Speaker project: Bill of Materials

Audio Club

Speaker Project – Bill of Materials

Parts to build a set of speaker are available through the ISU IEEE student branch. If you are interested in obtaining a kit contact IEEE or G. Tuttle.
You will need to decide if you want to make the cross-over using the "audio-grade" inductors and capacitors as specified by Carmody (option 2a) or if you prefer to go the economy components (option 2b). Spoiler alert: The total cost for two speakers with the Carmody components is $140 and the economy version is $110. (We discussed the tradeoffs at the recent club meeting.) When making a request for kit, be to sure to specify which set of components you want to use.
Most items come from either Parts Express (PE) or DigiKey (DK). (One item comes from Mouser, since Digikey is out of stock for that one.) The PCBs, wood panels, and other miscellaneous parts are provided by IEEE.
You should stick with drivers and cross-over components as specified below. However, there are opportunities for some variation. See the list below the BoM tables.

**1. Drivers, port tubes, binding posts**
item	manufacturer	vendor	quantity	item cost	total
midrange	HiVi B4N Mid-bass (4 in)	PE 297-429	2	17.40	34.80
tweeter	Dayton ND20FA-6	PE 275-030	2	9.49	18.98
Port tube 1-3/8" adjustable	Parts Express (1-3/8", adjustable)	PE 260-388	2	2.76	5.52
set of 4 binding posts	Parts Express	PE 091-0250	1	15.98	15.98
Total					75.28

**2a. Carmody cross-over components**
item	manufacturer p/n	vendor p/n	quantity	item cost	total
1.1-mH inductor	Jantzen 000-1078 (air core. 0.57 Ω)	PE 255-252	2	12.18	24.36
0.35-mH inductor	Dayton AC20-35 (air core. 0.4 Ω)	PE 257-030	2	3.89	7.78
6.8-μF capacitor	Dayton DMPC-6.8 (poly)	PE 027-424	2	1.89	3.78
2.2-μF capacitor	Dayton DMPC-2.2 (poly)	PE 027-415	2	1.89	3.78
1.5-μF capacitor	Dayton DMPC-1.5 (poly)	PE 027-412	2	0.69	1.38
0.22-μF capacitor	Dayton DMPC-0.22 (poly)	PE 027-402	2	0.49	0.98
10-Ω resistor	Dayton DNR-10 (10 W)	PE 004-10	2	0.99	1.98
6-Ω resistor	Dayton DNR-6.0 (10 W)	PE 004-6	2	0.99	1.98
terminal block	Phoenix 1935161 (2 position)	DK 277-1667-ND	2	0.55	1.10
terminal block	Phoenix 1935174 (3 position)	DK 277-1578-ND	2	0.77	1.54
PCB	custom	available from IEEE	2	2.50	5.00
Total					53.66

**2b. Economy cross-over components**
item	manufacturer p/n	vendor p/n	quantity	item cost	total
1-mH inductor	Murata 1410516C (ferrite-core, 0.46 Ω)	Mouser 580-1410516C	2	2.27	4.54
0.33-mH inductor	Murata 18R334C (ferrite-core, 0.34 Ω)	DK 811-1314-ND	2	1.42	2.84
6.8-μF capacitor	Murata FA16X7R1E685KRU06 (ceramic)	DK 445-180434-1-ND	2	0.87	1.74
2.2-μF capacitor	Murata FG14X7R1H225KRT06 (ceramic)	DK 445-173138-1-ND	2	0.52	1.04
1.5-μF capacitor	Murata FA24X7R1H155KRU06 (ceramic)	DK 445-180637-1-ND	2	0.63	1.26
1.5-μF capacitor	Murata FG24X7R1H224KNT06 (ceramic)	DK 445-173377-1-ND	2	0.26	0.52
10-Ω resistor	Yageo SQP10AJB-10R (10 W)	DK 10W-10-ND	2	1.32	2.64
6.2-Ω resistor	Yageo SQP10AJB-6R2 (10 W)	DK 6.2W-10-ND	2	0.82	1.64
terminal block	Phoenix 1935161 (2 position)	DK 277-1667-ND	2	0.55	1.10
terminal block	Phoenix 1935174 (3 position)	DK 277-1578-ND	2	0.77	1.54
PCB	custom	available from IEEE	2	2.50	5.00
Total					23.86

**3. Miscellaneous**
item	Description	cost
Wood panels	Approximately 5 sq. ft. of 1/2-in thick medium-density fiber (MDF), cut into 6 panels for the enclosures. These are supplied by IEEE and will come precut and predrilled. If you want to do the cutting and drilling (assuming you have proper tools), one 2'x4' panel is more than enough for a set of speakers.	7.50
Wood glue	A couple of ounces of standard wood glue. Supplied by IEEE. If you want to buy your own bottle, something similar to this is good.	1.00
Speaker wire	Approximately 3 1-ft lengths of 16 gauge wire for internal connections. Also supplied by IEEE. If you want your own spool of speaker wire, this is one good option from Parts Express. Speaker wire is also available from any big box store or Amazon.	1.00
Screws	#6 x 3/4" screws – 24 total. Supplied by IEEE. (Parts Express sells a bag of 25 – 081-423 – for $1.79. Also available at any hardware store.)	1.50
Wood filler	As needed, depending on how you choose to finish the exteriors. Something like this. A small amount should do.
Paint	As needed, depending on how you choose to finish the exteriors.
Total	(Not including paint or wood filler.)	$11.00

A few options

The best way to make your speakers unique is to give them a good paint job. Of course, you can always go with nothing at all. But we've seen it all in past club builds: neon, pastel, tie-die, camo, decopage, wraps, an abundance of sticker — almost any finish you can imagine.
You could use a better quality of wood for the enclosure. Using something like oak or birch plywood would allow for staining rather than painting. Obviously, you would have to acquire and cut the panels and holes yourself.
There are other options for external connections. Parts Express has many variations of basic bindings posts. Here is type that I have used PE 091-1245. Or you could use a terminal cup like like this to get a more flush back surface. (This would require cutting an extra hole.) I also like Neutrik connectors, which make for easier plugging/unplugging. These require two pieces — a panel mount that goes on the back of the speaker and the mating connector that goes on end of the speaker cable.
Finally, you might consider adding some damping to the interior to try to improve the sound, either Polyfill or fiber mat.