KEF LS50s

Letitroll98 · « **Reply #20 on:** 31 Jan 2013, 05:54 am »

Sound and Vision's measurements:

Which are seemingly at significant odds with JA's measurements at Stereophile:

(The red trace shows the KEF LS50's spatially averaged response. The blue trace is a set of Rogers LS3/5a's for comparison, which for our purposes here try to ignore.)

At odds unless you look at another set of graphs JA has in the same article:

Which look a lot more like the S&V graphs.

The only thing that seems the same is a general falling off of the response below 100hz, with the -3db point being arbitrarily set on what you think is the average response. Also there appears to be a BBC saddle in the presence region, a very British speaker curve.

AJinFLA · « **Reply #21 on:** 31 Jan 2013, 02:47 pm »

Quote from: Letitroll98 on 31 Jan 2013, 05:54 am

The only thing that seems the same is a general falling off of the response below 100hz, with the -3db point being arbitrarily set on what you think is the average response. Also there appears to be a BBC saddle in the presence region, a very British speaker curve.

In the nearfield/port slice above, the 0 line can be considered the average reference, so the 50hz bass extension is realistic. Perceptually, the descriptions seem appropriate that the speaker has good heft for it's size, which of course is also dependent on position/room loading of the LF.

cheers,

AJ

Letitroll98 · « **Reply #22 on:** 1 Feb 2013, 04:18 am »

Yeah, I'd agree with the zero crossing point being the avg freq response of the speaker system. However you'd never get the 50hz -3db point if you didn't have a 3-4 db rise just above 100hz. (Before the spellcheck I typed "didn'y have", now I'm typing with a Scottish brogue) Anyway, just considering the bass response alone, it falls off below 100hz. This behavior is quite common in small box speakers, and to many ears a desirable trait to add some mid-bass warmth and apparent low frequency extension in one fell swoop. The curves are near duplicates of Polk A3 speakers, a popular model. Others disagree, Paul Barton's PSB Alpha B1 (for example) averages nearly flat in the bass regions until it falls off at about the same rate, albeit at a somewhat higher frequency. And of course frequency response doesn't describe the sound of a speaker, but it can give us clues to what we are hearing.

roscoeiii · « **Reply #23 on:** 7 Feb 2013, 04:28 am »

So how about some updates?

Well, AC member Irish 51 (who will hopefully chime in with his thoughts too)came over to listen to the LS50s and compare them to my SP Tech Minis and the VonSchweikert VR-4 Gen IIs. Happy to say that we both agreed that all 3 speakers, despite their differences and limitations, were all certainly in the same league sonically. It is really a matter of priorities and space between these three.

To get it out of the way first, yes the LS 50s were not able to compete in the deep bass octaves. The SP Minis go to around 35Hz, and the VR-4s go down to 20Hz. In the majority of the music we listened to (except for the real bass torture tracks like James Blake), it was tough to distinguish the VR-4s and the SP Tech Minis. That Mini is one helluva monitor to be able to go that low, with that level of detail.

The LS50 had superb bass detail on the bass that it had, which is down to 50Hz or so. Here it was more obvious that some bass was missing on more listening material. But if you expect deeper bass out of speakers this size, you have not been paying much attention to the laws of physics. For their size, the bass is remarkable. And detailed and well-defined all the way down to its dropoff point. Very very impressive.

roscoeiii · « **Reply #24 on:** 7 Feb 2013, 04:51 am »

Now with the bass out of the way, here is where all three speakers became merely a matter of preference. Which should speak very highly of the LS50s, considering that the SP Tech Minis retailed for over double the LS50s cost, and the VR-4s were about triple the cost of the LS50s!!

The major dimension on which we noticed a difference was the degree to which the presentation was a bit forward or laid back. The VR-4s were the most laid back of the bunch (and I would ultimately like them to be just a tad bit more forward, not sure if there are tweaks or gear changes that could help with that; hell I have a DSPeaker Dual Core 2.0 with EQ in the digital domain, maybe tinkering with that could get me what I am looking for...). And the SP Techs were the most forward of the three. More in your face, with a greater sense of dynamics. Leading edges were a bit more prominent, whereas I was noticing the decays more on the Von Schweikerts.

The LS50s? I'd say they were between the other two speakers, and a bit more towards the SP Mini (forward, dynamic) side of the spectrum than the Von Schweikerts. Compared to the SP Minis, the LS50 may have had a tad less detail overall, though that is something I want to go back and listen for once the LS50s have 100+ hrs on them.

From top to whatever bottom-end rolloff point they had, all three were excellent performers. Making it a quite difficult decision of which I will eventually part with.

lonewolfny42 · « **Reply #25 on:** 7 Feb 2013, 06:11 am »

Thanks roscoeiii...

Quote

...all three were excellent performers. Making it a quite difficult decision of which I will eventually part with.

No need to part...keep all three.

(I have 8 pairs of speakers...

)

steveoat · « **Reply #26 on:** 11 Feb 2013, 05:53 pm »

How do they sound without stands? Do they sound good on a desktop in a computer audio setup?

konut · « **Reply #27 on:** 11 Feb 2013, 11:32 pm »

Quote from: roscoeiii on 7 Feb 2013, 04:51 am

Now with the bass out of the way, here is where all three speakers became merely a matter of preference. Which should speak very highly of the LS50s, considering that the SP Tech Minis retailed for over double the LS50s cost, and the VR-4s were about triple the cost of the LS50s!!

The major dimension on which we noticed a difference was the degree to which the presentation was a bit forward or laid back. The VR-4s were the most laid back of the bunch (and I would ultimately like them to be just a tad bit more forward, not sure if there are tweaks or gear changes that could help with that; hell I have a DSPeaker Dual Core 2.0 with EQ in the digital domain, maybe tinkering with that could get me what I am looking for...). And the SP Techs were the most forward of the three. More in your face, with a greater sense of dynamics. Leading edges were a bit more prominent, whereas I was noticing the decays more on the Von Schweikerts.

The LS50s? I'd say they were between the other two speakers, and a bit more towards the SP Mini (forward, dynamic) side of the spectrum than the Von Schweikerts. Compared to the SP Minis, the LS50 may have had a tad less detail overall, though that is something I want to go back and listen for once the LS50s have 100+ hrs on them.

From top to whatever bottom-end rolloff point they had, all three were excellent performers. Making it a quite difficult decision of which I will eventually part with.

Thanks for the detail on the comparison. What I'm wondering is about the sense of soundstage between the LS50 and the Mini. Do you sense any difference in the spacial representation WRT imaging? In theory the dual concentric nature of the LS50 might have an edge in the illusion of realistic imaging, particularly in the crossover region. Your lack of comment about this might be construed as a point of similarity between the 2.

K Shep · « **Reply #28 on:** 12 Feb 2013, 12:17 am »

These speakers are impressive. I have had mine for about one month, they're part of a secondary system I'm assembling.

roscoeiii · « **Reply #29 on:** 12 Feb 2013, 12:53 am »

Quote from: konut on 11 Feb 2013, 11:32 pm

Thanks for the detail on the comparison. What I'm wondering is about the sense of soundstage between the LS50 and the Mini. Do you sense any difference in the spacial representation WRT imaging? In theory the dual concentric nature of the LS50 might have an edge in the illusion of realistic imaging, particularly in the crossover region. Your lack of comment about this might be construed as a point of similarity between the 2.

Yes, I have not noticed much of a difference between the 2 on imaging, but that comes with 2 caveats. 1) I don't fixate too much on imaging. Pretty far down my list of audio priorities. 2) I don't feel that I had either the SP Minis or LS50s dialed in for imaging. They aren't my primary speakers at this point so their positioning hasn't been optimized.

roscoeiii · « **Reply #30 on:** 16 Feb 2013, 05:01 pm »

The secondary system for the KEFs will have to wait. They were sold to help fund a tonearm upgrade. Though this is no comment on how I found their sound. The plan is to purchase another pair once I have absorbed the cost of the tonearm.

okan1977 · « **Reply #31 on:** 7 Mar 2013, 07:59 pm »

I listened these speaker last month in extreme audio showroom it was really impressive

iluzun · « **Reply #32 on:** 8 Mar 2013, 02:57 am »

I just want to note how well the LS50s match up w/EL34 type amps. I've a Prima Luna
Prolouge II, & this really is a fun & musical slice of 'midrange heaven'. A great bedroom
system & the LS50s have replaced my ProAc 1sc w/more bass & only requiring single wiring
to get best performance, I just find them very easy to live with. They r definitely transparent
and quickly showed a musical preference for some blue bottle el34s over a quad of black treasure
KT-88s. A highly natural & musical match, very much recommended.

harley52 · « **Reply #33 on:** 31 Mar 2013, 12:39 am »

Check out the response between apprx. 2k-5k. Way too hot. A couple songs and I'd have to turn it way down. But I find about 95% of speakers, including 5 figure ones to be unlistenable for more than a few minutes.

roscoeiii · « **Reply #34 on:** 31 Mar 2013, 01:05 am »

I did find them to be more forward than my Von Schweikert VR-4s. Wonder if the 2-4k bump is part of that? Though the bump doesn't look as big in the Stereophile measurements.

Still trying to figure out what contributes to one speaker feeling more forward or laid back...

K Shep · « **Reply #35 on:** 9 Apr 2013, 09:01 pm »

Quote from: iluzun on 8 Mar 2013, 02:57 am

I just want to note how well the LS50s match up w/EL34 type amps. I've a Prima Luna
Prolouge II, & this really is a fun & musical slice of 'midrange heaven'. A great bedroom
system & the LS50s have replaced my ProAc 1sc w/more bass & only requiring single wiring
to get best performance, I just find them very easy to live with. They r definitely transparent
and quickly showed a musical preference for some blue bottle el34s over a quad of black treasure
KT-88s. A highly natural & musical match, very much recommended.

Thank you, I have the new Prima Luna Dialogue Premium integrated amp on order, slow boat, to pair with my LS50's.

AJinFLA · « **Reply #36 on:** 10 Apr 2013, 06:02 pm »

Heard a pair of these last night at the local club meet, powered by a Cary 300b SET amp. Sounded very nice, plopped on top of a pair of little Klipsch Cornwalls!

roscoeiii · « **Reply #37 on:** 10 Apr 2013, 06:09 pm »

Quote from: AJinFLA on 10 Apr 2013, 06:02 pm

Heard a pair of these last night at the local club meet, powered by a Cary 300b SET amp. Sounded very nice, plopped on top of a pair of little Klipsch Cornwalls!

Interesting. I would have thought these would need a bit more power than a 300B SET amps could provide. At any point did the amps seem to run out of steam?

AJinFLA · « **Reply #38 on:** 10 Apr 2013, 06:19 pm »

Quote from: roscoeiii on 10 Apr 2013, 06:09 pm

Interesting. I would have thought these would need a bit more power than a 300B SET amps could provide. At any point did the amps seem to run out of steam?

Oh yeah, we had to turn it down

. 15w amps and 5" drivers still obey the laws of physics.
Large room too (20' ceiling). But at medium volumes (the amp is good for >10w), female vocals etc were nicely rendered. As noted previously, nice full bass for such a tiny box. I should have taken a pic with them sitting on the Cornwalls.

K Shep · « **Reply #39 on:** 10 Apr 2013, 07:17 pm »

Quote from: roscoeiii on 10 Apr 2013, 06:09 pm

Interesting. I would have thought these would need a bit more power than a 300B SET amps could provide. At any point did the amps seem to run out of steam?

I'm concerned about the speakers sensitivity (2.83V/1m) 85dB too. While the LS50's sing driven by my A21 amp 250 watts RMS @ 8Ω I will wait to hear how they sound with 38 tube watts linear or 21 tube watts triode.