KEF LS50 disappointment :(

[BigH]

well I had the mission 780se, they are about the same size as CM1s. I much preferred the 780s, in fact apart from looks I don't think I could live with the cm1s. One speaker designed described the CM1s as some of the worst speakers he had ever heard. OK there are better modern speakers than the CM1s.

I rather enjoy the CM1s. They play all day while I work and I've ditched several deemed better speakers and stayed with the CM1s.

That 3dB dip in the presence region (upper midrange) is a deal breaker for those that listen to music for 1-2 hours per day or per week and expect the hi-fi to blow them away each time with excitement and details.

i think a lot is down to taste, some people will like the way the CM1s present the music, however some will prefer something more accurate. The main problem I have with the Cm1s is the bass. Also I believe people get used to a certain sound, so going from an old set up which they like maybe something of a shock to them.

 

[Vladimir]

i think a lot is down to taste, some people will like the way the CM1s present the music, however some will prefer something more accurate. The main problem I have with the Cm1s is the bass. Also I believe people get used to a certain sound, so going from an old set up which they like maybe something of a shock to them.

It depends at what point in the frequency response your mind decides to use as a reference point. If it happens to be the bottom of the midrange dip, the midrange will sound OK but there will be too much bass. If you choose the bass peak as a reference point, then midrange and presence will feel lacking and the speakers will sound dull. The key is to have your setup and room positioning in that way it makes your mind choose a refference point for a somewhat balanced sound.

A video for shkumar on this topic.

 

[shkumar4963]

Thanks Vlad. I really liked the video and subscribed to Rocky Mountain Audio Fest series of videos. THANKS

 

[lindsayt]

... and Heybrook just made a chipboard box and wired some OEM stock drivers to a crossover.

I think Peter Comeau might have applied a little more thought to their design than you suggested there.

I mean no disrespect to Peter Comeau. I'm simply suggesting why the B&W CM1 and Heybrook HB1 are not very comparable design and price wise. All flaws lindsayt might point to the CM1, I confirm without hesitation. However, if we need to find a vintage vs modern speaker design comparison to determine how much speaker design has/hasn't progressed, we need a smaller vintage speaker to compare to the CM1 or a bigger modern speaker to compare to the HB1.

Is there a 2 way mini monitor with a 5" woofer that can do what the CM1 does but in 1970 or 1980, and of course available for the everyday consumer?

Ok, so what modern speakers do you propose we should compare to the HB1's?

And the big thing that I'm comparing is what speakers we can get for the price - adjusted for inflation.

So we're looking at modern speakers that retail at about £400.

Are there any that sound better than HB1's?

If not, then at the budget end, it's fair to conclude that there has been no progress in sound quality in budget speaker design over the last 30 years.

And for all those who scoff at what I'm saying, let me bring my HB1's round to your place to compare against your modern budget speakers. Or buy a pair of your own. They'll only set you back about £30.

 

[matthewpiano]

To be fair most things could better the CM1s. Horrid things. In my opinion of course. Other opinions are available.

 

[lindsayt]

You'll be telling us cars, mobile phones, TV's, CD players, motorcycles and just about everything designed and built 30 years ago are better than todays. Of course it's nonsense and demonstrably so. Your posts are a perfect illustration of the much loathed 'good old days' syndrome.

Not at all. As in my previous post, get a hold of some HB1's and compare them to any modern speaker that sells for about £400 new.

Your post is a non sequitor. Speakers are speakers. They are not cars, mobile phones, TV's, CD players, motorcycles.

Some things have improved over the last 30 years. Some things haven't.

Compare a 1984 BMW E28 5 series with a 2014 5 series and it will be immediately gobsmackingly obvious that the modern car is better overall.

Do the same with budget speakers and it will be immediately obvious that they are not similar to cars.

When it comes to speakers and progress in sound quality for the price paid, they are more similar to cameras (picture quality) than they are to cars, TV's, mobile phones.

I am not a luddite. I do not suffer from the "good old days" syndrome. I am a realist. And I am merely telling you the way it is. If you don't believe me, go and do your own listening tests.

 

[steve_1979]

Hi Jack Oclee-Brown.

I've enjoyed reading your posts. It's always interesting to read comments from knowledgeable people who work in the HiFi design business. A couple of questions if you may.

1. Are KEF planning any more active versions of their speakers from further up the product range or is it only going to be limited to the 300A speakers? I bet active Blade's or Reference speakers would be great. Or even a unique range of active speakers separate to the passive ones.

2. What are your thoughts on coaxial drivers in two-way speakers compared to coaxial drivers in three-way speakers? I've always preferred them in three way speakers where there's a coax mid/tweeter and a separate woofer for the bass so that there's less movement in the midrange part of the coax driver causing doppler interference with the tweeter. I'm less convinced by their use in two-way speakers even though it's only a relatively minor issue and I have to admit that while I'm not a massive fan of KEF two-way speakers I've never heard one which I disliked either.

 

[Vladimir]

Not at all. As in my previous post, get a hold of some HB1's and compare them to any modern speaker that sells for about £400 new.

Plenty of KEFs, MAs, B&Ws, Tannoys, Yamahas, Behringers etc. that better the HB1s, including the B&W CM1. I replaced the HB1s with Tannoy Profile 631s.

Are you saying Vifa has never made a better OEM driver since the HB1s?

 

[Jota180]

You'll be telling us cars, mobile phones, TV's, CD players, motorcycles and just about everything designed and built 30 years ago are better than todays. Of course it's nonsense and demonstrably so. Your posts are a perfect illustration of the much loathed 'good old days' syndrome.

Not at all. As in my previous post, get a hold of some HB1's and compare them to any modern speaker that sells for about £400 new.

Your post is a non sequitor. Speakers are speakers. They are not cars, mobile phones, TV's, CD players, motorcycles.

Some things have improved over the last 30 years. Some things haven't.

Compare a 1984 BMW E28 5 series with a 2014 5 series and it will be immediately gobsmackingly obvious that the modern car is better overall.

Do the same with budget speakers and it will be immediately obvious that they are not similar to cars.

When it comes to speakers and progress in sound quality for the price paid, they are more similar to cameras (picture quality) than they are to cars, TV's, mobile phones.

I am not a luddite. I do not suffer from the "good old days" syndrome. I am a realist. And I am merely telling you the way it is. If you don't believe me, go and do your own listening tests.

Ok I'll start this off by asking you to define 'sound quality' in a meaningful way so we can apply your definition to speakers from different era's.

 

[Frank Harvey]

However, if we need to find a vintage vs modern speaker design comparison to determine how much speaker design has/hasn't progressed, we need a smaller vintage speaker to compare to the CM1 or a bigger modern speaker to compare to the HB1.

Is there a 2 way mini monitor with a 5" woofer that can do what the CM1 does but in 1970 or 1980, and of course available for the everyday consumer?

Many vintage speakers used sealed cabinets, so had to use larger mid/bass drivers to improve bass output compared to more modern ported loudspeakers. They'll certainly sound different, just by their very nature.

While the HB1 was excellent in its day, particularly for its price, I did get to hear a set a few years ago that a customer brought in. My memories of them are better than the reality. I found them a bit too "spitty", which to be fair, their treble was never particularly smooth. Good in their day, but up against newer speakers that have been designed with a more modern understanding of loudspeakers, they lack now. THey'd be a good used buy for the price though, as I guess they'd fetch £50 or less nowadays.

 

[Vladimir]

I can have the HB1s back from my neighbour anytime I want. I just don't want them. *unknw*

So. Any consumer grade 2-way speakers with a 5" woofer in the 70's and 80's that better the horrid B&W CM1? Shouldn't be hard, they are only a small box, two drivers and 3 component crossover.

 

[Native_bon]

Most popular does not mean correct. Of course in general tech has moved on in terms of sound quality. But this applies to a very small percentage. I would confidently say about only 5% the rest are just nice looking HIFI with horrible sound. To me the sound the HIFI industry promotes sounds hard, bright & disjointed.

 

[shkumar4963]

Jack... that explains it. In one dealer set up R300 were so superior thar I wondered what the fuss was all about for LS50. But at another dealer LS50s were in a different league and I bought them on the spot.

But I do have a question that has been bothering me.

Does amplifier have to march the speakers?

Other than having sufficient current to handle low impedence and power to compensate for low speaker sensitivity, what else is there that makes one amplifier match with a perticular speaker.

Your thoughts on this speaker to amplifier matching will be much appreciated.

Jack: Would love to hear your thoughts on needing to match an amplifier with a speaker. For example, when you do testing of LS50, do you choose a different amplifier than when you are testing R300?

I heard from some people who used to design speakers at Allison and AR Inc, that if an amplifier is of sufficient power and impedence capacity and of reasonable amplifier design (which is very mature now), it does not matter if the amplifier is 300 watts or 3000 watts and if it is at $700 or $27,000. In most all cases speaker characteristics and distortion overwhelm any distortion or frequency response of the amplifier.

On the other hand, you have audiophile magazines (like Stereophile etc.) describing the beautiful sound they get from $25,000 amplifier that is not possible from $1000 amplifier.

What is your view?

 

[BigH]

Jack... that explains it. In one dealer set up R300 were so superior thar I wondered what the fuss was all about for LS50. But at another dealer LS50s were in a different league and I bought them on the spot.

But I do have a question that has been bothering me.

Does amplifier have to march the speakers?

Other than having sufficient current to handle low impedence and power to compensate for low speaker sensitivity, what else is there that makes one amplifier match with a perticular speaker.

Your thoughts on this speaker to amplifier matching will be much appreciated.

Jack: Would love to hear your thoughts on needing to match an amplifier with a speaker. For example, when you do testing of LS50, do you choose a different amplifier than when you are testing R300?

I heard from some people who used to design speakers at Allison and AR Inc, that if an amplifier is of sufficient power and impedence capacity and of reasonable amplifier design (which is very mature now), it does not matter if the amplifier is 300 watts or 3000 watts and if it is at $700 or $27,000. In most all cases speaker characteristics and distortion overwhelm any distortion or frequency response of the amplifier.

On the other hand, you have audiophile magazines (like Stereophile etc.) describing the beautiful sound they get from $25,000 amplifier that is not possible from $1000 amplifier.

What is your view?

My view on reviews and hifi mags. is they promote hifi, they want you to spend as much money on hifi as possible, because they are in the hifi industry, the more people spend the better off they will be, they will benefit from more advertising etc. Take the reviews with a large pinch of salt. How many bad reviews do you read?

 

[BigH]

Jack... that explains it. In one dealer set up R300 were so superior thar I wondered what the fuss was all about for LS50. But at another dealer LS50s were in a different league and I bought them on the spot.

But I do have a question that has been bothering me.

Does amplifier have to march the speakers?

Other than having sufficient current to handle low impedence and power to compensate for low speaker sensitivity, what else is there that makes one amplifier match with a perticular speaker.

Your thoughts on this speaker to amplifier matching will be much appreciated.

Jack: Would love to hear your thoughts on needing to match an amplifier with a speaker. For example, when you do testing of LS50, do you choose a different amplifier than when you are testing R300?

I heard from some people who used to design speakers at Allison and AR Inc, that if an amplifier is of sufficient power and impedence capacity and of reasonable amplifier design (which is very mature now), it does not matter if the amplifier is 300 watts or 3000 watts and if it is at $700 or $27,000. In most all cases speaker characteristics and distortion overwhelm any distortion or frequency response of the amplifier.

On the other hand, you have audiophile magazines (like Stereophile etc.) describing the beautiful sound they get from $25,000 amplifier that is not possible from $1000 amplifier.

What is your view?

My view on reviews and hifi mags. is they promote hifi, they want you to spend as much money on hifi as possible, because they are in the hifi industry, the more people spend the better off they will be, they will benefit from more advertising etc. Take the reviews with a large pinch of salt. How many bad reviews do you read?

Re amps they maybe not be much difference between 300w and 3000w amps but they may well be between 30w and 300w.

 

[CnoEvil]

My view on reviews and hifi mags. is they promote hifi, they want you to spend as much money on hifi as possible, because they are in the hifi industry, the more people spend the better off they will be, they will benefit from more advertising etc. Take the reviews with a large pinch of salt. How many bad reviews do you read?

There can be useful information there.....once you cut through the hyperbole and read between the lines.

 

[lindsayt]

Ok I'll start this off by asking you to define 'sound quality' in a meaningful way so we can apply your definition to speakers from different era's.

Start a separate thread for that and I might give you my definition.

Put HB1's and CM1's in the same room. Play a variety of tracks on each speaker, one after the other at the same volume and you'll hear what I mean by the HB1's sounding significantly better than CM1's.

The CM1's are too soporifically boring to listen to. To the extent that I could never get any enjoyment from listening to them, unless I was playing XTC's Somnabulist. The HB1's, whilst they are flawed in a few areas, at least have enough enjoyable zest to them to make them enjoyable enough to listen to. I think that HB1's have a broadly similar blend of strengths and weaknesses to the LS50's. The are both a good blend of compromises.

 

[lindsayt]

I can have the HB1s back from my neighbour anytime I want. I just don't want them. *unknw*

So. Any consumer grade 2-way speakers with a 5" woofer in the 70's and 80's that better the horrid B&W CM1? Shouldn't be hard, they are only a small box, two drivers and 3 component crossover.

Your whole argument doesn't make sense to me.

I could reply by saying:

"OK, any consumer grade, small-medium sized modern sealed box 2 way speakers with an 8" woofer from the 2010's that betters the horrid HB1's? Shouldn't be hard with all the advances we've had in the last 30 years."

But that would completely miss the point that I was making in reply to Jack's small essay on speaker improvements in the last 30 years.

What is so desirable about a small speaker with a port and 5" drivers over a small-medium speaker with a sealed box and 8" drivers? I can't think of anything important. Certainly not when compared to the sound quality for the price paid.

And I for one can't understand why anyone would listen to CM1's in preference to HB1's for a variety of music. No actually I can. The sort of listener who would prefer CM1's to HB1's would be the sort of listener who wants his left brain stimulated, but doesn't care if his right brain is stimulated or not. It's the same sort of person that would take a SME 20/12a over an LP12 SE. That's fine. We're all different.

But let me make this clear. For my tastes, I want both my left brain and my right brain stimulated when I listen to music.

 

[jackocleebrown]

Hi Jack Oclee-Brown.

I've enjoyed reading your posts. It's always interesting to read comments from knowledgeable people who work in the HiFi design business. A couple of questions if you may.

Hi Steve,

Thanks!

1. Are KEF planning any more active versions of their speakers from further up the product range or is it only going to be limited to the 300A speakers? I bet active Blade's or Reference speakers would be great. Or even a unique range of active speakers separate to the passive ones.

I'm sure you'll understand that I can't really comment on future product plans. I guess that what I can say is that technically an active approach can give some benefits and if we feel are enough potential customers out there then we'll develop more. There are some challenges, in particular the electronics inside the loudspeaker would need to match up to our high standards for the acoustics. Historically our focus has been on acoustic technology for passive loudspeakers because that is our original market. Personally, I find the prospect quite exciting so hopefully we'll do some more.

2. What are your thoughts on coaxial drivers in two-way speakers compared to coaxial drivers in three-way speakers? I've always preferred them in three way speakers where there's a coax mid/tweeter and a separate woofer for the bass so that there's less movement in the midrange part of the coax driver causing doppler interference with the tweeter. I'm less convinced by their use in two-way speakers even though it's only a relatively minor issue and I have to admit that while I'm not a massive fan of KEF two-way speakers I've never heard one which I disliked either.

In general, with coaxial drivers or otherwise, I think that a three-way system is probably the best option for a proper full range loudspeaker. With a two-way system you can't really cover the full frequency range. You have a choice either to use a small LMF driver and compromise the low frequency output in some respect. Or you can use a large driver, which will allow you enough air displacement to get a decent amount of bass, but then you compromise with directivity and breakup at the upper end of the large LMF driver.

Three-way is just enough that you can cover the whole range down to a decent bass cut-off with all drivers operating pistonically and without compromising the directivity.

Going higher (to four- of five-way) it gets very hard indeed to integrate all the drivers into a single cohesive source. Directivity control gets trickier because you have a lot of drivers to fit into the speaker. You also tend to inevitably end up with a lower than ideal bottom crossover frequency, which can easily lead to a lot of group delay (time smearing) in the upper bass.

In terms of coaxial drivers in particular. For our higher end models we use only three-way configurations so that the MF cone movement is minimised to avoid modulation of the HF. However, for lower priced products, or product configurations/sizes where we cannot go three-way, I believe the other benefits of the Uni-Q outweigh the modulation issue. The other benefits primarily being a lack of lobeing and inteference at crossover and matched driver directivity giving a smoother off-axis and power response.

The Uni-Q has come a long way since the first version back in 1989. I think that the early versions showed the promice of the technology but were perhaps a little compromised in some other areas. Much of our engineering focus in the last few years has been on how to mitigate these issues. The latest versions are very much optimised to avoid interaction between the drivers. The large region around the tweeter that does not move is a key feature, as is the smooth surround designs that you'll find on the latest models.

All the best, Jack.

 

[jackocleebrown]

Jack: Would love to hear your thoughts on needing to match an amplifier with a speaker. For example, when you do testing of LS50, do you choose a different amplifier than when you are testing R300?

I heard from some people who used to design speakers at Allison and AR Inc, that if an amplifier is of sufficient power and impedence capacity and of reasonable amplifier design (which is very mature now), it does not matter if the amplifier is 300 watts or 3000 watts and if it is at $700 or $27,000. In most all cases speaker characteristics and distortion overwhelm any distortion or frequency response of the amplifier.

On the other hand, you have audiophile magazines (like Stereophile etc.) describing the beautiful sound they get from $25,000 amplifier that is not possible from $1000 amplifier.

What is your view?

Hi shkumar4963,

THD is quite a poor guide to the audibility of distortion. A typical loudspeaker generates mostly second and third harmonic distortion, typically highest in the bass region. This type of distortion is relatively quite benign (although we would obviously prefer not to have it). A poorly designed amp can generate much higher order harmonics, which are far more audible and annoying (even if they only measure a few fraction of a percent THD). One of the most audible types of distortion is a discontinuity in the output signal at the zero crossing point. This type of distortion can be generated in a poor class-B amplifier design. I believe that this is the reason you can hear the difference between amplifiers with THD measurements of say 0.05% through speakers with say 0.2%. Also keep in mind that THD is a measurement of one type of distortion (the simplest) and there are also other distortions generated with complex signals like music.

The other thing to say is that loudspeakers are in general a horrible electrical load and much more difficult for the amplifier than the test loads that are used for the distortion measurements. Info on this here: http://www.stereophile.com/reference/707heavy/

Finally, typical listening is only at a few watts of rms continuous output but music is very non-stationary and has large peaks that the amp needs to be able to reproduce. For example, 15W rms continuous output into an LS50 is very loud indeed. But with a music signal at around 15W rms you'll have something like 40V peaks in the music, which is equivalent to 400W instantaneous power for a 4ohm speaker. With conventional amp technology (class-A, B or AB) it is expensive to make an amp that can handle high instantaneous power (because this increases the waste heat dissipation substantially, putting more demand on the output stage and heatsinking etc).

I've had the opportunity to hear a lot of amps of various different prices. There are audible differences and there are designs that I have liked and disliked at all prices.

We tend to do the majority of our testing on large amps that we know well. We do this so that we focus on maximising the speaker performance in an absolute sense. The danger of using a lower performance amp is that you start to tune the speaker to compensate for the character of the amp. We generally always will then do some final testing on typical partnering equipment to check there are no nasty suprises.

Kind regards, Jack.

 

[steve_1979]

I'm sure you'll understand that I can't really comment on future product plans. I guess that what I can say is that technically an active approach can give some benefits and if we feel are enough potential customers out there then we'll develop more. There are some challenges, in particular the electronics inside the loudspeaker would need to match up to our high standards for the acoustics. Historically our focus has been on acoustic technology for passive loudspeakers because that is our original market. Personally, I find the prospect quite exciting so hopefully we'll do some more.

Fingers crossed that you do and hopefully there'll be a market for them too.

 

[steve_1979]

The Uni-Q has come a long way since the first version back in 1989. I think that the early versions showed the promice of the technology but were perhaps a little compromised in some other areas. Much of our engineering focus in the last few years has been on how to mitigate these issues. The latest versions are very much optimised to avoid interaction between the drivers. The large region around the tweeter that does not move is a key feature, as is the smooth surround designs that you'll find on the latest models.

The majority of coaxial speakers that I've heard have seemed good in some areas but tend to be quite compromised in other areas. My experience of KEF speakers is quite limited but what I've heard has been very good. You certainly seem to be leading the field where coaxial speakers are concerned as the compromises that I've noticed in most them seem to be much less present in the KEF's.

You mentioned the region around the tweeter that doesn't move and the smooth trim ring that covers the basket area around the edge of the mid/woofer where it meets the enclosure. Was this easy to develop as it looks like a relatively simple idea in concept? I know how these sort of things often tend to get very complicated once you start looking at the details required to put it into practice.

Also what are your thoughts on the Genelec 8260A speakers? They seem to be the only other company that are pushing forward with development in these areas. They seem to have similar ideas to yours but have taken it a step further by effectively having an almost perfectly smooth acoustic wave guide that goes all the way from the edge of the tweeter, across the mid-range cone (which barely has any movement on the 8260A) and right to the edge of the enclosure. The results are the best that I've ever heard from a coaxial driver.

 

[Vladimir]

I bought the B&W CM1 because they stimulate my right hemisphere. They measure badly, sound dull and are overpriced but I am a fan of the B&W dark sound. My left side and my ego would much prefer a Dynaudio.

Anyway.

Between a new pair of KEF R300 and B&W DM6, which one would you buy (for the same price) and why?

 

[Vladimir]

Building a powerfull amplifier ignorant of loudspeaker load down to 1 ohm is not expensive or difficult. Problem is you don't find those for cheap in Hi-Fi, only in the Pro world. Any typical audiophile will prefer to buy a $5000 50W hi-fi amp over a $500 500W pro amp simply on brand recognition, reviews and commentaries. Stronger watts and purer current is something I hear on all hi-fi forums constantly. Just now on the Abrahamsen v2.0 thread everyone is in proper disbelief why Abrahamsen costs 3 times less than its twin Electrocompaniet. "Something must be wrong with it", "I think I hear sibiliants in the midrange".... The disposable income wallet is used as a measuring stick for performance in Hi-Fi, not technical knowledge.

In many ways Hi-Fi is like American Pro Wrestling. To say the game is rigged, is a big understatement.

 

[Native_bon]

The Uni-Q has come a long way since the first version back in 1989. I think that the early versions showed the promice of the technology but were perhaps a little compromised in some other areas. Much of our engineering focus in the last few years has been on how to mitigate these issues. The latest versions are very much optimised to avoid interaction between the drivers. The large region around the tweeter that does not move is a key feature, as is the smooth surround designs that you'll find on the latest models.

The majority of coaxial speakers that I've heard have seemed good in some areas but tend to be quite compromised in other areas. My experience of KEF speakers is quite limited but what I've heard has been very good. You certainly seem to be leading the field where coaxial speakers are concerned as the compromises that I've noticed in most them seem to be much less present in the KEF's.

You mentioned the region around the tweeter that doesn't move and the smooth trim ring that covers the basket area around the edge of the mid/woofer where it meets the enclosure. Was this easy to develop as it looks like a relatively simple idea in concept? I know how these sort of things often tend to get very complicated once you start looking at the details required to put it into practice.

Also what are your thoughts on the Genelec 8260A speakers? They seem to be the only other company that are pushing forward with development in these areas. They seem to have similar ideas to yours but have taken it a step further by effectively having an almost perfectly smooth acoustic wave guide that goes all the way from the edge of the tweeter, across the mid-range cone (which barely has any movement on the 8260A) and right to the edge of the enclosure. The results are the best that I've ever heard from a coaxial driver.

I will buy a Genelec speaker any day. Opened, relaxed unforced sound & very good seperation of frequency ranges. But will depend if you like passive as suppose to active.