Raspberry-Pi-Play-It-All-Luxury-Bamboo-3-Way-Musicbox Projec


Note: I also posted this in the diyaudio.com forum. Since there´s a higher chance
that I can be better helped with my volumio specific questions on this forum,
I also post this here. Also, I think that it might be interesting for you guys.

I started sourcing parts for my latest project and I would like to hear some
feedback from you guys about whether I am on the right track or not so…
To justify some of my picks, first I wanted to use some parts I have anyway, like
the 5" display, the Pi,the bamboo front plate, the OLED display,… and second, I am a polymer materials
scientist guy and therefore I am totally into Aramide speakers and fancy Polyimide AMTs … :mrgreen:
I also wanted quite some high quality sound without paying more than 200€ for
the whole thing.

I have a CNC router where I am going to carve the Bamboo wood plate and metal front with.

Ok, so here’s the mockup I made since I wanted to see how It’s going to look upfront without doing too much CAD work first:

Ok, first let’s start with the speakers:

I have chosen this woofers which I have a mixed feeling with, first they are quite
cheap, have a good size for the project and they look damn sexy , on the other hand they might not be as Hi-Fi as I wanted it to be … let’s see.

Skytronic 5 1/4" Woofer, 100W RMS, 8Ohms, Range: 35 Hz – 8 kHz

As for the midrange/full (let´s see If I use filters) I am going to use this (I don´t know if its original H/K or chinesium fake):

Harman/Kardon 2 3/4", 12W RMS, 6Ohms, Full-Range

And for the highs, I fell in love with this little beasts:

No-Name Polyimide Ribbon (“Air Motion Transformer”) 2" , 15W, 8Ohms, 3,3 KHz-40 kHz

I have little knowledge about speakers, but to me It looks like this combination
will be useable. The “full spectrum”/midrange could be driven with the full
spectrum or just the mids… I have no clue what´s better in this case.
Also, I will use two 2.1 class-D-amps which have a crossover built in (can be
adjusted too) and so the bass is already separate. I could then put the full sound
range straight out of the amp to the full range speakers and then use just one
highpass for the AMT-tweeters. Would that be feasible?

Let´s see what I will be using as an amplifier:

TPA3118 2.1 30W/30W/60W Digital amplifier
I have chosen this since the new TPA3116/3118 have excellent reviews and seem
to be superior to the already good TDA7498 class-D-Amps. The advantage here
is that it has an active crossover already built in, so I will be using two of this
which will give me 4.2 channels (with stereo audio off course). So I have 2x 60W
for the woofers and 4x30W for the rest, which is more than I need. I am not sure
if I will use two channels for the tweeters and two for the midrange or just use
two channels and omit the unused two.
See picture:

I think I need some advise at this point since I am not quite sure if this is a good
Idea or not.
Maybe an other amp? Different wiring? DSP? Crossover?

Next up is the DAC. I already have this one:

HifiBerry DAC 2.0 clone with TI PCM5122 silicon:
It produces great sound and I am satisfied. Had this part already in use and so I
will likely keep using it. I have an eye on this one:

I2S DAC with AK4495SEQ silicon:
aliexpress.com/item/AK4495SEQ-D … 01584.html

So, I am not sure if this will actually make a difference with the complete setup.
The DAC seems superior, I could swap opamps If I wanted and such. But I am not
sure If I would actually hear a difference for twice the price. Advice?

For the other stuff, I have a yellow 128x64 OLED screen which would display
track info or an EQ or so… Had this in my parts bin and never found a use for it.
on the mockup it looks great.

The raspberry pi is either going to be a pi1 model B rev 2.0 or a pi3. I have both
and initially wanted to use the pi3 since I thought the pi1 model B didn’t have an
I2S port. It turns out that the pi1 rev 2 DOES have an I2S port, although there is
no header. I would have to solder it.

Does anybody have experience running volumio on a pi1? I think that using the pi3
instead of the pi1 would be overkill for just a music player and the pi1 is unused
anyway at the moment, so It would be a shame not to use it. So it´s likely going to be
the pi1 which should be fine for volumio. Btw, I want to use Amazon Alexa with it
too. Amazon recently opened the Alexa API and it can be used on DIY projects.

As display I use is this:

5 Inch Touch Screen HDMI 800x480 TFT:
amazon.co.uk/d/Computers-Ac … 013JECYF2/

I am already using some for several projects and I am happy so far. Colors are a bit on the washed out side since it´s no IPS panel but for the price It’ s fine. Size is about perfect for this project.

Knobs and “glue logic” will be made as I go. I will also be updating this thread and make a bit of a log here.

So, before I just start and fail, I first wait and hope for some feedback and possible better ideas regarding amps, speakers, wiring and such.
What do you guys think? :open_mouth:

Best regards, Phil

Hi Phil,
quite a project you have there!! Meet Squeezebox Boom Plus :astonished:
In case you want to make full use of your woofers you might want to look at the Piano 2.1 DAC offered by Allo.
I know, it might top your budget in the end, as you would need an extra amplifier too.

Keep us posted, very interesting…

– Gé –

It´s a miracle!

THIS is the DAC I have been looking for all day!
I actually saw that thing yesterday and today I spent thinking some time about how I would end up filtering for the speakers and thought: DSP would be cool :slight_smile:
Then it came to my attention that I saw this thing yesterday but couldn’t find it anymore.
As I said, It´s a miracle! Thanking for pointing me at it without me asking you :slight_smile:

Question: Would it be possible to run the Piano together with another i2s DAC? In parallel so to speak?
This way I could have two DSP´ed DACs for lowrange and highrange and one DAC that gives out just the plain unaltered audio?
In theory, i2s is a one-way street, right?

Answer :sunglasses: : I don’t think so, but you could pose this question in the DAC section for people like @allo to answer.
Perhaps he has an idea, they are really into DSP and corresponding issues.

– Gé –

I want to build this.