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Official Kef LS50 owners thread

Discussion in 'New Gear - Values' started by canuckaudiog, Feb 11, 2014.

  1. EngineerNate

    EngineerNate AK Subscriber Subscriber

    Messages:
    3,136
    For movies I'd make sure you're feeding the LFE signal ONLY to the sub. Certain receivers will mix it into the mains mix depending on speaker size selection.
     
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  2. wgb113

    wgb113 Well-Known Member

    Messages:
    967
    Location:
    Chester County, PA
    TBH, with so many people reporting problems after firmware updates I've avoided them like the plague. I'm still rocking the original firmware and, knock on wood, no issues. The channel swap was something I requested (and I'm sure others as well) in order to shorten my signal paths but I ended up making new interconnects before they released that updated feature.
     
  3. jazzmans

    jazzmans Super Member

    Messages:
    2,312
    Location:
    devils playground, NV
    Just a little update, I've swapped in my infinity Qe for my M&K S 150's again, driven by my bryston pre and carver PM-350 and have been listening to them as my main speakers, (instead of my Magnepan 2.5r driven by carver PM 1.5) so I switched my KEF LS-50's over to my chromecast audio, running into my lepai 7498 chip amp, (100 wpc @ 4 ohms) and chose my 'Micheal Stearns playlist on google music, and I gotta say,

    good googly moogly! they really reproduce damn near everything really, REALLY well, including the bass. I don't claim to know how the hell they do this, but the 'beam' sounds fuggin amazing. The only thing it doesn't do is the subterreanian bass, but they sure sound like they do!
    I'm serious. Good goddamn these are amazing speakers. They sound wa-ay bigger then they are.

    Half the fun, for me, is listening to the same things through different transducers, and noting the differences. My overriding goal is to find transducers that are so alike, that I can't tell them apart.

    Most of the time I'm playing my KEF's with the mighty subwoofers, my JL audio Fathom and my M&K S-something something, (dual 12" in a push/pull /hyperbaric situation) and I just attribute the bass to the subs, even though both are crossed over LOW, somewhere above 40hz, but less then 55, haven't tone checked them lately. Playing them(KEF) without any subwoofer support is amazing, because I almost don't miss any bass, I'm serious, only the thorax vibrating stuff is missing, all the 'sounds' and perceptions are there.

    Amazing little speakers!
     
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  4. neevo

    neevo Super Member

    Messages:
    1,417
    Location:
    Sydney, Australia
    @jazzmans have you tried lifting the crossover point? I used to cross mine at 48hz but have since gone to 70.

    The LS50’s do an amazing job down low hence why I had them at 48 as I didn’t want to lose that bass from the mains but have since worked out that my subs do a much better job down there and hence have lifted it.

    Might be worth playing with it a bit.
     
  5. Nick V

    Nick V New Member

    Messages:
    15
    Location:
    Edmonton, Alberta, Canada
    I'd go as high as 100-150Hz with the high pass filter on the LS50's depending on what subs you're using and their positioning relative to the speakers.

    I sold my LS50s, but most subwoofers (of similar quality to the LS50's) are much more capable in that 100Hz region than a 5" woofer (IMO).
     
  6. neevo

    neevo Super Member

    Messages:
    1,417
    Location:
    Sydney, Australia
    I’ve found something a bit different. When I changed from a 65wpc amp to 80+ I thought I’d forgotten to turn off the subs. The level of bass from the LS50’s was incredible for such a small driver. I’d read about their incredible bass but it wasn’t until I changed amps that I experienced it.

    Having said that I have mine crossed at 70hz and find I still keep some of that bass from the mains, but let the subs do a much better job below that and means I don’t push the mains too hard if the volume creeps up a bit.
     

     

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  7. Nick V

    Nick V New Member

    Messages:
    15
    Location:
    Edmonton, Alberta, Canada
    Some of it is personal preference, but technically speaking, it's easy to dig a little deeper into it.

    Below is a graph of their anechoic frequency response vs total harmonic distorion + noise @ 90dB (from Soundstage! at the National Research Council of Canada). As you can see, the thd+n starts to rise sharply below 200Hz.

    [​IMG]

    If you have a UMIK-1 with REW, you can test this in your system.

    Below is just an example of a pretty good subwoofer (the Monoprice Monolith 15" ported subwoofer). If you look closely, it has a very low 4.3% THD @ 80Hz at maximum output (much louder than the 90dB in the LS50 graph above). I wished they showed distortion and output at 100Hz and 150Hz, but this is what I could come up with quickly.

    [​IMG]

    Here's another example from Data-Bass. A Martin Logan Dynamo 1500X (I have one in my main system). You can see that the THD @ 100dB is below 5% all the way to 200Hz. It plays flat to about 150Hz.

    [​IMG]
     
    Last edited: Oct 13, 2018
  8. johnvb

    johnvb Active Member

    Messages:
    214
    I had been high passing the KEFs for a while now, with a MiniDSP digital box ahead of the DAC, and a multi-channel preamp. Recently change the pre to a 2 channel W4S mPRE, to match the pair of mAMPs I use. Ditched the MiniDSP unit up front, also the iFi tube buffer, kept in the Schiit Loki EQ and added an iFi SPDIF iPurifier in front of the old Channel Island DAC I use. Also changed the speaker wire from cheapo magnetic stuff to 4' lengths of Black Mesh Oval 9. Once everything gets broke in, will try the built-in DAC of the mPRE.

    The upgrade resulted in deeper bass, and higher resolution. So my opinion is that high passing the KEF thing may not be as important as one would think.

    Next step is raising the pair of sealed subs with diy sub trap platforms, and adding a MiniDSP balanced 2x4 on to the bass, after the pre. Hopefully keeping the sub delay low. The one big advantage of the Mini DSP unit ahead of the DAC was the ability to delay all channels. We'll see if removing this is going to cause an issue. Right now running sub-less and still enjoying the sound.

    [​IMG]
     
    Last edited: Oct 16, 2018
    roadie1 and Nick V like this.
  9. wgb113

    wgb113 Well-Known Member

    Messages:
    967
    Location:
    Chester County, PA
    Good info @Nick V . Do you know of anyone that's measured the LS50W vs the LS50 passives? I wonder if KEF's DSP keeps that distortion under control?

    I lived with the original LS50s paired with a McIntosh MC5200 and a pair of Dayton SUB800s for a number of years and the LS50W trounces that trio in every regard.

    Bill
     
  10. roadie1

    roadie1 AK Subscriber Subscriber

    Messages:
    2,204
    Location:
    Chillicothe, OH
    I bought a pair after reading several glowing reviews but they didn't do much for me. Maybe it's the room or amp or any of many variables. Just for fun I'm going to try them again today. I read somewhere maybe here, that the reviewer thought the music sounded fake. That's sorta what I hear.

    I'll be using a Rega Elex and Rega Apollo-R. I can't wait to try them again.
     
  11. Route 66

    Route 66 AK Subscriber Subscriber

    Messages:
    714
    Location:
    Burbank
    I've had a pair for about two years now. About every six months I switch them out for my Maggie .7s. They each have their strengths and weaknesses but I love them both.

    IMG_0869.jpeg
     
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  12. roadie1

    roadie1 AK Subscriber Subscriber

    Messages:
    2,204
    Location:
    Chillicothe, OH
    Crap! I just had to read this thread. Now I have another to choose from in my stable. Seriously, they do sound mighty fine don't they. Fun this afternoon for me!
     
  13. wgb113

    wgb113 Well-Known Member

    Messages:
    967
    Location:
    Chester County, PA
    The active "wireless" version put them in another league altogether.
     
  14. jazzmans

    jazzmans Super Member

    Messages:
    2,312
    Location:
    devils playground, NV
    So, I've been listening to the LS-50 more often lately, and I gotta say, without any subwoofer assistence, that tiny little speaker presents an amazingly full frequency soundfield. I was playing Carnage Visors by the Cure, (was originally available as side b of the cassette tape "Faith" and is a glorious slow, subtle bass solilaquy (feck spelling)

    seriously amazing speakers!

    And realize I'm comparing them to Infinity's nearly TOTL speaker in the early eighties, which means Emit tweeters and Emim midranges(RS2b), and Magnepan's glorious true ribbon(2.5R), so they are playing with big boys for sure.


    I love mine more and more the more I listen to them.
     
  15. prighello

    prighello Super Member

    Messages:
    1,192
    Location:
    Fountain Hills, AZ
    I'm surprised no one has mentioned the new LSX. A smaller active version of the LS50w. They look interesting but are tiny. I'm happy with my passives for now.
     
  16. FastG

    FastG AK Subscriber Subscriber

    Messages:
    208
    Location:
    laurel MD
    I listened to the LSX at the Capital Audio Fest, there outstanding considering there even smaller size. I love my LS50's but the LS50W were amazing, so I am going to sell off mine and a couple of other stuff I have laying around to finance a pair.

    Graham
     

     

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  17. prighello

    prighello Super Member

    Messages:
    1,192
    Location:
    Fountain Hills, AZ
    That dsp must make a real difference as both active versions dig lower than the passives. I'm surprised to see a -3db in the mid 50s hz for the LXS vs 79db for the larger passives. Need to hear these active versions sometime!
     
  18. FastG

    FastG AK Subscriber Subscriber

    Messages:
    208
    Location:
    laurel MD
    It was interesting with the LW50W (not sure about the LSX) you can drive them via ethernet cable, WiFi or Blurtooth. The sound quality was in that order as well. But it was fun to see them get swapped around, very versatile.

    Graham
     
  19. wgb113

    wgb113 Well-Known Member

    Messages:
    967
    Location:
    Chester County, PA
    I've mentioned before but I lived with the original LS50 paired with a McIntosh MA6300 for 4 years and the LS50W is a different speaker altogether. It only amplifies everything I loved about the passive version and adds substantially more low end.

    With the passives I ran dual 8" subs to fill in the lows. With the LS50W I feel no need for a sub 98% of the time.
     
  20. johnvb

    johnvb Active Member

    Messages:
    214
    The one thing I miss with my old Maggies, that the KEFs can't do, is the whole backwave thing. Earlier this year, I pulled out my old modded MMGs, and propped them up to the height of what a new 1.7 would be. The resolution couldn't touch the KEFs, but still love that Maggie di-pole sound. I may have to get a pair and switch them off every now and then, like you and Route 66 do.
     
    Last edited: Nov 13, 2018 at 8:20 PM
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