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KEF LSX Review (Wireless Speaker)

VintageFlanker

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Any updates on this product lsx 2 version ?
93a54355-kef-lsx-ii-les-petites-enceintes-actives-de-kef-signent-leur-grand-retour__w1280.jpeg
 

thewas

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Too bad it's not not gen 12 Meta
The metamaterial tweeter absorber is great as a scientific research result and proof of concept (and also for marketing) but is probably one of the least audible improvements of the latest KEF innovations/evolutions, I wouldn't really miss it thus on the LSX (I own both generations of LS50) if all other driver, electronics and usability aspects are improved (hope there will be soon some measurements and white paper). Possibly they didn't use it also for product series hierarchy reasons.
 

Vacceo

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The minijack, to me, is a clear nod to PC users. I´d rather use the HDMI as the DAC on the speakers is probably better isolated than the one on a PC.
 

Darwin

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Again, instantaneous in Roon.

I personally don't understand why someone would use the provided apps for stream control to any of these types of systems, they're invariably bad.

Roon all the way for both these and my Buchardts. And if/when they support Tidal/Spotify Connect/etc, that's the way to go if you don't want to pay for a license for secondary software.
Not Sonos. You should expect to be able to use the app on something that costs this much. it's not complicated.
 

sfdoddsy

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As previous owner and fan of KEF coaxes (LS50, R3, Reference) I've been eying the LSX to replace the Sonos One's in my bedroom system.

But have been put off by the dismal reviews of the software and reliability.

I'm not planning on using the KEF streaming apps, but if you search for 'Roon has lost control of audio device' pretty much all involve KEF wireless speakers. And there are streams of horror stories about connection issues and bugs.

But when I spied a set on Amazon Warehouse for $600 I thought what the heck. I have a 30 day window to return them.

Mine arrived a couple of days ago and I guess I struck it lucky (ish).

Initial setup and firmware upgrade was a breeze. Easier in fact than initial Sonos setup.

The speakers were recognised by Roon directly and by Airplay (Roon and Apple Music) and music was forthcoming on demand.

I'll be streaming music, but direct connection to the optical and aux inputs also worked as advertised.

The audio quality is excellent. They have a strong family resemblance to the LS50, with similar strengths (coherence and soundstage) and weaknesses (frequency extremes). Because I listen to them at much lower levels than when I had the LS50s in my main system, I actually get better bass extension.

My quick REW measurements to work out whether to use room EQ via Roon were a good match to Amir's, although my treble droop came a little later.

It hasn't all been sweetness and light though. Whilst it was easy to get both speakers merrily playing via the wireless connection, I noticed that the slave speaker was occasionally (and very briefly) dropping out. Switching to the cable connection solved the problem but I'd prefer wireless for aesthetic reasons.

So I crossed my fingers and did a full factory reset. This time setup was just as easy, but so far wireless is working as it should.

I also have had the problem alluded to earlier where Roon reports that it has lost control of the audio device. Whilst I have numerous issues with Roon's network performance, dropouts and memory leaks, I haven't had this one before.

It only happened vis the Roon direct connection. Not via Airplay.

It also only happened whilst I was fiddling with Roon's DSP EQ settings, so I would sheet the blame at both Roon and KEF.

Given the price I paid I'm happy (if slightly nervous).

They are the only affordable wireless speaker I can think of with both notably better sound than Sonos and notably better aesthetics. The latter is crucial for me (and my partner).

For pure sonic quality I suspect the Neumann KH80 with a Sonos Connect or Wiim are superior. But they are small (good) and ugly (bad).
 

Mal

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??? I downloaded the app a couple of days ago. How could it be old?
What about the firmware? I just bought the speakers new (heavily discounted in UK!) and the app asked if I wanted to download the latest version (5.2), so I did. But quite right about "???". Shouldn't "the latest version" of "whatever" just get downloaded with the app?

The app was also suggesting very techie repairs when things didn't quite work - like "give your wifi frequencies two different names" or "don't use a mesh network". I just ignored that and turned it on and off (the old solution!), stuck a paperclip in the hole as recommended, and things progressed quite well.

At least... I can watch TV from my firestick with *much* better sound than my nobsound/Wharfedale 9 combination was producing. Even music sounded pretty good from Spotify Premium amd Amazon Music HD - though I've only get them working over Bluetooth. Amirm - you said at one point you had to reboot the master speaker to get Spotify Connect working when moving from Bluetooth. So do I need to stick the paperclip in that hole again? I think I'll go and watch some TV instead... "One foot in the grave", imagine Victor Meldrew with these speakers...

Unbelievable! (in both senses...)
 

nick-v

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I just ordered LSX II for my desktop system (now that they're certified Roon Ready).

I'll be crossing them over to a currently unused Paradigm Ultracube 10 subwoofer that will sit under the desk. I really appreciate that the system allows for low pass and high pas filtering (otherwise I probably would have gone in another direction).

I always used larger professional studio monitors in my desktop rig, but my wife is now working out of our home office more than I do so I'm trying to maintain high performance with a much higher aesthetic.
 

Mal

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Even music sounded pretty good from Spotify Premium amd Amazon Music HD - though I've only get them working over Bluetooth. Amirm - you said at one point you had to reboot the master speaker to get Spotify Connect working when moving from Bluetooth. So do I need to stick the paperclip in that hole again?...
Why did I ask? I did it and it worked - Spotify connect now working a treet. In Spotify App on my Fire Tablet I can connect to LSX so the tablet becomes a great remote! I felt the lack of HD though - solved this using optical splitter on Amazon fire tv to feed Amazon music unlimited & all TV sound to lsx optical input. My favourite soaps never sounded so good (and the music is just about as good as from my CD player... subjectively, at least...)
 

nick-v

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I set up my LSX II a couple weeks ago.

Most recently in my desktop system I was using Dynaudio BM6a mkII active monitors, then JBL HDI-1600 for a while.

My wife has been splitting our home office with me for a couple years, so this was mostly a downsize for her sake (also an aesthetic upgrade).

Good news, I don't feel like I'm missing anything. I'm crossing them over at 100Hz to a Paradigm Ultracube 10, and if anything it might be a sonic upgrade. I feel like these are perfect desktop speakers. Such an attractive size and aesthetic.

Keep in mind this is a small home office, and these are definitely small room speakers.

I'm using Roon for music, USB for computer audio and eARC for TV sound. These are so flexible. Also, there's a Control4 driver which is a nice touch because Control4 is automatically setting the correct input based on whatever is playing.
IMG_20221115_103954_201.jpg
 
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withoutsuit

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Anybody has experience in using them as rear speakers? I´m curious how this will fit to my fronts, being KEF LS50 Meta.
 

Mal

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For pure sonic quality I suspect the Neumann KH80 with a Sonos Connect or Wiim are superior...
Why would you suspect this?

The following video starts with a nice graph suggesting the frequency response is very similar (and very good!) The responses are fun... honours equal?

 

Harryharryharry

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Can anyone tell me if it's possible to turn off the LED indicators when music is playing or are they permanently on?
 

Purité Audio

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Actually the LEDs go off automatically when music is playing.
Keith
 

Mr. Knowitall

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New LSX II owner. LOVE them. Replaced a set of Klipsch Heritage ProMedia on my desk. But, I cannot get Google Home to recognize them. Any tips or lessons learned?
 

capslock

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Distortion at 86 dBSPL is reasonable. Not so at 96 dBSPL:

View attachment 139695

View attachment 139698

I could hear massive distortion in low frequencies as the sweep was running in the lab. This is typical of many small powered speakers as I think the amp is running out of power, not the driver.
Do we know what kind of amplifiers (chipset type?) are used in the LSX? It is interesting that 3rd harmonic dominates below 500 Hz. Usually, for speaker driver distortion, in the very bass region 2nd dominates.

Overdriven amps would show in higher order distortion, but 4th and 5th are very well behaved above 50 Hz. Were these data generated in a sweep or with a drive signal that contains any frequencies simultaneously (e.g. Farina method)? If bass excursion was driving the amps to their rails, I would expect this distortion to show up at higher frequencies, too, if something other than a sweep was used.

Edit: I found pics of used (defective) LS50 wireless I boards on fleabay. Very definitely class AB with the the emitter resistors clearly visible. Good pictures of LSX boards are hard to come by, even though they presumably keep burning out.
 
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