Designer:
Ryan Michael Clark

Project Category:
Bookshelf Speakers

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
Under $100

Project Description:
“Robot Boots” – Office Speakers for Stand up Desktop

Design Goals:
Utilize 4” industrial paper cores for a cylindrical design
Design for optimal stereo placement at stand-up desk
No or minimal enclosure cost

Driver Selection:
295-378

Enclosure Design:
Cylindrical enclosure using 4” industrial paper cores with 45-degree angled for on-axis positioning at standup desk
0.08 ft3 internal volume modelled F3 of 65 Hz
Base made of 3 layers of .75” MDF with a center flared vent 1.5” x .75” 7.75” (Fb 65 Hz)

Enclosure Assembly:
components:
Baffle made of 0.5” plywood, glued and nailed to core
enclosure is 3/8″ wall 4″ diameter industrial paper core glued to base
Base is constructed of 5 pieces of 0.75″ MSD which houses a 1.5 x .75 vent

Crossover Design:
Nope

Tips & Tricks:
Sanded MSF surface on base and bottom of cylinder to ensure a good bond.

Conclusion:
Sound is clear, accurate and non-fatiguing. I am very pleased with these in a near field set up. A perfect match with a Tang Band W5 subwoofer and Dayton DTA-2.1BT, although I would be please with them in this set-up without a sub.

About the Designer:
I have always been an aspiring audiophile, although I don’t consider myself one. I am just a guy that loves music (listening to and making it), movies and building things out of wood. I still have my Infinity SM-62’s I bought out of a Crutchfield catalog in the early 90’s (~14 years old).

Project Parts List:

Designer:
Johnnydart431

Project Category:
Home Theater

Project Level:
Advanced

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
MTM center channel

Design Goals:
I wanted a sleek Art Deco style center channel for my home surround sound

Driver Selection:
Hivi b4n

Enclosure Design:
Mdf and bubinga wood

Enclosure Assembly:
MDF and hardwood

Crossover Design:
Crossover was used with parts from overnight sensations kit

Tips & Tricks:
Lots and lots of sanding!

Conclusion:
I love the looks and full rich sound.

About the Designer:
I’m a beginner and this was my first build. Thank you to parts express for this wonderful hobby and forum.

Project Parts List:

Designer:
Bob

Project Category:
Amplifiers

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
Under $100

Project Description:
Saw the practice amp kit in a sale flyer, didn’t really have a use in mind but thought it too cute to pass up.

Design Goals:
Part of a vintage suitcase set of my (grand?)parents which not really of any service these days. Just screaming for a “reuse” project.

Driver Selection:
Speaker came with kit.

Enclosure Design:
Mendel, Cincinnati USA nice classic luggage , tweed over pine, stitched leather trim.

Enclosure Assembly:
easy lay out & assembly, case just the right size. Assume this little amp should be open baffle but opening case seems to suffice.

Crossover Design:
NA

Tips & Tricks:
DO NOT MISTAKE 9V 3.5 mm plugs for input jack (upper far right). I fried a tablet.

Conclusion:
still looking for useful application… a pickup for the accusstic guitar I can’t play will cost quite a bit more than this amp!

About the Designer:
Too much time on my hands.

Project Parts List:

Designer:
Bob

Project Category:
Tower Speakers

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
$100 – $500

Project Description:
Cabinet reload of spent pair of Realistic Optimus T-100’s

Design Goals:
revitalize load speakers

Driver Selection:
GRS PRT Phenoic Ring Tweeter
8″ Pioneer type B2OFU20-51FW full range speaker
10″ square frame GRS10SFPC-B

Enclosure Design:
Realistic Optimus T-100’s. Originally this was an 8″ 6 ohm driver with a sealed 2 ohm tweeter with L-pad & diffuser and a 10″ passive radiator. Foam surrounds shot on radiators, also one driver replaced & also rotted out. tweeters worked but replaced anyways.

Enclosure Assembly:
Just because I have a bunch of hand tools & a job site style table saw – it doesn’t make me a cabinet maker. Much easier to adapt an existing housing. Got these walnut veneer cabinets tossed in during house sale haggling for $25 or less. After washing off a decade or two of nicotine & restoring an oil finish, additional internal bracing, foam backing, etc.., rebuilt as an three-way speaker cabinet.

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

Tips & Tricks:
Had to make a plug for the L-pad hole and moved the off set tweeter back on axis. The midrange cutout was a hair big & also required help to except new drivers. Two part plumbers putty or the slightly more expensive JB Weld wood putty did the trick.

Conclusion:
Initial thoughts “What a waste of time & $$”, but after about 4-6 hours of burn in they started to find their voice. Quite happy with the results using bargain components.

About the Designer:
I’m still using the first two pairs of Realalistic speakers which were purchased back in the 1970’s when I was still in high school. My friends could afford the more popular Japaneese brands back in the day, I had to watched for “2 for 1” clearance at Radio Shack. Have served me well.

Project Parts List:

Designer:
Carmen

Project Category:
Portable Speakers

Project Level:
Intermediate

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
Lighter weight solid wood enclosure with great portable sound.

Design Goals:
Looks good indoors or outdoors.

Enclosure Design:
Black Limba is an exotic wood from Africa
The wood is relatively soft and easy to work. Medium coarse texture. Open pores require filling for a smooth surface.

Conclusion:
Great sound – Great look!

About the Designer:
Weekend woodworker always looking for new challenging projects.

Project Parts List:

Designer:
RWS

Project Category:
Home Theater

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
Under $100

Project Description:
JLB 135 Resurrection

Design Goals:
Putting a powered subwoofer back into action

Driver Selection:
Peerless by Tymphany

Enclosure Design:
JLB 135 Home theater speakers

Enclosure Assembly:
Needed to make an adapter board to fit new plate amp to enclosure.

Crossover Design:
Dayton Plate amplifier

Tips & Tricks:
Satellite speaker nearly an exact match, had to elongate holes to fit (drill press & file). Original speaker was shielded, hope that doesn’t become an issue.

Conclusion:
Not a big fan of powered subwoofers, so kept this simple. Original amp went out & couldn’t see scrapping the unit, too much stuff going to landfill as it is.

About the Designer:
Weekend Redneck, the point of life is doing it yourself.

Project Parts List:

Designer:
Kyle

Project Category:
Bookshelf Speakers

Project Level:
Beginner

Project Time:
8-20 Hours

Project Cost:
$100 – $500

Project Description:
This is an MDF based 0.4 cu ft box with walnut veneer. The box is ported and tuned to roughly 58 Hz. Full range Tang Band drivers were used to simplify the design.

Design Goals:
This was a build I wanted to do with some high quality full range drivers that would give a great sound without going into crossover design. I wanted to make an enclosure small enough to go most places in an office, tv room, or elsewhere in the home without being too obtrusive while still giving a great listening experience.

Driver Selection:
Tang Band W5-1611SAF 5″ Full Range driver

Enclosure Design:
0.4 Cu Ft ported box with a tune of 58 Hz

Conclusion:
I feel the final product looks and sounds great!

About the Designer:
I have a smaller YouTube channel focusing on home theater and DIY projects. The full build can be seen on my channel “Life of Bliss”. I have been building various car and home audio enclosures for over 12 years.

Project Parts List:

Designer:
Ben B.

Project Category:
Tower Speakers

Project Level:
Intermediate

Project Time:
8-20 Hours

Project Cost:
$500 – $1,000

Project Description:
The Skylark Flying Towers are short nested line array speakers designed to utilize the Denovo Audio Knock-Down Tower Speaker Cabinet. It’s a 3-way design with a Fountek ribbon tweeter for the high frequency part of the array. The mid frequency portion consists of 2 full range drivers; 1 above and 1 below the tweeter. The low frequency portion consists of 4 woofers; 2 above and 2 below the mids. The speakers utilize a sealed alignment, as they are designed for augmentation with a subwoofer (or multiple subwoofers). Since the arrays are short and the listening position should be near the tweeter axis, the speakers need to be placed on a stand or otherwise elevated off the ground (thus they become “flying towers”). I consider this a 6 ohm design with 89-90 dB sensitivity, and full baffle step compensation. The speakers are very dynamic and were designed to achieve high output levels.

Design Goals:
The goal of this design is to make a nested array speaker that’s inexpensive and easy to build. In contrast with other types of arrays, this design is free of comb filtering, and requires no DSP delays, nor equalization. By following particular design rules relating driver placement, crossover frequencies, and crossover slopes, this design significantly reduces floor and ceiling reflections over a very wide bandwidth. In contrast, the horizontal dispersion is wide and lateral reflections are not attenuated. By maintaining lateral reflections but attenuating vertical reflections, the design seeks to optimize the trade-off between apparent sound-stage width and perceived detail.

Driver Selection:
The tweeter selected is the Fountek Neo X 2.0 (296-709). This tweeter has the appropriate height to maintain a similar vertical dispersion as the rest of the speaker, and can support the crossover frequency and slopes required. Also, ribbon tweeters are known for their detail and transient level, and this one does not disappoint.
The mid frequencies are covered by the Tymphany TC9FD18-08 (264-1062) full range drivers. A small full range is most appropriate here because the design calls for shallow crossover slopes for the mids. Also, the small size maintains good horizontal dispersion across the frequency range used. These drivers are smooth, with low distortion over the applicable frequency range, and very cost effective, too.
The woofers are the Dayton Audio RS150T-8 6″ Reference Woofer Truncated Frame (295-342). The truncated frame is required to fit all 7 of these speakers in a cabinet that’s only 34 inches tall. These woofers also have smooth frequency response and low distortion. They also maintain wide horizontal dispersion over the frequency range used in this design. Using 4 of them keeps the impedance high, while increasing the sensitivity, and gives the desired vertical dispersion.

Enclosure Design:
This design utilizes the Denovo Audio Knock-Down MDF 1.16 cu. ft. Tower Speaker Cabinet (300-7066). This is a very sturdy and precision cut cabinet that is easy to work with and represents a good value, particularly to those of us without great woodworking skill. There is an enclosure inside to isolate the mids from the woofers. The speakers are centered on the baffle horizontally. The tweeter is also centered on the baffle vertically. The mids are placed immediately above and below the tweeter, with no separation.
Measuring from the bottom of the speaker, the woofer center heights in inches are 3.0567, 8.5033, 25.497, and 30.943.
The mid center heights are 13.112 and 20.888 inches.
The tweeter is centered at 17 inches.
I made the mid enclosure out of 1/2 inch mdf. The enclosure is 12.25 inches tall and 6.25 inches wide (external). The internal depth is 3.5 inches. I cut 4 inches off of the center brace to account for the mid enclosure. I also had to cut 5″ out of the front part of the other 2 braces in order to fit around the woofer holes.

Enclosure Assembly:
Woodworking is not my area of expertise. I put the speaker together largely using liquid nails to attach the pieces and create seals. It’s probably good practice to avoid screwing into the end of the mdf pieces. Since all the drivers have faceplates of very similar thickness, flush mounting is optional but not required. I did not flush mount mine.

Crossover Design:
Since the design has goals for on axis and vertical off axis behavior, the target responses had to be followed closely. This required a somewhat complicated crossover, particularly for the tweeter. The crossover frequencies are 800 Hz and 3 kHz. Crossover pictures and measurements are included.

Tips & Tricks:
None.

Conclusion:
The design goals have been verified with measurements. The speaker is extremely detailed but easy to listen to (when augmented with a subwoofer). It’s very dynamic and plays loud and clean. There’s no comb filtering, and the response is very similar out to +/- 15 degrees from the vertical axis.
Since there is no DSP nor equalization required, this design makes for a great introduction to arrays that’s relatively simple and inexpensive. Anyone who’s been considering an array design but has been intimidated by the complexity or cost should consider these. Also, anyone interested in a speaker with wide horizontal but narrow vertical dispersion should consider this design.

About the Designer:
Ben Butterfield is an electrical engineer who designed his first speaker in college and used it in his senior design project. He was active in the DIY community in the early 2000s, but took a break after assessing his own designs as lacking innovation. An innovative idea for optimizing the response of multi-way nested line arrays rekindled his interest in DIY speaker building in 2016.

Project Parts List:

Designer:
Acoustic Spheres

Project Category:
Freestyle Speakers

Project Level:
Beginner

Project Time:
8-20 Hours

Project Cost:
$100 – $500

Project Description:
How to replace the Bozak LS-200s my dad bought for me in 1979?

To do them justice, I mimicked the one woofer and tweeter layout.

But, I’d heard that a sphere is acoustically best. So, I bought 24″ white acrylic globes with an 8″ opening. I thought they should be elevated, so I worked with copper pipe to make an industrial, functional base on a circe of copper pipe to echo the sphere.

Design Goals:
Unique design using spherical enclosures.
Elevated cabinets to enhance listening
Aluminum cone woofers (nod to Bozak)
Quality sound

Driver Selection:
Dayton Audio DC28F-8 1-1/8″ Silk Dome Tweeter
Dayton Audio RS225-8 8″ Reference Woofer

Enclosure Design:
24″ Acrylic lighting globe with 8″ opening for woofers
110 mm polished steel hemispheres for tweeters

Enclosure Assembly:
Lined acrylic globes with fiberglass bondo for strength.
Drilled holes for fittings to mount base and tweeter enclosures.
Glued 3/4″ quilting filler padding inside enclosures for insulation.
Low voltage lighting wire used to connect drivers and banana plugs at the base of the stands.

Crossover Design:
Dayton Audio XO2W-2K 2-Way Speaker Crossover 2,000 Hz

Tim at Dayton Audio helped me pick out tweeters and crossovers to match the aluminum cone woofers I picked out.

Tips & Tricks:
I put concrete at the back of the spheres to set the wooden plate where the crossovers are fastened. The concrete helps balance the weight of the drivers.

Made sure to reinforce the opening in the globe. the acrylic globe material was thin and fragile!

Conclusion:
I’m pleased with how the speakers sound and look!

I thought about a ported speaker design, but abandoned the idea.

I rounded out the sound with a Dayton Audio SUB-800 8″ 80 Watt Powered Subwoofer

About the Designer:
58 year old desk jockey who prefers to work with his hands.

Project Parts List:

Designer:
Clay

Project Category:
Bookshelf Speakers

Project Level:
Advanced

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
Egg shaped speaker called the Clam Snail Egg MTM+RT

Design Goals:
I wanted to build a new version of egg speakers like the ones that I published in “Speaker Builder Magazine,” issue 3, 1986 called the un-boxed egg. I wanted it to provide a symmetrical radiation pattern by using an MTM arrangement and good low-end extension by incorporating my internal spiral transmission line. Also, I decided to add a rear facing tweeter in order to qualify for InDIYana speaker design competition requirements.

Driver Selection:
I had some awesome little ND105-4 woofers (Part # 290-212) on my shelf so I purchased some OX20SC02-04 tweeters (Part # 264-1528) to go with them.

Enclosure Design:
After attending several speaker competitions, I often noticed that exposed fasteners on the front baffle were not pleasing to the eye. So I came up with a clam shell construction method using long bolts made from 1/4″ all-thread and barrel nuts used for Knock down furniture. I like speakers with handles, so I added a rear drawer pull in front of the switch area recess.

Enclosure Assembly:
Two layers of vinyl plank flooring form the outer shell. The layers split to form a flared terminus and an internal spiral waveguide. 3/16″ ABS plastic are applied to front and back to create an integrated base. Acrylic solid surface counter top material is shaped, routered, sanded and polished through a grit progression. The drivers are rear mounted with stamped grills formed from gutter screen. A thumbnail profile router bit was used to create waveguides to load the tweeters and improve time alignment with the front woofers.

Crossover Design:
The epoxy that I added to the center of the woofer cones complicated the crossover design and lowered their sensitivity. But I thought it necessary to utilize the full potential of the internal spiral, by getting Fs closer to the 1/4 wavelength tuning frequency of the line. So using my omnimic I ended up with a forth order crossover containing 13 components. It is accessed by a removeable plastic panel recessed into the bottom of the base. I have much to learn about passive crossovers. I also wired two DPDT toggle switches in the rear to change the rear tweeter polarity. For dipole or bipole operation and 0 to -3 Db attenuation. The overall sensitivity is quite low, less than 80 Db

Tips & Tricks:
If I can do it, how hard could it be?

Conclusion:
I love them. The bass is tight and musical, That is what I love about transmission line speakers. However I am not sure if I consider them a do over, due to their complexity. The flared terminus shows strong output at a tuning frequency of 38 Hz with a fist overtone 14 Db down at 350Hz so that is what I consider to be the most successful aspect of this project. They do not need a subwoofer, unless you need sound below 35 Hz

About the Designer:
I am a self-employed cabinet and furniture maker in rural Evansville IN. I build wooden rectangles almost daily, so i enjoy using my artistic ability and my electrical background along with my accumulated knowledge of techniques to manufacture items from various materials. I also enjoy using big words to make me sound more photosynthesis.

Project Parts List:

Designer:
Mark Bussow

Project Category:
Loudspeakers/Cabinets

Project Level:
Intermediate

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
Started with the Blast Box speaker kit, but built my own cabinet and control panel. The outside is oak, but it has a MDF box for the sub and I used wood from the kit for the mids and tweeters.

Design Goals:
I wanted something that sounded good and blended into the old school decor of our office. I like the look of old amplifiers, so tried to mimic that while fitting in a tight space between two doors.

Tips & Tricks:
I built the custom control panel and logo using laser toner transfer from photo paper onto aluminum sheet, and then touched up with a paint pen. This gives it a professional look, and everyone loves the logo with our last name on it.

I also laid out the entire design in photoshop first with precise measurements, which was critical to getting everything to fit together right and getting the speaker boxes the right volume in a custom design.

Conclusion:
I’m really happy with the result and my family loves having the new speaker in our office. It sounds amazing and using the kit gave me the building blocks I needed to get going.

About the Designer:
I’m in an office most of the week, but have spent weekends for the last few years renovating my 1940s home. Now with a little confidence and a workshop full of tools, I’m starting to branch into other woodworking/craft projects.

Project Parts List:

Designer:
Ryan Clark

Project Category:
Subwoofers

Project Level:
Intermediate

Project Time:
8-20 Hours

Project Cost:
$100 – $500

Project Description:
Slot vented cabinet. MDF joined with glue and pocket screws. Painted with interior white paint to match rest of entertainment components. This project was driven by curiosity and that I was fortunate enough to get the driver as a restock deal. My entertainment center had space for one more subwoofer so… why not?

Design Goals:
Optimally performance in relatively small vented cabinet
Aesthetically pleasing and matching cabinet
More delicious bass

Driver Selection:
295-469

Enclosure Design:
This was my first sub build with a slot vent. I used an online box calculator to recommend 2.76 ft3 tuned to 27 Hz with an F3 of 30 Hz which was consistent with the PE recommendation on their product page. My finished design ended up slightly larger at 2.86 ft3 which after modelling made little variation to original plan.
I designed the L-shaped slot vent to also functioned as part of the cabinet bracing system.
Slot vent 3” x 10” ~32.75” long

Enclosure Assembly:
0.75″ MDF
0.50″ plywoof for internal baffle section. I like using plywood here because the T-nuts set much better in it then MDF

Crossover Design:
The speaker is powered by a Crown XTI 4000, utilizing the built-in DSP functions, specifically high pass crossover, which it set at 12db/oct at 22 Hz. I may tweak this, but I think it is adequate to protect the driver from heavy subsonic excursions well below the tuning frequency. (My 18” Ultimax is boosted 10db at 20Hz to get those lows this guy doesn’t get and flat out its ~30Hz F3)

Tips & Tricks:
Plan – being that this was the most complicated enclosure I have built to date, I took extra time to lay out the pieces and make sure I had a well-order construction plan.
Baffle – I like to make sure the baffle is cut correctly before attaching to the cabinet. I also set the t-nuts in the baffle and mount the driver to make sure they all line up well. It is much easy to fix any issues before the cabinet is mounted.

Conclusion:
This is a great subwoofer and I am pleased that the cabinet came out well. It is fun to compare it to my 18” Ultimax in a sealed enclosure by turning on/off each channel. It is definitely not the beast of the UM-18, however it is a great subwoofer and is on the top of my list for bang for the buck in relatively little space. Considering you can put this 15” sub in a ~1.5 cubic foot sealed enclosure is awesome! Would be great for a car.

About the Designer:
I have always been an aspiring audiophile, although I don’t consider myself one. I am just a guy that loves music (listening and making), movies and building things out of wood. I still have my Infinity SM-62’s I bought out of a Crutchfield catalog in the early 90’s (~14 years old).

Project Parts List:

Designer:
Blackhawk111

Project Category:
Subwoofers

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
$100 – $500

Project Description:
Replacing the amplifier in a Polk PSW110. This will be the 2nd time this amp board has failed, the original and replacement. Seems they only last 18 months. In my case, one of the caps is swollen and the unit just hums. This is a nice size subwoofer, good quality cabinet, good speaker and unfortunately poor quality electronics. I reviewed direct replacement options but the current prices are too high and availability short. I decided to find a replacement and knew Dayton had options. I chose to upgrade in power and capability. To ease in mounting, I also ordered the mounting frame..

Design Goals:
Repair and improvement in performance of a Polk Subwoofer.

Tips & Tricks:
The mounting frame solves several issues with the original opening size. I chose to use some thin MDF to make a cover for the original opening and just cut a simple slot for the speaker leads. I had the leads come out of the top to avoid proximity to the power supply portion of the new amp. I used flat head wood screws and sunk them deep into the MDF to keep the new mounting area relatively flat. `

Conclusion:
This was a great option for a replacement and upgraded amplifier for this subwoofer. I did use some power tools but this could easily be done with limited tools. The results look great and the sounds is excellent. I wish I had done this on the first time replacing the amp.
Total time spent was about 2 hours.

About the Designer:
I’m a DYI person. I have an electronics background and like to do woodwork.

Project Parts List:

Designer:
David Hall

Project Category:
Home Electronics

Project Level:
Intermediate

Project Time:
20+ Hours

Project Cost:
$500 – $1,000

Project Description:
Refinish and revitalize an old 1936 Philco 36-760X radio into a powerful Bluetooth system.

Design Goals:
• Restore and retrofit a dead 1936 Philco 36-760X radio as a Bluetooth speaker
• It must capable of filling a large room with high quality low distortion sound.
• Due to the small space available in the cabinet a solution is needed to provide a healthy lower end of the frequency spectrum.

Driver Selection:
For this application I selected the ND140-8 drivers as they have good power handling capability considering the motor size and provide a decent low end for a 140 mm mid-bass driver. Each channel had two ND140 wired in parallel, providing 80 watts per channel.

For the high end, I selected the XT25BG60-04. It has respectable off-axis performance, which is important for this application as both channels are physically close to each other due to the relatively small cabinet size.

Enclosure Design:
While a 2.67 cubic-foot ported cabinet is optimal for the ND140-8, even one speaker cabinet would not fit in the Philco cabinet. I had to go with a closed speaker cabinet for two ND140-8 in parallel. According to BassBox Pro the idea closed chamber would be is 0.62 cubic feet. Due to space constrains, the final closed speaker cabinet for each channel was 0.589 cubic feet, which did not adversely change the roll-off portion of the curve, having an F3 of 76 Hz, versus the desirable 31 Hz for a ported box. Both channels were built in one enclosure with a reinforced divider separating each resonation chamber.

For cabinet esthetics, I sanded the Philco cabinet down to the wood then sprayed it with three coats of gloss lacquer, and one final coat of matte lacquer. The original mustard colored grill cloth was rotted, so I replaced that with an acoustically transparent burgundy grill cloth. I purchased a replicate radio dial because I damaged the original when I unsuccessfully cleaned it with alcohol, dissolving the printed bands on the dial. One knob was missing so I purchased an original knob I found on-line.

Enclosure Assembly:
I employed simple box construction using butt joints with reinforcing gussets and window frame strut to dampen any resonance from the box. I installed a drawer on glides for the electronics. Unlike the original radio, I added a back channel as 110 volts would be available to prying little fingers. Nothing really challenging here.

Crossover Design:
In order to boost the lower end an active solution is required, not a passive crossover. I tried the Dayton Audio DSP-408 digital signal processor (P/N 230-500) combined with Sure Electronics’ 4×100 W amplifier board (P/N 320-305). I have used the amplifier board in several applications and have had no problems in achieving a clean sound. The system was powered with a 24V, 350W Mean Well switching power supply (320-3167).

Let me say at the start, the Dayton DSP-408 is amazing, and a great value for what it does. Dayton’s user interface is simple and very clean, and easily navigable. I will use more of these in future designs as they provide amazing flexibility and the ability to compensate for delays between drivers as well as the listening space. The DSP truly allowed for easy optimization of the frequency spectrum. I have used other DSP and this one carries its own weight with ease. I really like and am impressed with the unit.

I used Seismic’s 1-foot double patch cables to make connections between the Bluetooth receiver and the DSP, and the DSP to the amplifier board. The size is perfect for this application. I wish these, or ones like them, were available on Parts-Express, as the 1.5-foot cables Parts-Express are too long for a clean organized layout of the electronics.

All the electronics were secured to a drawer on linear glides in the upper part of the Philco cabinet, where the original radio receiver resided. The glides allow for easy access to the electronics.

Tips & Tricks:
When refinishing vintage radios, be prepared to do a LOT of hand sanding. Give the DSP a try; you will not be disappointed.

Conclusion:
Dayton’s ND104-8 combined with their DSP-408 is a perfect combination to achieve a fantastic lower end. This paired with the Tymphany XTBG60-04 pumps out a clean crisp quality that fills any room with amazing sound. The DSP-408 provides a lot of bang for the buck. Oh, did I say I really like the DSP?

About the Designer:
I am a custom speaker and home theater designer. The favorite part of my job is speaker design and fabrication. I pursue unique cabinet designs and drivers that offer clients the look and quality of sound they desire. My philosophy is audio should be as pleasing to the eye as it is to the ear. It has to look as good as it sounds, and it must sound awesome! I focus on choosing drivers with optimal qualities to achieve the finest sound in order to diminish or avoid the electrical and acoustic challenges of crossover design.

Project Parts List:

Other things used in this project:

1 – BassBox Pro Software
1 – TinySine Bluetooth Audio Receiver board (Amazon Tin-8305)
3 – Seismic Audio Premium Red 1 Foot Dual RCA Male Audio Patch Cable (SAPRCA1-RD)
1 pr. – AB-5000 Ball Bearing Drawer Slides, 10 Inch, Nickel Plated-Steel
1 – URBEST Inlet Module Plug, 5A Fuse Switch Male Power Socket, 10A, 250V, 3-Pin, IEC320 C14
1 – 10 ft Standard Computer Power Cord (NEMA 5-15P to IEC 320 C13) – 18 AWG

Designer:
Laurel Loudspeaker

Project Category:
Tower Speakers

Project Level:
Beginner

Project Time:
20+ Hours

Project Cost:
$100 – $500

Project Description:
Floor standing single driver full range speaker. It is my first project so wanted something simple to try out my wood working skills

Design Goals:
Speakers for our main system used for home theatre and audio so wanted them to sound and look great

Driver Selection:
Wanted a full range driver with good bass and flat response. My ears don’t go to much into the high end so wasn’t to concerned about the top end. The specs on the Tang Band W6-2144 look good so went for them.

Tang Band W6-2144 6-1/2″ Paper Cone Full Range Driver 8 Ohm
Part # 264-959

Enclosure Design:
Simple box with bass reflex. Due to the furniture in the room I chose to place the base port above the driver. I chose a maple plywood for a classic wood finish. Height 4ft width 9” depth 10”

Enclosure Assembly:
I choose a maple ply wood panel for looks and cost. The shop cut it don’t to the size I wanted, which made everything simpler. I glued and used pocket screws to fix the main box then braced all the joints. Before closing I glued acoustic foam on the internal walls. Sanded and stained the exterior with a natural stain.

Crossover Design:
Not applicable

Tips & Tricks:
Spend the time up front to get the basics right and make come together quicker.

Conclusion:
Look and sound great, just wish I had better wood working skills.
They go as deep as advertised and the mis are really nice. There is a bit or resonance at the high end and some distortion when I put too much power through them but that really loud. Over all I really like them and enjoyed making them

About the Designer:
I am beginner with wood working but enjoy good sounding music

Project Parts List:

Designer:
John A Nelson

Project Category:
Portable Speakers

Project Level:
Beginner

Project Time:
8-20 Hours

Project Cost:
Under $100

Project Description:
Custom designed Bluetooth speaker using the #300-7304 Bluetooth kit with an additional battery backup and the KAB-PMV3 panel mount. Found some awesome Marvel Cricut paper, and custom decorated the speaker.

Design Goals:
Build a cool, fun and portable Bluetooth speaker for my Marvel obsessed 13 year old. She loves the finished product, and while I am just a beginner, I think it turned out OK!

Enclosure Design:
Simple plywood box made this design easy and simple. I used 1/2 inch plywood that I had left over from another project.

Enclosure Assembly:
Ported the enclosure to improve bass response, 1″ tube cut to about 3″ deep.

Crossover Design:
Not required because I used full range drivers

Tips & Tricks:
I used modpodge to “set” the paper in place on the box It was sort of like working with wallpaper, so it was pretty messy and easy to mess up, so be careful! After the paper was in place, I added another coat of modpodge to the paper, coating the whole thing. Then, after a week I coated the whole thing with two coats of clear sealer designed to work with the modpodge to give it some durability.

Conclusion:
The overall build was pretty simple, using the full range driver and the KAB board really made the development easy and straightforward. Box constructed from some scrap 1/2 in plywood I had from a previous project.

About the Designer:
Hobbyist woodworker and tinkerer from New Jersey. My basement shop is my happy place.

Project Parts List:

Designer:
Zachary Zisman

Project Category:
Bookshelf Speakers

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
$100 – $500

Project Description:
Assembled the Passive Agressive speaker kit using Rust-Oleum Hammered Copper paint as the finish.

Design Goals:
Small, room filling speakers with a nice, semi-industrial look

Driver Selection:
ND20FB-4 x2
ND91-4 x2
ND90-PR x4

Per pair of speakers

Enclosure Design:
Dual passive radiator small sealed enclosures.

Enclosure Assembly:
MDF and wood glue

Crossover Design:
Per kit

Tips & Tricks:
Watch the cabinet pieces when assembling, they wanted to slide around a bunch. I ended up post sanding the enclosures and they came out fine.

Conclusion:
Awesome little speakers. I’m testing them in straight stereo right now and they sound amazing for tiny little bookshelf speakers. I plugged them in in place of my Infinity Beta 20s and they’re competing nicely. A bit less bass but not the Passive Agressive has a really nice sound and tone.

About the Designer:
I didn’t really design these, but I am a design engineer and program manager when I get paid to design and build things. I like to build all sorts of stuff out of wood and metal.

Project Parts List:

Designer:
PFKIRCHNER

Project Category:
Portable Speakers

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
$100 – $500

Project Description:
4 inch kickers with Dayton Audio 2X50 bluetooth amp and LI b battery extension board.

Design Goals:
First build so I wanted to do it as cleanly as possible

Driver Selection:
50 Watt Kickers

Enclosure Design:
.50 Cal Ammo Can

Enclosure Assembly:
Dayton Audio 2X50 bluetooth amp and LI b battery extension board.

Tips & Tricks:
Make sure you plan out the location of your equipment, and ALWAYS buy good tools. Makes things so much easier.

Conclusion:
Had an absolute blast putting this together, and love the way that it turned out.

About the Designer:
Former Navy EOD Tech. Electronics novice and thought this would be a great project during the pandemic lockdown.

Project Parts List:

Designer:
Winkleswizard

Project Category:
Subwoofers

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
$100 – $500

Project Description:
I needed to put my bookshelf speakers on stands and figured I could significantly enhance their bass for the same I would spend buying fancy stands for them.

Design Goals:
Wanted a driver that would act as a subwoofer for my bookshelf speakers without taking much space and still add serious bass. I recommend a subwoofer amp like the inexpensive Dayton APA-150. There is room for plate amp, but I like to keep anything that might rattle way from bass drivers.

Driver Selection:
Given the target cabinet size and desire for significant bass output with good sensitivity, decided to use the Dayton RS225-8 woofer. I have good experience with them and they are rugged enough to use without a grill too.

Enclosure Design:
Started with the high fidelity option in Bassbox Pro. For a 1.3 cubic foot cabinet, can do f3 in the upper 30s. I tuned a bit higher, as I liked the overall results. I maximized the use of MDF and minimized the number of cuts to make the design easier for newbies. See attachment for details.

Enclosure Assembly:
The enclosure is pretty straightforward and simple. For best stiffening, remember to glue in braces before to many parallel sides are attached. The original design (attached) uses remaining scrap pieces for braces. I later decided on a window pane style brace placed just below the woofer (see pictures). I left the original braces as it does not affect volume significantly.

Crossover Design:
This design uses the crossover in a standard subwoofer amplifier. If you do not have outputs to drive the subwoofer amplifier, can use something the Metra IBLOC01 to adapt speaker outputs to RCA.

Tips & Tricks:
To keep the design easy for the beginner, I designed to keep cuts to a minimum. Normally would double the front baffle thickness, but wanted to allow cutout to be done without need for a router.

If doing smaller braces, would place one across back just a couple of inches above the port. The other should go on the fron baffle just under the woofer.

Conclusion:
While still deciding on final finish, am very pleased with the overall performance of these bass stands. Without adding much added footprint, they really transform my bookshelf speakers into a much fuller listening experience.

About the Designer:
Have been an audio enthusiast for more than 40 years and have been designing subwoofers for about 30. I have built many DIY speaker designs and has been a great learning experience. When not listening or building, I help my wife (Winkle), family and others with their computer issues.

Project Parts List:

Designer:
Bret A Morrow

Project Category:
Loudspeakers/Cabinets

Project Level:
Advanced

Project Time:
20+ Hours

Project Cost:
Under $100

Project Description:
This project is a tribute to Bose’s legendary 901 speakers. The 901s were made from 1968 until 2016 and were a unique design that received both acclaim from critics and intense dislike from some audiophiles. These DIY speakers follow the basic design and goals of the 901’s to more realistically represent live music by using direct and reflecting sound. The speaker is a pentagon shape with 9 identical drivers in each speaker—1 forward facing and 8 rear facing.

Design Goals:
The primary goal is to create speakers that can generate an ‘omnipole’ sound pattern–no single ‘sweet spot’ but a broad, consistent sound distribution. The original plan was to use these in a basement shop where I could be working in many different parts of the room and wanted to be able to have the same quality of music in all the areas. The project was started out of curiosity—I remember hearing a pair of 901s in the 70’s and was very impressed with the sound, although it could have been the girls and beer at the party.

Driver Selection:
Pioneer 4 inch Full Range Driver (269-570). The Bose driver is a unique unit—4.5 inch, 1 Ohm impedance with a good frequency response from 100 to a bit above 10,000 Hz. While a replacement unit for the Bose 901 is available, there are many alternatives that can cover the 100 to 10,0000+ Hz. Because a set of speakers will use 18 drivers, driver cost is a major factor in deciding on the unit. The units used here were a Parts Express ‘Buy-out’ costing less than a dollar each.

Enclosure Design:
The enclosure design follows the size and shape of the final Bose 901 design from the 2000’s—approximately 21 inches wide by 12 inches tall and 12 inches deep to the point of the rear. The 2 rear facing panels are set at a 120 degrees angle to each other and to the sides. The front panel is gently curved so that the center of the speaker is about 1 inch in front of the front edge of the sides, which are about 6.5 inches deep. The speaker terminals are placed in a recessed cylinder on the bottom panel, as in the original Bose design. The visible part of the box is painted black, but the cloth speaker grills are major part of the design. The rear grill is a traditional frame design but extends beyond the speaker body while the arced front grill is slightly recessed and wraps around to cover part of the side panel. The grill cloth was selected to give a vintage look similar to that of the Bose 901s from the 60’s and 70’s.

Enclosure Assembly:
The construction was a little challenging due to the unusual shape of the box. The box was made out of BC grade plywood with a top layer of either ¼ inch MDF (painted black) or 1/8 inch hardboard with a clear finish. Internal bracing was used to add rigidity and to help clamping these panels at the odd angles. The speaker holes were cut with a 4 inch hole saw on a drill press prior to assembly and then laminated with hardboard when the box was completed. The driver holes in the hardboard were cut at 4.25 inches to accommodate the flange of the driver—this also allowed space for silicon sealant. The arced front panel was made from a flat center section of plywood, 6 inches wide, where the driver sits joined to curved struts approximately 7 inches long to connect to the side panels—the entire front was laminated with 1/8 inch hardboard. The rear grill is a traditional frame design with a 30 degree bevel on the side so that they were in line with the side panels. The rear grill is designed to extend beyond the speaker body and it is connected using 6-32 Tee nuts. The Tee nuts were placed into the plywood body prior to applying the hardboard. The front grill is 1/8 inch hardboard with laminated hardboard strips to maintain the arc of the speaker and is just shorter than the top and bottom of the speaker. The hole for the driver has 3 pieces of thin wood to maintain the appearance of the arc. It is secured to the sides using implanted Tee nuts as the rear grill. Both grills are covered with a pale green burlap material secured with hot glue.

Crossover Design:
The Bose 901 were famous for having no cross-over. Later versions had all nine speakers wired in series to give a ~9 Ohm impedance speaker. Since the drivers in this project are 8 Ohm, they are laid out in 3 parallel sets of 3 drivers in series. This gives us an 8 Ohm speaker where each driver carries an equal part of the load.

Tips & Tricks:
Since so many holes needed to be cut, having a hole saw on a drill press was very helpful. The external fit and finish of the speaker was difficult compared to other speakers. Creating a template with speaker and Tee nut placement would be helpful—I did not do this. I used a form cut from a 2×4 on a bandsaw to bend the front panel and grill into the arc. This was essential to get a nice consistent bend as well as provide a way to clamp the hardboard strips to the back of the front grill.

Conclusion:
The speakers share the unique appearance of the Bose 901s that is distinctly different than most speakers—uniquely a mid-century modern look. The sound is also definitely unique compared to other speakers. The imaging is huge! There is almost no location in the room where you cannot hear a good representation of the music—the primary goal has been met. Frankly, you can go into the next room and the music still sounds quite good. The imaging is full and detailed compared to other designs. There is some more blurring than other speakers, as would be expected. In this way, they represent live music better than most other speaker designs. The most obvious deficiency is that they lack a strong bass. The sealed boxes have a gentle roll-off, however, it starts about 100 Hz. While this is noticeable, in listen trials, I felt that it was less important than the uniquely full sound they could deliver. A subwoofer could be added and might be in the future. The upper end has some cone breakup but, again, this is not a deal-breaker for the design. Adding a tweeter to the design could solve that, but would introduce the problems that crossovers and separate range drivers bring with them. Right now, I am continuing to use them as living room speakers. Maybe they will go to the shop at some time in the future.

About the Designer:
The designer (aka JazzzSpazzz) is a long-time tinkerer interested in everything.

Project Parts List:

(This is where you should investigate what is available in Parts Express Speaker buyout. Currently, these look interesting: 289-2346, 289-2078, 289-2248, 289-2294, 289-2318, 289-2324. It would be worth getting a few of them and audition them before buying the 18 drivers needed. 4 Ohm drivers would require a different wiring setup to get an 8 Ohm speaker.)