Ikea Symfonisk Sonos into a desktop monitor

Project SYMFONISK: I appear to have accidentally butchered the Ikea Sonos SYMFONISK into a pair of proper speakers.

A bit of an expensive gamble but HE ROLLS AND WINS!

The WhatHiFi review of the SYMFONISK refers to it as the best sounding bookshelf ever… which is a unique and rarely challenged title on the whole. They sound okay - but they the "half the price of a Sonos" per unit, and this is evident in the sound they produce as functionality is the same.
I found an article where someone was tearing the guts out of one and using a single desktop speaker.

I share an office desk with a 90's Kenwood big-knob amp, and two rather underused AVI Biggatron's on shot filled Atacama Stands I had for my now perished AVI Nu Neutron's. These were my intended prey. It would be ace to end this experiment with two working Sonos speakers, and a chunk of metal off my desk and with the recycling people / new life. Goal set.

The plan was to put a phat hole in the rear, disconnect the high-end crossover, and bi-wire the two drivers to two digital amplifiers in the SONOS compatible SBC. The Bigga-Tron's sport two drivers that still appear to be shockingly expensive within a sealed / infinite baffle enclosure.

Woofer: Vifa C17WG-69-08 91db 8ohm
Tweeter: Scan-speak D2905/930000
Cabinet: Greaves of Sheffield.

The cabinet bears the stamp inside saying Greaves of Sheffield May 1989 - Sweet Jesus these are 30 years old! Wowser. Anyway - the MDF is veneered outside and in. Cherry outside, and unfinished inside grain. High-density mineral boards are attached to the long faces inside, and a vast amount of glass-fibre-like wadding (without the itching hell). This is not a Friday afternoon with a glue gun affair… and losing a little class with me putting a hole in its back.

Having read the article that started it all, and witnessed the size of the heat sink, it struck me that this would need ventilation. The designed Ikea enclosures are ported reflex so they would in essence 'breathe' while in operation. The Bigga-Tron's are sealed. This I am not pleased with. So as a temporary measure I have mounted left the smarts in place, and dragged out two runs of speaker cable via the port, and wired directly to the now disconnected from the crossover drivers - CAREFULLY noting the polarity and the wiring (which is the opposite in terms of colour coding to the AVI).
Reassembling the antiques and firing them up - they sound 'okay'. Then I used the Sonos TruePlay … Oh My God. Okay - this works.

Allowing the wonder of Psycho Acoustics which is quite impressive with a little Sonos Play One lose on a pair of high-end units is something really rather special (replacing one of the four drivers would set me back more than the two Ikea units for perspective).

Ladies and gentlemen - if you are a Sonos home, and you have some underused beautiful speakers - you are inquisitive, not a danger to yourself or others with a soldering iron, and in a position to experiment… then this is a very satisfying thing to do on a rainy afternoon.

Separation, clarity, drive, musicality - hello to you.

3 Responses to “Ikea Symfonisk Sonos into a desktop monitor

  • Hi, great article! I’m currently trying to return a pair of Biggatrons back to standard specifications as mine have been modified, please let me know if you can give any info regarding internal damping like sheet thickness, how many walls it lined or how dense the stuffing was? Thanks,


    • anthony
      3 years ago

      Hello there! First of all my question would be how were they modified?
      There were dense mineral boards stapled to the side panels. I did not mess with them as I had no need.
      I returned all of the wool also. It was weighty, and it filled the enclosure. The kind of quantity you would expect from a sealed enclosure.

      Since this article I have reworked it having monitored the heat sink temperatures. Now having secured the units inside the enclosures, and yes, while this will mess with their internal volume, and the plate in there to keep the airspace separate and…. well the list goes on really – the hardware is now enclosed inside the units. The bass driver is wired to the rear terminal posts also, should I wish to add a speaker level sub at some point. Relying on the fact that my days of dedicated listening space, trailing cables, and dedicated hardware are long behind me. A bit of tuning from the Sonos App and I am a happy boy again.

      My only issue / complaint being the degrading state of the foam around the main drivers. There is only so much the occasional coat of silicone will do for you.

      SO – show and tell – how were yours modified, and how are they now?

      • Hi, thanks for the reply! When I say modified I meant internally since they were different to yours, only being stuffed full of wool and a piece of bitumen on two sides. When I first got them they were dull and flat in sound, the highs were recessed and nothing sounded real or dynamic, this was down to several things stacking up, the foam was old and stiff and I could hear it affecting the music straight away so I sent them off to be refoamed with the correct foam (ordered supposedly correct foam from a German company but was totally wrong and thankfully my speaker guy knew what he was doing) and I ordered the correct type of ferrofluid from a scanspeak dealer. Replacing the ferrofluid was a big improvement since most of the old stuff had dried out but nothing sounded real still so I turned my attention to the crossovers and replaced all the caps for better spec poly caps, I also replaced the internal wiring for jantzen silver plated stuff as it had corroded, I wanted tin plated like the originals but couldn’t find any. I was told to only replace the electrolytic caps but I had to go with my ears as I wasn’t happy with the sound still, turns out they were all ready for replacement as replacing them removed the vagueness and lack of detail and gave me back what I knew these speakers were capable of. Mine are stamped 99 inside and are likely to be the later updated red spot versions. I have spoke with AVI and they were kind enough to entertain my query and confirmed that internally the speakers are correct, two bits of bitumen and 300g of wool and that’s it. I felt the boxes were too noisy at first but since servicing the crossovers and drivers it is pretty perfect. The other issue is sheep’s wool clumps and flattens over time and isn’t as affective as when it’s all fluffed out, spending some time teasing the wool seems to have totally silenced the box. I will say if you can get the correct foams they will sound much better when they’ve loosened up, my old ones where stiff and so the parameters of the driver were altered making them sound a bit dull and rubbish. I’m afraid I don’t know how to put pics up on here or I’d show you the serviced crossovers

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