Wrapping Up

It's all but over now. Just need to install the front driver.

64. Solder speaker wire to the two voice coils of the remaining driver.

65. From the "Internal Speaker Distribution" block in the Isobaric Chamber, connect a speaker wire to the wires you just soldered as well as the two sets of binding posts labeled "Isobaric Voice Coils".

Tip: You'll note that we are wiring each of the voice coils in parallel and using the Matchit Autoformer to bump the impedance up to a reasonable load - at least for the amp I used.

66. Apply the speaker caulk to the perimeter of the driver.

67. Install the driver into the cabinet.

68. Find two or three close friends to lift this beast into position.

69. Connect it to the subwoofer pre-out on your receiver or SSP.

70. You're done. Celebrate and enjoy!

Conclusions

As you can probably tell, I wasn't a design expert when it came to speakers before this project - heck I'm not much better now. But, if anything, the Pyramid Powered Isobaric Subwoofer Project shows that with the right tools and a willingness to work though issues, even an amateur can get a lot of boom for the buck. I can't say all my design goals were met - I did spend 400 bucks on a used Adcom GFA Mark II Amp. But I'm happy with the way things turned out.

Thanks again to Ron for the help.

- Kevin Lichterman -

Appendix 1: Parts and Prices

For those of you interested in constructing your own copy of the sub, I've included a list of the parts I used, the sources where I purchased them, and approximate prices. I may have missed small things, but this should get you started.

Speaker Components

	Part #	Quantity	Use	Source	Total Cost
4x8 MDF Panel	N/A	2 @ 24.00	Main structural component	Home Depot	48.00
Red Oak Veneer	N/A	2 @ 16.00	Makes the cheap box look expensive	Menards	32.00
Shiva Mark III Subwoofer	N/A	2	Pushes Air	Adire Audio	250.00
Dayton Audio Binding Posts	091-1245	3	Internal Speaker Wire Connection	Parts Express	22.50
Audioplex Matchit 300 Autoformer Protection	302-305	1	Impedance Multiplier: Reduces Impedance seen by amplifier to make speaker easier to drive.	Parts Express	33.95
Magnetic Grill Guide	329-045	1	Connect the grill to the box	Parts Express	4.88
Black Grill Cloth	360-335	1	Protect the driver!	Parts Express	6.90
Speaker Sealing Caulk	269-300	2	Keep it Air Tight	Parts Express	1.96
1 ¾ " square drive coated deck screws.	N/A	1 Pound	Mechanical fastener	Home Depot	7.00
1 inch round oak dowel	N/A	5 feet	Box bracing	Menards	4.00
Durham's Wood putty	N/A		Box smoothing	Home Depot	4.00
WBT Binding Posts – Red	089-589	1	External Speaker Wire Connection	Parts Express	8.88
WBT Binding Post – White	089-587	1	External Speaker Wire Connection	Parts Express	8.88
WBT 0716 Mounting Kit	093-566	1	Pretty way of connecting the Binding Posts	Parts Express	11.25
12 gauge speaker Wire	N/A	4 feet	Connecting the Electrical Dots	Home Depot	4.00
Egg Crate Foam	N/A	N/A	Box Dampening	N/A	0.00
2" Flared Precision Ports	268-348	2	Lets the Air Out (box tuning)	Parts Express	21.40
Dayton Audio Chrome Spiked feet	240-715	1	Couple the Sub to the Floor	Parts Express	19.95
T nuts 10x32 x 7/16	N/A	24 @ 0.39	Driver and Port Mounting	Menards	10.00
Phillips Head Screws 10x32x1"	N/A	16 @ 0.20	Driver Mounting	Menards	3.20
Black Allen head nuts 10x32x1"	N/A	8 @ 0.80	Port Mounting	Menards	6.40
Gorilla Glue	N/A	1	Secure T-nuts and Bracing	Home Depot	7.00
Copper Single Hole Mechanical / Solderless Terminal Lug	N/A	2 @ 1.97	Provide rewiring potential in chamber	Home depot	3.94
3M Multipurpose Spray Adhesive	N/A	1 Can	Attach Foam and Veneer	Home Depot	10.00
Used Adcom GFA 555II	N/A	1	My choice for power – 850Watts into 4 ohms	N/A	400.00
Minwax Stain – Color of Choice	N/A	8 oz	Box finishing	Home Depot	5.00
Brush on Polyurethane	N/A	8 oz	Box finishing	Home Depot	4.00
Spray on Polyurethane	N/A	1 can	Box finishing	Home Depot	6.00

Speaker Total: $580
Amp Total: $400

Grand Total: $980

Appendix 2: Tools and Consumables

Here's a list of the tools and shop supplies I used to complete the project. Your mileage may vary.

Tools:

Table Saw
Japanese Flush Cut Saw
Circular Saw with Tilt feature
Router with ¼" Straight cut bit.
C-Clamps
Soldering Iron
Random Orbital Sander
Carpenters Square
Tape Measure
Veneer Roller
Jasper Circle Jig
Phillips Screwdriver
Allen Head Screwdriver
Drill with bits
Utility Knife

Consumables:

Elmer's Professional Wood Glue
Sandpaper 100 – 100 Grit
Silver Solder
Nylon Paint Brush
PVC Glue