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KEF LS50 Bookshelf Speaker Review

JRiggs

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Wannna thank u guys for recommending crossing the LS50's at 100hz. I fiddled around a bit and set the crossover at 95.2 on my Yammy RX-A2040 and there was a noticeable improvement. I previously had them set on the default 80hz, which wasn't bad by any means but its rounded out the overall soundstage now.

Danka!
Yes! If it sounds better to you then do it. have played with mine from 80 - 120 Hz. My LS50 sit on top of a pair of Monolith 10 subs and currently have them crossed over at 110 Hz. Takes the strain off of the LS50.
 
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This review made me register and I'm skipping formal introduction. I doubt anyone's interested, but if you are, I'll do it later.

I have a question which will ask of you to speculate, so if you have a wooden pencil lying around, please bite on it. ;-)
To ask this question I can't hold nothing back so I'll say I'm extremely satisfied with these speakers and most of these comments how it's just another unremarkable speaker don't bother me. I'm holding onto mine until death or lottery.

But what I really can't comprehend is this lack of bass you all talk about. (???????) When I was shopping for bookshelves no other had lows nowhere near what these spouted (Revel included, perhaps it was a poor set up in the shop). First of all these speakers venture into tactile bass. Me sitting 9 feet from them and vibrations enter through couch (then my ass, sorry to say) and shake my guts at 80dB measured.

All my guests drop their jaw when they hear the lows and most of them state it's too much and want them lowered. (No DSP, Pure Direct on an Yamaha ax-890 110Wpch into 8). I have them foot and a half from the back wall and 5 feet from side walls.

And now for the walls (as Oclee stated himself about the difference in US and EU houses and in room response). I have these speakers in a 22 square meter room (240 square feet) in front of a very hard, bare concrete wall. It is 5,5 meters long (16-17 feet). Simple formula speaks of a bump in 60Hz region.

But is this enough to explain so much bass? I'm sharing a (not so precise) spectrogram of these speakers playing a song that goes bellow 30Hz. You can see the activity in the lower region, but on the bottom half, take a look at four red stripes (upper left corner of the lower half of the image) extending well beyond 50Hz. That is the EDM heavy and low beat that is played in this song.

One thing that makes my visitors laugh is when I say I plan to get a sub.

Could you give your opinions and assumptions on this huge difference you see in these measurements and the output I'm getting at my place, please?
Screenshot_20200614-135106.png
 

whazzup

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This review made me register and I'm skipping formal introduction. I doubt anyone's interested, but if you are, I'll do it later.

I have a question which will ask of you to speculate, so if you have a wooden pencil lying around, please bite on it. ;-)
To ask this question I can't hold nothing back so I'll say I'm extremely satisfied with these speakers and most of these comments how it's just another unremarkable speaker don't bother me. I'm holding onto mine until death or lottery.

But what I really can't comprehend is this lack of bass you all talk about. (???????) When I was shopping for bookshelves no other had lows nowhere near what these spouted (Revel included, perhaps it was a poor set up in the shop). First of all these speakers venture into tactile bass. Me sitting 9 feet from them and vibrations enter through couch (then my ass, sorry to say) and shake my guts at 80dB measured.

All my guests drop their jaw when they hear the lows and most of them state it's too much and want them lowered. (No DSP, Pure Direct on an Yamaha ax-890 110Wpch into 8). I have them foot and a half from the back wall and 5 feet from side walls.

And now for the walls (as Oclee stated himself about the difference in US and EU houses and in room response). I have these speakers in a 22 square meter room (240 square feet) in front of a very hard, bare concrete wall. It is 5,5 meters long (16-17 feet). Simple formula speaks of a bump in 60Hz region.

But is this enough to explain so much bass? I'm sharing a (not so precise) spectrogram of these speakers playing a song that goes bellow 30Hz. You can see the activity in the lower region, but on the bottom half, take a look at four red stripes (upper left corner of the lower half of the image) extending well beyond 50Hz. That is the EDM heavy and low beat that is played in this song.

One thing that makes my visitors laugh is when I say I plan to get a sub.

Could you give your opinions and assumptions on this huge difference you see in these measurements and the output I'm getting at my place, please? View attachment 76261
My bad, saw that you listed the amplifier already. The measurements are close mic-ed? And you have pink noise measurements rather than a specific song?
 

thewas_

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This review made me register and I'm skipping formal introduction. I doubt anyone's interested, but if you are, I'll do it later.

I have a question which will ask of you to speculate, so if you have a wooden pencil lying around, please bite on it. ;-)
To ask this question I can't hold nothing back so I'll say I'm extremely satisfied with these speakers and most of these comments how it's just another unremarkable speaker don't bother me. I'm holding onto mine until death or lottery.

But what I really can't comprehend is this lack of bass you all talk about. (???????) When I was shopping for bookshelves no other had lows nowhere near what these spouted (Revel included, perhaps it was a poor set up in the shop). First of all these speakers venture into tactile bass. Me sitting 9 feet from them and vibrations enter through couch (then my ass, sorry to say) and shake my guts at 80dB measured.

All my guests drop their jaw when they hear the lows and most of them state it's too much and want them lowered. (No DSP, Pure Direct on an Yamaha ax-890 110Wpch into 8). I have them foot and a half from the back wall and 5 feet from side walls.

And now for the walls (as Oclee stated himself about the difference in US and EU houses and in room response). I have these speakers in a 22 square meter room (240 square feet) in front of a very hard, bare concrete wall. It is 5,5 meters long (16-17 feet). Simple formula speaks of a bump in 60Hz region.

But is this enough to explain so much bass? I'm sharing a (not so precise) spectrogram of these speakers playing a song that goes bellow 30Hz. You can see the activity in the lower region, but on the bottom half, take a look at four red stripes (upper left corner of the lower half of the image) extending well beyond 50Hz. That is the EDM heavy and low beat that is played in this song.

One thing that makes my visitors laugh is when I say I plan to get a sub.

Could you give your opinions and assumptions on this huge difference you see in these measurements and the output I'm getting at my place, please? View attachment 76261
It is normal that with the lowest room mode, room gain and gain through placing loudspeakers close to solid surfaces you get a much enhanced bass compared to the anechoic measurements, here is a moving microphone measurement of my LS50 around my listening position when I used them as my desktop system, you can see they go down linearly till aproximately 33 Hz!

1596364331600.png
 
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My bad, saw that you listed the amplifier already. The measurements are close mic-ed? And you have pink noise measurements rather than a specific song?
I'm sorry, but no, I don't. The mic was at my LP. I can do a pink noise. Will this reveal low in room response?

All cards on the table, I don't have any measuring gear, this is just my smartphone app. I do, however, have the pink noise on a Sheffield Test CD.

Sorry, how close should a mic be? One third octave or full bandwidth?
 
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It is normal that with the lowest room mode, room gain and gain through placing loudspeakers close to solid surfaces you get a much enhanced bass compared to the anechoic measurements, here is a moving microphone measurement of my LS50 around my listening position when I used them as my desktop system, you can see they go down linearly till aproximately 33 Hz!

View attachment 76271
So all these things combined will reinforce the lows enough for this listening experience I and most of my guests are having? In other words, I had some "luck in the draw"? A speaker with more lows might have been too much and I could've ended up REQing them of?

Would this also mean that a sub would provide smoother and deeper lows rather than more lows?
 

thewas_

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So all these things combined will reinforce the lows enough for this listening experience I and most of my guests are having? In other words, I had some "luck in the draw"? A speaker with more lows might have been too much and I could've ended up REQing them of?
Exactly, in such a placement a loudspeaker with deeper linear bass often needs some EQ to reduce bass.

Would this also mean that a sub would provide smoother and deeper lows rather than more lows?
The biggest advantage of a well integrated sub is that you take the lower bass away from the satellites, making them playing with less distortions and higher SPL limits. Also with subwoofers you have more degrees of freedom in placement being able to compensate more problems like SBIR and with many subwoofers you can also have more constant bass at different locations in the room or even use them against room modes
 
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@whazzup what does this pink noise tell you? Do you see anything different?
Note that I don't have the LS50. Though from the graph, there's a clear dropoff from ~130hz onwards, which is more in line (though still different) with the measurements on the 1st page. As for your earlier graph in #422, I suppose your recorded song has a lot of bass for the graph to show that way?
 
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Note that I don't have the LS50. Though from the graph, there's a clear dropoff from ~130hz onwards, which is more in line (though still different) with the measurements on the 1st page. As for your earlier graph in #422, I suppose your recorded song has a lot of bass for the graph to show that way?
Well, thank you for your comment. Don't mind me saying but I get the feeling that the comparison you're making would make more sense if I was trying to prove my pair has more bass than the tested pair.

But I wasn't. I was trying to say that in my room they perform better in the low region. That's why I delibratly posted the graph of a bass heavy number to try and demonstrate that they do deliver when asked to.

Thank you for your input, though. I think I got it covered now.
 

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