Turn any hifi speakers into bi-amped Sonos speakers (with optional sub) by hacking Ikea Symfonisk

[@todd.parker]

Hi all - I created a new video with details and wiring diagrams for bi-amping here: kzbin.info/www/bejne/b3PZoJlmnatngqc

[@user-pi2nl6iu2n]

Lovely demonstration. No way am I going to buy the £700 Sub now!!!

[@todd.parker]

Nice to hear this was helpful

[@ytbengpf]

Very interesting video (the others too). I am currently running Elac FS 67 (3 drivers, 6 Ohm, no Bi-Amping unfortunately) powered by Yamaha RX-497. I am not sure if the power of one Symfonisk is sufficient for one FS 67. What do you think?

[@todd.parker]

From what I can see, may be a 2.5 way speaker where one woofer is crossed over at 500hz so they both run in parallel below that. The Symfonisk is good for bi-amping so this might not be a great fit unless you direct wire the tweeter to the symfonisk amp and run the symfonisk woofer amp to the passive crossover for the woofers. You could try simply wiring the 2 woofers in parallel and hooking it to the woofer amp and letting TruePlay sort it out too. Give it a try and report back!

[@ytbengpf]

@@todd.parker I just tried and I can confirm that it works wonderfully. Tried up to 70% volume which is enough for me.

[@todd.parker]

@@ytbengpf awesome. I feel like 70% is about where the amp starts sounding harder for me too, might just be it’s limits. Glad that worked! How did you wire the woofers?

[@ytbengpf]

@@todd.parker Parallel. So, 3 Ohms. Volume is perfectly fine for me. Crystal clear sound. Way better than with my Yamaha Amp. Trueplay magic. Can't wait to get a second Symfonsik and run stereo.

[@geoffsmith117]

Great video, but what impedances can the Symfonisk handle?

[@todd.parker]

I'd stick with 4-8 ohm driver loads to be safe but I don't know the specs.

[@geoffsmith117]

@@todd.parker Thank you.

[@miguelsobejano3692]

Hi. Great video! Do you think that it would it be possible to drive a small (8”/10”) passive subwoofer from the woofer speaker level connector?

[@todd.parker]

That’s a good question, I bet it would. I believe this is a good quality 50w amp.

[@bradfordchild9036]

Where do you think the Sonos XO is? Or do you think trueplay can alter the XO? I have bookshelf speakers where the XO is at 1000hz and others where it is 3000hz. Is one more compatible for biamping with the Sonos? I also have bookshelfs where the tweeter volume is reduced by the crossover to mate with a less efficient mid-range. You seem to be suggesting that if I remove the XO from different pairs of bookshelf speakers and biamp with the Sonos, trueplay will optimize the XO and dampen the tweeter as necessary? Am I understanding you correctly?

[@todd.parker]

I think it’s around 2-3k. Trueplay won’t optimize the crossover frequency but it will EQ the drivers for a flat response so it will compensate for differences in driver efficiency and response. What you don’t want is a passive crossover in the path since dividing between the woofer and tweeter happens pre-amplification. If the speaker that has a 1k crossover has a large driver that will struggle to get up to 2-3k, that might sound rough but most 2 way speakers are crossed over at 2-3.5k so the Sonos bi-amp set should work well. I guess a fragile tweeter than can’t operate that low is also a potential problem to keep in mind but that’s atypical

[@BobTurgeon]

@@todd.parker I did a real time analyzer run on this and the notch is very close to 2.5K. There is also a low freq notch placed under the assumption that the original small woofer is being used. It looks like the crossover is 2 simple preamp input side X-overs created on the channel input stages for L and R. With the chip pack input impedance it should be possible to alter the actual X-over for both HF and LF outputs. Still hunting down the notch filter . It maybe based in truplay, but I suspect it is a the .1 feature on the chip itself.

[@todd.parker]

@@BobTurgeon very interesting, let me know if you find more. Is your impression that it rolls off the bass or is or just reduces the level a bit? When I connected a sub, I was seeing some surprising deep bass

[@na6464]

Hi, I want to try this setup with some KEF in ceiling speakers I have, but the kef speakers only have one “binding point/port” model Ci160ER on them, but you examine them closely it has a tweeter and mid woofer sitting on top each other, any idea how I could set this up?

[@todd.parker]

On the ceiling speakers, you want to disconnect the woofer and tweeter terminals from the passive crossover on the back and direct wire each driver from the amps in the symfonisk. Details in my latest video: kzbin.info/www/bejne/b3PZoJlmnatngqc

[@earlfenwick]

When you did your hack with the subwoofer, how did you specify the placement of the symfonisk in the sonos app? Did you set it as a rear or front speaker? Was it setup as a seperate room? Subscribed!!

[@todd.parker]

I haven’t used this in a home theater setup but I’d suggest grouping the symfonisk to your HT room if you’re using it just as a sub gateway. My hunch is the rear channels don’t have enough low frequency signal to be worth it.

[@earlfenwick]

@@todd.parker Thanks Todd. In surround mode the rear channels give you the option of ambient or full volume signal so that might be a mitigating factor. I have never ever been interested in the surround sound thing until the last few days, but now I am. it's fun and it works great with normal stereo mixes. The living room and kitchen are basically one room, so sitting on the couch the sound was great but I am usually in the kitchen and only got a sideways stereo image. Now I get much better sound off-axis.

[@todd.parker]

Yeah a proper surround setup is great. I should swap my play 3’s with the symfonisks to test the sub behavior...

[@earlfenwick]

@@todd.parker I can't wait to dig into these ikea boxes.

[@drsureet]

Hi Todd, awesome stuff and video. i want to try it with an active sub. do you think there would be any audio lag between the symfonisk and the sub? thanks

[@todd.parker]

Nope, none at all because it’s analog

[@drsureet]

@@todd.parker thank you !!

[@todd.parker]

Hi all - If you're going for a 2.1 system with sub, I've put together a list of recommended subwoofers on Amazon for ~$100: Polk 10" - amzn.to/2RcWV1q Monoprice 8" - amzn.to/3696umd Monoprice premium 8" - amzn.to/2Rdl73O Acoustic Audio 8" - amzn.to/2TVfCZt Note: any subwoofer will work as long as it's amplified and has speaker level inputs - if it only has RCA inputs, look elsewhere.

[@florentvg8535]

Hi, this is great. I just bought two symfonisk, and i would like to try to dissassemble those and use the electronic from it to power DIY speakers. I have a DAYTON AUDIO DC130B-8 woofer and dayton audio nd16fa-6 tweeter. Will it work ? I have no filter or crossover with those drivers. I just happen to have those around, worth the try ?

[@todd.parker]

Florent Van Goidsenhoven If those are around 8 ohm drivers, they should work great. One thing to be careful of is the tweeter is only rated down to 3,500hz. I’m not 100% sure of what the crossover frequency is but it seems somewhere between 2-3k so it’s possible the tweeter may be working hard, just listen for distortion if you turn it up. Be sure to use Trueplay, it should make a big difference.

[@florentvg8535]

@@todd.parker Thank you, I will come back with the result ! I'll try to do some measurements.

[@florentvg8535]

I just tried it in free air and tested the frequency response. No trueplay yet, it works, and pretty good too !! :-) thanks for this video.

[@florentvg8535]

Done the enclosure, closed one. this is via wifi and the measurement was with my samsung and sprectroid app ibb.co/YhvRG5t ibb.co/vkmJWXZ ibb.co/F6RJnw7

[@RiderLiving]

Amazing work. Gonna test this with some old pioneer bookshelf speakers. What's the impedance of the original drivers? How far off can you go from that?

[@todd.parker]

I have a video where I cover the driver and impedance measurements but if you stick to loads in the 4-8 ohm range and run trueplay, this will work well for most speakers. Higher efficiency is better, these amps are pretty small.

[@magnusnielsen2648]

thank you for your excellent videos on the symfonisk speakers:). at the moment I am planning a home audio system... I have a few questions :) do you think that the lamp model and the bookshelf has the same amp? How/where did you find the power rating of 50w for the bookshelf speakers? I would like to be using a 8" 8 ohm seas driver and a tweeter for each symfonisk bookshelf speaker (with an active subwoofer box) tho I wo´nder if the setup is going to be able to play loud enough for lets say a home party?

[@todd.parker]

I think the bookshelf and lamp speakers have the same internals, also the same as play 1. I feel like I saw 50w somewhere, maybe 25w x2.m but it’s all a guess. Since these are smaller amps, higher efficiency drivers are best but if you don’t need super loud even lower efficiency is ok

[@magnusnielsen2648]

@@todd.parker just checked the woofers and they are actually 4ohms. But how loud would you say You were able to play with the focals and the klipsh?

[@todd.parker]

The focals probably only hit 90db or so but they are small, inefficient and have no bass. The Klipsch get really quite loud and dynamic, even at 60-70%

[@FlabberQuestion]

So the switches on the back of the Sonos turns the internal woofer or tweeter on or off? If we focus on the woofer switch for example. This means you can have a signal going to your external woofer and symfonisk woofer when turned on. While turned off only the external woofer works? Why would you want your external and internal woofer work at the same time? Wouldn't it be more conveniant to have a switch turn off external and turn on internal and the other way around? Meaning only one woofer at the same time will work? Or am I missing something here?

[@todd.parker]

If you just want to add a sub to your symfonisks there is no need for switches. I added them to allow me to turn off the internal drivers when I want to either use the internal amps to bi-amp and external pair of speakers (see my video on that) or if I want to just use the synfonisk to connect a sub but don’t want the internal drivers to play so it basically acts as a gateway.

[@FlabberQuestion]

@@todd.parker HI Todd. Yes I understand why you did it. But this would mean if you hooked up your external speakers (let's forget you have a sub and hooked up directly to bi-amped speakers) and not put the switch in the correct mode you would have your external speakers work and internal symfonisk. Correct? I think a On-Off-On switch would be better in this case. One plus wire would come off the symfonisk speaker and connect to the switch (the switch has 3 connector points in this case) then one wire goes to the symfonisk plus and the other to the speaker terminal plus. That way only one speaker would work at the same time. Without having to remove the external speaker cables for example.

[@todd.parker]

Flabber Question That scenario is why you’d want a switch, yes, because the symfonisk amps couldn’t driver both internal and external drivers well and you probably don’t want that anyway. I suppose a 3 way switch might be better but Here’s how I wired it: I disconnected the wire from the amp and hooked that to the binding post. I then jumped the positive wire from the binding post back to the woofer. I did the same for the negative but cut the wire and attached a two pole switch in between. In the on position it completes the circuit and the internal driver turns on. In the off position the internal driver is disconnected. The binding post is always “live” but you can choose what to hook to it

[@thomasposborgmunster8669]

Hi Todd. I was wondering, by hacking the ikea speaker I end up with a bi-amp amplifier - how can I then connect that to a 2-way speaker?

[@todd.parker]

I cover the wiring in detail in my Sonia hacking guide video

[@soanis6362]

Hey There, very inspiring hack! question: after the trueplay setup it is mentioned as a comment that the more you listen to the music, the better the sound will get. Does this mean that the mic will be constantly used on my phone? Any clues on that? Thanks in advance!

[@todd.parker]

No, I think that is just Sonos saying that as you acclimate to the new tuning, it will sound better to you. HomePod and the Move both constantly adjust for the room so they are listening in some form but ara are Trueplay shouldn’t be

[@soanis6362]

Todd Parker weird to me. I have the Sonos One SL without any mics on it. Moreover I think I read somewhere on reddit that android users could notice the use of their phones mic when the Sonos app was open in the background. Perhaps Android users can confirm this!? Thanks again

[@suparnollie]

Hi, do you think the IKEA speaker can survive driving the internal elements as well as one 40w element on each? At the same time? So a total of 4 elements with the internal and the external at the same time. No problem right?

[@todd.parker]

That’s hard to say without knowing the impedance of each driver and if you’re wiring in series or parallel. If these terms are new, don’t connect all that stuff :) In general, the driver load needs to be 4 ohms or greater to avoid overheating the Symfonisk amps. If you’re using the internal woofer (4 ohms) and connect a second 4 ohm woofer in parallel (positive to positive) that will half the impedance to 2 ohms which would be bad for the amp. In you connected them in series, it would be 8 ohms which is fine.

[@suparnollie]

@@todd.parker Thanks for the answer! My idea is to connect a 5" 40W 8 ohm on the tweeter and a 5" 40W 8 ohm on the woofer. Both of them are installed in the ceiling in the bathroom and have separate cables and I would like them to be connected to my sonos-system. And the Symfonisk is going to be in another room where I could use the internal speakers from the Symfonisk, at the same time. You think this would fry the Symfonisk? Thank you for all the help!

[@todd.parker]

Andy R I think that might stress the amps too much, yes. More importantly, I do t think it will sound very good because you’d have a 5” driver trying to reproduce tweeter frequencies. The bu-amp technique works best if you’re tiring off the internal drivers and wiring the amps up to another pair of passive 2 way speakers. Full range speakers aren’t a good fit for this.

[@mikevg]

Any idea what the crossover frequency of the active crossover is? Can the focal midbass driver handle the mid high?

[@todd.parker]

It unsurprisingly seems to be in the 2,500-3,500 range. My Focal mid bass seems fine up to there since it’s only a 5.5” driver. The speakers sounded a bit dark at first but Trueplay fixes all that

[@MrShimai]

Love this id, and like to use this as a 2.1 on my Loewe L1 speakers (don't know how and if i have to remove the internal crossovers). But here's my question, and Perhaps a real stupid one, how do you generate a stereo sound? Is speaker 1 modified as a left channel and the other one as a right channel?

[@todd.parker]

Yes, that’s exactly it. You use a symfonisk speaker for each channel. You can add a sub too

[@MrShimai]

@@todd.parker Thnx Tod, I'm a bit scared about opening the Loewe speakers for diasembling the crossovers! | I thought there was a video from you about the wiring in the Sonos but can't find it anymore. Soryy for al these questions.

[@todd.parker]

@@MrShimai Well, it it helps it's less about dissembling and more of a bypass. You just straight wire from the driver to a binding post. More info in my newesrt video on wiring: kzbin.info/www/bejne/b3PZoJlmnatngqc

[@thunameet]

Thanks a lot for this genius solution & insctructions! One more stupid question: How exactly do I set up one speaker for left and one for right when it's not connected to an AVR and I just use the sonos app/stream?

[@dagwallander9265]

Great video! What app do you use for measuring frequency response?

[@todd.parker]

There are a lot of these in the App Store but this is the one I have: apps.apple.com/us/app/spectrum-analyzer-rta/id490078884

[@fotvalas]

And what about the watts of the woofer , tweeter can handle? We must know that to prevent using too low power.

[@todd.parker]

Power handling and efficiency are both factors but trueplay will normalize the levels. Most of the time, you’re using a fraction of a watt. If you have low efficiency drivers, the amp may not get very loud before it distorts but I’d be surprised if the is too much power. It’s only a 50w max amp

[@fotvalas]

@@todd.parker I was thinking if we underpower our speakers. That's why we need to know the efficiency dB and how match power of the original IKEA speakers to match with the knew ones. Its good that we know the ohms.

[@todd.parker]

@@fotvalas my hunch is the drivers are pretty low efficiency, maybe 86-88 (esp the woofers) so I’d expect most speakers would be ok. My Klipsch are super efficient and it sounds amazing so, if you can, use more efficient drivers since it’s a pretty small amp

[@quidryan]

Do you have any picture of how you wired the switches, internally?

[@todd.parker]

I don’t but I basically just cut the wire (can be the + or -) and wired it to each side of the switch so it’s in the middle of the flow. Super simple if you get a DC switch.

[@iladdiewhiskynerd4924]

Hi! Do you have any idea how many watt the amplifier can produce inside the ikeas?

[@todd.parker]

They don’t publish specs but the guesses I’v heard are in the 30-50w range so pretty solid for most speakers unless they are very inefficient

[@MartinmelchiorBe]

Excellent idea and analysis. Thanks! I think I'll use this hack with ceiling speakers.

[@unprezz]

You will have to bypass the internal crossover in the ceiling speakers. I my crossover was hard to get to without destroying the speakers. I ended up changing speakers to make it easier.

[@Inneper]

Awesome hack. Have you compared the sound to the Sonos connect amp or Sonos amp? I assume those are better amps but with the lack of trueplay, maybe not?

[@todd.parker]

I have the older amps but it’s hard to compare these as you said. I think the bi-amping and Trueplay (and price) makes the symfonisks appealing but the connect or amp will be cleaner and more powerful

[@alvieben89]

Would I be able to hook up 1 Ikea Symfonisk to power 2 speakers? I plan on using 1 Ikea Symfonisk (amp only) to power 2 in-ceiling speakers rated at 8 ohms each. Would this work?

[@todd.parker]

In theory, yes. If you connect them in parallel it will be a 4 ohm load. I wouldn’t push the amps too hard because that is going to be a bit stressful for them to handle if you crank it up but for normal listening, I’d guess you’re ok. Honestly, I usually listen at a level that uses 1w or less

[@todd.parker]

Remember, you need to disconnect any passive crossovers in those ceiling speakers

[@alvieben89]

Also, do I hook up the 2 in-ceilng speakers in parallel to match the 4 ohm woofer in the Symfonisk? or in series (16 ohms)?

[@todd.parker]

I’d do parallel

[@earlfenwick]

I've got a beam and two symfonisks and be loving them. The Sonos app sold me on this system after fighting with the AudioPro app for a couple days. I am thinking a next step could be to just move the guts of the ikeas into the belly of the old speakers. Hmmm.....

[@DjFugazi]

Would you be able to take out the hardware components from the Symfonisk and put them inside a bookshelf speaker with only one pair of binding post, I.e. regular speakers instead of two pairs (bi-wiring)? How much room would you need to fit everything? I've a couple of q acoustics 3020 that I'm willing to take apart...

[@simonbeasley989]

I have just done similar to install Sonos in the bathroom. Bought Symfonisk and a pretty cheap Adastra ceiling speaker. Had to slightly rewire the speaker to give separate woofer and tweeter terminals but ended up spending less in total than a Sonos One SL and it sounds great.

[@todd.parker]

Cool, yeah you can bypass the passive crossover on those and bi-amp them with the Symfonisk. How do they sound? Do you run true play?

[@simonbeasley989]

@@todd.parker I don't use Trueplay but sounds really good, way better than expected especially as I only bought a cheap speaker on the grounds it's only for the bathroom. Goes way louder than I need too! The speaker is an Adastra C5D 5.25" costing around £20 in the UK. It is described as having a directional tweeter but it is just a gimmick that you can adjust the angle, in reality it spreads the treble well.

[@quidryan]

Success! Thanks for your guidance Todd. I ended up using 18AWG wire and it was a nice match for the existing wires. I used twist nuts caps to attach the wires, which did work, but I found them rattling around inside, so I had to use a glue gun to attachment them the case. I'm not sure if it would have been worth soldering the wires together. Matching up where to drill holes for the posts and switches were a little problematic, mostly because the DC capable switches were so big.

[@todd.parker]

Awesome! So you even added switches, eh? It’s nice to have a lot of flexibility to re-configure but I agree it’s tight to fit everything. Hot glue always saves the day! I figure most people will just add the subwoofer output binding posts but it’s good to know you were able to get everything done.

[@fwiler]

I like this and may try it. But getting the new Sonos amp might be the way to go as there is no hacking involved for the speakers or the sub. Of course you pay more for convenience.

[@todd.parker]

Yep, that's your choice. This technique is best for making a 2.1 or 5.1 setup with Symfonsks, or bi-amping a two way set of passive speakers (and adding an optional sub). If you need line in/out or amplification or don't want to open up your gear, the amp or connect is a better option.

[@holly160684]

Thanks, very interesting. I guess it's not possible to build an audio jack input into the Symfonisk?

[@todd.parker]

Not without more advanced knowledge and soldering into the board. It may not even be possible to get a full range signal since it splits it for the low and high frequencies digitally.

[@steveduvall3137]

@@todd.parker what you might consider is getting a pair of usb to ethernet adapters and plugging bluetooth dongles into them. How to get separate left and right channels via the 2 dongles? I haven't worked that out yet...

[@steveduvall3137]

... If the ethernet ports don't have power, they can't power the dongles. Maybe network the 2 speakers to a single board computer like a Raspberry Pi. From there, the worlds your oyster.

[@todd.parker]

steve duvall Interesting ideas but I think Bluetooth would add quite a bit of delay and by the time you buy those adapters you’re probably better off getting a Connect.

[@felixlaboy1453]

Great video buddy. Do you think it would work with a set of B&W D602

[@todd.parker]

Sure, those are two ways and even have dual binding posts. You’d just want to straight wire from each driver to the binding posts to circumvent the passive crossover

[@denischo2964]

Could you please explain why the crossover would need to be removed from the speaker.

[@todd.parker]

Sure. In a traditional passive speaker, the amp sends the whole frequency spectrum to your speaker. Inside, the passive crossover splits the spectrum up so the lower frequencies can be routed the the woofer and the highs to the tweeter. In a Sonos speaker like the symfonisk before the signal is even amplified, it’s split into highs and lows then sent to separate amps for each driver (bi-amplified). You can disconnect the internal symfonisk drivers and essentially hook those to B&W drivers so now it’s a bi-amplified speaker BUT you don’t want that passive crossover in the way so you need a way to directly connect wires to the tweeters and woofers by adding binding posts on the back and just having direct wires to each.

[@rogaschuler6971]

What App Are you using for Analising the Soundcurve?

[@todd.parker]

apps.apple.com/us/app/spectrum-analyzer-rta/id490078884

[@donniemccrorie19]

How could I wire that into a full range ceiling speaker?

[@todd.parker]

You’d need to disconnect any passive crossovers in the ceiling speakers and basically direct wire from the tweeter amp to the ceiling speaker, same for the woofer. I’d use 4 conductor wires to keep it tidy

[@justlionaround]

Is it possible to hook up the hacked symfonisk to 2 way speakers?

[@todd.parker]

Yes, I made a video on that.

[@techburst949]

Which app are you using on your phone to do spectrum analysis?

[@todd.parker]

apps.apple.com/us/app/spectrum-analyzer-rta/id490078884

[@techburst949]

awesome thank you!

[@kbhasi]

6:11 Sonos Connect doesn't support their own Trueplay feature?!

[@todd.parker]

Not as far as I know

[@iladdiewhiskynerd4924]

This would mean you could make a couple of ls50 speakers your rear satellites! I wonder if you could use the cheapest Sonos soundbar and use the Amps in that for front and centre channels

[@todd.parker]

You certainly could. I have LS50s but didn’t want to crack open the enclosures to bi-amp them. that’s the key here: you’ll want to pick passive speakers with a similar driver setup since the sonos are bi-amped with a fixed crossover. You can’t power a 3 way speaker for example

[@iladdiewhiskynerd4924]

@@todd.parker if you are upto it, I remembered this video, kzbin.info/www/bejne/e3bLYWSGjZKkb6s and it could be an excellent encasement for a ikea driven system ;)

[@felixlaboy1453]

Wow nice. I wonder would you consider making a set and selling them. ?

[@todd.parker]

I don’t think my craftsmanship is quite enough to sell them. The binding posts are cool for experimentation but may be overkill if to just want to power your favorite two way speakers. For a permanent install, I’d remove the amps and install them into the cabinets if they are large enough to fit

[@maxherman11]

Is it at all possible to turn this into an Aux Port?

[@todd.parker]

I don’t think so, not without a lot of hacking

[@lylesahlin5536]

how many ohms are the drivers inside the symfonisk speaker?

[@todd.parker]

I’ll check next time I open them up

[@magnusblomqvist4571]

The woofer is 4 ohms and the tweeter is 7 ohms!?

[@todd.parker]

Magnus Blomqvist nice, you measured them?

[@magnusblomqvist4571]

@@todd.parker I used an ohmmeter on the disconnected drivers

[@Slorv]

Thank you - great video, very infomative!

[@frankpasmans3019]

Is it a tpa3116d2 chip? Inside?

[@magnusblomqvist4571]

CPU: MCIMX6X2EVN10AC, www.nxp.com/part/MCIMX6X2EVN10AC DAC: TI PCM5101A, www.ti.com/product/PCM5101A AMP: TI TPA3116D2, www.ti.com/product/TPA3116D2

[@johanahlner5974]

Thank you! I now have a seventies Rank Arena in my kitchen with far better sound then the symfonisk. Next step stereo!

[@todd.parker]

Cool. Very retro

[@integra8502]

You have a review of the symphonic Ikea speakers??

[@todd.parker]

I guess I haven’t done an official review but I have lots of videos on how to use them. They sound good, very similar to a play 1. Much improved with a sub!

[@janerikborge]

I wish Sonos made mono amps. Well done. I will try this on my infinity speakers. Than you.

[@stevenneese2823]

Cool stuff what you're doing. But I don't think trueplay can dictate what frequencies your bookshelf speakers play compared to your subwoofer, as they are wired in parallel off the sonos speaker. I believe what's happening when you begin using the subwoofer is that power is being diverted from the bookshelf speakers to send to the subwoofer, reducing low frequency output of the bookshelf speaker. Even though the bookshelf speakers lose power, you end up with louder overall low end due to the subwoofers internal amplifier.

[@todd.parker]

Hooking up the sub doesn't make the internal woofer quieter. You're right that Trueplay isn't sending different signals to the Symfonisk and sub, it "sees" them as one thing but still accounts for the room. In my testing it best to leave the sub off or fairly low so Trueplay doesn't hear too much bass and over compensate by reducing the low end.

[@leonpjhb]

Very interesting build. Thanks for the detailed share.

[@todd.parker]

Sure thing, let me know if you try it

[@mamaxwell]

Wonderful video! Thanks. Can’t wait to see more.

[@todd.parker]

Thank you, I appreciate it

[@Floppydonkey]

Time to transfer the contents into them!

[@todd.parker]

I want to try this out on those Klipsh KG4's in the video. I think they would be perfect because they are high efficiency and have plenty of space to put the guts inside them. I'm having fun tinkering with my Symfonisk so I don't think I want to commit quite yet.

[@iladdiewhiskynerd4924]

Ah, at the end of the video you mention 50 watts :)

[@todd.parker]

Yeah, it’s kind of a guess though since they don’t publish specs. I’d say there likely the max, could be lower but it powers my Klipsch KG4s to a pretty loud volume

[@jojjebroby]

You change the impedance on the Sonos speaker so I wouldn't recomend this.

[@todd.parker]

In a passive crossover, I agree this might be a problem but with an active crossover, I don’t think it’s an issue

[@na6464]

Hi, I want to try this setup with some KEF in ceiling speakers I have, but the kef speakers only have one “binding point/port” model Ci160ER on them, but you examine them closely it has a tweeter and mid woofer sitting on top each other, any idea how I could set this up?

[@todd.parker]

Just googled that speaker and on the back you can see a small board with electronics - that's the passive crossover. In this setup, you want to completely bypass that and it looks very easy. I see a tab with 4 connectors which I assume are the + and _ for the woofer and coaxial tweeter. So you should be able to just disconnect the crossover wires go the those terminals and straight wire to the woofer and tweets amp in the Symfonisk. I juts posted a in-depth wiring tutorial here: kzbin.info/www/bejne/gqHIfHuDadZ1oc0