KEF LS50 Meta Review (Speaker)

[David_M]

https://www.audioholics.com/bookshelf-speaker-reviews/ccb-8-bookshelf/measurements

Not good. Until proven wrong, I consider that only Genelec and KEF solved the coaxial question.

Measurement aside, the reviewer concluded the following:

"The CCB-8 speakers are the kind of addition to an audio setup that makes you want to re-listen to your music collection to see how it sounds on this new gear. Their holographic imaging is the best I have heard in my own room to date. It is eerie how precisely sounds seem to emanate from specific locations over the soundstage. It is not just center imaging either, which I have heard lots of speakers do well (although few do this as well as the CCB-8s); it is over the entire soundstage which the CCB-8s stretch out as a large swath extending well outside their physical locations. As I type this, I am listening to the CCB-8s in my home theater room. I normally write on my desktop computer, because it is easier to write there, but I wanted to listen to the CCB-8s some more, and it is worth the inconvenience of writing on this laptop to hear their magic on my old albums (by the way, current album: William Orbit’s ‘Hinterland’ under his ‘Strange Cargo’ moniker)"

 

[q3cpma]

Cabasse

Few measurements I've seen of La Sphère show suboptimal directivity.

 

[Frgirard]

Few measurements I've seen of La Sphère show suboptimal directivity.

La sphère is an old history.

 

[jhaider]

Arguably the LS50 is much much more décor friendly thanks to design and colors - this is what people are paying the premium for, and doing it gladly!

Not really, because there's little in speakers that's less decor friendly than exposed drive units. I wish KEF had grilles for these. If they did I would buy a set and do kind of a Gradient Revolution thing with them - coax atop open baffle bass bin stands.

 

[aarons915]

But - doesn't the high crossover recommendation presume your sub (or subs) have lower distortion in that 90-120hz range than these speakers? I'm sure at some volume level that's true, but does anybody even publish distortion numbers in that range for subs? (In general the measurements for subs seem pretty minimal compared to regular speaker stats). I think the "with sub" ratings on ASR, for example, presume a perfect sub. In that case, buy two and cross them over at 20kHz.

A 10-18" Subwoofer will have much less distortion than a 5" woofer, a few subs have been measured but I haven't seen any great distortion measurements. The only thing to really worry about with higher crossover points is localizing the subs and you have to make sure the sub has flat frequency response above 100Hz, some don't. As others have said THD isn't even that audible under 200Hz but I have seen a few studies that showed IMD distortion is much more audible, this is the main reason for higher crossover points, you want to minimize how much the midwoofer cone moves.

 

[Everett T]

A 10-18" Subwoofer will have much less distortion than a 5" woofer, a few subs have been measured but I haven't seen any great distortion measurements. The only thing to really worry about with higher crossover points is localizing the subs and you have to make sure the sub has flat frequency response above 100Hz, some don't. As others have said THD isn't even that audible under 200Hz but I have seen a few studies that showed IMD distortion is much more audible, this is the main reason for higher crossover points, you don't want to minimize how much the midwoofer cone moves.

The JTR RS1 keeps distortion under 10% across most of its frequency response until around 16hz.

 

[Steve Dallas]

If you are asking for subwoofer recommendations and xover frequencies, I'd choose SVS sealed subs, the SB3000, SB4000, or SB Ultra-16. You might want to get two lower-priced subs (SB2000, SB3000, SB4000) to form a killer 2.2 channel system.

I'd recommend crossover frequencies of at least 100Hz minimum (150Hz preferable), based on the measured distortion specs of the speaker.

You do not necessarily need to cross it that high. Reducing low frequency demand on the speaker also reduces the distortion from the woofer. Crossing it at 80Hz may clean it up enough to play clean and loud. I believe I used 90Hz on my non-Meta LS50s with good results.

 

[Helicopter]

The $800 LS50C Meta center channel is just one of these speakers sold individually rather than in a pair; useful for most surround setups.

Which brings me to another thought. These could be awesome in a HT with150Hz crossover, subs, and external amps. You'd probably want subs placed for the higher (80-150 Hz) versus the lower ones.

How high is the HT bass track on a 4k Blueray or similar?

 

[sarumbear]

The JTR RS1 keeps distortion under 10% across most of its frequency response until around 16hz.

That I need to see the measurements of.

 

[sarumbear]

How high is the HT bass track on a 4k Blueray or similar?

I assume you meant the LFE track, the .1 of the surround track? It’s bandwidth is 3-120Hz.

 

[laurelkurt]

Funny you mention that I recently recall someones post about how the passive membranes in a room full of speakers can influence the sound of the speakers that are playing in that same room.

I apologise I searched for the post but I cannot provide a direct link.
Maybe someone else knows where it was mentioned?

Recent Audioholics video on room treatments discussed bass traps with tuned/weighted panels only a few inches deep. Could that be it? I don't have the link.

 

[sarumbear]

You do not necessarily need to cross it that high. Reducing low frequency demand on the speaker also reduces the distortion from the woofer. Crossing it at 80Hz may clean it up enough to play clean and loud. I believe I used 90Hz on my non-Meta LS50s with good results.

If you look at the distortion chart in the review you will see that distortion increases fast below 150Hz and at 90Hz it reaches 10%.

 

[Chromatischism]

I assume you meant the LFE track, the .1 of the surround track? It’s bandwidth is 3-120Hz.

Based on a recent discussion here:

Technically the bandwidth of the LFE channel is full-range. Some 5.1 music albums put content there for some reason.

But AVRs by default implement a LPF at 120 Hz, and most movie studios filter there anyway. I change that to 250 Hz, the max my AVR allows, for testing purposes at times.

 

[phoenixdogfan]

What's your xover frequency of the sb2000? Hope its at least 100Hz or more.

The low pass is adjustable, the high pass is set--it's an 80 hz second order filter. If you want something different, there's away miniDSP on the hardware front and Ekio, Dephonica, and JRiver for software.

 

[sarumbear]

Technically the bandwidth of the LFE channel is full-range. Some 5.1 music albums put content there for some reason.

Dolby will disagree.

https://www.dolby.com/uploadedFiles/Assets/US/Doc/Professional/38_LFE.pdf

 

[Everett T]

That I need to see the measurements of.

https://www.audioholics.com/subwoofer-reviews/jtr-captivator-rs1/conclusion

 

[sarumbear]

https://www.audioholics.com/subwoofer-reviews/jtr-captivator-rs1/conclusion

I’m impressed. Thank you.

 

[phoenixdogfan]

You do not necessarily need to cross it that high. Reducing low frequency demand on the speaker also reduces the distortion from the woofer. Crossing it at 80Hz may clean it up enough to play clean and loud. I believe I used 90Hz on my non-Meta LS50s with good results.

Before my miniDSP 2 x 4 HD bit the dust, I crossed over my heavily EQ'd OG LS 50s at 100 hz to a single SB 2000 with very satisfactory results.

 

[Everett T]

I’m impressed. Thank you.

You're welcome

 

[phoenixdogfan]

The $800 LS50C Meta center channel is just one of these speakers sold individually rather than in a pair; useful for most surround setups.

Which brings me to another thought. These could be awesome in a HT with150Hz crossover, subs, and external amps. You'd probably want subs placed for the higher (80-150 Hz) versus the lower ones.

How high is the HT bass track on a 4k Blueray or similar?

In the process of doing exactly that: JRiver will handle the front end, pass everything to the soon to be delivered Octo 8, and the Octo will pass the L-R to the Purifi Eval1 from there to the Metas, the single SB 2000, and to a Behringer A500 to the OG LS 50s, for L-R surrounds. I am awaiting the delivery of the Octo 8 next Wednesday, and should have everything set up by next Saturday. I may want a second sub, but I doubt I'll want or need a center.

When I have everything set up, I'll post some MMM measurements of the system.