Hacking the Sonos IKEA Symfonisk into a High Quality Speaker Amp | Hacker News Reader

Hacking the Sonos IKEA Symfonisk into a High Quality Speaker Amp

makezine.com

255 pointsmochtar47 comments

Quite dangerous to leave this without an enclosure, since the power supply is on the same PCB, several of the components and solder points carry mains voltage.

I'm surprised an outlet as high profile as Make don't at least recommend one, or have any of the usual warnings about high voltage.

On a side note, it's no mean feat integrating large through hole components and tiny SMD parts onto the one PCB, normally power supplies are wave soldered while SMD parts need reflow instead, and hence TVs and the like use seperate PCBs. Pin-in-paste[1] is possible, but only with some parts, so maybe they used automated selective soldering[2] instead?

[1] https://www.7pcb.com/blog/the-application-of-the-pin-in-past...

[2] https://www.nordson.com/en/divisions/select/soldering-proces...

From TFA: "... maybe build yourself a nice enclosure for the electronics ..."

At the very end. It also uses the word "maybe" to equivocate on the subject, and describing it as a "nice enclosure" both minimizes the importance and avoids mentioning the very dangerous risks. The sentence assumes prior knowledge on the part of the reader, which even for a site like Make, isn't always the case. People without that knowledge, who weren't necessarily the intended audience, find their way to these sorts of tutorials as well.

That doesn't detract from the article's interestingness by any means, but pointing out at least some of the risks is the sort of thing that should happen more often in them. The off-hand way in which the enclosure was mentioned detracts a bit, in my mind, from an otherwise interesting article. Maybe I'm overthinking things a bit.

IKEA seem to be killing it in speaker area these days. Even as Swede, that's kind of unexpected. I guess they saw a market segment where a lot of wood is used (this one's plastic though), and there were high margins for the premium products and then decided to go for it.

There's obviously a great deal of outsourcing to chinese and taiwanese manufacturers going on here, but they seem to be very competent in the customer role.

I love my IKEA Eneby BT speaker from last year. (This one, with the add-on battery: https://www.ikea.com/us/en/catalog/products/00357636/)

I would love for IKEA to go into the standalone analogue speaker segment with a fantastic living room speaker, just to piss off those (often) European and quite pretentious speaker brands. Take on B&W and the likes!

Eneby is one hell of a speaker for the price. I use a the one you linked to at work for "play along" when a practicing new pieces for the orchestra. Before it I had a hard time finding a portable speaker with enough pinch and battery life with a reasonable price.

This is cool! I wonder if you connected just one of the audio outputs to a speaker with a crossover, the system would adjust to put the whole frequency range through it?

It may also be that there's somewhere on the pcb you can tap into line level full frequency audio (or maybe not - they could easily do the filtering only in the digital domain)

One thing to keep in mind when doing this is the impedance of the speakers.

I'd measure the resistance across the IKEA ones and whatever speakers you're using first. It may be that the IKEA ones are not the common 8 ohms. If they're more (eg 16 ohms) there's a risk that an 8 ohm speaker will result in too much current through the amplifier.

If they're built like other active speakers (studio monitors and the like), the crossover is line-level and there is a power amp for each driver. So any full-range signal you get is going to be at line level, not amplified.

A speakers' impedance has substantial reactances, and the nominal ohmic ratings have little practical meaning.

Almost all modern class D amplifier ASICS have short circuit protection on their outputs

The description of the tuning app makes it almost certain that the crossover is purely digital, possibly integrated with the codec as well.

Fun fact: the author of this piece, Ben Hobby, is the son of David Hobby, the photographer who maintains Strobing, one of the best blogs on off camera lighting: https://strobist.blogspot.com/?m=1

Really thought this post was going to somehow circle around to Hobby Lobby as I was reading it.

Nope, but you can read it while your plane is circling around Houston Hobby airport.

Ugh, Strobist. This is what I get for typing this on my iPhone :-\

Most wireless speakers released nowadays have a digital EQ to compensate for differences in frequency response to simulate accuracy. However the fact that this EQ is now being utilized on a different set of speakers makes this build far from "high quality".

While the little hack is surely fun, this is an underrated comment. The tuning that SONOS speakers do at setup will also not help if the speaker's own signal characteristics are taken into account for generating the system transfer function between input signal, speaker, and room. That's how SONOS, BOSE, et al. achieve a consistent sound in the first place.

So the result with different speakers will be mediocre at best and indeed far from high quality, even with a high quality speaker strapped on to it.

There's very little chance that the crossover filter topology, as well as any biquads in either bandpass are appropriate for a two way loudspeaker other than the original.

Solid looking unit from the teardown, I might have to get one...

This is really awesome! Is there any issues with the mismatch of inductive resistance/impedance of the bookshelf speaker vs the original speakers? I would imagine the board is designed for a very specific ohm range.

Anyone knows how much power that amp can source? Impossible to find any numbers.

He turned a speaker amplifier into a speaker amplifier.

He just pluged in the speaker cables into a different speaker. Started with a speaker and amp all in one box, and a speaker needing an amp. Ended up with a speaker and separate amp in bits on the table, and, if he screws the sonos box back together, a speaker that now needs an amp.

He is now wondering about building a box for this amp. ;)

I would recomend he put the bits back in the box they came in!

Pretty pointless. I've dont the opposite "hack" of mounting amps inside passive speakers, saves on untidy cables.

If you want an external amp for your speaker. Well, go buy one: when you buy it, they will tell you the numbers :)

> If you want an external amp for your speaker. Well, go buy one: when you buy it, they will tell you the numbers :)

Sonos Amp costs $599, so this is an interesting alternative.

https://www.sonos.com/en-us/shop/amp.html

What would it take to connect those two outlets to the line ins of a sub / speaker?

You would have to take the line-level signals from before the power amps, and the crossover is probably around 2500-3500Hz, way too high for a subwoofer.

It looks so much of an overkill on the digital side. A fully fledged SoC with PCI Express and standalone WiFi NIC just to do network, and audio decode?

Chinese factories make such Internet radios on $2 Espressif or Realtek microcontrollers.

It looks like the processor is doing some form of DSP, so some smarts are required. It can also play from Spotify etc. and the binaries for that are probably bloated like most cloud services.

With this said, had this been a lower end product, the SoC would probably have been an Allwinner or MTK with a soldered Realtek SDIO WiFi solution.

What I see on photos is a genuine PCI Express WiFi, just like one you see in notebooks.

And the fact that the module is 3rd labeled, suggests that either Broadcom or Realtek is involved

Why do you need PCIe WiFI for audio?!

> It can also play from Spotify etc. and the binaries for that are probably bloated like most cloud services.

One of my favourite things about my Sonos setup is that it avoids me having to run bloated cloud service binaries on my personal computing devices. (Most notably, of the services I use, SiriusXM digital services have always been most unpleasant to use.)

That's what made me ditch sonos 4 years ago. Being forced to run everything through the awful Sonos app instead of casting from the dedicated app or playing through Bluetooth without any delays.

What do you use now? Seems to me like the only decent solution is UPnP.

Last I checked, the Sonos app is better than the SiriusXM app. Not that I use it much anyway, I mostly use Sonos/Sirius via Alexa control.

But the cost of that convenience is in giving random devices full access to both your LAN and the Internet.

You could VLAN them into a separate audio-devices network and whitelist their Internet access but the effort in doing that would seem to outweigh any advantages of network audio devices.

Sometimes a dumb, network-unaware Bluetooth audio sink just works...

I've never found either Bluetooth, or the Sirius app to "just work". And Sonos is an established company, their speakers aren't "random devices" in the same sense as random IoT devices from Amazon.

Worth noting on the wireless side that this unit, if plugged to Ethernet, will create a dedicated SonosNet network your other Sonos speakers would then automatically join. So it’s not just a client, it’s also a base station.

And it does some signal processing to make sure all the audio across all the Sonos devices is playing in sync. And there’s a mic in there that is used to tune the audio to the room it’s in, etc.

Much more than just playback.

Clever. Don't go frying the amp hooked up to those big towers. :)

IIRC the only way to fry an amp is to hook it up with no load. Putting not enough load will fry the load when the amp overdrives it, putting too much load will simply make for a quiet speaker.

Really dependance on the kind of amp you tot. For older tube amps, this is a major concern indeed because they drive by current, not voltage, thus exploding the voltage when there’s no path for the current to flow. Modern class D amps don’t have this problem, those just hate short circuits as they drive by voltage.

That's not correct. These are class D amps. No load = no current flowing.

Too much load (low ohmage speakers - things that dip below 1.5ohms for extended intervals) means too much heat dissipated as switching current in the amplifier IC, which burns out a driver FET or some other part of the silicon die.

Wasn't SONOS already exposed for being a CIA front? Like streaming the audio encrypted to a receiver station. I would have expected the hacker looking into this instead.

This speaker is conspiracy-theory-proof: it has no microphone

You don't know. Traffic is encrypted and articially enlarged with some spooky Mesh Networking talk.

And one of the founders got caught.

The speaker itself could be turned into an one giant microphone.

I find it odd to have a hacker project that connects to a proprietary ecosystem (Sonos). In general, I'm disappointed that Ikea went with Sonos, it's not very "people and planet" to be dependent on one company and app to enable different sound ecosystems, without even a Bluetooth option.

I don't think there's any alternative open standard that can do what Sonos does - group speakers arbitrarily, do line-in without requiring separate computers/phones, auto-balance speaker volume/lag for room positioning, have the same speaker set switch between surround sound and other inputs with minimum hassle, etc, and all wirelessly without a specific server hub needed.

There are proprietary competitors (Alexa is moving into that space, and Bose has an even more expensive equivalent), but nothing to allow true interop, and Ikea trying to build out that same functionality from scratch would take huge effort and expense, certainly a lot more than the simple-by-comparison requirements of smart bulbs.

Personally, I'd be happy to see Apple eat everyone's lunch here (they're already partway there with arbitrary speaker output from arbitrary input devices), but that's mostly because there's preexisting homebrew that will that bridges arbitrary speakers to virtual Airplay devices and arbitrary input to virtual Airplay streams.

> preexisting homebrew that will that bridges arbitrary speakers to virtual Airplay devices

Got a recommendation?

Some examples, including both software and dedicated hardware options:

https://www.makeuseof.com/tag/4-airplay-receivers-that-are-c...

https://github.com/philippe44/AirConnect

https://www.airserver.com/

https://github.com/mikebrady/shairport-sync works great. I've been running it for years.

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