How do you read AV grades?

[Steve81]

To offer a couple pennies re: the LS50...

I have heard the KEF and I think it is a neutral sounding speaker (neither too much bass nor too much treble), and overall I think it would be a very satisfying speaker to own for the long run.

The primary weakness (if you want to think of it as such) is simply the physical limits of the design. A speaker with a single 5.25" woofer has output limits, even when crossed over to a subwoofer. This is more of an issue with the LS50 for two reasons:

1. Some of the Sd isn't there to make room for the concentric tweeter; in that respect, it's probably more equivalent to a 4.5" woofer.
2. The LS50's woofer has a reasonable amount of linear excursion; however, longer throws will affect the dispersion pattern of the tweeter.

A three way version of it would be neat, but that's where the Reference line starts (which is a heck of a lot costlier).

I think the retail price in the US of $1500 is high, and there are other very good speakers that are available in the US, but probably not available in Croatia.

FWIW, if the discount I got for my gear is indicative of dealer pricing, there's a considerable amount of margin there to negotiate with.

 

[Swerd]

The primary weakness (if you want to think of it as such) is simply the physical limits of the design. A speaker with a single 5.25" woofer has output limits, even when crossed over to a subwoofer. This is more of an issue with the LS50 for two reasons:

1. Some of the Sd isn't there to make room for the concentric tweeter; in that respect, it's probably more equivalent to a 4.5" woofer.
2. The LS50's woofer has a reasonable amount of linear excursion; however, longer throws will affect the dispersion pattern of the tweeter.

About your first point…
That's one of those arguments that may be correct in theory, but maybe not in practice. When I compared it to the CAOW1, which has a 5.25" Seas woofer without a coaxial tweeter, the KEF didn't seem to suffer. If anything, it's bass sounded a bit more potent than the Seas driver.

 

[Steve81]

About your first point…
That's one of those arguments that may be correct in theory, but maybe not in practice. When I compared it to the CAOW1, which has a 5.25" Seas woofer without a coaxial tweeter, the KEF didn't seem to suffer. If anything, it's bass sounded a bit more potent than the Seas driver.

It just depends on how hard you're pushing them. At "ordinary" levels, no big deal. If you're planning to use them in an HT for reference level audio, it's something to keep in mind.

 

[KenM10759]

In theory Steve81, there may be an issue.

I practice, I can assure you there is NOT. I've heard the LS50 hooked up to a high end multi-tube amp (Prima Luna DiaLogue Premium HP w/KT120 tubes) and it was cranked loud enough that the speakers must have been near their limits. I could barely stay in the room.

And it was absolutely GLORIOUS.

 

[Steve81]

In theory Steve81, there may be an issue.

It's not theoretical mumbo-jumbo. SPL at any given frequency is directly related to volume displacement. Compared to something like your R500s, there will naturally come a point where a set of LS50s can't keep up. In this one respect, the LS50s are closer to a speaker with a single 4.5" woofer. This doesn't mean they can't fairly loud; it just means other, larger speakers that can get louder, potentially much louder. Depending on your situation & requirements, this can be significant...or not.

 

[KenM10759]

So Steve81, you've heard the LS50's playing at full tilt? I know of no speaker with a 4-1/2" driver that could approach the lows that the LS50 reliably hits.

I know from KEF's own specs that the R500 tops out at 111dB while the LS50 is distortion limited to 106dB. I presume that because the 3-way crossover is sending everything over 500hz to the twin woofers whereas the LS50's Uni-Q driver has to handle full range up to 2200hz when it kicks over to the tweeter.

At either volume I probably couldn't stay in the room. I doubt the OP needs to worry about such levels either.

 

[Steve81]

So Steve81, you've heard the LS50's playing at full tilt? I know of no speaker with a 4-1/2" driver that could approach the lows that the LS50 reliably hits.

I've had several opportunities to hear them move some air; however, that's neither here nor there with respect to the facts/science of the situation. Anyone can go to KEFs website and check out a head on shot of the LS50 to confirm that the tweeter assembly takes away a significant fraction of the cone's radiating surface; by my reckoning using the power of MS Paint, it's about 25-30% of the diaphragm by area, or roughly the drop you'd expect in going from a 5.25" woofer to a 4.5" woofer. That the LS50 manages to dig fairly deep is a matter of T/S parameters and enclosure tuning, not Sd. Still, KEF can't cheat physics. Referring back to the FR:

By the graph posted at Stereophile, the LS50's port is providing its max output around ~50Hz. However, looking an octave higher to 100Hz, the woofer is basically doing all the heavy lifting. This higher range is quite important for several reasons.
1. It's usefully above the THX standard 80Hz sub XO, so a sub won't significantly reduce the burden unless you cross higher.
2. It's an extremely active region for all types of content.
3. More volume displacement is required to pull it off than most people realize.

So lets do a comparison using a basic excursion calculator between a single 4.5" woofer and a pair of 5.25" woofers; to make things easy, we can assume both have 3mm of one-way excursion (note: this represents the Klippel tested xmax for the LS50's woofer, with the limiting factor being compliance variation). At 100Hz, at 1 meter, our 4.5" woofer can put out 95dB of sound, which is a far cry from the 106dB specified by KEF (with no qualifiers, making it worthless). Mind, 95dB at 1m is nothing to sneeze at, and in a smaller space, and/or for someone who doesn't need reference level output, it's probably adequate. However, that kind of output isn't going to cut it for everyone. In comparison, a pair of 5.25" woofers @ 100Hz @ 1m will deliver 103.5dB of output representing a gain of nearly 9dB, which is quite significant any way you slice it.

 

[killdozzer]

I hope killdozzer can find a pair of KEFs at a good price for him. Then it should be easier to find an integrated amp with enough power, let's say 50-100 watt/channel, to drive them, and with the right hook up jacks for what he plans to use.

Thanks for that. I was on a business trip so I couldn't post here. The thing actually got a little out of hands. Buck by buck I'm talking about a 1300€ speakers. I have to take it down a notch. I'm a bit swept away. 1000€ was my upper limit with no amp and a year to get enough money to buy something decent (at my rate of collecting). I have to see if I can find a lower price, or simply scale it down and look for cheaper speakers.

You did help me to give up on ATC's only because they imply a heavy spending on amp. So one thing leads to another, you buy a 1000€ speakers and then you HAVE to buy at least a 700€ amp. It's because of this and the possibility of hearing cabinet flaws that I gave up.

How much could shipping to Zagreb be for the SongSurrounds here:

http://forums.audioholics.com/forums/threads/salk-songseries-speakers-for-sale.98189/

It was only a matter of time. Next we'll be egging him on to buy a table saw and stacks of raw MDF.

No, no. Don't do that. I'm not buying a table saw. I live in a high-rise in a small apartment. What would my neighbors say?

I just remembered that the only thing you said about the TEAC option is; it's a class D. So this is out of the question for you, do you think it can't be good? I remember reading an article here on Audioholics about all the classes and differences, and I remember the author saying that a lot of people in hi-fi don't think much about this, is it really so? Are there some detectable flaws or is it simply the idea of a filter removing something from the signal that bothers you?

 

[killdozzer]

@Steve81 Thanks for joining. I'm not trying to see LS50 as a 5.25" woofers. That's not something I expect from them. I don't even have a problem with setting the sub a bit higher as you said. I'm not trying to get bookshelves to reproduce below 50Hz (or even 60). I already came to terms of the necessity of a sub.

I'm looking for a high quality sound reproduction, as flat frequency as possible, as neutral and true as possible. I like the idea of a speaker "disappearing from the picture" and simply conveying. That's why I got interested in these LS50's (and in ATC's as well, but people here said measurements don't read well). This is also why I'm interested in studio monitors, however, asking me to pay for an ugly speaker is... how can I explain this, the same as asking you not to mind a whole bunch of flaws in sound. My eyes also detect flaws, I'm not entirely ear orientated (even LS50's are ugly if you ask me, but not too much, I could forgive them as long as it is not the "piano black/orange heat combo")

The price is my biggest concern. It's out of my reach. (or at least for now)

I see you also understand a lot about the subject so I would like to ask you this: if you treat these speakers as 4.5" woofers, do you find them lacking in performance? Because, as I understood this, the point of UniQ is a source point speaker (like some Tannoy's) and not cheating the surface measurements.

hope to read you around
killdozzer

 

[Steve81]

if you treat these speakers as 4.5" woofers, do you find them lacking in performance?

Not at all. If you understand the inherent limitations of the mini-monitor form factor and are OK with those limitations or build your system to help mitigate them, the LS50's are the cat's @ss (which their original look was also commented to resemble ).

 

[fuzz092888]

However, that kind of output isn't going to cut it for everyone.

*Raises hand*

 

[Alex2507]

I just remembered that the only thing you said about the TEAC option is; it's a class D. So this is out of the question for you, do you think it can't be good? I remember reading an article here on Audioholics about all the classes and differences, and I remember the author saying that a lot of people in hi-fi don't think much about this, is it really so? Are there some detectable flaws or is it simply the idea of a filter removing something from the signal that bothers you?

I don't remember why I don't want class d.

 

[fuzz092888]

I don't remember why I don't want class d.

You like those big iron amps too much. Pure class A.

 

[Alex2507]

You like those big iron amps too much. Pure class A.

I think everything I have is a/b. I think class a is out of my reach financially and I can't have the heat. Isn't a/b the most sane option considering watts/dollar? I remember hearing some of these once. MSRP $10k IIRC. I would take those and I do remember why. They sounded just a little nicer than the Aragon competition.

 

[fuzz092888]

I think everything I have is a/b. I think class a is out of my reach financially and I can't have the heat. Isn't a/b the most sane option considering watts/dollar? I remember hearing some of these once. MSRP $10k IIRC. I would take those and I do remember why. They sounded just a little nicer than the Aragon competition.

Well, you could go class A biased A/B. Idk, I've heard some class D amps that I could be perfectly happy with. The Threshold S/300se is 150 WPC, but is class A to 50 watts.

Those look interesting. All things considered, I think my class A choice would be these or these in dreamland. However a much more realistic option would be these or these

 

[killdozzer]

@Steve81 - Thanks for the answer, but I think I know now why you started the subject of woofers, it is the fact that the LS50's data sheet is rating them as 5.25, isn't it?

The fact that I wouldn't expect them to perform as good as 5.25 but rather as a 4.5 would be doing them a huge favor. Expecting a lot less then what they say they stand for. I get it.

I expect this would also mean I have to look for a pretty good sub that would be, first of all, detectable, meaning; since it would have to actually play as a speaker you would know exactly where it is located?

And this would also mean I would have to find a good performer, not just something to fill the bottom range because it would have to do some of the work of the speakers, is that right?

 

[KenM10759]

This seems a little over the top. In the simplest terms, the LS50 is an absolutely amazing speaker that performs well above its price point. Yes, that is an opinion formed from my hearing them though backed up by countless professional reviews and owner reinforcement. It plays, clear, clean and loud (when asked to do so.) Driver size, the levels at which it would distort and all the overly technical postings about it do not diminish how it sounds and what it actually does in almost any listening environment.

With a moderate sealed subwoofer added at some point you will be very, very happy. Do not worry about locating it close to the bookshelf speakers, low frequencies are by nature harder to pinpoint source.

 

[Steve81]

This seems a little over the top. In the simplest terms, the LS50 is an absolutely amazing speaker that performs well above its price point.

@Steve81 - Thanks for the answer, but I think I know now why you started the subject of woofers, it is the fact that the LS50's data sheet is rating them as 5.25, isn't it?

The point of it all is just to understand what the LS50 is, and what it isn't. The loss of Sd in and of itself isn't huge; the LS50 is still a great speaker. It's just not going to be all things to all people. Given that the LS50 represents a very significant investment for the OP, it's something to keep in mind, not some great critique meant to steer people away from it.

I expect this would also mean I have to look for a pretty good sub that would be, first of all, detectable, meaning; since it would have to actually play as a speaker you would know exactly where it is located?

In terms of mating to a subwoofer, I'd aim for something with a flat response out to at least 200Hz. There are plenty of decent subs that will accomplish this; if SVS is available in your area, something like the SB2000 would work reasonably well. That top end extension will allow you some flexibility in setting a crossover point. I suspect 120Hz would be a good starting point that would allow you to eek out a bit more effective dynamic range and keep the LS50's woofer unruffled while minimizing the potential for localization.

If all that is a bit too rich for your blood, I'd still also keep the Q100's in mind in lieu of the LS50s. At less than half the cost, it's still a very good sounding speaker that when paired with a sub would offer you years of enjoyment.

 

[killdozzer]

With a moderate sealed subwoofer added at some point you will be very, very happy. Do not worry about locating it close to the bookshelf speakers, low frequencies are by nature harder to pinpoint source.

How about if you have to crossover high? Would this make it more easy to locate, because a small amount of midd's would go into the sub making him take the part of a center speaker?

 

[KenM10759]

True that the higher the frequency the easier it is to zero-in on the location of the source, but 100hz isn't quite there.