-)
  2. 2x for tweeter to T/M Circuit Board
  3. 2x for the mid to the T/M Circuit Board
3. Qty 2 - 36” length from binding posts to T/M Circuit Board (+T-)
Strip 3” of white outer insulation from each wire pair and ¼” of red or black inner insulation from each wire end (see Fig. 13). It may be better to strip more than ¼” on the ends that will be connected at the SmartNode boards.
Use the red wire for positive and the black wire for negative and insert the wire ends of the appropriate length wire though the appropriate holes on the SmartNode boards.
Connect the inserted wire ends to the appropriate lettered nodes using the supplied jumper wire if necessary.
Solder all twisted connections (see Fig. 14 and 15).

Fig 10 - Crossover Boards and Components

Fig 11 - Components Installed on Boards

Fig 12 - Twisted Leads on Bottom of Board

Fig 13 - Strip White Insulation

Fig 14 - Assembled Crossover (Mid/Tweeter)

Fig 15 - Assembled Crossover (Woofers)

Final Assembly

CAUTION: It is recommended to test your speaker after final assembly by starting at a very low volume and listening to each driver by placing your ear closely. You should hear highs coming from the tweeter and lows form the woofer. You should hear no crackling or static. If everything sounds normal, proceed to turn up the volume and enjoy.

Mount the SmartNode boards with the tweeter and mid section on the side wall below the midrange chamber (behind the top woofer) and the woofer board on the side wall behind second woofer from the top (see Fig. 16).
Take the wire pair coming from the +M- holes on the board and send it through one of the 2 holes in the bottom of the midrange enclosure (see Fig. 17). Mark this hole with an “M” for future reference using pen, pencil, etc. Pull the wire through so there is a little slack below near the board, but most of the wire is in the midrange enclosure.
Take the wire pair coming from the +T- holes on the board and send it through the other hole in the bottom of the midrange enclosure (see Fig. 17). Mark this hole with an “T” for future reference using pen, pencil, etc. Pull the wire through so there is a little slack below near the board, but most of the wire is in the midrange enclosure.
Crimp quick connect terminals to the ends of the wires coming from the SmartNode boards.
1. There are 2 sizes red of quick connect terminals and 3 sizes of black quick connect terminals. Each pair of wires that goes to a woofer should be connected with the smaller red terminal on the red wire and the smallest black terminal on the black wire using a crimping tool (see Fig. 18). The tweeter uses one large red quick connect and one medium black. The binding posts use one large red and one large black.
2. The wire pairs coming from the +IN- holes on each SmartNode board should be sent down the back of the cabinet and out the terminal plate hole on the rear of the speaker. Here the 2 red wires should be twisted together and a large quick connect crimped to the joined red wires. Likewise, the 2 black wires should be twisted together and another large quick connect crimped to the joined black wires (see Fig. 19).
Connect the binding post to the input wires. Keep in mind that the quick connects may need to be compressed a little for a tight slide-on fit with a pair of pliers (see Fig 20). Insert the terminal cups into the opening and screw in place using the supplied #6 x 1” screws.
Insert 2 pieces of the 7” x 6” x 3.5” thick recycled denim into each midrange enclosure, one piece above the brace and one piece below (see Fig. 21).
Cut the 10.5” x 24” piece of eggcrate foam into sections to line the walls around the woofers and above the port.
Pull the tweeter wire (marked “T” in step 3) through the tweeter hole and slide the quick connects on to the tweeter terminals – large to large and small to small. Give a light tug on the wires to check the grip. If they slide off easily, close the opening a little on the quick connects with a pair of pliers and repeat until a snug fit is achieved. Then install the tweeter in the proper place using the included screws.
Repeat step 8 for the midrange and woofer drivers.

Fig 16 - Crossover Mounting Locations

Fig 17 - Midrange/Tweeter Wires

Fig 18 - Crimp Quick Connects

Fig 19 - Connecting to Terminals

Fig 20 - Adjusting Fit of Quick Connects

Fig 21 - Installing Midrange Damping

Fig 22 - Installing Eggcrate Foam

Troubleshooting

No Sound From the Whole Speaker - No sound from one or both speakers typically means you have a problem on the amp input side of the crossover. Check your input wires are properly connected to the crossover (including ground wires coming back to the negative connection) as well as the binding post side. Ensure the input wires and binding posts are not shorted by stray wires or other metal creating a conductive path between the negative and positive.
No Sound From One Driver - No sound from a single driver most typically results from a bad connection in the crossover. Review all connections to make sure only similar letters are on the same connection points. Ensure inductors are properly connected on tinned/bare wire and not over the insulation (the colored section of wire on the inductor is the insulation and the silver part is where you should be soldering). Ensure there are no loose connections anywhere.
Crackling Sound – Crackling sounds are usually the result of a loose connection. Check to make sure you have secure connections on all driver and binding post wiring. Ensure crossover wiring has solid connection and solder welds are tight. You should see no movement in the joint itself. Check crossover wiring for any bare wiring that is inadvertently touching where it shouldn’t. If the source cannot be identified, contact us.
Amp Shuts Down – An amp shutting down is likely cause by a straight short to ground, meaning your amp is seeing minimal or no resistive load. The most likely cause is wiring touching where it shouldn’t be. Check crossover wiring for any bare wiring that is inadvertently touching where it shouldn’t. Ensure binding post terminals are not inadvertently touching. An amp shutting down is likely a straight short to ground, meaning your amp is seeing no resistive load. If the source cannot be identified, contact us.
Lack of Bass – There are a few things that can cause lack of bass. Check to make sure your connections all have the same polarity on both the inside and outside of the binding post. Inverting the polarity of one speaker will lead to bass cancellations. Ensure there is free airflow around the port openings and it is not being blocked by stuffing material. Ensure the woofer is connected to the woofer W +/- section of the SmartNode board and not the tweeter T +/- section. Ensure the port is adjusted to the correct length. If the source cannot be identified, contact us.