Article: KEF LS50 (David) Versus JBL 4722 Cinema (Goliath) Speaker Comparison with Binaural Recordings

[nefilim]

ps. When I started with AudioLense early last year, I was looking for a mic preamp to go with my RME ADI2-Pro ... it seemed like many of them added some kind of signature or colouration which I guess is desirable to many recording engineers (can we still not add any of this in post?). One of the few I could find that seemed more suitable for accurate measurements was the Grace Design m101 ... pretty pricey but bit the bullet, been happy so far. 

[mitchco]

On 1/7/2019 at 10:20 PM, folzag said:

Thank you, Mitch.

 

The recordings were awesome and really took this review to the next level.

 

To my mind, if money and space were no object, the JBL's are hand's down the winner. Their sound felt more natural and balanced. The song coming out of them had less of a reproduction feel, like the singers were present in the room. In contrast, the KEF's I coldn't shake the feeling that the song sounded like a playback of recording made in a studio. A very good recording, but a studio all the same. It didn't make me feel "presence" for lack of a better word that the JBL did. A little too "clinical" may be.

 

Next, the KEF's with and without sub's were interesting to me because the difference is very similar to what I experience listening to my pair of Emotiva Airmotive 6s" powered monitors with and without sub's. Without sub's, it sounds nice and perfectly clear, but there's something missing... it doesn't get my body responding to the music. As soon as the sub's turn on, though, it's like the bottom half of the music comes alive and now I can feel it. At the same time, if I stop and consider it, it also feels a little made-up. Too much energy underneath. That is also something I struggle with on my sub's -- keeping the bottom from getting too strong where it starts to be fake. And again, I don't get that "fake" feeling from the JBL's.

 

I reckon the million dollar question is whether it's from the room and the speaker placement that could be easily solved, or something else, like directivity, that can't be captured without big boxes like the JBL's. In any case, I am looking forward to more reviews and more binaural recordings.

 

Many thanks and much appreciation,

Allan F.

 

Allan @folzag, thanks for taking the time to listen to the binaural recordings and your response.  It would seem our listening preferences are similar 🙂 I am still amazed at how much directivity difference there is between these two speakers, which is on the binaural recordings.

 

I feel confident that the differences are predominately directivity related. My room has enough treatment to make the decay time (RT60) not only smooth across frequency range, but within industry guidelines for my size room. It does measure towards the livelier side of the spec...

 

Thanks again,

Mitch

[mitchco]

12 hours ago, nefilim said:

ps. When I started with AudioLense early last year, I was looking for a mic preamp to go with my RME ADI2-Pro ... it seemed like many of them added some kind of signature or colouration which I guess is desirable to many recording engineers (can we still not add any of this in post?). One of the few I could find that seemed more suitable for accurate measurements was the Grace Design m101 ... pretty pricey but bit the bullet, been happy so far. 

 

The Grace Design m101 is really nice kit! Gets great reviews. It was a toss up between the Grace and the ART, and I just emptied my pockets on a sub upgrade, and went with the ART. I am happy to hear it is working well for you. Good to know. Thanks.

Mitch

[folzag]

10 hours ago, mitchco said:

 

Allan @folzag, thanks for taking the time to listen to the binaural recordings and your response.  It would seem our listening preferences are similar 🙂 I am still amazed at how much directivity difference there is between these two speakers, which is on the binaural recordings.

 

I feel confident that the differences are predominately directivity related. My room has enough treatment to make the decay time (RT60) not only smooth across frequency range, but within industry guidelines for my size room. It does measure towards the livelier side of the spec...

 

Thanks again,

Mitch

 

Oh yeah, I forgot to say...  on the other hand, for the vast majority of us where size and cost does matter, the KEF's are d*mn impressive. If one did not have a pair of big boxes to directly compare against, I find it hard to believe anyone would be dissatisfied with them paired with a properly tuned/weighted sub.

 

There is incredible price-to-performance available to us today. It's good to remind ourselves of that from time to time, and keep a proper perspective, which you have. So thanks for that too.

[isleofskye]

Very interesting article -- a very welcome departure from the preponderance of cliched fluff pieces clogging up the 'net. Well done sir.

 

I am really intrigued by the JBL 4722, so have to ask Mitchco (or anyone in the know): what do you lose or gain from a speaker like the sub $4,000 4722 (pair) versus the $5,000 JBL 4429 or the $15,000 4765? (other than the looks)  I know these are "studio" monitors not "theater" speakers, but the similarities are so many: very high spl, huge dynamics, very high/ high sensitivity, horn, etc?

 

In other words, for listening at home, why not save a boat load of money and buy these 4722s instaed of the far pricier studio monitors? 

[BattleScarze]

 

Outstanding article,  knowledge is power and I am looking forward to reading your book. Thanks for sharing your experience.  

[mitchco]

15 hours ago, isleofskye said:

Very interesting article -- a very welcome departure from the preponderance of cliched fluff pieces clogging up the 'net. Well done sir.

 

I am really intrigued by the JBL 4722, so have to ask Mitchco (or anyone in the know): what do you lose or gain from a speaker like the sub $4,000 4722 (pair) versus the $5,000 JBL 4429 or the $15,000 4765? (other than the looks)  I know these are "studio" monitors not "theater" speakers, but the similarities are so many: very high spl, huge dynamics, very high/ high sensitivity, horn, etc?

 

In other words, for listening at home, why not save a boat load of money and buy these 4722s instaed of the far pricier studio monitors? 

 

Thanks @isleofskye The 4722's ($2K US a pair) are bit narrower directivity than the 4429 or 4365. If you biamp the 4722's like I have, then you require digital or electronic XO. A multi-channel DAC, four amps, protection capacitors for the compression drivers. I upgraded the compression drivers on my 4722's based on a really long thread on AVSForum where one of the members tried several different compression drivers. Some DIY along with DSP is required to make these sound their best. Whereas, the 4429 or 4365's are ready to go as is.

 

The JBL M2's are the closest to the 4722's, as they use similar tech, but with upgraded components in the M2. If I had the dough at the time, I would have gone with the M2's. But if you have the space, like huge dynamic speakers and willing to diy a bit, the 4722's are a good choice, if you can stand how fugly they are 🙂

[davide256]

The one thing I note about the LS50's is that you are very aware they are a point source. If you don't have the center of the driver at the same level as your ears,

imaging becomes  less persuasive.

[isleofskye]

On 1/10/2019 at 8:08 AM, mitchco said:

 

Thanks @isleofskye The 4722's ($2K US a pair) are bit narrower directivity than the 4429 or 4365. If you biamp the 4722's like I have, then you require digital or electronic XO. A multi-channel DAC, four amps, protection capacitors for the compression drivers. I upgraded the compression drivers on my 4722's based on a really long thread on AVSForum where one of the members tried several different compression drivers. Some DIY along with DSP is required to make these sound their best. Whereas, the 4429 or 4365's are ready to go as is.

 

The JBL M2's are the closest to the 4722's, as they use similar tech, but with upgraded components in the M2. If I had the dough at the time, I would have gone with the M2's. But if you have the space, like huge dynamic speakers and willing to diy a bit, the 4722's are a good choice, if you can stand how fugly they are 🙂

 

Thank you very much for your reply. The careful integration of supporting electronics to make the 4722 viable for home use that you chose belies a degree of understanding that, if I'm honest, is way beyond the ken of this humanities major! The M2s and the 4367s are a bit rich for my blood but the 4429s might be contenders. But some irrational part of my brain is drawn to these 4722 monstrosities and the enormous sound they must surely produce...

[John Fitzpatrick]

On 1/10/2019 at 7:45 PM, davide256 said:

The one thing I note about the LS50's is that you are very aware they are a point source. If you don't have the center of the driver at the same level as your ears,

imaging becomes  less persuasive.

To an extent that's my observation too, I had these for a while. But its off-axis response bothered me far less than with speakers with regular drivers. KEF did many things right with LS50.

[davide256]

47 minutes ago, John Fitzpatrick said:

To an extent that's my observation too, I had these for a while. But its off-axis response bothered me far less than with speakers with regular drivers. KEF did many things right with LS50.

Agree, they are very good for dispersion in the horizontal plane, especially compared to Magnepan's. Just be sure to buy the right height or adjustable height stands for your preferred listening chair. Maggies by contrast pretty much require you to sit at the sweet spot but act as a line source so  you can sit or stand, ear height doesn't matter.

[Ragera]

Thank you Mitcha for a great review! Since you have reviewed great speakers like Dutch&Dutch 8c, Kii3, Genelec 8351, LS50, I need your help for a 5.2 set up for movies and use the same for a 2.2 set up. My living room is 38 m2 and the listening area is 25 m2. My listening distance is 3,5 meters and the speakers will be 4 meters apart. Moreover my living room is very lively with large glass windows on the side. I have done some minimalistic room treatments with curtains but more I could not do due to WAF. 

 

Due to the room situation, I have to look for speakers with a great directivity index to prevent early reflections from the glass windows and use the room correction additionally. I had narrowed my LCRs earlier to Genelec 8351 (used with software GLM) or XTZ Divine Delta (use Anthem AVR or MiniDSP for room correction). With your review KEF LS50 seems to be back in the list and has the best WAF. Moreover I will be well within budget with LS50. I love JBL speakers especially M2, 708P but getting an identical center channel for my low board is difficult and the same goes for Kii/DD 8c. XTZ is a great price worth speaker with Accuton drivers providing great detail/clarity and very musical but they do not have a waveguide or horn like Genelec or JBL and I will have a difficulty in taming reflections with XTZ. Hence I am wondering to remove XTZ off the list. 

 

How do you compare Genelec 8351 to LS50 with respect to sound quality. What amps would you suggest for LS50? I did listen LS50 in two different stores. One was excellent whereas the other was mediocre. Probably it had to do with amps. I have also listened to JBL 4429 and love them (issue with center channel). 

 

Any recommendations/suggestion from you would be very helpful for me. 

 

Kind Regards, 

 Ram

 

 

[AMR/iFi audio]

On 1/1/2019 at 5:48 PM, mitchco said:

 

View full article

 

 

Very cool work, thanks!

[mitchco]

On 1/16/2019 at 1:14 AM, Ragera said:

Thank you Mitcha for a great review! Since you have reviewed great speakers like Dutch&Dutch 8c, Kii3, Genelec 8351, LS50, I need your help for a 5.2 set up for movies and use the same for a 2.2 set up. My living room is 38 m2 and the listening area is 25 m2. My listening distance is 3,5 meters and the speakers will be 4 meters apart. Moreover my living room is very lively with large glass windows on the side. I have done some minimalistic room treatments with curtains but more I could not do due to WAF. 

 

Due to the room situation, I have to look for speakers with a great directivity index to prevent early reflections from the glass windows and use the room correction additionally. I had narrowed my LCRs earlier to Genelec 8351 (used with software GLM) or XTZ Divine Delta (use Anthem AVR or MiniDSP for room correction). With your review KEF LS50 seems to be back in the list and has the best WAF. Moreover I will be well within budget with LS50. I love JBL speakers especially M2, 708P but getting an identical center channel for my low board is difficult and the same goes for Kii/DD 8c. XTZ is a great price worth speaker with Accuton drivers providing great detail/clarity and very musical but they do not have a waveguide or horn like Genelec or JBL and I will have a difficulty in taming reflections with XTZ. Hence I am wondering to remove XTZ off the list. 

 

How do you compare Genelec 8351 to LS50 with respect to sound quality. What amps would you suggest for LS50? I did listen LS50 in two different stores. One was excellent whereas the other was mediocre. Probably it had to do with amps. I have also listened to JBL 4429 and love them (issue with center channel). 

 

Any recommendations/suggestion from you would be very helpful for me. 

 

Kind Regards, 

 Ram

 

 

 

Hi Ram @Ragera Thanks.. I have not reviewed the Genelec 8531, so can't comment. Ram, the main issue is that few speaker manufacturers publish their directivity specs. I don't see any listed for the XTZ for example. You can  get some ideas from Soundstage measurements from the NRC: https://www.soundstage.com/index.php?option=com_content&view=article&id=16  

 

While the LS50's are a steal for a grand, they are geared more towards near and mid-field listening and not best suited for your application given size of room and listening distance. Unless of course your preference is for more room sound, but you indicated you wanted to reduce  early reflections...

 

Tough to recommend due to lack of speaker manufacturer's directivity data. As a rule of thumb, which you already know, is speakers with waveguides tend to have a higher directivity index than domes... This is why I use JBL, not only for the waveguide, but they publish their directivity specs. Without the data, it is difficult to recommend...

 

Regards,

Mitch

[Kvalsvoll]

A well done experiment where you have actually done some effort to make it possible to listen for differences in the speakers alone, and you provide recorded samples so that we all can hear at least some of it.

I am not that much into brands, especially other people's brands, so I will use the names big and small for the speakers.

Listening to the samples in Room2 I find:

- Big is dry with quite flat soundstage, small is livelier with more 3D and depth.
- Big is much better in the low-mid and upper-bass, where small sounds like something is missing, transients and attack lacks power, big simply has more realism and power.
- Tonal balance is different.
- Minor differences in high freqs, where small sounds a little more colored.
- The original sounds much better - clarity, bigger more precise soundstage with real 3d, better highs. But this is expected, and explained in your article. The big speaker comes quite close to preserve balance and realism on bass and lower mid.
- Big speakers sound more like the original, but that does not mean is sounds better, becaus this is a recording that now includes the room. When I play back this on my system, all the room and coloration from my system adds to the sound.

So why do they sound so different, when they measure equal. Thing is, they do not measure equal.

If you look at the recorded samples, there is visual difference in the waveforms, wich is caused by differences in phase shift. Frequency spectrum reveals that there are quite large differences below 500hz. At 55hz the small has a huge dip. Differences are in the order 10dB, which is expected to be clearly audible.

So even though the speakers where calibrated with room correction to the same target and measured similar, they actually are different, and this can be measured.

Differences can be caused by radiation charactertistics, which alter not only decay and room contribution, but also frequency response through interaction with boundaries. The DRC did not fix all of that.

The small speaker is most likely overdriven and compress in the lower mid - upper bass. If your calibrated playback is 83dB for -20dBFS each speaker, this is about the same as 0dB on my systems, and that is quite loud, louder than most trad hifi-systems can do. Lowering the master by 10dB will give a sound level closer to what many people listen to, and less chance of overload. I suspect this will still be bordeline for this small speaker, at least you should cross over at 120hz.

To try to play at 0dB with this small speaker is not fair, they do not have the capacity needed, but they may still be good speakers and for someone who never play that loud, it would be interesting to know if there are other aspects of the sound that is compromised. Or can the small speaker sound as good as a big. This is what makes your experiment interesting.

Reducing the master volume by 10dB is one thing to try. Then both system should be properly calibrated to the bass system, crossed over perhaps around 120hz, with proper eq on the bass system and delay settings for the main speakers. That will isolate the differences more to the speakers alone - big vs small.


Regards,
Øyvind Kvålsvoll

[mitchco]

Hello @Kvalsvoll I see you just joined  CA and this is your first post. Welcome!

 

Thanks for your feedback. The only fair comparison is the LS50 plus sub vs JBL with sub as they have a similar frequency response, but very different directivity index. The LS50 standalone was to let people listen to what it sounds like without a sub.

 

Checking on the specs, The little speaker is rated at 106 dB SPL max output and 2nd & 3rd harmonics (90dB, 1m) <0.4% 175Hz-20kHz with 85dB (2.83V/1m) sensitivity. I don't think the speaker was overloaded. at 83 dB SPL at the LP.

 

I follow these levelling best practices using pro gear. 83 dB SPL I do not find too loud and has the right balance of bass to treble. For overly compressed material I drop the level down to 77 dB SPL.

 

Kind regards,

Mitch

 

 

[Kvalsvoll]

@mitchco, I should have specified exactly which of your recorded sample files I used for comparing. I am sure I used the speaker+sub files for both the large and the small speakers:

JBL 4722 plus subs

Kef LS50 plus subs

 

Those recordings are not from 2 systems that measure equal, the differences in those samples show that there are significant differences both in frequency domain and time domain. I attached 2 pictures of the frequency spectrum, one smoothed and one raw. To see for yourself you can open the samples in audacity, look at the waveforms (phase differences), analyse frequency spectrum (just make sure you select exactly the same time interval from each sample).

 

If the 2 systems measure equal, they would not present differences in frequency spectrum in such magnitudes. As to why they actually are different, when you measured them to be similar, that is another question, several possibilities exist. And finding what causes the differences in response has significance for the validity of this test, because it is not necessarily caused by the speakers alone.

[mitchco]

@Kvalsvoll I think you are taking my article too literally 🙂 I said similar frequency response, not exact. As already caveated in the article, several times, the LS50's were placed in a room null whereas the JBL's were not. This accounts for the difference in the 50 to 60 Hz dip. Again, as noted in the article, had I moved the LS50's to the exact same spot as the JBL's, would have resolved this issue and perhaps a few others. Also noted in the article, the science shows our ears/brain are not too sensitive to narrow band dips in frequency response below Schroeder.

 

 

The JBL has a near infinite baffle whereas the LS50 does not. This will cause a different Speaker Boundary Interference Response (SBIR) above 100 Hz to around 400 Hz (directivity related as the polar response will be different for both speakers in this frequency range, aside from the fact that the LS50's were not in the same physical position as the JBL's...).

 

The JBL's "constant directivity" comes into play at around 400 Hz:

 

 

Where as the LS50's does not. The rest of the differences on up in the audio band are due to the directivity differences between the two speakers.

 

As Floyd Toole and Sean Olive have often said, one cannot eq directvity. So both the measurement and correction software are "blind" to directivity, as we are measuring and correcting the sound power in the room (i.e. steady state response).

 

The point of the article is to show that two speakers eq'd "similarly not exact" sound remarkably close, yet the big difference being how much room sound is let into the recording by the wide directivity differences between these two specific speakers that represent the near opposite ends of the directivity index scale. The intent is to have folks listen to binaural recordings to hear the audible difference and determine what one's preference is with respect to how much room sound one likes mixed in with the direct sound. It is nothing more than that.

 

Enjoy the music!

 

[Kvalsvoll]

3 hours ago, mitchco said:

...

The point of the article is to show that two speakers eq'd "similarly not exact" sound remarkably close, yet the big difference being how much room sound is let into the recording by the wide directivity differences between these two specific speakers that represent the near opposite ends of the directivity index scale. The intent is to have folks listen to binaural recordings to hear the audible difference and determine what one's preference is with respect to how much room sound one likes mixed in with the direct sound. It is nothing more than that.

 

Enjoy the music!

 

And I believe you did a good job at that, the recordings show off those differences very well.

 

My findings led me to suspect that some kind of minor configuration error during the recording session could cause the responses to be more different than your measurements indicated. Looking at the plots once more, and from reading your comments, I conclude the differences in music sample spectrums are within what can be expected.

 

Would they sound more equal if setup was more accurate? Perhaps, but that would require more effort, which may not be worth it, considering the experiment actually show what you wanted as it is.

[John Fitzpatrick]

On 1/14/2019 at 7:57 PM, davide256 said:

Agree, they are very good for dispersion in the horizontal plane, especially compared to Magnepan's. Just be sure to buy the right height or adjustable height stands for your preferred listening chair. Maggies by contrast pretty much require you to sit at the sweet spot but act as a line source so  you can sit or stand, ear height doesn't matter.

 

Very good point!

[ShawnC]

@mitchco, I'm considering the LS50 Wireless for a second room and for all the conveniences of an all in one speaker to run Roon on and possibly a 5.1 setup.   I have an extra Rel subwoofer that I could hook up but was wondering about if it's possible to hook both the Low Level input from the LS50W speaker to the sub and the .1/LFE input on the sub from a receiver.  What I can't do is use Rel's high level input, which is what makes them so convenient for setting up a sub-bass system.

 

I realize you didn't review this particular speaker model but was wondering if you or someone has some input.  I'd like to run the powered speakers as full range and not use any internal crossover filters (on KEF's app) to run the sub.  I can't seem to find an answer to this question online.  There's no manual that I can find on KEFs site.

 

I would consider running the receivers Left and Right pre-outputs to the KEF's analog inputs and forgo the .1LFE option.  My main concern is running the speakers as full range and run the REl sub as it should without external crossover filters from another source (LS50W, receiver, preamp ect...).

 

Thanks for any information

[mitchco]

Hi @ShawnC Sorry, I have no experience with either. You might have better luck with your q's on AVSForum, as the LS50W is popular there... Here is one thread: https://www.avsforum.com/forum/113-subwoofers-bass-transducers/2805681-kef-ls50-wireless-sub.html

Kind regards,

Mitch

[Trdat]

Great article!

 

Interesting to see that the differences are not that big but there must be a reason why you prefer the larger JBL's?  What are those differences that make you enjoy large 15's and compression drivers when essentially you point out that the difference is minimal? 

 

"I spent quite a few years in pro sound and recording studio control rooms. The former used pattern controlled speakers and the latter was in rooms that were pretty absorbent. I got used to liking more direct sound than diffuse sound. If I was a classical music lover and frequented concert halls, likely my preference would be reversed."

 

When you mention concert halls do you mean only classical music concert type halls or general live venue halls playing a variety of music but essentially in halls?

 

[mitchco]

Thanks @Trdat Yes, as the saying goes, "there is no replacement for displacement."  🙂 At reference volume, the LS50's are nearing there max output level before audible distortion sets in, whereas the JBL's are idling. But with new tech drivers like the Purifi PTT6.5, the gap is closing...

 

Yes, classical music concert halls where the sound is mostly diffuse, for un-amplified music. This is opposed to concert halls with monster PA systems for rock bands, etc. which are designed to cover the hall with much more direct sound versus reverberate sound. There is a concept called critical distance at play here...

[Trdat]

18 hours ago, mitchco said:

Quote

Thanks @Trdat Yes, as the saying goes, "there is no replacement for displacement."  🙂 At reference volume, the LS50's are nearing there max output level before audible distortion sets in, whereas the JBL's are idling. But with new tech drivers like the Purifi PTT6.5, the gap is closing...

Fascinates me that the difference is so little. But yes of course the larger the speakers, higher SPL and more air being pushed. But it seems at lower volumes your not really feeling that difference in displacement... 

 

18 hours ago, mitchco said:

Quote

Yes, classical music concert halls where the sound is mostly diffuse, for un-amplified music. This is opposed to concert halls with monster PA systems for rock bands, etc. which are designed to cover the hall with much more direct sound versus reverberate sound. There is a concept called critical distance at play here...

 

But I am guessing that to recreate a concert hall with monster PA's at home with your sound system you will still need a certain amount of reverberate field, keeping lateral reflections though ensuring stronger direct sound from narrow dispersion speakers. 

 

So the critical distance needs to be based on the end goal of what we want to create in terms of the acoustic field.

 

P.S Your articles are sensationally educational and your hitting the spot with so many questions with many of your articles. I am sure all audiophiles are appreciating them!