KEF LS50 Upgrade

[beagleman]

a comparison of what I somewhat preferred to the LS50., The Kef is the top graph. The lower graph is the Polk Rtia3. I feel bad comparing these completely different priced speakers, but now looking at tonality, they are NOT radically different, except in the deeper bass of the Polk and a bit of treble boost at the top end of the Polk.

 

[Angsty]

I get where you are going with all that, I really do, but I guess just expected "more". In what way I am not sure.

I guess where I am coming from, far less hyped speakers, have sounded really good, even on a quick listen in my past, and they were not dependent on everything else being "just right" as you mention.

I am left feeling neutral about them.
I heard mine through a friend, but one that is 2 hours away. Will find an excuse to visit him again, and take a pair (or two) of my smaller speakers and maybe do a comparison in the near future.
I think what bothered me most, is my relatively cheap speakers, (polk Rtia3) seemed better in some ways, but it is possibly just my preferences in the end. Not sure.

I feel like I should give them a try again, based on your comments.

I’m kind of a “you like what you like” guy. Not every speaker is going to work for everyone, for a whole slew of reasons. I like my LS50s in my setup and am enjoying them at this minute. Who knows, I might like the Revels even more, but I’m not changing just to change.

Price was a big factor in my ultimate decision to try the KEFs. I got them used at half of the original $1500 retail. I’m not sure they are the best $1500 small speaker even for me, but at $750 they do really great things when paired appropriately.

One thing that made a difference was speaker height. KEF recommends 24” stands; I found this to be too low for my sitting position. My stands are 29” and I greatly preferred that. The speakers are about 8” from the back wall. Near to corner placement could be appropriate for a larger room.

I would not recommend that they be placed in the middle of a room without some boundary reinforcement for low frequencies, unless you are also using a subwoofer. I had a spare 15” subwoofer in my office, but that was overkill and not a great match for the LS50.

Like I said - finicky. A bit like a diminutive diva.

 

[simplywyn]

I didn’t feel the LS50 was great until I stuck them in my main system and was surprised at how similar the midrange was to my main Thiel CS6s. I came to realize then that the problem was not my LS50s, but that they were revealing some deficiencies in the other accompanying gear and placement. A few modest tweaks and swaps in the other gear got them to sound much better. The LS50s are power hungry and really do need an amp that can handle a minimum 3.2 ohm load with sufficient current.

The LS50s seem to be finicky and it’s quite possible that the Revels sound better under a wider array of equipment and placement scenarios.

What amp did you end up pairing with the LS50s? I have Denon 600ne that only push 45W into it, do I need more power? I also have a SB1000, maybe I need another?

 

[Angsty]

As my daily driver, I use a NAD C272 with my LS50s. It’s rated at 150W into 8 ohms, with dynamic power of 460W into 2 ohms. The design is very similar to the NAD 2200 that Amir reviewed. My other system uses a Bryston 4B-ST rated at 400W continuous into 4 ohms. Both amps drive the KEFs well.

The LS50 should be used with amps that can comfortably handle a 4 ohm load. The low-ish sensitivity of 85dB/2.83V/m suggests a minimum of 50W continuous rating into 4 ohms, 100W in a larger room.

With my my NAD amp, I can push the LS50s harder than I feel comfortable with, but having the additional power on hand means I never have to worry about clipping, “soft” or otherwise.

If you have a lower rated amp, and you don’t want to change it, you’d probably be happier with speakers that present an easier to drive load. It’s a diminutive diva, but she really can sing with the right accompaniment!

 

[OMas]

Sorry for the noob question, is there a software that can generate optimal parametric Eq based on one room's readings?

Hey Mitoda,
“Optimal” EQ? I assume that would be some variant on the inverse of the in–room response to create “flat” in–room. Though I do use linear phase EQ to “voice” speakers, optimal to me is Dirac’s room compensation solutions. The best I’ve heard and I’ve heard quite a few. They correct for amplitude and phase, rather than just plain EQ.

 

[Angsty]

Recently, I had the opportunity to use my KEFs with two different amps: A Sony STR-SE501 AV receiver and a Bryston B100-SST integrated amp.

To be fair, I picked up the Sony at a thrift store for an inexpensive audio system in a spare room. The Sony is rated at 100W into 8 ohms and is 4 ohm capable with a slide switch. Its spec is THD 0.09% and SNR -96 db at a reference level that is unknown to me at this time. The Sony was able to drive the KEFs to my listening level (60-75 db) with no issues - I didn't try to push it, as it was merely being used as a back-up. The sound was a little bright, but pleasant. Bass was all there. There was some low-level hiss/noise that was masked at higher volumes. It sounded a bit flat and 2-dimensional, but okay for background usage. I was not wowed, but I was not repelled, either. The point here is that the nominal 100W mass-market amp had no glaring issues with the load at reasonable volumes.

The Bryston, on the other hand, was spectacular. Very clean, very neutral, very detailed. Much less background hiss/noise. The Bryston is rated at 100W int 8 ohms and 180W into 4 ohms. The sound quality rivaled that of my main system with more expensive Thiel & Bryston components (with less bass, of course). I'd highly recommend the B100 or B135 if it's within your budget - it plays superbly with the LS50 and really shows what the speakers are capable of.

So, my finding was that 100W of rated power is more than enough for this speaker pair if the amp is 4 ohm compatible.

However, the higher quality the amplification, the better results you will get from the LS50. It responds well to quality (high SINAD, flat FR, high dynamic range, etc). Feel free to start with a mid-range amp and move up as your budget allows if you like the sound from this speaker. What is upstream of the LS50 is likely to be more of a restriction than the LS50 itself.

My NAD is currently being refurbished at Quirk Audio, hence the "pinch hitters".

 

[renevoorburg]

Kef LS50 Meta anechoic measurements: https://www.soundstagenetwork.com/i...&catid=77:loudspeaker-measurements&Itemid=153

Seems pretty good, at first sight!

 

[thewas]

Also discussed here https://www.audiosciencereview.com/...bsorption-technology.15713/page-5#post-566483