KEF LS50 Meta Spinorama and Measurements

[jonfitch]

Honestly, imo all KEF really needs to do is just glue an LS50 Wireless II on top of a KC62 and it would have a near-perfect active bookshelf.

Even as separate cabinets, if you literally just sit an LS50 Wireless 2 on top of a KC62, the dimensions are still just 22x10x12.

That's just a little bigger than a Genelec 8351B(18x11x11), and presumably KEF might be able to shave a few inches if, you know, it actually tried to keep everything in the same cabinet.

By comparison, a pair of the 8351B costs ~$8,000, while a pair of LS50WII + dual KC62s (again just as separate devices) would be $5,500. As tuned out of the box, at least, the KEF combo would have far more bass (and lets face it, most people are not doing fancy DSP tricks to extend the bass extension of their speakers).

Yeah I wouldn't recommend the top and bottom slot vented woofers, they really limit the speakers placement abilities when you have deep bass coming out from the bottom of the speaker, it does seem to cause some unwanted reflections that makes the bass really undefined and boomy with the Genelecs unless you have completely unobstructed placement.

That's an interesting concept for sure, I guess the question is in that case is would KEF do something like that? Aren't most 3 ways build with higher XOs, like around 300-400hz? With a subwoofer driver like that I would imagine it would be best to cross over lower, but at that point people might just wonder why not get a sub.

 

[napilopez]

Yeah I wouldn't recommend the top and bottom slot vented woofers, they really limit the speakers placement abilities when you have deep bass coming out from the bottom of the speaker, it does seem to cause some unwanted reflections that makes the bass really undefined and boomy with the Genelecs unless you have completely unobstructed placement.

That's an interesting concept for sure, I guess the question is in that case is would KEF do something like that? Aren't most 3 ways build with higher XOs, like around 300-400hz? With a subwoofer driver like that I would imagine it would be best to cross over lower, but at that point people might just wonder why not get a sub.

Well, the problem is many bookshelf speaker owners don't want a separate sub =] you can always just get a sub and significantly improve sound quality.

There's certainly no need to cross that high in an active design in particular. The D&D 8C sounds great by all accounts and it's basically a cardioid 3 way, but has it's crossover at 100 Hz. The Buchardt A500 has its lowest driver crossed at 150Hz. And since subwoofer localization wouldn't be an issue in my theoretical FrankenKEF, I'm sure they could find the sweet spot crossover.

The KEF R3 has its single 6 inch woofer crossed at 400Hz, but obviously the Uni-Q unit can handle extending lower than that, else the Meta would be an awful speaker!

 

[Ron Texas]

Well, the problem is many bookshelf speaker owners don't want a separate sub =] you can always just get a sub and significantly improve sound quality.

There are problems. Subs are large. If hidden in a corner somewhere, then delaying the mains may be necessary. There is also the bass management issue with rolling off the mains. Mains with 5" mid/woofers sound best with a 100 hz crossover making two subs necessary to avoid localization. However, if these issues are resolved, the result is worth it.

 

[Sancus]

There's certainly no need to cross that high in an active design in particular. The D&D 8C sounds great by all accounts and it's basically a cardioid 3 way, but has it's crossover at 100 Hz. The Buchardt A500 has its lowest driver crossed at 150Hz. And since subwoofer localization wouldn't be an issue in my theoretical FrankenKEF, I'm sure they could find the sweet spot crossover.

The KEF R3 has its single 6 inch woofer crossed at 400Hz, but obviously the Uni-Q unit can handle extending lower than that, else the Meta would be an awful speaker!

Well that's only true if you ignore IMD, the D&D/Buchardt are not coaxials. I suspect there is a reason that Kef and Genelec both choose crossovers at 300-500hz for their 3-way coaxials. After all if they could get away with tuning the woofers to only play at 100hz and below they probably would and get a bit of extra headroom out of it or maybe extension.

Of course I am sure adding the KC62 would help, but I'm not real sure it even counts as a "sub" with the ability to only reach 80dB anechoic at 20hz

 

[aarons915]

The KEF R3 has its single 6 inch woofer crossed at 400Hz, but obviously the Uni-Q unit can handle extending lower than that, else the Meta would be an awful speaker!

Well that's only true if you ignore IMD, the D&D/Buchardt are not coaxials. I suspect there is a reason that Kef and Genelec both choose crossovers at 300-500hz for their 3-way coaxials. After all if they could get away with tuning the woofers to only play at 100hz and below they probably would and get a bit of extra headroom out of it or maybe extension.

Of course I am sure adding the KC62 would help, but I'm not real sure it even counts as a "sub" with the ability to only reach 80dB anechoic at 20hz

The UniQ in the 3 way KEFs are a bit different and designed for pure midrange production, the surrounds are the most noticeable difference. I actually think you lose a bit of the point source magic in a 3 way compared to the 2 way KEFS but you obviously get lower distortion with the 3 way. I would like to see all of their designs prioritize the point-source nature of the design by using the LS50 drivers in the 3 ways and cross them over somewhere around 150Hz, this would let them play loud while retaining the point-source nature down into the non localizable bass frequencies.

 

[napilopez]

Well that's only true if you ignore IMD, the D&D/Buchardt are not coaxials. I suspect there is a reason that Kef and Genelec both choose crossovers at 300-500hz for their 3-way coaxials. After all if they could get away with tuning the woofers to only play at 100hz and below they probably would and get a bit of extra headroom out of it or maybe extension.

Of course I am sure adding the KC62 would help, but I'm not real sure it even counts as a "sub" with the ability to only reach 80dB anechoic at 20hz

For sure, but it sort of depends on what your goals are. I mean, of course they can reduce IMD further by crossing the Uni-Q unit higher, but it's also likely unnecessary for the average living room. Plenty of people are have been happy with the LS50s and presumably even more with the Metas in their stock form. Having crossed the Metas at 80, they already seemed to sound cleaner, and even crossing at 60 had an audible benefit. I figured a sweet spot might be around 150-200Hz, as @aarons915 suggested.

I also still firmly stand by the idea notion that 80dB anechoic (seems to go a bit higher anechoic actually) is enough for music, especially having heard the sub now. Plus you'd have two KC62s with the FrankenKEF.

The UniQ in the 3 way KEFs are a bit different and designed for pure midrange production, the surrounds are the most noticeable difference. I actually think you lose a bit of the point source magic in a 3 way compared to the 2 way KEFS but you obviously get lower distortion with the 3 way. I would like to see all of their designs prioritize the point-source nature of the design by using the LS50 drivers in the 3 ways and cross them over somewhere around 150Hz, this would let them play loud while retaining the point-source nature down into the non localizable bass frequencies.

Good point. I'd be happy too if KEF decided to stick some woofers on the side, like a smaller blade.

 

[jonfitch]

So after I demoed the 8341s against the Kef Reference 1 and preferred the latter, I did note that the Reference 1 sounded more diffuse and spacious than the 8341s and wondered if it was because the 8341s were more of a point source design. So a buddy brought over his KEF LS50 Metas which I had not heard at length before. We A/B'd them side by side for about a good 4-5 hours, and tried our best to level match them. Since they were hooked up to separate outputs we were able to rapidly switch between them during songs with only a slight half-second or so delay.

The LS50 Meta had similar qualities that the Reference 1 had when pitted against the 8341s as well. It sounded more diffuse and spacious compared to the 8341s which sounded much more centered between the speakers, even though the LS50 is an actual point source design, and the 8341s have multiple woofers venting output above and below the coaxial driver through slot ports with a 500hz crossover.

So I think the tighter tolerances and flatter FR above 1K is probably contributing to the much more anchored center image with the 8341s, but similarly as with the Reference 1s, the general 2-3db of extra sound power from the 8341s from 300-700hz made them sound forward, drums and piano had an extra amplitude and vocals were much more forward that made it a bit more fatiguing to listen to, in addition to the more compressed soundstage depth caused by the hotter lower mids. Vocals are slightly clearer on the 8341s, but also more fatiguing with female vocals--it's hard to tell if its because the vocals are more accurate, or they are just clearer because of the slightly boosted lower mid range in the power response of the 8341s, because female vocals sounded somewhat deeper than I used to as well.

Overall we both agreed the LS50 Meta was much more spacious and laid back, sounded pretty similar to a bass limited R3 or Reference 1, and in general more enjoyable to listen to. These are really giant killer speakers and I might get a pair for a secondary desk setup or something.

 

[Descartes]

I seems that it is worth upgrading to the KEF LS50 Meta from the original KEF LS50!

 

[thewas]

I seems that it is worth upgrading to the KEF LS50 Meta from the original KEF LS50!

If you don't use EQ or DSP than absolutely, if you can use there are still differences but not so large so its a matter of personal priorities (I own both generations and have compared them here).

 

[phoenixdogfan]

Well I took the plunge at bought a pair of Metas at Crutchfield. Got them in carbon to match my OG LS 50's. I've literally just unboxed them and have yet to listen to them. Of note, I bought them at Crutchfield's "scratch and dent price" which was around $150 less than "fool" retail. And guess what? They aren't scratched or dented at all. If you look hard you might be able to see something that looks like a very slight scuff on one baffle. From listening distance, it will be completely unnoticable, and unless I'm in a really bad mood, unnoticable at even closer distance.

 

[phoenixdogfan]

View attachment 116967

So after I demoed the 8341s against the Kef Reference 1 and preferred the latter, I did note that the Reference 1 sounded more diffuse and spacious than the 8341s and wondered if it was because the 8341s were more of a point source design. So a buddy brought over his KEF LS50 Metas which I had not heard at length before. We A/B'd them side by side for about a good 4-5 hours, and tried our best to level match them. Since they were hooked up to separate outputs we were able to rapidly switch between them during songs with only a slight half-second or so delay.

The LS50 Meta had similar qualities that the Reference 1 had when pitted against the 8341s as well. It sounded more diffuse and spacious compared to the 8341s which sounded much more centered between the speakers, even though the LS50 is an actual point source design, and the 8341s have multiple woofers venting output above and below the coaxial driver through slot ports with a 500hz crossover.

So I think the tighter tolerances and flatter FR above 1K is probably contributing to the much more anchored center image with the 8341s, but similarly as with the Reference 1s, the general 2-3db of extra sound power from the 8341s from 300-700hz made them sound forward, drums and piano had an extra amplitude and vocals were much more forward that made it a bit more fatiguing to listen to, in addition to the more compressed soundstage depth caused by the hotter lower mids. Vocals are slightly clearer on the 8341s, but also more fatiguing with female vocals--it's hard to tell if its because the vocals are more accurate, or they are just clearer because of the slightly boosted lower mid range in the power response of the 8341s, because female vocals sounded somewhat deeper than I used to as well.

Overall we both agreed the LS50 Meta was much more spacious and laid back, sounded pretty similar to a bass limited R3 or Reference 1, and in general more enjoyable to listen to. These are really giant killer speakers and I might get a pair for a secondary desk setup or something.

So they sound pretty close to Reference 1's save for the bass?

 

[killdozzer]

I was amazed by this video, so I wanted to share. I hope no one did already in some other thread. In this hour long video, many of the strong points are being discussed. A lot of good details of the applied technology and knowledge. Even if you go only for the last part that explains meta in some more details, it is still amazing. But I would recommend the entire video bc a lot of these specs and nuances I haven't seen anywhere prior.

 

[Kachda]

I was amazed by this video, so I wanted to share. I hope no one did already in some other thread. In this hour long video, many of the strong points are being discussed. A lot of good details of the applied technology and knowledge. Even if you go only for the last part that explains meta in some more details, it is still amazing. But I would recommend the entire video bc a lot of these specs and nuances I haven't seen anywhere prior.

Surprising how much detail they reveal..I hope they patented some of the stuff.

 

[killdozzer]

Surprising how much detail they reveal..I hope they patented some of the stuff.

I was thinking about that, but it's very specific to the UniQ and the specs are tailor made for the LS50 in regards of enclosure, baffle, driver... So I think the only way to make use of it is to replicate the entire speaker and that's less than likely.

 

[phoenixdogfan]

I was amazed by this video, so I wanted to share. I hope no one did already in some other thread. In this hour long video, many of the strong points are being discussed. A lot of good details of the applied technology and knowledge. Even if you go only for the last part that explains meta in some more details, it is still amazing. But I would recommend the entire video bc a lot of these specs and nuances I haven't seen anywhere prior.

I am one of the people who have actually owned all three speakers discussed here: The LS3/5as, the LS50s, and now the LS50 Metas.

 

[Descartes]

I am one of the people who have actually owned all three speakers discussed here: The LS3/5as, the LS50s, and now the LS50 Metas.

So which one do you like best and why?

 

[phoenixdogfan]

So which one do you like best and why?

Each one seems better than the last. I have only one day with the Metas, but it seems considerably smoother and mellower than the LS 50s.

 

[thewas]

I am one of the people who have actually owned all three speakers discussed here: The LS3/5as, the LS50s, and now the LS50 Metas.

So do I (have still also the LS50 Anniversary) and my choice is clearly the Meta.

 

[killdozzer]

What are your general feelings on whether the Wireless II is worth the money? I know a lot of you see this "worth the money" far more loosely than I would, but still, I'd give your thoughts and reasoning some time to see if they could help me decide should I go for WII when I get the chance.

Some side notes:
- I wouldn't mind getting rid of my big, heavy amp (a monster that is still weaker than the ones built in WII)
- I find "pre-amp" section of active speakers lacking with inputs
- I intend to keep my TT and use it (it doesn't have a phono pre-amp built in)
- I generally go for more lean systems and, while on one hand loosing an amp would hint at that, OTOH needing a lot of dongles causes mess
- I believe WII are still a single-BT wireless speaker
- Since they have DSP, would I still need something for room correction (I genuinely don't know if their proprietary DSP can do room correction)
- From the video I linked, I learn that every single detail left after designing was smooth out so WII slightly outperforms the passive Meta
- If I don't already own REQ gear, would you say this is the way to go
- Do we know exactly which amps are built in?
- Does this "wireless" imply they could be connected to my NAS audio mass storage? In other words, is wireless=BT and only BT?

Thanks!

 

[thewas]

Imho if you plan to do room correction and already have an amp the passive Meta is the significantly cheaper solution without significant listening deficiencies. The active is of course more comfortable and chic without cables and amps but also has a higher risk of defects and being discontinued from software side in the future. The amps used in the active one are of very good audio quality though so not really a disadvantage.