KEF LSX Introduction

(Phong Vuong) #81

Can I connect/play directly using Spotify without having to hit the power button on the speakers? I had to do this with the LS50w.

(Mike) #82

Just acquired the KEF LSX. Sound great via the KEF built in apps. I can connect to Tidal and see my library on my local NAS. What I cannot see is the LSX in Roon. I can see everything else in Roon…my ultrarendu, Sonos speakers etc. I have updated to the latest software (3.0) and rebooted my system. Unplugged and reconnected the LSX’s. No luck. Anybody have any ideas?

(John Aiello) #83

Do you have them plugged into ethernet?

(Mike) #84

I have tried plugged into ethernet and just on wireless. I can hear the LSX’s via the KEF apps for both options. But see nothing either plugged into ethernet and wireless from Roon.

(John Aiello) #85

When you are trying to get Roon to see the speakers do you have them on the correct input?

(Mike) #86

On wi-fi. I can hear output when using the KEF apps, no problem; but I’m still trying to figure out why I cannot see in Roon. Must be something stupid I’m doing…

(John Aiello) #87

A number of things come to mind. First of all in my Roon Audio settings the LSX are the last entry under KEF. All the way at the bottom. I missed them there when I first tried to set them up. They have to be enabled there before you can use them. Make sure that the IP address of your Core and the IP address of your speakers are on the same subnet.

(Mike) #88

I confirm that the speakers and Roon Core are on the same subnet. Still cannot see KEF in the Roon Audio settings. I’ll have another look at everything tomorrow again. Thanks for responding.

(Mike) #89

It has been solved. I re-booted my Roon Core on my Sonic Transporter. Turned the LSX’s off and waited a while. All now connected and running just fine. The LSX’s are a very close version of the passive KEF LS50’s that I have but much better suited to near field and my desktop set up. KEF technical guys were very helpful and prompt on getting a solution to me once I reached out to them.

(John Aiello) #90

Glad you got it solved. I had thought that you said earlier that you rebooted the Core. I guess I missed that.

(Christoph Longree) #91

How on earth do you go from existing Ethernet to WiFi with the LSX… really can’t figure it out… terrible KEF App - otherwise fantastic little speakers…


From my, somewhat limited, knowledge of speaker design it’s always easier making a smaller speaker rigid and “correct” in that sense. The bigger the box, the bigger the issues by multiples.

I have a friend who recently purchased the LSX. I always tried to make him buy the bigger sibling but I think the looks and size scared him off. Now that the LSX entered the stage it was a given buy. The little I have listened I’m quite impressed by the performance! :ok_hand:t3:

(KEF Product Training Specialist) #93

Hi Cristoph, Ben (Product Training Specialist) from KEF here - how do you mean? Do you mean source wise between ethernet input and wifi?

(Christoph Longree) #94

Hi - thanx, got it sorted out. Works a lot more stable and easier with Ethernet though. I’ve gone to hardwiring the whole house for streaming - solved all problems. Best thing I ever did :blush:

(ein) #95

Yep. 100% solution. LAN and go :wink:


Hi @Ben_Hagens, nice to see KEF staff on the forum!
A couple of questions if you don’t mind…
The LSX has a limitation of 96kHz internally, but will accept up to 192kHz input and then downsample. Is this only for the ethernet input? What about 176.4kHz? Will this be converted to 88.2kHz or resampled to 96kHz?

The LS50W has a time/phase correction in it’s DSP. Is a similar correction done in the LSX?

(KEF Product Training Specialist) #97

Hi! Sorry, only just seen this.

Firstly, to answer the last question, LSX does indeed have the phase correction in the DSP.

In regards to the sample rates, the optical is limited to 96kHz, and the networked inputs (wifi/ethernet) will accept 192kHz, as you rightly say. They will then be resampled based on the interspeaker transmission, so if you’re in wireless mode, the new sample rate will be 48kHz, if you’re in cable mode, this will be 96kHz. This is the same for 44.1kHz multiples as well.

The analogue input will go through A/D, and sampled to the transmission being used, i.e. if you’re in cable mode, it will be sampled directly to 96kHz, 48kHz if using wireless mode.

Hope that answers your question.


Thanks for replying @Ben_Hagens It is all clear now! Are you allowed to reveal which A/D converter chip is used?
I’ll most likely use the ethernet input and a cabled interspeaker connection, but a RAAT enabled DAC to the analog input is also an option even if there is an extra D/A-A/D conversion on the signal.

(KEF Product Training Specialist) #99

No problems! Happy to help where I can. Unfortunately, I can’t help on the A/D chip front.

Cabled is my go-to for interspeaker. Wireless is more than fine, but I’m a lazy so-and-so, and don’t want to go find and plug in the interspeaker cable when new firmware updates are available :joy: Just make sure that you enable cable mode in the KEF CONTROL app. Plugging the cable in doesn’t automatically switch to wired transmission.

KEF LSX not downsampling 192kHz files in Roon
(Dan Brown) #100

Hi @Ben_Hagens. I notice you say the signal gets converted to 96khz in LSX with a wired interconnect. Do you know if this is the same for The LS50W?

Or do the LS50W pass a 192/24 signal between speakers?