New 10W Speaker

Hey everyone! Firstly welcome to my new website! I hope to publish tutorials, laser cutting files, past projects, and more over here. The new bAudio shop will operate from the website, and I have plans on setting up a forum over summer where we can all share our ideas and designs in one simple place.

If you haven't seen it already, I'd like to introduce you to the new 10W speaker design! It's taken a while to arrive; thank you for your patience! This speaker has some significant improvements over the last model. Firstly, it features a more compact, easier to assemble, enclosure. It features a new pair of outstanding drivers, a new generation of CSR8645 bluetooth and amp board, now custom programmed for this speaker. 

 

Here's a rundown on some specs and features:

 

  • Dual 5W fullrange drivers
  • 12 hours battery life on high volume
  • 70 Hz - 20 kHz frequency range
  • Built in microphone for phone calls
  • Solid walnut enclosure with pine top
  • Laser engraved patterns
  • Bluetooth 4.0 & programmed DSP

 

 

 

 

 

As before, I've decided to make kits with the parts needed for the project. But of course, you could probably source most of the parts yourself if you would prefer to. Some parts have been custom made for the project, but there are plenty of good alternatives if you choose to source parts yourself. 

 

Parts Used: 

  • (2x) 5W drivers
  • (1x) passive radiator
  • (1x) custom programmed & tuned CSR8645 bt+amp module
  • (1x) enclosure
  • (1x) 1500uF 10V capacitor
  • (1x) 3mm blue LED
  • (1x) microphone
  • (1x) 2 way slide switch
  • (1x) TP4056 charging board
  • (1x) MT3608 step up module
  • (4x) rubber feet
  • (1x) 10k ohm resister
  • (1x) protected 18650 battery
  • (5x) push-to-make buttons

 

All the parts listed above are included in the speaker kits, except for the protected battery, which I cannot ship due to safety reasons. The best priced batteries are available at NKON.nl. I would recommend the Keeppower 2600mAh protected cell, as it offers great value for money for a high quality cell. 

 

 

 

 

STEP 1: Building the Enclosure:

 

 

In this step I'm going to cover building an enclosure identical to the one included in the kit, or an enclosure with a similar footprint. In case you like my design, but would rather cut your own enclosure, you can use my laser cutting files over here <<link up tomorrow>>. The kit with panels includes five 4mm laser cut solid walnut panels, and one 3mm plywood laser engraved panel for the top of the enclosure. I've designed the top panel to be very easy to paint. The engravings are deep, which act as miniature ridges to stop paint from spreading. I would recommend using water colour paints, applied thickly. Of course only paint the panel after sanding, to avoid damaging your paint coat. For some painting inspiration, check back to my old 10w design. 

Although laser cutting is very accurate, the margin of error is still too great for precision based work like this. Whether you're buying enclosure panels from me, or building your own, you'll most likely have slight variations in length by +/- 0.4 mm. So before glueing any panels together, it is important to sand them down to the EXACT size. Failure in doing so will result in small panel gaps which will become especially noticeable after sanding down the enclosure. 

Once the panels are down to their exact size, it's time to glue them together! Make sure that you have flipped them the right way around, so that any laser burns on the surface of the panels is facing inwards. I recommend using a Super Glue Gel for glueing the panels together. Normal super glue is unsuitable for gluing panels like these, as it simply seeps into the wood before the panels bond together. Super glue gel has a much thicker consistency and doesn't seep into the glue as much. It provides a stronger bond than wood glue, and dries within minutes. Remove any excess glue using a damp cloth.

 

After glueing on the side and rear panels, finish by glueing the front panel on, using only a few tiny blotches of glue in the corners. This allows us to easily remove the front panel again after finishing the wood. 

 

 

 

Now that the enclosure is glued together, it's time to sand it down! We're going to start by sanding down the sides, so we have perfectly flat surfaces. I've left an extra 0.2/0.3mm at the edges of the panels so I can get a clean, flush side once sanded down. 

 

 

 

      

Now that everything is flush, we can start rounding the sides. We're going to sand down sides that follow the grain to a radius 4, and sides that don't follow the grain to a radius 2. 

 

 

 

      

Once complete, we're going to lightly sand down all the sides using fine sanding blocks until everything is smooth. The whole process of assembling and sanding took over 2 hours. Don't rush it. The results pay off, I promise you!;) 

 

 

 

      

Now that our enclosure is sanded, it's time to finish the wood! For this, I'm going to use a polyurethane based clear coat. This will protect it from dirt and splintering, and bring out a much richer colour in the wood. I applied coats as recommended on the back of the can, and allowed the enclosure to dry for 24 hours. 

 

Now that the enclosure is dry, it's time to remove the front panel. We do this buy sticking a scalpel in the seam connecting the front panel to the rest of the enclosure. Tackle it from a few points, until the front panel pops off. You can use this same method to get into the speaker if something ever breaks in the distant future. 

 

 

 

 

 

 

STEP 2: Electronics

 

Now it's time to put together the electronics! It's pretty straight forward. Here's a schematic. 

 

 

 

Rather than going through how to wire each individual component, since you can just read it off the schematic (each label on the schematic is marked exactly as printed on the components), I will talk a little about the components. 

 

Battery:

In this build, I decided to use a protected 18650 lithium ion battery. Nowadays lithium ion batteries are generally accepted to be the standard for these sort of projects. They're compact, powerful, and cost effective. I decided to recommend a protected 18650 battery (as in, the protection circuit is prebuilt into the battery), as they're much more reliable than using an unprotected battery and soldering on your own protection circuit, if you're inexperienced with electronics. By using a protected battery, you don't risk over charging or discharging your battery, as the built in protection circuit will automatically cut off power flow before it damages the cell. I recommend using the Keeppower 2600 mAh battery from NKON.nl. NKON.nl provide some of the cheapest 18650 cells online, and are guaranteed genuine, unlike batteries from China (which are likely to be more expensive too!)

 

Bluetooth and Amp Module:

As before, I'm using the CSR8645 bluetooth chip for connectivity. This time, it's integrated into a new and improved pcb. The PCB also features dual 5w mono amps for powering the drivers. Also for the first time, I'm getting the boards pre-programmed, meaning that the on-board DSP module is perfectly tailored and tuned for this setup of drivers and enclosure. This means extra bass and crisp treble. I'm having the modules pre-programmed by the manufacturer in China, so the modules arrive ready to go out of the box. 

 

Drivers:

This speaker features brand new drivers. These are hands down, the best drivers I have ever tested in my years of speaker building. Period. They feature rich bass similar to that of the fake Bose SL Mini drivers going around the internet, but at the same time feature really good treble. The mids aren't too loud, unlike those of most drivers of these size. Speaking of their size, they're extremely small! 40mm in diameter, about 23mm deep. They have quite an interesting design; they have no cone, so to speak, the dust cap connects directly to the rubber surround. This makes them splash proof, perfect for outdoors. Unfortunately I haven't seen these exact drivers available elsewhere on eBay or Aliexpress yet.

 

Passive radiator:

I'm using the same, high excursion passive radiator as I did last time. Nothing quite beats them.

 

Function buttons:

I decided not to use function buttons in this build (push-to-make buttons for controlling the music), but I have them included in the kits, and have also included them in the schematic above, in case you want to use them yourself. 

 

Microphone:

This speaker features a microphone for the first time, which is suitable for making phone calls through the speaker. It can just make hands-free use a little easier. The microphone truly is micro. 4 mm x 2 mm small to be exact. It connects right in to the bluetooth and amp board. 

 

Step Up Module:

We're using the same step up module as last time. Before connecting the bluetooth and amp board to the other side, you need to step up the voltage. This is done by twisting the potentiometer on the step up board anticlockwise until you get a readout of 6.5 v on the output. To make sure that the module has enough power at spikes, we're also going to wire in a 10v 1500uF capacitor. The longer prong signifies positive, and the latter, negative. The capacitor simply connects across both terminals. 

 

 

  

I've decided to lightly sand the LED to give it a frosted appearance. This means that the light will disperse better, and appear softer. I've also filed down the slide switch slightly, to make it slightly more flush, and give it a more round, soft feel. These details serve no mechanical purpose of course, but I think it's definitely worth the extra few minutes of hassle.

 

 

 

When making speakers with passive radiators, it is extremely important to make sure that the enclosure is 100% airtight. That means that we need to be certain that that the ports are completely sealed. This involves using a lot of hot glue. Pay particular attention to make sure that you don't shoot hot glue into the micro USB port or moving components within the slide switch. To avoid this, apply the hot glue in thin layers, so it cools before it seeps right into the crevices. 

 

Once our main components are in, we'll line the edges of the enclosure with wood glue. This is to ensure that absolutely no air can escape from the edges. 

 

 

 

Now it's time to glue on the drivers and passive radiator! For this, I'm using the same super glue gel that we used earlier. The drivers and passive radiator pop perfectly into place, so it's just a matter of holding them there for a minute until the glue dries. Once dry, I lined the surroundings with wood glue to ensure that they're completely airtight. Remember to leave 4 mm clean around the edges, so that the the front panel can fit flush to the rest of the enclosure. 

 

 

 

Now that the electronics are done, and the drivers installed, we can glue on the front panel. Just remember to connect your speakers to the bluetooth module before doing so! And of course, carry out a quick est to make sure everything is working first; powering on, connecting, playing music, charging, microphone, LED, etc. As before, we will use super glue gel to glue on the panel. This time, we will run a bead of glue along the edges, instead of a spots like last time, as we want to make the enclosure completely airtight. Line up the panel carefully, take your time, you only have one shot to get it straight, and press it into place! Hold for 1-2 minutes to let the glue dry. 

 

 

Last but not least, stick on the rubber feet. 

 

 

 

That pretty much finished the build! Overall, I think it's a pretty simple and straightforward build. But if you have any questions, post them down below and I'll get back with to you with an answer. Remember to take your time with building. It does pay off! 

 

 

So the speaker kits (both with and without the enclosures) will be going on sale on the website on Wednesday. Be sure to take a look at the shop then. Since I've got a lot on my plate over the next month (with exams and the likes), I won't have time to make a full YouTube video about the speaker. But considering how simple the build is, I don't think it's terribly necessary. I will however post a sound test of this new speaker at the end of the week. Keep an eye out for that! 

 

With university starting in September, it may be the case that the bAudio store will be closing for good. As a result I'm only doing a limited run of this new design. When they're gone they're gone. If you're interested in picking one up, be sure to keep an eye on Facebook and Instagram for announcements. I hope this guide has helped in some shape or form, would love to hear your thoughts below! 🙂

 

-Barry