Legacy Studio HD vs KEF LS50

KEW

KEW

Audioholic Overlord
For anyone interested, test data for the sister - Twin6 Be, is available in this pdf file:
https://www.focal.com/sites/www.focal.fr/files/shared/catalog/presse/resolution-2.pdf

Note that the horizontal and vertical off-axis graphs indicate that this speaker should be stood up so as to limit floor and ceiling bounce! I'm not sure if the are a formal MTM (probably not since the two woofers have different XO points), but they are close enough to suggest standing them up!
 
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<eargiant

Senior Audioholic
Got them yesterday. Have been listening, tweaking positioning and gathering impressions.
 
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<eargiant

Senior Audioholic
So far, there are things I like about this speaker, some things I'd prefer and some things that surprised me - but before I give my thoughts on the LS50 I wanted to ask those of you that own or have ever owned a pair a question on the driver excursion and the "rated" max spl of this speaker.

I'm finding that on certain tracks (well recorded stuff) some bass/mid-bass impacts take the the speaker to its limit and I can hear a thap-thap-thap that is clearly a mechanical limitation of the driver. I get that these are small speakers and I was expecting to miss out on a lot of low end content and impact but I was not expecting to hear that excursion noise on a speaker of this caliber especially one that is rated to 106db.

My concern is that if/when I add a sub I would like to run these full range but will be unable to play some dynamic music at a slightly higher level without hearing that noise.

Any thoughts or suggestions?
 
Steve81

Steve81

Audioholics Five-0
Any thoughts or suggestions?
The LS50's mid/woofer xmax is about 3mm, with an Sd of ~75 square cm, which isn't a whole lot of linear displacement to work with. Even with a port to augment output below 100Hz, there's obviously limits as to how much clean output you can expect. This is exacerbated by running the system full range, as there is nothing to protect the driver below tune, so it can very easily hit its mechanical limits with the right material.
 
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PENG

Audioholic Slumlord
I have never heard any such mechanical noise nor audible distortion but I have also never pushed them to anywhere near even 90 dB from my seat or say 95-96 dB at 1 meter.

I am now test driving them with my new 5 watt amp full range, sounds just as transparent so far.
 
KenM10759

KenM10759

Audioholic Samurai
I have a KEF Kube 10b subwoofer with my LS50's and because I use them on my desktop, the Bluesound Powernode 2 streamer/amp's 60 watts per channel can drive them far louder than I ever want to listen at only 30" from them. I have the audio output settings of the Powernode 2 set to "no subwoofer" so the LS50's are getting full range signal. Never have had anything close to excursion limit problems. I love 'em.
 
KEW

KEW

Audioholic Overlord
So far, there are things I like about this speaker, some things I'd prefer and some things that surprised me - but before I give my thoughts on the LS50 I wanted to ask those of you that own or have ever owned a pair a question on the driver excursion and the "rated" max spl of this speaker.

I'm finding that on certain tracks (well recorded stuff) some bass/mid-bass impacts take the the speaker to its limit and I can hear a thap-thap-thap that is clearly a mechanical limitation of the driver. I get that these are small speakers and I was expecting to miss out on a lot of low end content and impact but I was not expecting to hear that excursion noise on a speaker of this caliber especially one that is rated to 106db.

My concern is that if/when I add a sub I would like to run these full range but will be unable to play some dynamic music at a slightly higher level without hearing that noise.

Any thoughts or suggestions?
Why would you want to run these speakers full-range? If you listen loud, it is never a good idea to run a small ported (especially, sealed speakers aren't as prone to bass issues) speaker full range. KEF may have put some type of filter to reduce signals below the port tuning frequency.
Can you give some examples of what music and how loud and what you are using for the amp? That can help verify that you are putting high demands vs a defective speaker (which is very unlikely, but worth verifying) or amp clipping with bass(?).

In light of Steve81's well informed comments, the obvious is that you can add a sub crossed at 100-120 Hz and get the superb quality of these speakers while avoiding the problem areas you are having with bass.
 
E

<eargiant

Senior Audioholic
The LS50's mid/woofer xmax is about 3mm, with an Sd of ~75 square cm, which isn't a whole lot of linear displacement to work with. Even with a port to augment output below 100Hz, there's obviously limits as to how much clean output you can expect. This is exacerbated by running the system full range, as there is nothing to protect the driver below tune, so it can very easily hit its mechanical limits with the right material.
Interesting, thanks. Would you happen to know how that compares to the CM5 S1 or S2?

This seems to support what I am hearing, I just figured since they're rated at 106 dB that I would be able to play something like the song I reference in my response to KEW down below at a little over 90 dB in a small room without issues.

I have never heard any such mechanical noise nor audible distortion but I have also never pushed them to anywhere near even 90 dB from my seat or say 95-96 dB at 1 meter.

I am now test driving them with my new 5 watt amp full range, sounds just as transparent so far.
That's actually the exact point where I start to hear that noise, in the low 90dB range @ about an 8' distance. Keep in mind that the room I have them in is very small, 13' x 10.5' x 7'. It's not like I'm trying to achieve that spl in a large space.

I have a KEF Kube 10b subwoofer with my LS50's and because I use them on my desktop, the Bluesound Powernode 2 streamer/amp's 60 watts per channel can drive them far louder than I ever want to listen at only 30" from them. I have the audio output settings of the Powernode 2 set to "no subwoofer" so the LS50's are getting full range signal. Never have had anything close to excursion limit problems. I love 'em.
Yes, as I was tinkering and setting them up in order to get the best possible imaging I quickly realized that nearfield is what these are really designed for and is what they excel at. I will discuss more about my impressions of the LS50s in a later post. I figured we'd get past this excursion issue first.

Why would you want to run these speakers full-range? If you listen loud, it is never a good idea to run a small ported (especially, sealed speakers aren't as prone to bass issues) speaker full range. KEF may have put some type of filter to reduce signals below the port tuning frequency.
Can you give some examples of what music and how loud and what you are using for the amp? That can help verify that you are putting high demands vs a defective speaker (which is very unlikely, but worth verifying) or amp clipping with bass(?).

In light of Steve81's well informed comments, the obvious is that you can add a sub crossed at 100-120 Hz and get the superb quality of these speakers while avoiding the problem areas you are having with bass.
I guess I was hoping that the LS50 would at least handle dynamic impacts as well as the other two ~$1.5k retail speakers I've had in here recently. For example the slightly larger CM5s can handle everything (within reason) that I can throw at them without flinching, I can also say the same for the LSiM 703s (but of course they are large cabinets). I guess it boils down to an application thing.

As far as I know the Yamaha A-S801 has a sub out that crosses at 90 Hz but I believe the speakers still run full range. The Hsu unit you linked is interesting, thanks.

Anyway, I kinda like using a stand-mount that I can run full-range. I was a heretic when it came to subs and stand-mounts for 2 channel music but I tried a REL sub and I became a believer. I connect it as they suggest, directly to the amps speaker terminals (same ones that the stand-mounts are connected to so the speakers and sub get the same full range signal) and the results are fantastic. I guess it could sound good also with a line level but you know how it is, it's human nature to stick with something that you've had excellent results with.

One of my test songs where I can hear this excursion limit is Chuck Mangione's Children of Sanchez (Overture). This is an old school recording, we're not talking about a loudness compressed recording or even a recording with overcooked bass, these are just highly dynamic impactful drum hits. At the 3:38 mark the drums kick in and you can hear it there. The LS50s can't handle them at slightly above 90dB.
 
Steve81

Steve81

Audioholics Five-0
Interesting, thanks. Would you happen to know how that compares to the CM5 S1 or S2?

This seems to support what I am hearing, I just figured since they're rated at 106 dB that I would be able to play something like the song I reference in my response to KEW down below at a little over 90 dB in a small room without issues.
Can't say I know much of anything about the B&W drivers (the raw LS50 driver was tested over at medleysmusings.com, which isn't working at the moment apparently). However, for comparison, I can offer the Philharmonitor and the BMR.

The Philharmonitor uses a 5.5" Revelator driver with a Sd of 95cm^2 and an xmax of 6.5mm, or about 2.7x the displacement of the LS50 midwoofer.
The BMR uses a 7" Scan Classic driver with a Sd of 145cm^2 and an xmax of 6.5mm, for more than 4x the displacement of the LS50.

Just driver to driver, ignoring port contributions, those differences in displacement are worth ~8.5dB and ~12dB respectively.
 
P

PENG

Audioholic Slumlord
That's actually the exact point where I start to hear that noise, in the low 90dB range @ about an 8' distance. Keep in mind that the room I have them in is very small, 13' x 10.5' x 7'. It's not like I'm trying to achieve that spl in a large space.
Those speakers are obviously not designed to take a lot of power and/or to play loud, but they should do fine in that room to get you 90 dB average without issue. One thing you should double check is all the connections, especially if you are using banana plugs. If they are even slightly loose, you are going to get that funny noise during the high current flow moments.
 
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<eargiant

Senior Audioholic
Those speakers are obviously not designed to take a lot of power and/or to play loud, but they should do fine in that room to get you 90 dB average without issue. One thing you should double check is all the connections, especially if you are using banana plugs. If they are even slightly loose, you are going to get that funny noise during the high current flow moments.
Yup, first thing I checked was the connections. Everything was tight and tidy, I was using cleanly cut bare wire on both ends and the contact points were perfect. As a matter of fact, in that room I have the amp several feet away from the speakers and I was using 14 gauge wire. Although the run was within the Audioholics recommended distance limits for a 4 ohm load using 14 AWG wire I didn't take any chances. I physically moved the Yamaha between the speakers and used a very short run of the same 14 gauge wire. The results were the same. I agree, as good as they are - they are not designed for for higher dynamic spl.

I'll post a brief summary of my impressions tomorrow if I have a chance. I found much to like about these speakers as well as a few surprises, especially in light of their reputation.
 
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E

<eargiant

Senior Audioholic
As promised, some brief impressions.

I won't go into the dynamic driver limitations since we already covered that.

I found them harder to set-up for proper imaging than I expected. That's when I realized that they are really designed for true nearfield applications. As I got really close (desktop/mixboard close) they seemed to image better and open up. The speakers were about 6 feet apart and I was sitting about 9 feet away so after much trial and error I settled on a toe-in with the drivers aiming behind my ears. The song I've been using lately as a final test for center image is Stevie Wonder's Village Ghetto Land from Songs in the Key of Life. On this track, as soon as he starts singing his voice should be projecting slightly to the right of center. As he gets to the end of the very first sentence and says "with me" you should be able to clearly hear his voice turn toward the center. As he continues to sing you should be able to hear his voice projection move from slightly right of center to center and back to slightly right of center. The closer I got to the LS50 the easier this was to achieve.

The soundstage is not as open and spacious as I would have liked. This wasn't helped by the toe-in angle I selected. Everything seemed a bit compressed into a smaller space. To me this further supports my opinion that they are really best for very nearfield listening.

Midrange was clear and articulate and slightly forward. I did notice that it suffered more so than some other rear ported speakers when placed closer to the front wall than what is optimal.

While they are neutral as most good speakers are I would not classify them as highly resolving or totally transparent. They were hard to classify in a tidy box. For example, analog tape hiss was apparent/pronounced as well as vocalists breaths yet on some tracks faint instrumentation and details (that I know are there) were hidden/lost in the presentation. Hard to describe.

I found the upper midrange and highs on them to be a bit harsh on some recordings. This was a huge surprise to me and totally unexpected. For example, Una Furtiva Lagrima on Pavarotti 24 Greatest HD Tracks (24/96kHz) when he hits the high notes it was a bit jarring.

The size of this speaker is what I was looking for and the solidity of the cabinet was excellent. Not sure why they made it a two piece design with the baffle screwed in from the back (probably a cost saving move). I think it would look cleaner as a one piece design with no seam and I also would have preferred if they came with grills to cover the conspicuous drivers. These are minor quibbles but I think the "perfect" LS50 for home use would incorporate those features plus a larger midbass driver.

In the end, I personally would not group these with "Class A" speakers as Stereophile did. IMO opinion they are a solid "Class B" with the caveat that they be used nearfield and at lower to moderate spl.
 
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KEW

KEW

Audioholic Overlord
Sorry if I missed it in an earlier post, but did you cross these and run a sub?
That was the one thing I really wish I had tried when I auditioned the LS50. I had intended to, but just forgot it!
 
Irvrobinson

Irvrobinson

Audioholic Spartan
I found them harder to set-up for proper imaging than I expected. That's when I realized that they are really designed for true nearfield applications. As I got really close (desktop/mixboard close) they seemed to image better and open up.
I've only heard the LS50 in near field installations, and while I believe they could be used full-range, my impression is that one would have to have very modest loudness expectations. When used near field, as in about four feet away, I still think the LS50 is the best small monitor I've heard. And I suspect a good part of the experience is due to the concentric driver. I just heard a pair a few weeks ago, the owner had them at the back edge of his mixing board, he was using small Velodyne sub I didn't recognize with a 100Hz low-pass filter (so he said), and I thought it was a pretty compelling experience. Better than my Audioengine 5+ set-up, though in fairness the 5+ monitors are a lot cheaper.
 
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PENG

Audioholic Slumlord
As I mentioned before, the LS50 are really for near field listening (9 to 10 ft for me, wish I could sit much closer) and not designed to play loud. I also found them tricky to set up for good imaging and reported that I finally got good results using JRiver parametric EQ to EQ left and right independently. So my conclusion is that they are very sensitive to any channel level imbalance in the mid through high frequency range, at least that's what I found in my room. I cross them at 100 Hz.

By the way, I have been using them with my new 5 WPC amp for more than a week now so I can say for sure, and as expected, that they sound just fine without the power that are not used. Hungry speakers are not like hungry animals, their hungriness is highly dependent on what they are asked to do in a particular environment.
 
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<eargiant

Senior Audioholic
Sorry if I missed it in an earlier post, but did you cross these and run a sub?
That was the one thing I really wish I had tried when I auditioned the LS50. I had intended to, but just forgot it!
No, I didn't try them with a sub. I only have one sub and it's part of my main set-up. I have everything pretty well dialed in and am very, very reluctant to move anything. I did consider placing the KEFs in that system but I run the stand-mounts full range so even if I swapped the speakers to test the LS50s in that set-up with the sub it wouldn't have been productive because I have no way of crossing the speakers and clearly the LS50 need to be crossed especially if they're going to be pushed into the upper 80 dBs (especially since that is a larger room than the one I was already playing the LS50 in).
 
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