KEF LSX ii measurements, what am I looking at exactly?

[nvidia_7]

I got a pair of KEF LSX ii speakers for my desk and so far I am blown away by the sound that these tiny speakers put out, especially in the lower bass region for jazz. I have not used the custom EQ setup yet because I don't like changing EQ settings without seeing what exactly the setting is doing to the sound. I had an old SA4140i mic lying around that is used with an app called mobiletools. It has RTA and FFT measurements as well as few others features.

Attached are the RTA and FFT measurements I got using a pink noise generator. It has been a few years since I last dabbled in this hobby and I am entirely clueless as to what exactly I am looking at. I guess what I want to know is, with KEF's out of the box settings, how are these LSX ii's looking and what needs to be adjusted? I have a KEF Kube 12b on the way to help fill in the low bass end.

 

[Ellebob]

Depends on where the mic is placed and what orientation. I am guessing at the seating position, pointing up and ~3m away?
That measurement wouldn't be bad if at the seating pointing up. High frequencies gradually roll off the further the seating distance.

 

[nvidia_7]

Depends on where the mic is placed and what orientation. I am guessing at the seating position, pointing up and ~3m away?
That measurement wouldn't be bad if at the seating pointing up. High frequencies gradually roll off the further the seating distance.

Hi, yes the mic was placed 9 feet back, center, and pointed straight up.

 

[Ellebob]

Overall it looks pretty good. The highs are starting to roll off and that's a typical in-room response for a relatively neutral measuring speaker. It would be good to also measure the speaker directly and preferably do this outside. You sure you would measure the on axis and off axis response. Then when you look at both graphs and forgetting about the high frequency roll off you can see if some of the problems are inherent in the speaker or caused by problems in the room. If it's something with the speaker or a good chance EQ would help.
You could just take your chances and do things like cut down that peak at approximately 800 Hertz. And if you want to be real precise you could do a couple others. But depending what's causing those problems it may or may not help. So there would be trial and error of testing the EQ, listening and deciding if it made an improvement or not.

 

[nvidia_7]

This is what I got measuring a single speaker from about 3 feet away, mic pointed directly at the speaker. Is this little speaker really putting out 40hz+ of usable output? Seems impossible with such a small driver and enclosure. I wasn't expecting much usable output below 80hz from a speaker this size, as in the past that has been my experience with much larger bookshelf speakers. In this case, what should I set the high-pass and low-pass frequencies to for my KEF Kube?

 

[Ellebob]

The measurement looks pretty good and except for adjusting for room size and stuff there's no real EQ in their app. So other than testing it's various settings that's what you're going to get and honestly that's pretty good. Yes it does 40+hz of output. But, don't go too loud as distortion kicks in trying to push a 5" driver. Using a sub and crossing higher will reduce distortion in the bass region
There is a setting for the Kube crossover in the settings. I think it sets it at 65 or 67hz depending on model. I would go higher and depends on measurements in your room but definitely not below 80hz. I have mine at 95hz but I am sure my room is different and I am using different sub (Kali WS-6.2). Take measurements with sub and find best location. Place mic at seating location pointing up. You can use pink noise and move sub in real time to find best location. You will also notice moving your seating makes a difference as well. So if possible try that as well. Avoid any big dips. Then check sub level and polarity and see changes.

 

[nvidia_7]

I got a KEF Kube 10b today and set it up with the app, as well as setting the limited EQ settings. This is my final measurement I was able to get, taken from my seating position. The KEF app seems to basically be a 3 band PEQ. While id wish for more bands, id say these results are very good.

 

[nvidia_7]

FFT from listening position:

 

[Ellebob]

Looks very good!

 

[HarmonicTHD]

Hi. Good start. Set your smoothing to 1/12 instead of 1/3. This way you can better identify room modes and potential for sub/mains alignment (ie phase, xover, volume).

As you have a mic already maybe even familiarize your self with REW.