Designer:
Tom Denton

Project Category:
Bookshelf Speakers

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
$100 – $500

Project Description:
2-Way bookshelf speakers

Design Goals:
Make a set of bookshelf speakers for under $300.00 that had a great low bass sound.

Driver Selection:
Dynavox LW6004PMR-N 6-1/2″ Poly Cone Woofer
Dynavox TD2801XL 1-1/8″ Silk Dome Tweeter

Enclosure Design:
I used a standard 2-way box design with inside bracing & laminated foam insulation.

Enclosure Assembly:
3/4″ MDF with 1/4″x1/4″ slot and rabbet for the sides. 1/4″ rabbet for both front and back to snugly fit these into enclosure housings. 2″ x 4″ pvc port tube on rear baffle. Gold plated binding posts.

Crossover Design:
I used X-Sym to design a simple crossover.

Tips & Tricks:
None, just followed many forums and took their advice as it applied to what I was doing.

Conclusion:
These ended up having more bass from a such a small 6-1/2″ driver than I could have ever though them having. Already have 2 orders from friends to make more.

About the Designer:
I have been doing many woodworking products for years and wanted to make a decent pair of bookshelf speakers.

Project Parts List:

Designer:
Bill Ferrell

Project Category:
Bookshelf Speakers

Project Level:
Advanced

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
Bookshelf 3-Ways for our RV to go with new Pioneer in-dash stereo.

Design Goals:
I wanted sturdy, professional-looking, high-quality, 3-Way-vented, bookshelf speaker systems. These will sit in the back part of a Class C RV and be the main speakers for the new in-dash head unit. They will be on long cables to allow them to be taken outside the RV when desired.

Low Frequency Response: at least 35 Hz @ -3dB point
Power Handling: 100 Watt RMS (new Pioneer in-dash head unit is 55 w/x4-channel, RMS).

Mid and High Frequency Response: at least the same amplitude as the low frequency response; can be more because my hearing of high frequencies is diminishing and I can roll the mids and highs off using the head unit.

Driver Selection:
Woofers – Part #: 295-198, Dayton Audio DCS165-4 6-1/2″ Classic Subwoofer 4 Ohm

Midranges – Part #: 295-422, Dayton Audio DS90-8 3″ Designer Series Full-Range Driver 8 Ohm

Tweeters – Part #: 275-045, Dayton Audio DC25T-8 1″ Titanium Dome Tweeter

Enclosure Design:
Used BassBox Pro to design the cabinets.

Cabinets – Part #: 300-7064, Denovo Audio Knock-Down MDF 0.56 cu. ft. Bookshelf Speaker Cabinet

Cabinet external dimensions = 16″ H x 8.5″ W x 11″ D

Unfinished Interior volume = 0.56 cu. ft.

Finished interior volume = 0.507 cu. ft., after subtracting midrange enclosure, interior brace, crossover, woofer, tweeter and vent interior volumes.

Vent dimensions = 1.375″ ID x 7.394 Length

No stuffing used.

Fb = 31.2 HZ

F3 = 32.86

Enclosure Assembly:
Straightforward enclosure assembly, with following notes.

Glued and clamped all joints, making sure all interior seams had plenty of glue along the entire length of the seam.

Midrange enclosure is a Pyrex 1-cup glass bowl, pn 7202-10, available in most department stores. I attached it to the back of the front baffle board using a nice bead of GE silicone sealant on both the inside and outside of the rim of the bowl. Mounted the midrange enclosure to the baffle board before assembling the enclosures.

Painted the assembled enclosures with 6 coats of black, high-gloss lacquer before assembling crossover and wiring, drivers and vent to the cabinet.

After mounting the drivers and screwing them down, I used Permatex pn 8158, Black Adhesive Sealant, Silicone RTV, to form a bead all the around the joint between the outside edge of the frame of the drivers and the front of the baffle board. Also used this on the rear connection panel and the vent tube.

Crossover Design:
Crossover – Part #: 260-210, Parts Express Speaker Crossover 3-Way 8 Ohm 800/5,000 Hz 100W

Tips & Tricks:
Using the Pyrex bowls as midrange enclosures – cheap and strong, only about $3 each, plus some RTV.

Conclusion:
These systems more than met my design goals and expectations. Can’t wait to hit the road this summer!!

See attached frequency response graph, -3db down point is 27.61 HZ. Not too shabby!

About the Designer:
I’ve been building speaker systems since high school in 1972. First book was by David B. Weems, “Designing, Building, and Testing Your Own Speaker System”, which introduced me to TS parameters (a new and revolutionary idea at the time!) and a calculator design process. I was hooked!!

Project Parts List:

Designer:
radishmcadish

Project Category:
Portable Speakers

Project Level:
Beginner

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
2.1 Bluetooth speaker with 6.5” Subwoofer.

Design Goals:
This is my first speaker build hence the 20+ hour build time! I wanted a large portable system that I really couldn’t find on the market. This turned out better than my expectations mainly due to the quality components available at Parts Express. The sound from the highs thru the lower mid range is amazing. The low end could be better. I wasn’t experienced enough to try a ported encloser. I ended up making it sealed and a bit bigger than recommended specs. Bass is good down to about 75htz below that it suffers a bit, but the volume and frequency of the sub can be adjusted to make it sound pretty darn good. I’m experimenting with ports and my possibly add one to this box.

Driver Selection:
1ea – #295-198 Dayton DCS165-4 Classic Subwoofer
2ea – #295-415 Dayton TCP115-4 Midbass Woofer
2ea – #264-1390 Peerless BC25SC08-04 1″ silk/w waveguide
1ea – 325-212 LBB-5v2 Battery board and #325-142 led light kit
#090-5012 DC jack
#060-924 Rocker switch
Amazon 2.1 TDA7498E high power amp board ZK-HT21

Enclosure Design:
Overall dimensions – 29.5″x7″x10.25″
Sub section 16″x7″x10.25″ about .33 cubes sealed w/3/4 sonic barrier on all surfaces
Stereo section each .06 cubes sealed Stuffed with polyfill

Enclosure Assembly:
Used 3/4″ MDF for the four sides front baffle and internal baffles. I went with 1/2″ MDF for the back to save some weight. The mid and tweeters are flush mount and woofer inside mount chamfered. The box is painted with Hurculiner bed liner spray can.

Crossover Design:
2 way 3500hz 12db for the mids and tweeters
The woofer is controlled by the amp from 200hz on down with volume control.

Tips & Tricks:
Always use a router counterclockwise with the piece on the right pulling it towards you. I learned the hard way.

Conclusion:
All in all, I’m very happy with how this turned out. It sounds really good and could be much better with a port on the sub and maybe a bit more volume. I will leave it as is for now as I’m already pushing the woofer too hard, so I don’t know if I want to lower the power handling.

About the Designer:
I’m a noobie speaker builder just getting started with lots to learn and build. I’ve always been into HiFi in home and auto. This is really rewarding, and I will be building a lot more.

Project Parts List:

Designer:
Dave’s First Speaker Project

Project Category:
Tower Speakers

Project Level:
Intermediate

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
I needed a project during Covid lockdown, so I decided to build tower speakers for our living room. The TriTrix kit seemed like a great place to start, so I bought the components without the cabinet. I followed the cabinet design, but built myself using 3/4″ MDF for the enclosure and 3/4″ mahogany for the baffle and top. I used dowels to reinforce the panel attach points, which added work/complexity, but yielded a stronger enclosure.

Design Goals:
I wanted the speakers to blend in with our living room furniture and decor, so I opted for a dark espresso paint and a stained mahogany baffle/top. The speakers are for music only, so I wasn’t concerned with low-end needing a separate sub. Mostly striving for clarity and accuracy.

Driver Selection:
I used the TriTrix component kit

Enclosure Design:
I followed the TriTrix MTM tower design

Enclosure Assembly:
3/4 MDF for the enclosure + 3/4 mahogany for the baffle and top (added on top of underlying MDF).

Crossover Design:
Used TriTrix component kit

Conclusion:
Very happy with the results. There was a wealth of information online regarding the TriTrix kit, so it was fairly easy to figure out. Using dowels for the construction was likely overkill, but created a rock-solid enclosure. The 3/4 MDF is easy to work with, but yields a really heavy speaker. Low-end output is good given the driver size, but requires high volume levels. If I had to do over again, I would probably opt for a design with integrated sub.

About the Designer:
Full-time job in tech, but like to tinker in the garage. Hobbyist woodworking skills.

Project Parts List:

Designer:
Roger Trinterud

Project Category:
Loudspeakers/Cabinets

Project Level:
Intermediate

Project Time:
8-20 Hours

Project Cost:
$100 – $500

Project Description:
A slim, good looking soundbar, with decent bass, and good vocals.

Design Goals:
Decent bass, clearity in frequency area for voice.
Small form factor.
Wide for stereo imaging.
Wall hung, hidden cables

Driver Selection:
Peerless by Tymphany SDS-135F25CP02-04 5-1/4″ Paper Cone Woofer (264-1658)
Dayton Audio PC83-4 3″ Full-Range Poly Cone Driver (295-154)

Enclosure Design:
12mm (1/2″) MDF.
3mmMDF for speaker grilles, recessed in the front.
Front port for sub used as design element… located according to the “golden ratio” to one side. The design of the sub box was derived from the port location (hence the odd shape of the volume).
Sealed box for the full ranges.
Back wall of the cabinet designed as a french cleat, screwed to the wall. The rest of the soundbar is then hung on the cleat, and secured by recessed machine screws from underneat.

Enclosure Assembly:
Glue, brad nails.

Crossover Design:
None

Conclusion:
Slightly longer Xmax on the sub would have been good.
Plays well at lower volumes with well defined bass.

About the Designer:
Office space rat, with an urge to do something practical.
My first attempt with DSP/active crossovers, using REW measurements, and the ARYLIC supplied tools.

Project Parts List:

Designer:
Ness Customs

Project Category:
Portable Speakers

Project Level:
Intermediate

Project Time:
8-20 Hours

Project Cost:
Under $100

Project Description:
This is a transmission line design that I built as an experiment.

Design Goals:
I wanted a low cost Bluetooth speaker for at work in a garage setting. I went with a transmission line design to get the most out of the speakers.

Enclosure Design:
Quarter wave transmission line

Enclosure Assembly:
.5″ birch ply for the exterior with .25″ oak for the interior and assembled with wood glue

Tips & Tricks:
It’s awesome that Partsexpress.com provides the T/S parameters for these drivers. That information made designing this enclosure much easier.

Conclusion:
I’m very pleased with this project overall and I am definitely satisfied with the speaker kit. It sounds great and it was fun to build.

About the Designer:
I do a lot of different carpentry and woodworking including building custom subwoofer enclosures for car audio applications. I got into these Bluetooth speaker kits as a way to learn a little more about audio and the way enclosures affect sound.

Project Parts List:

Designer:
Shawn

Project Category:
Bookshelf Speakers

Project Level:
Beginner

Project Time:
8-20 Hours

Project Cost:
$100 – $500

Project Description:
4 inch 2 way bookshelf speaker

Design Goals:
My first ported speaker project. Tuned to the drivers used.

Driver Selection:
Dayton tcp115-4
Peerless dx20bf00-04

Enclosure Design:
Solid red oak 3/4″. .086f3
I wanted them a bit bigger, but the wood was too expensive to redo.

Enclosure Assembly:
Rabbits of 3/8 on tops and sides. The rest butted with glue( no nails or screws) 1/2″ sonic barrier on all sides. 1″ x 4″ flared port in the rear.

Crossover Design:
Lw rl 3200 simple crossover.

Tips & Tricks:
If you want the best finish on speakers of any material use lacquer and many coats.

Conclusion:
The boxes were tuned to 70Hz with the calculator I used. I do believe the hit that mark and then some. Very nice!!
The tweeter however even though it’s matched really well is lacking some. I may upgrade them and the crossovers in the future and update you afterwards.

About the Designer:
Just a beginning builder who likes making my stuff look as good as I can.

Project Parts List:

Designer:
Alan

Project Category:
Car Audio

Project Level:
Advanced

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
Car Audio Subwoofer

Design Goals:
For this project I wanted to supply enough bass for rock and pop to be played at a slightly bass heavy level, with enough headroom to never risk distortion.

Driver Selection:
The Subwoofer used is the RSS265HO-44 (Part #295-463). I chose this speaker for the many reviews on the diy car audio website. With modeling in speaker box lite, I found that its response curve was very close to other subs I have liked in the past, from a small enclosure. This speaker has very low inductance and moving mass for its power handling, which usually translates to crisp fast drum hits. It’s also a perfect power handling match for my Kicker CXA800.1 at 2 ohm, rated 600 watts.

Enclosure Design:
I built a 1.37 cubic foot ported enclosure tuned to 31 Hz out of 1/2 mdf. I designed about a dozen boxes on paper before settling on one with a built in storage compartment. The port fires into the upper part of the storage box, and isn’t really visible with the trim in place.

A false wall surrounds the enclosure, with colors and textures matching the vehicle as closely as possible. Also the angles and shapes of the trim panels is laid out to replicate the interior styles.

Enclosure Assembly:
The enclosure is built with 1/2 mdf, glued with tight bond II. All joints were clamped with drywall screws which were later removed to avoid scratches on the interior.

The shapes for the trim panels were captured by cutting strips of cardboard and making an edge template. I trimmed small pieces over and over with strong scissors until they fit the interior contour I was matching, then I super glued it to straight base piece of cardboard. Repeating this several times up the side starting from the bottom, I worked the profile about 4-6 inches at a time until I had a fully contoured edge. I then glued this to a full length cardboard piece to give it rigidity from top to bottom.

This shape could then be used to trace onto mdf, then cut the shape out with a hand held reciprocating saw. I cleaned up all the edges carefully with a table top drum sander, going back and forth to the car test fitting, marking any high spots with a pencil and re sanding. Most of the edges were then 45 degree beveled with a router for a better look, as well as easier fitment. Another consideration is all panels need enough space between them for the thickness of the material you will be wrapping them in.

I also traced a Subaru logo with graph paper on my iPad, setting the image to be my background so it would stay up. This was transferred to some kids ‘construction foam’ I got from a craft store. I glued the foam to the box, taped on the tracing, then carefully and slowly cut the shapes with a razor knife. Once that was done, I removed all the negative foam with a razor blade and sharp chisel.

The carpet and vinyl were glued with contact cement, taking care to apply extra around to logo to hold the shape. Let the cement get bone dry! I can’t stress this enough.

When doing the logo I coated both surfaces with cement, then covered the entire box except the logo with wax paper. This allowed me to start working the vinyl down from the center of the logo out without it sticking to the box first. I worked all the edges of the shapes with a plastic spoon. Once the logo was done I slowly removed the wax paper, working down the vinyl watching for bubbles.

The trim is fastened in place with multiple counter sunk neodymium magnets. I lined these up by fitting everything in the car and drilling small pilot holes through the trim partially into the box. This gave me a center point to drill with a Forster bit to flush mount the magnet. Make sure your magnet polarization is the right way!

This type of trim is a long process and took the vast majority of the 5 days spent installing this.

Crossover Design:
I’ve played with the x over point quite a bit and it sounds great all the way up to my maximum 200 Hz. This speaker could easily perform as a mid bass in a home theater setup. I settled in on about 110 Hz because of a phase issue between my door speakers at 90, that seamed to blend it in nicely.

Tips & Tricks:
If I were to ever rebuild this box, I would delete the storage. It doesn’t get used very often. After more modeling I would change to 2.2 cubic feet tuned to 33 Hz with about 28-30 square inches port area. This should give me another 3 dB at 37 hz, and 1.5 from 31-57. The current box being tuned so low waisted a lot of energy below my 25 Hz subsonic filter.

Conclusion:
This subwoofer absolutely sounds awesome. Accurate and deep. It’s on par with any solid 500-700 watt 10 from brands like Rockford, JL, and Kicker SPL wise, and noticeable better on fast repeated drum kicks than any I have owned.

About the Designer:
I’ve been into car audio since 2001, the last decade or so I had other things going on. Recently I decided to rekindle the hobby, and this is my first project in a while.

Designer:
Mort

Project Category:
Loudspeakers/Cabinets

Project Level:
Advanced

Project Time:
20+ Hours

Project Cost:
Over $1,000

Project Description:
Take a pair of 1965 Fisher XP7s and modernize them but keep their vintage look.

Design Goals:
Create a good three way design that will fit the vintage speaker box.

Driver Selection:
I decided to go with all Dayton audio drivers. I like the look of the drivers and was able to make them work in my existing cabinets with some modification to the front baffle.
DSA315-8 Woofer PN # 295-534
RST28A-4 Tweeter PN # 275-131
RS52AN-8 Midrange PN # 285-020

Enclosure Design:
The original Fisher XP7 is a sealed enclosure with sub enclosures behind the midrange drivers. I decided to keep them sealed, and removed the original sub enclosures, the new midranges are a sealed back design, and I wanted to take advantage of as much cabinet volume as possible.

Enclosure Assembly:
I had to carefully remove the original grills as they were nailed on. I Plugged the original holes in the baffle that I was not going to use with with new MDF and wood glue. I modified the original tweeter hole the same way and cut the new hole using a palm router and some custom templates. I had to plug, and re cut the Terminal cup hole on the back of the enclosure as well. I made the original Grills removable with the small 3/8 neodymium magnet kit that Parts express sells. I then refinished the exterior and used Exohyde coating for the baffle and back of the cabinet. The cabinet is stuffed with poly-fill.

Crossover Design:
I used Xover pro to design the crossover. I went with a 750 Hz and 2500 Hz crossover points. I used second order filters on the low pass and high pass filters and a first order solen split on the band pass filter. I went ahead and incorporated the impedance EQs on all the filters. I wired the speakers so they can be bi-wired with separate amps between the woofers and the high frequency drivers. I built a separate filter board for each driver.

Conclusion:
This is the first time I have done this and I couldn’t be happier with the results. The speakers sound very clear and articulate. The bass needs a little boost with the tone controls but sounds great. I have played them for friends and family, and everyone was very surprised at how well they turned out.

About the Designer:
I have been an Aircraft structures mechanic for 25 years and an audiophile all my life.

Project Parts List:

Designer:
Custom Executive 200 BoomBox

Project Category:
Portable Speakers

Project Level:
Intermediate

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
I built a custom version of the Executive 200 portable speaker kit as a graduation gift. I leveraged the components from the kit, but built a custom cabinet, swapped the 8in passive for two 6.5in passives, and upgraded the battery pack to 5×26650 cells.

Design Goals:
I previously built the Blast Box as my own portable speaker, and was impressed with the results. For this build, I wanted something more boombox sized, so I started with the Exec200 kit. I wasn’t crazy about the front-mounted controls, so I designed a custom cabinet that maintains the same volume, but locates the controls on top. I also wanted to shrink the width and height, so I landed on a cabinet that measures 17x8x8 (w/d/h). To upscale the look, I used 3/4 poplar for the front and back panels. And finally, I wanted more battery power and capacity, so I upgraded to the 5×26650 pack.

Driver Selection:
I used all the components from the Exec200 kit, but replaced the 8in passive driver with two 6.5 passives (part 295-498).

Enclosure Design:
I used 1/2in Baltic ply for box construction and 3/4 poplar solid for the front and back panels. Overall finished dimensions are 17in x 9in x 8in (w/d/h). Volumes for the 4in drivers and the sub are the same as the kit, so no changes needed to the crossovers. Surface area and specs of the single 8in passive vs two 6.5 passives was close enough that I didn’t feel a crossover change was needed. Controls are mounted on top, with 1/2in spacer to keep knobs away from the handle. Power jack located on back panel in recessed hole. Battery pack mounted to inside of back panel. I made the back panel removable so I can get to the batteries and controls if needed.

Enclosure Assembly:
Insides, front, top and bottom panels all glued. Back panel attached via caulk and four bolts that secure to corner braces.

Crossover Design:
I used the kit crossovers without any modification.

Tips & Tricks:
Mounting the battery pack vertically on the inside of the back panel was an aha moment. There was no room on the floor of the cabinet, so this was the only solution without expanding the width. I painted the inside of the control cutout before painting everything else because the acrylic panel was mounted to the bottom of the cutout (i.e. no access after assembling).

Conclusion:
Fun project. Way more involved than just using the included kit cabinet, but I like the results. Finished size is exactly what I wanted, but it’s pretty heavy for a boombox. Sound quality is good, but doesn’t produce as much bass as the Blast Box. Getting everything to fit was tricky. I modeled everything in Sketchup first and built a mock version first before committing to final cabinet.

About the Designer:
Just a dad who likes tinkering in the garage. I’ve built several speakers from Parts Express now: two MK Booms, one Blast Box, one Exec200, and a custom TriTrix.

Project Parts List:

Designer:
Redneckjap

Project Category:
Home Theater

Project Level:
Intermediate

Project Time:
1-8 Hours

Project Cost:
$100 – $500

Project Description:
This is a 2.1 sound bar, built for a family member as a Christmas present. Fortunately, the recipient is patient because this was for Christmas 2021 and was just completed in May 2022!!

Design Goals:
I wanted to mimic somewhat Dayton AudioBar, so I used the 3″ drivers, Part #295-587 Model: DMA80-8 Instead of the Dayton Soundbar Amplifier, I used the TPA3116 2.1 amp, Part #: 320-622 because of the cost, remote control and input capabilities.

Driver Selection:
Dayton DMA80-8, 3″ driver was selected for it’s size and full range capabilities. The DMA80s are wired parallel, 2 on left and 2 on right. An old JBL subwoofer was repurposed to work with this since the amp was blown in it.

Enclosure Design:
The enclosure was designed to be a copy of the Dayton AudioBar without complementary passive radiators. I found some acacia charcuterie boards on sale at the local “Hobby” shop and used them for the front baffle. The remainder of the enclosure was 1/2 birch. Brother-n-law used CNC to mill the driver openings and did the finishes (two coats paint on plywood and two coats clear sealer on all)

Enclosure Assembly:
I found some acacia charcuterie boards on sale at the local “Hobby” shop and used them for the front baffle. The remainder of the enclosure was 1/2 birch. Brother-n-law used CNC to mill the driver openings and did the finishes (two coats paint on plywood and two coats clear sealer on all)

Crossover Design:
no crossover. signal is straight from the 2.1 amp to the drivers.

Tips & Tricks:
If you try something like this, it might be best to make the rear panel removable for connections.

Conclusion:
The DMA80 drivers sound suprisingly clean and work supremely well for this purpose. The TPA3116 bluetooth 2.1 amp provides supfficient power for all drivers and the sister-n-law loves her (late) christmas present! Fun project.

About the Designer:
Just a hobbyist

Project Parts List:

Designer:
Brad

Project Category:
Bookshelf Speakers

Project Level:
Intermediate

Project Time:
8-20 Hours

Project Cost:
Under $100

Project Description:
The B652 bookshelf speakers are a great entry-level speaker and deliver a lot of wow factor for the price. Driven by an older Yamaha receiver, and a 70’s Pioneer manual turntable with Ortofon Red cartridge, they rock!

Design Goals:
Simple goal was to replicate the cabinet, maintaining the inside dimensions, but use 3/4” mdf to significantly tighten up the enclosure, remove resonance, and hopefully get a little lower, and cleaner sound out of these.

Driver Selection:
The 6 1/2” polypropylene woofer and 5/8” polycarbonate tweeter that the B652 is manufactured with.

Enclosure Design:
Same exact design and cubic foot capacity with much thicker mdf.

Enclosure Assembly:
The B652’s hang at an angle about 7’ high in my shed/workshop and when driven hard, the cabinet resonance became noticeable. I built from scratch, a replica, but opted for 3/4” mdf to replace the 3/8” mdf they are made with. Installed a 7/8” dowel across the center, right side to left side, under a little tension, to cross-brace the cabinet. All internal and external corners were radius cut with my router. On the inside, peel and stick Boom Mat (normally used on cars) was used on the sides, rear panels and on the stamped steel frames to reduce noise, then the cavity was lightly stuffed with polyfill. 3M VHB double-sided tape on the back of each driver to seal them to the front baffle. Some new binding posts and two coats of black hammered, rolled-on Rustoleum enamel was used.
Cabinet weight before: 3.4lbs (empty)
Caninet weight after: 9.2lbs (empty)

Crossover Design:
Same as shipped in the B652, which is only a capacitor (filter) on the tweeter.

Conclusion:
Wow.
Sure would be nice if I could scientifically, and accurately measure the before and after specs, but I can say there is a very noticeable difference from the cabinet upgrade. I listened to a set of test tones, before and after, and could now faintly hear 30hZ (probably at -10dB) in the after.
The barely audible 40 hZ tone before, was now very clear, with some decent volume.. those poor woofers were getting their excursions tested, and came through in style.

About the Designer:
My first stereo system, back in the early eighties got me hooked. A Marantz receiver and a set of EPI 4’ tall towers with two opposing facing full-range drivers on top, column filled with fiberglass. Had them apart a few times, and probably every set of speakers after that to include a set of B&O massive 3-ways, some Cerwin-Vega rockers with 12” red-roll woofers, and others. Dayton Audio fills my life with sound now, from these B652s, to the pair of T4652 towers and the MKSX4 passive 4–driver subwoofer.

Project Parts List:

Designer:
jon

Project Category:
Portable Speakers

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
$100 – $500

Project Description:
drill battery boombox

Design Goals:
create a bluetooth boombox that would be powered by the Makita 18v batteries I have already.

Driver Selection:
2 x 295-586
1 x 295-484
2 x 295-492

+

Enclosure Design:
sealed enclosures for each full range driver, and for the woofer + radiators. the enclosure for the amp board is open to the battery compartment for at least a little bit of cooling.

Enclosure Assembly:
Quick and dirty. 3/4″ ply held together with cabinet screws and sealed with construction adhesive. Quick faceplate for the amp module made out of some Kydex that was lying around. The box is protected by an eco-cage / handle of sorts that I powder coated.

Crossover Design:
Built in to the TPS3116D2 Class D 2.1 Bluetooth 5.0 Amplifier Board. Printed out the instructions for EQ and taped it to the top of the boombox.

Conclusion:
Super fun! The Dayton full range drives give a nice wide listening angle, and with the 8″ woofer + passive radiators it fills out the bass better than any big box store bluetooth rig.

Does it have the soundstage and separation of my home stereo? Of course not. Does it get loud enough for a block party and play for 8 hours on one drill battery? Oh hell yeah.

About the Designer:
Long time listener first time caller.

built a home theatre subwoofer with parts express parts about 15 years ago, now jumping back in!

Project Parts List:

Designer:
Wudkrafter 73

Project Category:
Bookshelf Speakers

Project Level:
Intermediate

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
Bookshelf speakers with visual appeal

Design Goals:
practice complex cabinet building by hand while keeping internal components affordable while preserving sound quality within the same range of the visual presenation

Driver Selection:
HiVi B4n full range woofers Part# 297-429
HiVi T20-8 3/4 tweeters Part #297-464

Enclosure Design:
roughly 1.2L dual vented curved enclosure

Enclosure Assembly:
Layered 1/8th inch MDF formed using a jig with rabbet cuts at all joints for strength and rigidity. Santos and pau ferro veneer and magnetized front baffle allowing access to internals. all cutouts were done allowing for flush mounting

Crossover Design:
Paul Carmody MTM design based of overnight sensations.

Tips & Tricks:
magnetizing the front baffle to the speaker required a great deal of accuracy to get perfect alignment.
Applying veneer to curved cabinets also requires a careful planning and a veneer press or use of titan DX glue.

Conclusion:
Learning curve is aimed at individuals with a good working set of tools and amateur’s level of cabinet building. Curved cabinets with layered MDF (not using CNC) is challenging to get perfectly square. Cutting rabbet joints on curved sides requires skill. Great project and very happy with the final product

About the Designer:
Hobbyist that works in healthcare system and enjoys woodworking for personal therapy.

Project Parts List:

Designer:
Colonel7

Project Category:
Subwoofers

Project Level:
Intermediate

Project Time:
8-20 Hours

Project Cost:
$100 – $500

Project Description:
The Crab Pot Subwoofer. It is a downfiring 12″ high excursion subwoofer that doubles as a unique drum style table. The fabric is decorated with blue claw crabs that are native to Maryland.

Design Goals:
A sealed subwoofer that can produce any orchestral music and has good in-room low frequency output when watching movies.

Driver Selection:
I chose the GRS12SW-4HE (Part #292-820). This high excursion driver models well in a sealed configuration with a bass boost to get good and low in-room response.

Enclosure Design:
The enclosure is made from a 16″ concrete tube form, commonly called a sonosub. An 18″ form would have been better for ease of leg placement but are difficult to source right now. The enclosure is ~1.2 cubic feet, stuffed with a pound of polyfil, and has 3 vertical 7/8″ dowels for additional bracing. The tabletop is 1/2″ mdf to close the tube and is topped with a 1/2″ piece of birch veneered 18″ circumference plywood. The baffle is 1/2″ mdf glued and backed by 3/4″ plywood. The driver is secured with hex nuts. The tube has batting glued to it with 3M 77 adhesive spray and then an outdoor fabric glued the same way. The banding is made from additional cuts of the concrete tub with veneered edge banding ironed on. Finish is 2 coats of natural Danish oil and 4 coats of wipe-on polyurethane.

Enclosure Assembly:
Baffle and top of the sonosub were secured with wood screws and a combination of wood glue and liquid nails. I went with the dowels but the concrete form without it is still incredibly strong because of the cylinder shape. Once finished it is about 35 lbs.

Tips & Tricks:
Using a concrete form requires a lot of patience. My 16″ form was a shade over 16.5″ on average. I say on average because it is not nearly perfectly round when you purchase it and can even vary somewhat in the same tube.

Conclusion:
A fun project that adds a lot of low frequency presence and is a conversation starter too. Plus it’s a great place to put my coffee.

About the Designer:
I enjoy all things DIY when it comes to audio and would much rather have less than perfect results with something I designed and made. I’ll always think it sounds better than a finished commercial product anyway.

Designer:
Micah Paul Creative

Project Category:
Freestyle Speakers

Project Level:
Intermediate

Project Time:
20+ Hours

Project Cost:
$500 – $1,000

Project Description:
Custom frame made for ACDC print

-Print By: Adam Stothard / ECHO Print Gallery, 18 x 24 Lava Foil
-Laser cut speaker mount
-32 speakers from Parts Express
-Bluetooth amp
-Removable battery pack
-Authentic Tolex from Mojotone
-Stackable amp corners

Design Goals:
The goal of this project was to bring the ACDC print to life.
Instead of a boring frame, this is a fully functional amp and speaker cabinet. Allowing the client to play his favorite ACDC songs.

Driver Selection:
295-150

Enclosure Design:
The enclosure is a mix of mdf, baltic birch, and cedar. The speaker mounts are laser cut mdf, interior supports are baltic birch, and the outer frame is cedar. The outside dimensions are 26x32x3.

Enclosure Assembly:
The outer frame, speaker mounts, inner supports were glued and shot with a nail gun. Back is secured with glue and screws.

Crossover Design:
No customization

Tips & Tricks:
The laser cutter was a huge help in this project.

Conclusion:
This was a really fun and challenging project. I have built custom picture frames for 2 decades. This was my first speaker enclosure. The client and I are very pleased with the result.

About the Designer:
Micah Paul Creative have been designing and building award winning picture frames for over 20 years.

www.MicahPaulCreative.com

Project Parts List:

Designer:
Bobby Kinstle

Project Category:
Portable Speakers

Project Level:
Advanced

Project Time:
20+ Hours

Project Cost:
$500 – $1,000

Project Description:
This is a portable high quality 3 way Bluetooth Speaker for a music teacher who wants to evaluate his students in remote learning as well as enjoying high quality music. It was very important to cover the full capabilities of the instruments, especially Violin, Piano, and Cello.

Design Goals:
Design Goals
1. Be battery powered
2. Cover the entire frequency range of musical instruments
3. Be able to play over 100dB
4. Have enough armor to take on the NYC subway
5. Solid high figure black walnut

Driver Selection:
The heart of the system is the Peerless GBS135F25AL02-04 5-1/4″ midrange. This along with the 4-1/2” little brother offer tweeter level crispness on midrange detail, most especially evident in string instruments, but also really cover the human vocal range with authority and without harshness. If you were a music teacher you could hear what brand of rosin your students were using.

For Bass I selected the Dayton Audio LW150-4 6″ Low Profile Woofer. It was a toss up between this and the Tangband 4.5” subwoofer. The TB would play deeper, but it needed 4x the power and weighed a lot more. The Dayton slim woofer was able to meet the required frequency range just fine. Note, the Dayton woofer has some strange characteristics in its “ideal” box size and actually performs much better in an undersized box. Undersized to 8.1L flattens the bass response and even gives it a little boost from 50-100hz which saves power.

For the tweeter I selected the Vifa/Peerless DQ25SC16-04, 1″ Titanium Dome Tweeter because it had a reputation for playing flat to very low crossover points. I found the tweeter sounded pretty thin below 2.8hz which forced me higher than the 2.1khz I originally planned on. This tweeter also has lots of sibilance that had to be corrected in the DSP.

Enclosure Design:
The enclosure is made from a single slab of high figure black walnut. No MDF, no veneer. It’s a standard box with lock miter joints in the corners for extra strength. The front and rear faces sit 3mm recessed to protect from scratches and provide a nice cosmetic look. Every outside corner has a metal cap to protect from damage and the outside 4 corners of the box frame are chamfered 45 degrees again so the sharp corners on the lock miter joints won’t take damage from being bumped into things. The end user intends to take this speaker places and make it work. Not just a beautiful thing to sit on the shelf. All drivers have metal protection grills. Internal volume after subtracting the port and midrange sub enclosure is 8.4L. Accounting for driver displacements and the battery board brings it closer to 8.1L. Enclosure tuned to 48Hz. For portability I added a soft synthetic leather handle and to keep it from shaking the table too much I added some rubber feet. Final finish after sanding to 320 was Osmo Polyx Oil which is a super durable treatment for hardwood floors that can be easily applied in a dusty shop.

Enclosure Assembly:
I glued the box together with band clamps and Titebond 3 wood glue. The front panel is held in with metal L brackets and sealed with silicone all around its perimeter. The rear panel sits on a shelf with threaded inserts for the screws to really clamp down on. It’s sealed with gasket tap on the inside edge of the rear panel. The midrange sub enclosure is made of plywood and secured with screws in case I ever need to replace it. The midrange sub enclosure has a moderate amount of poly fill to prevent reflections. This limits the bottom usable crossover frequency of the midrange to 200hz.

The woofer, tweeter, and port are mounted on the front but the midrange is mounted on the back side because it’s frame is unattractive, and because the dome protrudes substantially. I decided not to cut a recess pocket for the tweeter because the faceplate was a perfect fit inside the grille cover and the two locked together into a very strong structure. To compensate for the tweeter moving forward, I freehand cut a recess pocket in the back side allowing the midrange dome to protrude forward of the front panel and have the same acoustic center as the tweeter. Because of the grille I wasn’t concerned with edge diffraction effects.

Mounting the port was very challenging. I like the precision port products because they roll in and out so smooth and you can mount them close to the walls but I needed 7” of pipe in between and PSP doesn’t make elbows. I used a normal ABS 2” pipe elbow and ABS cement to join them together. It’s not a perfect fit because the PSP tube wall is much thinner than a normal Sch40 ABS pipe.

Crossover Design:
Instead of a passive crossover I opted to use the new 4 channel DSP amp from Dyaton KABD-4100. They have a 3 way speaker template which I modified to include an analog input EQ (because the analog input sounds dull compared to Bluetooth) and I deleted the POT controls for individual channel output volume. I opted for 4th order Linkwitz Riley alignment on all the drivers because I had to cross the midrange/tweeter higher than I originally planned (2.1khz vs 2.8Khz) because I felt the tweeter sounded thin at its lower range. Also, the midrange had some nasty breakup at 4.5Khz that I needed to stay well away from.

I think active crossovers are the way of the future for powered speaker design. The DSP is incredibly powerful, and you can fix your mistakes with a few keystrokes. Even professional speaker designers say they usually have some trial and error in a good 3 way design. I don’t have a big wall of high quality crossover components to swap in and out to try. For using the DSP, I set up my measurement mic and play some test tones. First, I adjust the speaker for a flat response and then tweak by ear for personal taste. I always try to use the minimum amount of corrections to get to the final product. After that I listen to a lot of music on it and see if I find any aspect annoying, then sleep on it, and make another pass of minor corrections the next day.

The tweeter has a large cap to protect it. I’m not ready to fully trust software not to break things yet.

Tips & Tricks:
1. DSP lets you do crossover topologies that would be incredibly expensive or impractical to build with passive components. On battery powered projects software crossover can as much as double your battery runtime on a complex setup like this
2. Apply a high pass filter below the F3 of the woofer. This will protect the woofer from mechanical over extension trying to play notes that it can’t play anyway. This lets you listen at much higher volume levels with less distortion.
3. Apply a low pass filter to tame cone breakup
4. Using steep crossover slopes minimizes driver overlap and the often difficult problems they can create
5. Use a calibrated measurement mic for tuning like the Dayton Omnimic or UMIK-1. Tune the speaker reasonably towards a flat response first, and then adjust for your personal taste second. If the speaker if for another person, tune it for their taste with music they like to listen to.
6. Don’t calibrate a speaker at the tail end of having a head cold.
7. Always use a high quality battery board with individual cell monitoring and balance charging. Cheapo lithium battery systems are a house fire waiting to happen.
8. When applying a finish like Osmo, sand the wood as smooth as it will take, usually 240-320 depending on the wood. Generously rub the oil on every surface (including the back side so it doesn’t warp the panels). When areas look dry, push oil form the wet areas for a good 10-15 minutes. Then using a buffer pad on a random orbital sander or polisher buff the surfaces smooth and let harden overnight. Apply a second coat a few days later if desired for more sheen but never a third coat or it will feel waxy. The final color won’t be visible for about a week.
9. High figure woods like walnut often have numerous internal cracks, rotten areas, and inclusions that you will have to deal with. It’s just the way it is. For deep cracks I used ultra thin CA glue to run all the way through the crack until it came out the bottom. This stabilizes the weak areas of the wood. For large cracks, voids, and rotten wood I carefully cleaned out all the bad wood I could get and then filled the area with Starbond black thick CA glue and accelerator. This is a fantastic product just be sure to follow their directions and be patient. I spent 3 evenings filling cracks and voids before breaking down the slab too much, and even then had some surprises when I cut new holes like the rectangular cut out on the back.
10. When you have only one shot at making the perfect cut out in your expensive material, make the shape first on a piece of scrap wood and then stick it over the fancy wood with double sided tape and use the scrap as a template with a flush trim top bearing router bit.
11. Always use a high quality router circle jig like the one from Jasper Tools.
12. Find a handle that’s soft to touch but has a stiff core inside to help distribute the weight of your fingers.
13. Lock miter joints are a pain to set up but fantastically strong and never walk off during glue up.
14. Band clamps are great too but corner clamps help hold things in perfect 90 degree angles while clamping.
15. You can never have too many clamps.

Conclusion:
The speaker sounds fantastic. It smashed the design goals for musical instrument ranges. I don’t think I would use this tweeter again as it has some strong sibilance problems around 6K that thankfully I was able to fid in the DSP. Strings and vocals are just incredible. My favorite cello pieces give me goosebumps. The battery board works great and provides quite a long runtime even at pretty darn loud levels. I love that it can charge from 5V to 24V and that it even included a car cigarette lighter port adapter with the battery board kit.

Walnut is a fantastic material to work with. I was privileged to work with some high end parts and materials on this project and advanced my skill considerably.

About the Designer:
I grew up in the Mojave Desert in a small community of scientists, craftsmen, and engineers. We were the kind of people who didn’t accept “it’s impossible” or “you can’t do that”. If I want something that doesn’t exist, I’ll just make one. Now I’m a thermal engineer in the computer industry and I currently hold 17 patents worldwide.

Project Parts List:

Designer:
Heldesign

Project Category:
Bookshelf Speakers

Project Level:
Intermediate

Project Time:
8-20 Hours

Project Cost:
Under $100

Project Description:
Bookshelf speakers based on Infinity SM 85 crossovers for my son’s room and his Kenwood RXD-C3 compact system

Design Goals:
The idea was to reuse some crossovers from Infinity SM 85 speakers. Due to the limited space available, they were made with 6-inch drivers, which would look modern and attractive with a good sound.

Driver Selection:
I used a 6-inch midwoofer and a 1-inch tweeter with a small base to accommodate the design I had already developed. They had to be 4 ohm like the Infinity originals. I chose a Peerless by Tymphany BC25SC06-04 1″ Textile Dome Tweeter and a 6-1/2″ Poly Cone Woofer 4 Ohm Midbass

Enclosure Design:
The design I developed is trapezoidal to avoid some internal refractions with a reflex port on the back and a cover that will help me hide the edges of the woofer in a contrasting tone with the box. Use dark brown veneer on the box with a gloss lacquer finish and an almond-tone metallic vinyl for the lid.

Enclosure Assembly:
The box was assembled using only carpentry glue, it was made of 15mm MDF for the whole box and it was lined with gloss catalyzed lacquered Oak veneer. The top was also made of MDF and finished with metallic almond vinyl.

Crossover Design:
used a couple of Infinity SM85 speaker crossovers

Tips & Tricks:
Nothing should be wasted, reuse as much material as possible. the minimum thickness of the box material must be 18 mm. Always try to do the best possible finishes, you will not regret it.

Conclusion:
I achieved my goal, the boxes were modern, the sound is very decent, they complement the kenwood very well. The negative is that as I use 15 mm MDF there is a bit of resonance from the boxes, they have good padding material, I am thinking of reinforcing the interior walls but it would reduce the interior volume, for now I leave them like that, I am very satisfied.

About the Designer:
I am an Industrial designer, lover of good audio. I have been working with wood for some time.

Project Parts List:

Designer:
Jeff Bright

Project Category:
Home Electronics

Project Level:
Advanced

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
I had a piece of pine wood I cut using my log saw. It was so thin, you could see light through the sap lines. I saved it because I knew I was going to make something weird and cool. I don’t remember how this idea started, but I settled on a lighted boom box using this wood as a faceplate with white LED lights behind it. I built the cabinet out of particle board with 3 seperate compartments for a 2.1 system. I bought a Dayton DTA-2.1BT2, 2 Dayton Audio PTMini-6 Planar Tweeters, 2 Dayton TCP115-4 4″ Woofers, and 1 HiVi 5″ as a sub. Was on a budget on this project, and there was a ton of other choices, all being more expensive. I used a music controller for the lights. The result is nothing short of amazing! Everybody who sees it says the same thing, that is Fricken cool! Except they didn’t say Fricken! Yeah, I stole that!

Design Goals:
Make the weidest, coolest boombox ever.

Driver Selection:
Dayton DTA-2.1BT2, 2 Dayton Audio PTMini-6 Planar Tweeters, 2 Dayton TCP115-4 4″ Woofers, and 1 HiVi 5″ as a sub

Enclosure Design:
Particle board with 3 compartments for the 2 woofers and sub

Crossover Design:
woofers and tweeters crossed over at 4000hz

Tips & Tricks:
Making a particle board boombox with square edges is easy, making one with rounded edges is hard. I cut 3/4″ thick pieces 1″ x 8″ with angles on the long ends. Glued together, they made 1 180 deg turn. Then used a flap disc on a sisde grinder.

Conclusion:
This turned out pretty cool! I made for my wife and she said she is proud of it, not something she does often.

About the Designer:
Pilot and mechanic on a corporate jet. I built a log saw 15 years ago and have cut up hundreds of logs. I always have one of a kind, weird cuts of wood that I never know what I am going to do with, but eventually find a project.

Project Parts List:

Designer:
Bobby Kinstle

Project Category:
Bookshelf Speakers

Project Level:
Beginner

Project Time:
8-20 Hours

Project Cost:
$100 – $500

Project Description:
This is a full range design intended to explore the concept of purist simplicity popular in some audiophile circles. I’ve seen similar designs online with drivers from Fostex, Aiyima, and Mark Audio and wanted to see what all the fuss was about.

Design Goals:
The main goal of the design was to cover an acceptable frequency range with good bass, clear mids, and detailed highs. My other goals where to teach myself how to build a box using all miter joints and the work on improving my painting and veneering skills.

Driver Selection:
I chose the MarkAudio Pluvia 7.2HD driver because it had a flat response to 30khz, which is amazing for a full range driver, and also in simulation played down to F3 at 43Hz. Frankly the simulation results were unbelievable to the point of assuming something had gone wrong, but I checked it a few different ways and kept getting the same answer so I decided to try it out.

Enclosure Design:
The enclosure is a simple box but every board has a 45 degree miter joint on all sides to conceal the board ends at the joints. It’s made of ½” MDF which is fine since this is a low power application. Internal volume is 15L which is the ideal volume in simulation for this driver. Port calculations said minimum port diameter of 1.25” but I went with a 2” port 7 inches long so I could use a precision port as those always make the bottom bass range so lusciously smooth. The bottom has 4 rubber feet. The electrical connections were mounted about one fist above the bottom and 2” apart so I’d have enough room to comfortably tighten them with a lot of force.

Enclosure Assembly:
I glued the top, bottom, and sides using painters tape to hold everything in position until I could get the band clamps in place and that worked pretty well. After that was dry I dropped in the front and back with mild clamping pressure so not to bow the box outwards. Circular cuts were made with a circle jig on my router and done before box assembly. I drilled 2 holes for the terminals slightly smaller than the knurl and then hammered them into position to form a tight seal and strong joint that will never spin when tightening.

Crossover Design:
None. Zip. Zilch. Nada. Nope.

Tips & Tricks:
Tips and Tricks
1. Don’t be afraid to experiment. Make mistakes. Learn why they happened, and then fix them.
2. Test finishes with materials like dyed veneer and let them sit for the FULL cure time listed from the manufacturer. My veneer changed color 3 days after application.
3. Contact cement isn’t strong enough for natural wood veneer.
4. Always check the wire hole orientation on the binding posts before hammering them in.
5. Metric drivers require metric circle jigs.
6. The best way to get a smooth finish is to apply sanding sealer, sand it smooth and paint. Skip the primer. Causes more problems than it solves.
7. Invest in an HVLP sprayer. It’s so much better than rattle cans.
8. Beware experimental projects that you intend to give to your friends afterwards. You might like them so much it’s hard to let go of them. Or you can visit your friends more often and ask them to play music.

Conclusion:
TL:DR These MarkAudio Pluvia drivers punch so far above their weight class that they risk hitting airplanes.

These speakers absolutely smashed it. I didn’t expect much from these drivers as I’ve always been a disappointed with full range drivers in the past. But I can’t think of a time I’ve been more pleasantly surprised by a speaker. The sound is rich, clear, and full. Highs are clean and not overly bright. Midrange is smooth and mellow. Vocals are a little forward. Violins and brass are buttery smooth. Cello is thick and meaty. Did I mention lows? The bass on these is simply astonishing. How can such a small speaker produce so much bass and still be clean? Reading this you won’t believe me until you’ve heard a set yourself. I’m listening to them as I type this and I still don’t believe it.

They sound great from 60-80dB and have a very wide dispersion. Highs are perfect up to 30 degrees off axis and still quite good to 45. They play fantastic in near and mid field and are perfectly at home on the desktop close by but also have no difficulty filling my 16×24’ living room. The sound character is very similar to the TangBand bamboo cone drivers. I haven’t found any music that sounds bad on them, even bass heavy EDM comes out great as long as you don’t turn it up too loud. Male and female vocals both sound fantastic but with a slight forward bias on male vocals. When I show these to people they think the much larger speakers next to them are making all the sound. Amplifier quality matters on these speakers a lot. Small chip amps sound a little harsh in the midrange with these but good class AB and better amps sound wonderful. They pair well with a small class A or tube amp too.

The lack of crossover components means these are super easy to build at a reasonable price. I think they would make excellent surround sound speakers in a 7.1 Atmos setup, even if you had full size mains.

About the Designer:
I grew up in the Mojave Desert in a small community of scientists, craftsmen, and engineers. We were the kind of people who didn’t accept “it’s impossible” or “you can’t do that”. If I want something that doesn’t exist, I’ll just make one. Now I’m a thermal engineer in the computer industry and I currently hold 17 patents worldwide.