This project was born after the first time I heard the Sonos Play 5 speakers, I was so impressed by the sound quality with respect to the small size of the speaker, the low frequencies are absolutely impressive, for that reason I own 2 Play 5 ;-)
I have built several speakers over the years and there is one aspect I wanted to improve and it is the outer shell, which was usually always built with wood, also had built some speaker with 3D printer but the finishing was not entirely satisfactory.
One day visiting an IKEA store with my wife and daughter, I noticed the design of the Kuggis box, it seemed perfect for a speaker, so I decided to do what you should never do to start the house on the roof: - )
Or in this case build a speaker from a finished box, a totally crazy idea :-)
My friends have asked me why the name of erguro-one the answer is easy are the first letters of my name ERnesto GUtierrez ROdriguez and one for being the first multiroom speaker that I make.
Step 1: Deciding the Type of Speaker System
Following the concept of a speaker that was stereo and looking for a good response at low frequencies,I tough a very classic combination 2.1 and theoretically easy to implement.
For this I looked for speakers that had a good performance and quality assurance,(as I have already said I started the reverse of what is a logical process of speaker design) the normal would have been to design the box depending on the speakers and their Thiele-Small parameters, to make it more difficult I chose BOSE speakers, the 2,25" full range speakers (P/N 273488004 ) belonged to a Sounddock I and the 6" subwoofer speaker (P/N 111791K ) of an Acoustimass system.
At least having that value and being able to measure the rest of the values using the added mass technique, I could have more information to be able to direct me in the right direction
Step 2: Starting With the Carpentry Works
With the speakers already chosen, at least I already knew what size I had to make the holes :-)
The IKEA Kuggis box does not have much stiffness so the first thing I did was to stick an MDF board to the back of the lid to make it stiffer. Since I had some parquet scraps (which I had installed last week at home) I thought it would be a good idea to use it on the front to give it a more aesthetic appearance.
All boards were glued with UHU Polimax High Tack express clear,
Step 3: 3d Printing Parts
After making the cuts in the parquet, to avoid seeing theto avoid seeing the side of MDF I designed with Sketchup some trims to hide the screws, during this process I also thought about putting a grid, in order to protect the speakers, but at the end consider more appropriate to leave a more diaphanous and clean design.
I tried differente designs and as the finishing of the pieces in PLA was not very fine, I opted to add a rough texture with a stone effect spray.
When they were dried then I painted in white
Step 4: Interior Design
As I said several times, this project is a real madness, one of the most important issues in speaker design is the volume of the box, calculating the volume of Kuggis is very easy, the problem is calculate the volume with all the things inside. :-)
Amplifiers, speakers, Raspberry Pi, DAC, etc.
It is also necessary to separate the volume of the full range speakers from the volume of the subwoofer making both volumes independent, for that reason I made two chambers, with another 10mm MDF panel,with a hole in the middle that allowed the rear wave of subwoofer to pass to the second chamber,using a plastic tube of course a good absorption of the posterior wave generated by speakers by acoustic insulating materials
But the big problem came later when he can see that due to the thin walls of the box he got unwanted vibrations in spite of the installed MDF reinforcements and some 3mm thick galvanized steel sheet whose main mission was to support the speaker in case of hanging it
Everything has been a challenge in this project
Step 5: Electronics First Attempt- Not the Good One ;-)
For this system 2.1 I initially choose as main amplifier a Chinese board class D amplifier with the P/N XH-M139 V3 the chip that uses is the popular and known TPA 3116 and is assumed with its power would be 2 x 50 W + 1X 100 W for the subwoofer more than enough power for the project.
As a power source I selected a 24V and 6 A switching supply in order to go more than enough for this project
The heart of the project was the Raspberry Pi 3+ you can get more info of this great board in the programarfacil website here
Regarding Hi-fi DAC (in this first attempt with a Suptronics X920 V1.1 HI-FI DAC), I must say that in this case results a mistake due to a defective manufacture
To summarize finally change the amplifier board since its design is unfortunate, both in the low pass filter and in the way that adds the channels L+R for the mono subwoofer, there are also several problems with the impedances, but I do not want to dwell too much with this topic, better Do not use it at least until they release a V7 or V8 version :-) If you wanna go further you can find more info in DIYAUDIO Forum Topic here where I get schematic of P/N XH-M139 V3 explaining those issues.
With the HIFI DAC the main problem was a difference of 2dB between the left and right channel, mass production in China sometimes has these problems, so finally I did not use it either although the specifications on paper were not bad.
-Full-HD audio – up to 24-bit/192kHz playback
-Built in audiophile TI Burr Brown DAC (TI PCM5122)
-Class leading audio; 112db SNR, and -93db THD
-Integrated hardware volume control
-TI's LP5907 Ultralow-Noise voltage regulator for optimal audio performance
At the last 3 pictures you can see two white tubes with a black plastic caps, they are part of the fastening system, the black covers have an M10 thread for wall anchoring, they also contribute to the total reinforcement of the whole chassis.
You can also see how the first chamber dedicated to fullrange speakers is closed with acoustic absorbent material as if it were a sandwich :-)
Step 6: Electronics Second Attempt - the Good One :-)
For all the problems mentioned, and the the first sound tests, I was forced to rethink the project, I was about to abandon it, but in the end I decided to go ahead, even knowing that the only culprit was me for having started this crazy idea.
So I choose a new DAC ALLO PIANO 2.1 with 2 independent outputs configurable as full range or subwoofer, so now I needed 2 amplifiers, this is absolutely a great improve in the project, sounds amazing with outstanding specs as follows.
Dedicated two No’s of 384 kHz/32bit high-quality DAC PCM5142 for best sound quality
Available with different output connectors: 4 x RCADAC
SNR is 112dBDAC THD+N @ - 1dBFS are –93dB
Full Scale Output of DAC is 2.1VrmsDynamic Range of DAC is 112dB
Sampling Frequency ranges from 8 kHz to 384 kHz. (Sample rate is limited to 192kHz, for subwoofer modes - 2.
For the fullrange part I decided to use a scrap commercial NUVO amplifier manufactured by Legrand with the Class-D TDA8932bt amplifier that is about 25 RMS watts per channel, This amplifier works with 30V so I had to add a buck converter step up from 24V (main power supply to 30V
For the subwoofer I choose a mono TPA3118 board
I have to say that at the end the wiring it´s s bit messy but I'm quite satisfied with the sound, forget to mention a secondary switch with a 220v Blue led that closes perfect the Kuggis side hole ;-)
Step 7: Volumio Setup and Final Tests
Since Volumio 2.502 update there are some issues regarding to be able to configure the subwoofer output of the Piano 2.1 DAC, the people of Volumio have commented that it will solve it in a next update, I wrote a mini guide to solve this in Volumio Forum.
With the current version I had to do it manually via SSH look at the guide in page 2 of this LINK so that the subwoofer output would work and be able to determine the cutoff frequency of the low pass filter
The sound is clean and forceful although it fails in the lower frequencies, it is not a Sonos Play 5 but it has been a great challenge that has made me pass good and bad moments.
In next days I will edit this instructable, adding Volumio setup screenshots
it is very funny that just these days I found out that Ikea and Sonos have launched a new series of speakers called SYMFONISK curiosities of life :-)
Check the video and enjoy!
Hope you like it !