Kef wireless 50's

[Coolio]

We only have the record/cd or file of that recording that is all we have, the most accurate reproduction will be via the loudspeaker with the flattest response in a well treated room.
Keith

While fairly accurate, not entirely so. There are more factors involved, one important is related to distortion - sounds produced by the playback system + room that aren't there in the recording.

If you take a look at the distortion chart in Rew with speakers you have measured, you'll see that any system produces audible distortion with a combination of linear and nonlinear distortion.

Other factors relate to the time domain, measurable with group delay readings, impulse-response and step response- though more difficult to read right. I, for one, don't understand what the graphs are telling me.

And then you have the systems acoustical power response and accumulated acceleration level related to the spl level. (http://www.audioxpress.com/article/Measurement-and-Perception-of-Regular-Loudspeaker-Distortion)

It's not really possible to determine if something sounds good based only on the frequency response alone, although it's a good indication.

I always thought that the cd had a harder sound that made the piercing thin central spike of the trumpet sound irredeemably harsh. However I think there were and are many factors; my cd vs vinyl set up at the time, in particular. I once heard that 1991 cd on a very good system with WLM speakers that had these astonishing tweeters, and it made me rethink my vinyl vs digital thoughts on this recording.

To go back to what I was asking specifically, and what I claimed the LS50 cannot do; it is to convey with equal force the piercing central spike of the trumpet and the breathy halo around it that emerges particualrly in the quietest and breathiest moments. These are not separate sounds, of course, they are part of a very complex tonal whole, and yet they will invariably sound separate. The real task, I would suggest, is neither to homogenise them in some nice midrangey compromise, nor to make the central spike of the trumpet's tone seem starkly (and for some, painfully) detached and forward.

It is easy to make the sound more palatable by rolling off the frequency above about 11-12KHz. That can be mistaken for a more beautiful (and tolerable) sound. I think the Impex release, which has real finesse and class, does slightly roll off the sound there, although I couldn't swear to it.

I'd still be interested to hear from anyone who can compare the 1991 cd release (which is easily available on streaming sites I believe) on different speakers.

The way you explain the perceived soundeffect I suspect a time-domain issue before anything else.
Could be other stuff, like distortion from the elements. Interesting case, though.

 

[S-Man]

so you tried them 1 hour in your system and been claiming ever since that you prefer kef ls50 over p3esr?

yes, metalic tonality is obvious with my kef ls50. when I compare scm7v3 vs p3esr, its the same similar sound and both are very close to each other in many ways. plunk the kef ls50 in and its a totally different "sound".

Ill try again in my setup with my friends this week!

what is not natural with p3esr?

I think Elephantears will agree the listening tests on the LS50, whilst short were reasonably conclusive.
I had the P3ESRs over a week or so. I also tried them in another system. Maybe they don't work that well when used with an active crossover to convert them to 3-way? I thought they sounded over damped - transient decay of sounds ended abruptly rather than decaying to inaudibility. My pal who also tried them came to a similar conclusion although he described the effect differently.


BTW I have also heard the LS50s at length in another system, and without going into details, I can assure you that the room and and ancilliary components were exactly how they are meant to be used.

 

[Purité Audio]

I have just measured and compared the active and passive versions of the KEF LS50's written up here,
https://www.puriteaudio.co.uk/blog

Keith

 

[Tantris]

What is your chosen mix/mastering for this? I ask as it sounds like a bit of a minefield, especially digitally as it has been remixed from the multi-track at least twice and I'm not sure the original vinyl mix ever made it onto digital. I have three different digital versions; a mid-80s Japanese 32DP CD, the 1965-68 2nd Quintet box set and the version in the big Complete Collumbia Albums Collection and I've also had the early-90s Columbia Jazz issue with the border. All are different to some degree, and they certainly seem to be brighter the more recent they are. I actually prefer the 80s Japanese 32DP, though I don't know it it is the original mix or not. It has rather more warmth to it, the later issues sounding a bit thin to me. The box set is certainly a remix, and I think the version in the CCAC is another slightly later one. I'd actually like to find a proper US '2-eye' stereo 1st press just to try and figure out what it originally sounded like!

Hmm, it's probably the Miles Davis LP I play most, and it turns out I have an original 1965 stereo issue, not a 1971 reissue as I had thought. (The matrix stampers listed on discogs make it clear). I must check the rest. Anyway, it sounds very good indeed - the mastering sounds subtle and sophisticated, matching the understated complexity of the music. There's no loss of definition in the momentary spikes from the trumpet, nor in the ensuing dialogue between trumpet and tenor saxophone.

 

[Elephantears]

I have just measured and compared the active and passive versions of the KEF LS50's written up here,
https://www.puriteaudio.co.uk/blog

Keith

This is interesting, because from a quick look it shows a deep presence region trough when used close to the wall, then another trough (a bit more on the passive) at about 6KHz. I wonder if it is the recess in these regions, rather than the highest harmonics, that is the cause of the trumpet's lack of presence.

The task now is to show how your measurements translate into listening. If you could compare the Miles Davis track we are discussing on both active and passive, and then listen to it on your Kii3s, that should tell us some interesting things.

 

[Elephantears]

There's no loss of definition in the momentary spikes from the trumpet, nor in the ensuing dialogue between trumpet and tenor saxophone.

It should be said that this is one of the most exqusite dialogues between trumpet and saxophone in all of recorded music. The unity these musicians achieved on that recording is breathtaking, and borders on telepathy, hence the album's name.

 

[Tony L]

Graphs without scales are less than meaningless! I'll assume the badly cropped ones have the same scale as the intact one. I'm surprised how little top end both have, it looks to be over 20db down at about 15k to the bass. The mid-band notch when closely positioned to the wall is nasty. That certainly behaves diferently to other small speakers (e.g. my JR149s) though they are infinite baffle. Interesting to compare with Stereophile's measurements here. Evidence of some treble droop (that I tend to like with small speakers), but minus the mid-band notch and Keith's signature room boom! FWIW I've liked the LS50 when I've heard them and felt they gave a pair of ProAc D1s (twice the price) a very good run indeed, beating them in certain respects. It would be interesting to know what sort of amp money one has to spend on the passives to beat the actives. They seem to be one of those small speakers that really respond to good powerful amplification.

PS For contrast here's an old plot of my JR149s driven with ten watts of tube goodness, they are about 7-8" from the rear wall:

 

[Elephantears]

Graphs without scales are less than meaningless!

PS For contrast here's an old plot of my JR149s driven with ten watts of tube goodness, they are about 7-8" from the rear wall:

Yes, we really need detailed graphs, especially from someone who makes a living by asking people to measure their speakers and put up frequency response charts.

Tony, the JR149 looks like a nice benign curve (at least with the smoothing); pleasing mid-range emphasis, mild presence restraint. It actually looks a bit similar to how the SHL5Plus measures in my room down to the mid-bass, below which my room manages to mess everything up. How big is your record ship room with the JR149s.

 

[Purité Audio]

I am happy to send anyone the original REW MDAT files, they are most comprehensive, if you download REW your can open every parameter , I just don't think I can post them here.hence the screenshots.
Keith

 

[Elephantears]

Just post screenshots where the levels are comprehensible.

Are you willing to give the Miles Davis piece a comparative listen on your various speakers? This would help us get to the heart of the issue of brass instruments and the LS50s.

 

[Purité Audio]

This is the LS50 'wireless' active blue and the passive version red,both measured from the same position at 50cm from the rear wall, the wall behind the loudspeakers.
ls50 active passive 50cm
by
keith Cooper, on Flickr

 

[Ayya Khema]

I think Elephantears will agree the listening tests on the LS50, whilst short were reasonably conclusive.
I had the P3ESRs over a week or so. I also tried them in another system. Maybe they don't work that well when used with an active crossover to convert them to 3-way? I thought they sounded over damped - transient decay of sounds ended abruptly rather than decaying to inaudibility. My pal who also tried them came to a similar conclusion although he described the effect differently.


BTW I have also heard the LS50s at length in another system, and without going into details, I can assure you that the room and and ancilliary components were exactly how they are meant to be used.

imo, the kef ls50 are totally outclassed to my p3 or scm7. its not even a contest but ill give them another try: i own them afterall but cannot enjoy them onebiy so this is very subjective

i personally have had terrible experience with minidsp. but the p3esr when highpassed passively sounds very ghod, much better then played fullrange. when i cross them, the innacurate bass is gone. imo the p3esr lacks seriously under 120hz. i crossed them at 120hz and so the sub really fills in and it gives incredible weight to the p3esr.

interesting about decay of notes. i agree the p3esr seems to shorten decay a bit and also sounds a bit unnopen.. but i experience this only in the treble, the mid seem to decay naturally. id be curious to hear more about that.i have had the same experience and i find it very interesting phenomena (decay shorten) i will test this week vs scm7 and kef ls50 to understand the decay differences.

as for the transients mashed, when highpassed i find them clean. i have noticed that the transients can sounds mashed and slow with a underpowered amp, as i experienced very bad sound with p3esr with certain amps, but with a good or powerful amp, the attack is fine.
at this point i consider them almost unlistenable under 100hz since they sound so compressed, but when highpassed i find them very tight.

imo, kef ls50 overemphazing the transients: pushing the attack elements a bit unnaturally. this is all very subjective though

what speakers are you using sman?

 

[Tony L]

Tony, the JR149 looks like a nice benign curve (at least with the smoothing); pleasing mid-range emphasis, mild presence restraint. It actually looks a bit similar to how the SHL5Plus measures in my room down to the mid-bass, below which my room manages to mess everything up. How big is your record ship room with the JR149s.

The room is a typical back bedroom size, but I listen to them in a rather odd way, very near-field; the 149s are about 2m apart, but the distance from either to the listening bean bag is only about 1.4m, i.e. they are far wider apart than I am from them. I set them up very much how I remember near-fields in the better studios are and to give a really wide and deep soundstage. The negative is this puts me right in the middle of the room so they sound rather more bass-light than they do if I move a bit more forward or back. Even so they sound stunning with material that suits this kind of presentation, they really can vanish leaving a very believable image. There are many times I'm listening and wondering why I need anything bigger or more comlex, they just work!

I'm curious as to why the bass reads quite so jaggedly here, it doesn't sound it. I guess it might just be the mic in a null or something. As ever with this stuff the measurements are largely meaningless as one only needs to move the mic a cm or two and all the dips and troughs move, and often by a lot! At a very simplistic 'what note does my room boom on?' kind of level it is useful (though I can tell that at least as well with a bass or synth!), but to do something serious like try to align compression drivers, pair-match speakers etc it is in the chocolate teapot category unless one has an anechoic chamber and the ability to clamp everything down so it is with in a few mm between measurements IMO. I love the idea of measurement but have found the results next to useless for much of what I've been trying to do.

 

[AndyU]

TonyL - when you are playing your bass in the same room, where do you find yourself putting the speaker, and where do you play? Near the walls, well away from the walls, you close to the speakers, away from the speaker .. where is best for hearing what you are playing?

 

[Tony L]

TonyL - when you are playing your bass in the same room, where do you find yourself putting the speaker, and where do you play? Near the walls, well away from the walls, you close to the speakers, away from the speaker .. where is best for hearing what you are playing?

My bass amp is a little Roland Cube CB100, somewhere between a practice amp and small backline. I just have it tucked against a wall in the back room between one of the La Scalas and a Ikea Expidit I use for record shop customer's part-filled orders, i.e. it is in a convenient location rather than the best sounding one. I play so quietly it sounds clean and clear, though it doesn't dig deep at all, the bottom few notes definitely lack weight and heft (I guess due to it being so small). I can actually get a far better bass sound with the amp simulation in Logic Pro X! I've never actually cranked it up since I've owned it, it is just used to noodle/practice a bit when watching TV or whatever, so maybe 65db tops. If Im actually recording something I just plug into the MacBook, use Logic Pro and monitor through the La Scalas.

 

[DNM]

i crossed them at 120hz and so the sub really fills in and it gives incredible weight to the p3esr.

You cross a single sub at 120hz? Even situated in the middle of the two mains you'd be able to localise the sub and hear the lowest vocal freq's coming out of a separate box.

I've personally had excellent experience with minidsp. What passive filter are you using as a matter of interest?

 

[S-Man]

imo, the kef ls50 are totally outclassed to my p3 or scm7. its not even a contest but ill give them another try: i own them afterall but cannot enjoy them onebiy so this is very subjective

i personally have had terrible experience with minidsp. but the p3esr when highpassed passively sounds very ghod, much better then played fullrange. when i cross them, the innacurate bass is gone. imo the p3esr lacks seriously under 120hz. i crossed them at 120hz and so the sub really fills in and it gives incredible weight to the p3esr.

interesting about decay of notes. i agree the p3esr seems to shorten decay a bit and also sounds a bit unnopen.. but i experience this only in the treble, the mid seem to decay naturally. id be curious to hear more about that.i have had the same experience and i find it very interesting phenomena (decay shorten) i will test this week vs scm7 and kef ls50 to understand the decay differences.

as for the transients mashed, when highpassed i find them clean. i have noticed that the transients can sounds mashed and slow with a underpowered amp, as i experienced very bad sound with p3esr with certain amps, but with a good or powerful amp, the attack is fine.
at this point i consider them almost unlistenable under 100hz since they sound so compressed, but when highpassed i find them very tight.

imo, kef ls50 overemphazing the transients: pushing the attack elements a bit unnaturally. this is all very subjective though

what speakers are you using sman?

I don't think I mentioned "mashed transients", only the decay. I doubt that the several amps I own were struggling with the P3s, they seem to be able to drive Gale 401s to high levels without strain.
I didn't try the P3s without lf assistance. The improvement by converting all these small speakers to semi-active 3-way is so huge I don't even bother to listen to them as 2-ways anymore.

My own speakers are these:
http://murphyblaster.com/content.php?f=CAOW1.html

I wish I could find something that comes close to them, but so far have failed with JR149, LS3/5A, P3ESR, LS50, ESL57QA, ESL63, Gale 401 (all crossed to my lf system).
Suggestions welcomed!

 

[Ayya Khema]

I don't think I mentioned "mashed transients", only the decay. I doubt that the several amps I own were struggling with the P3s, they seem to be able to drive Gale 401s to high levels without strain.
I didn't try the P3s without lf assistance. The improvement by converting all these small speakers to semi-active 3-way is so huge I don't even bother to listen to them as 2-ways anymore.

My own speakers are these:
http://murphyblaster.com/content.php?f=CAOW1.html

I wish I could find something that comes close to them, but so far have failed with JR149, LS3/5A, P3ESR, LS50, ESL57QA, ESL63, Gale 401 (all crossed to my lf system).
Suggestions welcomed!

i couldnt agree more. the p3esr are so compressed down low without highpass id consider them useless for anything but 3 feet away

but when highpassed + sub, i agree minimonitors becomes beast

ill try proac d2 tomorrow

 

[Tony L]

I have no idea why anyone would expect to fill a room with loud music with a mini-monitor! For me they are for low-level near-field listening, ideally late at night with the lights out where they can do that real 3d 'transportation' thing. The LS50s appeal as they are a proper point source which should help in such a scenario. By saying that it really is astonishing just how big and powerful a sound can come out of certain small speakers (ProAcs, AE1s etc) when driven with a real cost no object powerhouse (Krell etc), but I'd still choose a 'good big 'un' to fill a room.

 

[S-Man]

I have no idea why anyone would expect to fill a room with loud music with a mini-monitor! For me they are for low-level near-field listening, ideally late at night with the lights out where they can do that real 3d 'transportation' thing. The LS50s appeal as they are a proper point source which should help in such a scenario. By saying that it really is astonishing just how big and powerful a sound can come out of certain small speakers (ProAcs, AE1s etc) when driven with a real cost no object powerhouse (Krell etc), but I'd still choose a 'good big 'un' to fill a room.

Because you can have your cake and eat it!

You lose none of the mini monitor 3D stuff when played quietly, but you can have world class full range monitor stuff when you're in the mood for a blast.