I've had KEF's new darling, the LS50 Meta, for a couple of months now, but have only just been able to complete measurements of them. I expected this one to be a fairly straightforward measurement, as luckily KEF provides its own spinorama for the LS50 Meta, complete with early reflections curves and all. It is available in the company's whitepaper(p10), but for ease of comparison and scale-matching, I've imported that spin to REW:
We see a pretty darn good speaker, whose deviations from neutral are just a dip in the upper mids, some on-axis diffraction, and a slightly warm tilt; we can see the on-axis and listening window curves have a slightly negative slope rather than being completely neutral.
Though my results are largely similar, there are some small but notable differences. These may be due to differences in measurement technique or my own error, but if anything, the speaker comes out looking better in my spin. Here's mine:
(Please note that some of the bumps from 400-800Hz are likely due to my new outdoor measurement rig, which I am still trying to refine.)
The differences are subtle, but worth noting:
Though the dip in the upper mids remains, my measurements show much better behavior on-axis. The most likely explanation for this is simply that I was not perfectly aligned with the center of the tweeter for the diffraction to take hold.
If so, it just shows how meaningless on-axis diffraction is so long as it gets smoothed out in the listening window. I repositioned my microphone about five times and was not able to match the on-axis diffraction shown by KEF. In any case, this is all but irrelevant considering KEF explicitly tells you to listen off-axis in the manual:
The more important difference is the tilt or slope of the curves. Both KEF and my measurements show smooth, mostly flat lines, however, KEFs are more tilted/darker/warmer than mine. For example, here are my Listening Window and Early Reflections curves vs KEF's (dotted):
If we line up the measurements in the low mids, KEF's measurements show roughly 2 dB less energy after 2kHz. This would definitely be an audible difference; while both sets of measurements indicate a good sounding speaker, KEF's suggest a slightly warm titlt, while mine suggest something more neutral.
I spent a while thinking about this difference in tilt. I thought it might be temperature, as it's getting colder here, and we've seen how temperature can affect woofer output in Amir's measurements. But the speakers were indoors right before I brought them out to measure, and 56 degrees isn't that cold.
So I decided to check out Soundstage Network's measurement of the LS50 Meta, as my measurements have always agreed closely with theirs. Indeed, digitizing their on-axis measurement, they seem to have the same achieved the same tilt as me:
The results are, for all intents and purposes, almost identical.
Moreover, if we compare my DI curves with KEFs, they are pracitcally identical too, which leads me to believe there's just a difference in our mic calibrations for some reason.
Either way, you're getting a very good speaker, but my results show a more neutral tonality than KEFs. Until someone else with reliable measurements gets their hand on the LS50 Meta, this might remain a bit of a mystery.
Still, I'm not complaining. I'll update with more detailed directivity stuffs and quick impressions a bit later. Directivity measurements and quick sound impressions in post #6.
We see a pretty darn good speaker, whose deviations from neutral are just a dip in the upper mids, some on-axis diffraction, and a slightly warm tilt; we can see the on-axis and listening window curves have a slightly negative slope rather than being completely neutral.
Though my results are largely similar, there are some small but notable differences. These may be due to differences in measurement technique or my own error, but if anything, the speaker comes out looking better in my spin. Here's mine:
(Please note that some of the bumps from 400-800Hz are likely due to my new outdoor measurement rig, which I am still trying to refine.)
The differences are subtle, but worth noting:
Though the dip in the upper mids remains, my measurements show much better behavior on-axis. The most likely explanation for this is simply that I was not perfectly aligned with the center of the tweeter for the diffraction to take hold.
If so, it just shows how meaningless on-axis diffraction is so long as it gets smoothed out in the listening window. I repositioned my microphone about five times and was not able to match the on-axis diffraction shown by KEF. In any case, this is all but irrelevant considering KEF explicitly tells you to listen off-axis in the manual:
The more important difference is the tilt or slope of the curves. Both KEF and my measurements show smooth, mostly flat lines, however, KEFs are more tilted/darker/warmer than mine. For example, here are my Listening Window and Early Reflections curves vs KEF's (dotted):
If we line up the measurements in the low mids, KEF's measurements show roughly 2 dB less energy after 2kHz. This would definitely be an audible difference; while both sets of measurements indicate a good sounding speaker, KEF's suggest a slightly warm titlt, while mine suggest something more neutral.
I spent a while thinking about this difference in tilt. I thought it might be temperature, as it's getting colder here, and we've seen how temperature can affect woofer output in Amir's measurements. But the speakers were indoors right before I brought them out to measure, and 56 degrees isn't that cold.
So I decided to check out Soundstage Network's measurement of the LS50 Meta, as my measurements have always agreed closely with theirs. Indeed, digitizing their on-axis measurement, they seem to have the same achieved the same tilt as me:
The results are, for all intents and purposes, almost identical.
Moreover, if we compare my DI curves with KEFs, they are pracitcally identical too, which leads me to believe there's just a difference in our mic calibrations for some reason.
Either way, you're getting a very good speaker, but my results show a more neutral tonality than KEFs. Until someone else with reliable measurements gets their hand on the LS50 Meta, this might remain a bit of a mystery.
Still, I'm not complaining.
Last edited:
