HiFiBerry 

Upgrading classic passive speakers

A lot of people still have classic speakers standing around somewhere but they aren’t used anymore as the old stereo system doesn’t support modern streaming services or Bluetooth audio. That’s a shame. Luckily if your a DIY guy, it’s quite easy to add a Raspberry Pi to implement things like Bluetooth audio, Airplay or Spotify. You might have seen already the Beocreate 4 channel amplifier. That’s the premium products to upgrade your speakers and even improve their sound by using an individual sound profile. However, specific DSP profiles are only available for some B&O speakers. If you’re not a DIY speaker guy, it might be a bit complicated to create your own DSP profile with the correct filter settings. Maybe you don’t even need a lot of output power (the Beocreate 4 channel amplifier can provide up to 180W). For a desktop audio system for your computer, even a very small 5W amplifier will do the job just fine.

In this post, we will show you 3 different methods to upgrade an older speaker with a Raspberry Pi and a HiFiBerry sound card. We will use the same speaker and the same software on all 3 systems. The speaker we’re using here is the Beovox CX100. Why? Because we just have 3 pairs of these laying around here which makes it easy to compare them. All 3 setups support Stereo, but will require a cable between the master speaker (with the integrated electronics) and the slave.

While the Beocreate software offers a new GUI to setup the system and change settings, it does not support the HiFiBerry MiniAmp and Amp2. Therefore, for this comparison we will use HiFiBerryOS. It doesn’t come with a nice GUI, but the only think we need to do here is setting the WiFi parameters (SSID, password, country) and the system name. If you can handle a text editor, you should be able to do this. For an initial setup it’s good to use a Raspberry Pi connected via Ethernet as this usually runs without any configuration (as long as you have DHCP available which is the normal setup in home networks).

The cheap one: Raspberry Pi Zero + HiFiBerry MiniAmp

Can a small 2x3W amplifier a mid-size speaker as the Beovox CX100? Let’s try it. To hold the Raspberry Pi Zero and the MiniAmp in the CX100, we created a small cradle that can be printed on any 3D printer.

TODO: Pic cradle in speaker

Opposed to the Beocreate setup that completely replaces the crossover with a new digital one, with this method, we’ll re-use the existing crossover. However, it needs to be removed from the external speaker connector.

External power supply will be a standard 5V/2.5A Raspberry Pi power supply.  Using a standard Micro-USB power connector also ensures that nobody plugs in an 18V power supply which would destroy the system. However, I couldn’t find any affordable screw-in type Micro-USB jacks. Therefore I needed to use a Dremel and lots of hot glue to make sure the system is airtight.

TODO: Pic power connector

We use the existing speaker connectors to create the connection to the other speaker. While the speaker DIN jacks used in this speaker aren’t popular anymore today, you should still be be able to get these at any larger electronics retailer.

The good thing: As the system is very small and dissipates very few heat. This allows us to the full set of the original damping material.

How does it sound? Not too bad. If you think that this runs on components that cost less than US$40, it’s pretty cool. The speaker won’t be able to run at its full volume, but this is often not needed. Think about using these as Bluetooth speakers for your PC or laptop. It is totally powerful enough for this! You wouldn’t use it for a party, but it’s a good setup for desktop use or even small rooms.

The mid-class solution: Raspberry Pi 3A+ HiFiBerry Amp2

As the maximum volume with the MiniAmp is a bit limited for a larger room, let’s now use the HiFiBerry Amp2 which provides up to 60W power. Will the be enough? Again, we created a special cradle that hold the Raspberry Pi and the Amp2 in place. As we’re not using the USB and Ethernet, we used the Raspberry Pi 3A+ for this.

TODO: Picture: cradle in speaker

This time, we added barrel jack connector to the back of the speaker to connect an external 18V/3.5A power supply.  You only need to drill a hole, no glue needed.

TODO: Picture power connector

How does it sound? Now we’re talking! The maximum volume is good enough for a normal room. Depending on your neighbours it might even be too loud for them. The speaker sounds as it always did. For desktop use, this is already too much power, but if you want to use it in your living room, this is the way to go.

The High-End solution: Raspberry Pi 3 + Beocreate 4 channel amplifier

Can this still be improved? Let’s try the Beocreate 4 channel amplifier.

How does it sound? Wow! This sounds like another speaker. With the specific customised speaker profile, low-frequency is greatly expanded. The speaker sound like it would be much bigger. While the volume is similar to the Amp2 setup, the additional low frequency boost makes a big difference here. Note that this has nothing to do with the amplifier itself, but with the new DSP profiles provided by B&O. If you’re setting something up with a non-B&O speaker, the Beocreate 4 channel amplifier will sound quite similar to the Amp2.

Why didn’t we use the newer Raspberry Pi 4 here? It’s simple: While the Pi4 is more powerful, it also consumes more energy than the older Pi 3. This doesn’t just mean that your energy bill will go up. The bigger issue with this is that it also runs a lot hotter and cooling is a bit more complicated. As we installed it in a small speaker without any additional cooling, the Pi3 is the better choice here. For the kind of software that runs on this system, even the single-core Raspberry Pi Zero is powerful enough.