Portable mpd player

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So I was looking at this overpriced exercise in design:

BeoPlay A2

and I was thinking wouldn't it make sense to build such a thing with a built in mpd player? You may control it via an LCD panel, or even better, from an old phone built into the unit to act as head. An SSD drive could contain a nice FLAC collection.

Then I was thinking of the components needed:
1. Old phone to run the mpd or volumio client. An alternative might be a screen on Beaglebone or rasberry.
2. A rasberry b+ or BBB with I2S
3. The IQ audio or similar I2S DAC
4. A LiFeO lithium battery
5. A power sipping class D amp of some sort, TPA311?
6. The biggest, most efficient speakers that could fit in the enclosure.

Although size is not really an issue (think of the old boom boxes in the Bronx!), it would be nice to make it as small as possible.

Finally, price-wise, it needs to beat the B&O by a mile.

What do you all think?
 
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Jamh I like your idea and that BeoPlay A2 looks intresting but yeah way overpriced tho there is something to be said about the RND that goes into things like that.

I am actually just embarking on making a Sonos Play:1 type speaker. I just want a nice mono portable speaker.
 
5 liters and up is where DIY starts to get interesting. <3 liter takes a lot of DSP'ing, custom drivers/PR's, custom PCB's and careful designing. Can be done, but probably will cost you in the neighbourhood of what a premade one costs. Will be a nice challenge 🙂

Look at the Boominator Micro for example. I'm in the progress of designing a project inspired by the Micro, trading SPL for bass extension. As I'm still learning a lot everyday, it might take a while.
 
Agreed. It doesn't have to be as small, just as small as can be made. After all, we're adding a head, a player and storage. Frankly, I would happily sacrify size for sound quality (larger and more efficient speakers).

Your going into the exact debate I had the last couple of days, what size/form factor would be appropriate. 4 inch woofer vs 5 1/4" woofer etc.

Like you could build the cabinet for your speakers and can get more low end but go with a smaller woofer etc.

Write your self a list of pros and cons and I would say pick you your speakers first that pretty much decides the rest of the components.
 
A Boominator MINI perhaps?

Right, but notice the title of the thread. Why an mpd player vs say a Bluetooth connected phone? Much higher quality sound for one thing. Also FLAC or high resolution audio files, which are large and would overwhelm Bluetooth. If you connect a dedicated FLAC player then you lose the ability to remotely control the player and you are limited in your collection.
 
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So I was looking at this overpriced exercise in design:

BeoPlay A2
Overpriced? 😱

€ 349 MSRP


Can you do something this high Tech, same specs, for less?
Very much doubt so.

and I was thinking wouldn't it make sense to build such a thing with a built in mpd player? You may control it via an LCD panel, or even better, from an old phone built into the unit to act as head. An SSD drive could contain a nice FLAC collection.
Why?
You have all that in your phone, which streams it vie Bluetooth to the Beoplay for reproduction.
Why duplicate`stuff you already have? 😕

Then I was thinking of the components needed:
1. Old phone to run the mpd or volumio client.
It's meant to be used with .... errrrrrr ...... your new phone?
Why also carry an old one?

An alternative might be a screen on Beaglebone or rasberry.
2. A rasberry b+ or BBB with I2S
3. The IQ audio or similar I2S DAC
You are already carrying the functional equivalent.

4. A LiFeO lithium battery
It already has that or better.

5. A power sipping class D amp of some sort, TPA311?
It already has that or better.

6. The biggest, most efficient speakers that could fit in the enclosure.
It already has that or better.

Although size is not really an issue (think of the old boom boxes in the Bronx!), it would be nice to make it as small as possible.
I think it already is ... while keeping that sound.

Finally, price-wise, it needs to beat the B&O by a mile.
A very difficult task.

What do you all think?
See above.
 
You're telling me that you'd be able to tell the difference between 384kbps MP3 compressed file which is the current state-of-the-art for bluetooth audio streaming and FLAC on a set of $20 speakers in a 3-5 liter box?

Bluetooth audio is in fact excellent quality. That there are next to no products that properly exploit it yet is not the fault of the codec. Bluecore5 chips even have the possibility of digital output if you want to supply your own DAC or have an amplifier with digital input.
 
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JMFahey,

I think it can be done 😉

I mentioned some of the advantages of a self-contained mpd player, but here they are again:
1. A large (potentially very large) music collection.
2. High resolution audio files.
3. Better sound reproduction, we can go all the way to 32bit 384khz dacs, although the Pi and BBB would need to do much better than what they do now. I hear that BBB with an external clock might be able to. But certainly 24 bit is doable. And if the I2S interface is used, much intermediary conversions (to USB) is eliminated.
4. A self contained unit, you don't need anything else, although multiple phones can act as clients, not to play their own content but just to control playback.

The idea of an old phone is to run the mpd client, like a on/off, selection, volume control, that's all. But selection of a huge collection does need a screen. However, you can also control the box from other (remote) clients.
 
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You're telling me that you'd be able to tell the difference between 384kbps MP3 compressed file which is the current state-of-the-art for bluetooth audio streaming and FLAC on a set of $20 speakers in a 3-5 liter box?

Bluetooth audio is in fact excellent quality. That there are next to no products that properly exploit it yet is not the fault of the codec. Bluecore5 chips even have the possibility of digital output if you want to supply your own DAC or have an amplifier with digital input.

I agree with the bluetooth sounding good. what bluetooth modules are you/recommend using?
 
I agree with the bluetooth sounding good. what bluetooth modules are you/recommend using?

For extended range capability (up to 100 meters/300 feet range) and good audio quality for a reasonable price it's hard to beat the Sony BM10.

But there's a host of other good products in this overview even ones that offers digital outputs if you happen to have a digital (or digitally capable) amplifier Other Good Bluetooth Music Receivers Review - Portable HiFi
 
For extended range capability (up to 100 meters/300 feet range) and good audio quality for a reasonable price it's hard to beat the Sony BM10.

But there's a host of other good products in this overview even ones that offers digital outputs if you happen to have a digital (or digitally capable) amplifier Other Good Bluetooth Music Receivers Review - Portable HiFi

Interesting! Are you familar with the bluetooth module on parts express?

https://www.parts-express.com/bluetooth-v40-audio-receiver-board-aptx--edr-12-vdc--320-351
 
I fail to see why one would choose to go for an MPD. Just use a high quality wireless music receiver and let everybody play their own music. You won't notice the 'lower' quality of 320kb/s on mobile speakers and you can store A LOT of it on a mobile phone. You can even use spotify and let people add music to your playlist.

All your 'advantages' are not really relevant or real advantages. The lower cost, lower power draw, higher flexibility of a BT/Airplay/whatever unit are BIG advantages that (IMO) far outweigh the advantages of a MPD.
 
I fail to see why one would choose to go for an MPD. Just use a high quality wireless music receiver and let everybody play their own music. You won't notice the 'lower' quality of 320kb/s on mobile speakers and you can store A LOT of it on a mobile phone. You can even use spotify and let people add music to your playlist.

All your 'advantages' are not really relevant or real advantages. The lower cost, lower power draw, higher flexibility of a BT/Airplay/whatever unit are BIG advantages that (IMO) far outweigh the advantages of a MPD.

So you have hijacked my thread. I am not interested in building another boominator. Yes, I can tell the difference in sound quality between a BT speaker and a wired hires DAC.
 
Interesting! Are you familar with the bluetooth module on parts express?

https://www.parts-express.com/bluetooth-v40-audio-receiver-board-aptx--edr-12-vdc--320-351

Yeah. An ok product and would be acceptably priced at $12-15. At $25 it's massively overpriced. Unfortunately output amplifier is set to a much too high gain and it uses the internal DAC in the bluetooth chip which is for obvious reasons not is nearly as good as an even low cost separate DAC as used in the Sony. It's also short range class 2 with 1/10th the range (10m/30 feet max) of the Sony. And the Sony has NFC tap-to-pair.

The Sony BM10 is easily worth paying twice for compared to the Sure module. They're not in the same league... it's an entirely different ball game. Let's not forget we also talking about the difference between a bare-board module and a real finished product in a cabinet.
 
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So you have hijacked my thread. I am not interested in building another boominator. Yes, I can tell the difference in sound quality between a BT speaker and a wired hires DAC.

I haven't hijacked it? Have you ABX tested wire vs wireless once? I can tell you it's very, very difficult.

If you want to take a challenge and go with the MPD, sure go for it. I just stated that I don't see the advantages, and so do some others.
 
I haven't hijacked it? Have you ABX tested wire vs wireless once? I can tell you it's very, very difficult.

If you want to take a challenge and go with the MPD, sure go for it. I just stated that I don't see the advantages, and so do some others.

I would call it a highjack if you take the original idea of the thread out of the thread and turn it into something that already exists. I do thank you for your feedback but what is the point of going on and on? believe me, you'd be able to A/B between:

mp3 on phone -> phone D/A -> BT -> air -> BT receiver -> amp

and:

hires source (FLAC, 24b, etc..) -> I2S -> DAC -> amp

And where is the challenge? Which component? And cost-wise, a BT is around $25. A good DAC same. Yes, there is the cost of the Pi or BBB, but with these you can have a substantial collection on the go. And you'll end up with a system that is self contained. Doesn't require anything else. Don't bring your phone to the beach..
 
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