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I followed the Hifiberry/Beocreate guide to install a Beocreate amplifier inside an old Beovox CX50 speaker.

https://www.hifiberry.com/beocreate/

Inside it runs HifiberryOS on a RPi 4, which I use to connect to Spotify and serve Bluetooth.

It runs pretty well, but the Spotify connection sometimes needs a kick (reboot) after a long idle period.

The main advantage of HifiberryOS for my setup is that it can control the DAC on the amp directly, including installing profiles for my specific speaker and managing the EQ.

It’s a shame the Beocreate amp is so expensive (£150), otherwise I’d set up a few more of these.

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Sure Audio makes an ADAU1701 set of boards that looks similar. Parts Express seems to carry Dayton Audio branded versions.

Can't say how well they work but a stack of IF board, DSP only, and Bluetooth programmer cost me around £50. Looks like the DAC resolution is better on the Beocreate though. No idea how good the amp is either - there are plenty of bad TPA3116 boards so sidestepping that problem might be worth the premium too.

The DSP is also much better on the beoamp (adau145x, the smaller variant). I run phase correct 250Hz crossovers as FIR on it. The 1701 has way too few taps for that. And the 1701's integrated DAC is considered quite poor.

The TPA implementation is pretty good as well. No audible noise or other obvious issues.

>phase correct 250Hz crossovers as FIR

These are things that make me excited about audio. I just wonder why it’s so expensive and less mainstream. I could honestly roll my own in a matter of hours for a 10th of the price. Why don’t market forces drive the price of proper high-end audio gear down?

I'm under the impression: Because it's all in the marketing. There is no incentive to build a "proper high-end" fully active system for 500 Euro when you're outcompeted on price and marketing by a manufacturer offering a "pretty good but not quite high-end" 400 Euro system that sounds good enough for all but a few (and then you're all of a sudden competing with much more expensive systems as well).

Also, your estimate seems off to me. I don't know your personal background, but prototyping a good-sounding speaker cabinet takes time beyond a few hours. Even more if you're aiming for mass production. Add to that the DSP + n-channel Amp board, this will be expensive, even when building 10000, AND it is not trivial circuitry to design.

Also, "proper high-end" is a relative term. When researching which speakers to build and where to source chassis, I found a nearby "proper high-end" manufacturer integrating realtime measurements of cone movement into their DSP corrections...

The physical speakers are not trivial to properly design and manufacture. The DSP and amplifier is not a headscratcher for any serious EE. The DSP chips themselves are only $10.

I haven’t looked into this space in a few years and I am of the “budget hi-fi” variety. At a glance, it does look like open source choices exist [0]. My last (finished) DIY audio project was an ODAC+O2 and that has been rock solid for 5 years.

Realtime corrections sound nice at first glance, but I’d be wary of the actual effect. It’s best handled with servo in the analog driver. DSP really shines with room and loudspeaker compensation, especially to linearize phase response (at the cost of delay). Room acoustic issues led me down a rabbit hole that ended with me working on a triple BA IEM with a teensy powered FIR crossover. I gave up on soldering wires to a tiny SM connector. It’s on my revisit list. I’ve been knocking some things out this year, so maybe it’ll be up in another year or two.

If only I could just play with toys instead of working :p

0. https://ohdsp.weebly.com/dsp-adau1452.html

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