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KEF LS50 Wireless - DAR's Product of the Year 2016

Blumlein 88

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#61
Well for what it is worth here are some measures of the Revel F12 plus LSR310 subwoofer in my video setup. In the first I used an omni mic. The second was done with the same mic using a hypercardioid capsule.


Anyway, the hypercard measurement shows about half the or less phase wrapping. My thought being that it is not seeing some of the sidewall and ceiling reflections very much due to the mic directivity vs the omni.

See the attached screen capture of the results.
 

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watchnerd

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#62
you're getting a relaxation massage, once from a person who doesn't know what they're doing - you're aware of every movement of the hands, you're irritated by the level of pressure, he's spending too much time in the wrong spot; and then from someone who really knows his stuff - you're taken to another place, you feel like you're having, yes, a magical experience. Both are nominally doing the same thing, but the expertise, "quality" makes a huge difference, subjectively.
Oh, I hate those kind of relaxing massages.

I like deep tissue, painful stuff that makes me wince but really works the knots out.
 

watchnerd

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#63
Well for what it is worth here are some measures of the Revel F12 plus LSR310 subwoofer in my video setup. In the first I used an omni mic. The second was done with the same mic using a hypercardioid capsule.


Anyway, the hypercard measurement shows about half the or less phase wrapping. My thought being that it is not seeing some of the sidewall and ceiling reflections very much due to the mic directivity vs the omni.

See the attached screen capture of the results.
Huh, this is without DRC, right?

And do you have any unwrapped graphs?

So this looks to be a Harman family approach to phase...?
 

fas42

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#64
Oh, I hate those kind of relaxing massages.

I like deep tissue, painful stuff that makes me wince but really works the knots out.
You should try acupressure - my wife does that one; she finds a point where there's a problem, and your scream can be heard houses away ...
 

watchnerd

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#65
You should try acupressure - my wife does that one; she finds a point where there's a problem, and your scream can be heard houses away ...
I do. And that torturous reflexology on the feet, too. All the stuff that seems like it was refined at the Hanoi Hilton is the stuff I like.
 

Blumlein 88

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#66
Huh, this is without DRC, right?

And do you have any unwrapped graphs?

So this looks to be a Harman family approach to phase...?
No DRC is correct. I don't know it is a Harman approach to phase, but my guess is a side effect of the type of dispersion they have as a target.

As Ray has shown, if I move up to within a meter of the speaker you get much less of this. I think it is from reflections. These btw were taken with a loopback timing reference.

So if you had a wide dispersion speaker like an MBL it might be worse. A panel puts you in the nearfield position almost at those upper frequencies. The Revel is capable of very nice looking graphs at the speaker. As you move away the room is adding reflections that cause this problem. My measurements shown were from about 11 ft away from the speaker. This also is both speakers at once.

I can show unwrapped phase, but it goes off scale so much it really is not very informative.
 

watchnerd

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#67
No DRC is correct. I don't know it is a Harman approach to phase, but my guess is a side effect of the type of dispersion they have as a target.

As Ray has shown, if I move up to within a meter of the speaker you get much less of this. I think it is from reflections. These btw were taken with a loopback timing reference.

So if you had a wide dispersion speaker like an MBL it might be worse. A panel puts you in the nearfield position almost at those upper frequencies. The Revel is capable of very nice looking graphs at the speaker. As you move away the room is adding reflections that cause this problem. My measurements shown were from about 11 ft away from the speaker. This also is both speakers at once.

I can show unwrapped phase, but it goes off scale so much it really is not very informative.
A quick skim of the literature would seem to indicate that if the phase shifts are linear, it's not noticeable, but if the shifts are non-linear, we notice it.

Maybe constant absolute phase (a la panels) isn't as important as following a smooth line, which the Harman products do?
 

RayDunzl

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#68
I think it is from reflections.
Shorten the right window down to a few milliseconds and the phase display loses most of its wraps.

I think that reduces the "same frequency in the sweep coming later in time" effect, so, it points toward reflections (maybe) as the culprit for insane phase with a distant in-room measurement.

upload_2016-12-30_19-35-35.png
 

watchnerd

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#69
Shorten the right window down to a few milliseconds and the phase display loses most of its wraps.

I think that reduces the "same frequency in the sweep coming later in time" effect, so, it points toward reflections (maybe) as the culprit for insane phase with a distant in-room measurement.

View attachment 4194
This was at 11' or so, right?

I would assume if you halved the distance it would have similar effects as shortening the window, in that case...
 

Blumlein 88

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#70
Shorten the right window down to a few milliseconds and the phase display loses most of its wraps.

I think that reduces the "same frequency in the sweep coming later in time" effect, so, it points toward reflections (maybe) as the culprit for insane phase with a distant in-room measurement.

View attachment 4194
Yes, I see. You can also check on a frequency dependent window and it makes for a similar change.

I have not used REW all that much, and there is plenty I need to figure out about how it works. I initially thought it windowed rather tightly around the frequency of the sweep which appears not to be so at default settings.
 

watchnerd

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#71
Yes, I see. You can also check on a frequency dependent window and it makes for a similar change.

I have not used REW all that much, and there is plenty I need to figure out about how it works. I initially thought it windowed rather tightly around the frequency of the sweep which appears not to be so at default settings.
So conclusion:

Nothing weird happening, just wide dispersion wave guide with reflections vs slightly beamy electrostats?
 

Blumlein 88

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#72
So conclusion:

Nothing weird happening, just wide dispersion wave guide with reflections vs slightly beamy electrostats?
Hardly. Wide dispersion wave guide with reflections makes for an excellent listening experience. Wide beamy electrostats are scientifically untenable speaker solutions according to Harman criteria. Says I, owner of Soundlabs which are bigger panels than Ray has. What do you think Ray, is it the sparse room reflections that hurt the ML's on the Harman speaker testing?
 

watchnerd

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#73
Hardly. Wide dispersion wave guide with reflections makes for an excellent listening experience. Wide beamy electrostats are scientifically untenable speaker solutions according to Harman criteria. Says I, owner of Soundlabs which are bigger panels than Ray has. What do you think Ray, is it the sparse room reflections that hurt the ML's on the Harman speaker testing?
Oh man are you going to make me drag my LSR305s from my office and compare them to my MLs, too, so I can join the electrostat hate fest?

I've never actually listened to them on the main rig. Maybe I'll be blown away.
 

Blumlein 88

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#74
Oh man are you going to make me drag my LSR305s from my office and compare them to my MLs, too, so I can join the electrostat hate fest?

I've never actually listened to them on the main rig. Maybe I'll be blown away.
I don't think you will be blown away. Now the 305s are good, amazingly so considering price for an active speaker. Evenness of the FR, and everything else is and sounds nicely done. I do think compared to some electrostats and even say monitor sized Harbeths or Spendors they lack something. They actually seem better balanced top to bottom than those yet while nothing to complain about it feels as if something is missing. This speaking from a purely subjective audiophool perspective. It isn't much and might not be missed except in a direct side by side comparison. And yes I have heard the 305s sitting on stands dead center of some Soundlabs so we could switch between them.

What seems missing is fine detail and apparent speed. Yes I know real speed isn't a thing other than frequency response. But subjectively the 305s sound not slow, but less fast. As if on acoustic guitar plucks they just miss the initial edge of the pluck. And they aren't bad in this sense the way bad boxes were way back when. The 305s are subtly slow on the uptake. Also while I don't really hear the box, the entity of being a speaker doesn't quite disappear the way highest quality speakers do. Plus this disappearing is less an issue used as monitors nearfield as they were intended to be used.

As a counterpoint to that, I have Revel F12 speakers. 42 inches high with tweeter, 5 inch midrange and twin 8 inch woofers. A decade old design aimed at the same criteria from Harman. If anything these may accomplish even more than the 305s for the amount of money. In basic measures like we have been posting the JBL and Revel aren't all that dissimilar. Yet the F12s do sound quick with in depth detail, and disappear very nicely thank you. They have the wide and very even subjective FR which puts them beyond the Harbeths and Spendors I referenced above. They play so evenly they don't favour one kind of music over another. All music is enjoyable over them. They also seem more dynamic in an easy going manner. These speakers also were designed to a rather low price point and construction quality is enough, but not going to impress anyone. They have me wondering if I could step up one more rung on the Revel ladder, and find something good enough I might finally let go of my electrostatic addiction.

So what accounts for the differences in the 305 vs F12 speakers in aural terms?

Apologies to the OP as we have turned this KEF LS50 thread into a different topic.

I have listened to the LS50 passive a good bit. It is very good. It has apparent speed and detail, but on its own wears that character on its sleeve so to speak. To sound balanced it simply needs a woofer (subwoofer), and a powerful amp. The speaker just doesn't seem to work hamstrung by low power regardless of the quality of that low power. Which is also part of the reason adding a sub is a good move. It unloads the lower couple octaves from the amp driving the LS50.
 

RayDunzl

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#75

watchnerd

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#77
The way I see it, if we believe that the speaker should project an anechoic rendition of the signal to our eardums, then yes, we would hope for a flat phase response there. A panel speaker does beam tightly at higher frequencies.

If, however, we believe (as I do) that the speaker should have a flat phase response, but that it is desirable for the room to make its own contribution at the listener's ear, then a phase measurement (and unsmoothed frequency response) is going to look arbitrarily chaotic at the listening position. The human listener won't hear it that way, though.

The KEF presumably has a controlled dispersion because of its concentric woofer/tweeter thingy, but not as tight as a panel speaker..?
Here's a thought question:

If I believe in the importance of phase, does that mandate I use minimum phase filters on the digital side?

Or, if the speakers + room are going to cock up the phase anyway, does it not matter?
 

Blumlein 88

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#78
Can't speak for Ray, but I think I know what he is referring to there. They test a mono speaker firing more or less from straight ahead. Rather than one from off center or of course a stereo pair each of which is off center. Assuming that is Ray's point, they have done some work and have some data to show mono testing is better than stereo testing, and that what is good for one is good for another. There is however the chance a panel is a different enough animal that maybe that data isn't definitive enough. And maybe Harman has tested that with the panel also. I know one thing that worries me is that the low end and lower midrange of panels is much more effected by spacing from the backwall. Done correctly it is enhancing to overall balance. Anywhere else is not using the panel speaker at its best. I don't see that Harman addressed that in the stuff I have read about it.
 

Blumlein 88

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#79
Here's a thought question:

If I believe in the importance of phase, does that mandate I use minimum phase filters on the digital side?

Or, if the speakers + room are going to cock up the phase anyway, does it not matter?
Here's a thought question:

If I believe in the importance of phase, does that mandate I use minimum phase filters on the digital side?

Or, if the speakers + room are going to cock up the phase anyway, does it not matter?

All available data is we aren't that sensitive to phase at higher frequencies (above 1500 hz to be arbitrary). If we are, then minimum phase filters will mess with phase in the treble more than conventional digital filters. Though the audio press gives one the opposite impression it is just one more case where audiophile conventional wisdom doesn't add up with the facts.
 

watchnerd

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#80
Can't speak for Ray, but I think I know what he is referring to there. They test a mono speaker firing more or less from straight ahead. Rather than one from off center or of course a stereo pair each of which is off center. Assuming that is Ray's point, they have done some work and have some data to show mono testing is better than stereo testing, and that what is good for one is good for another. There is however the chance a panel is a different enough animal that maybe that data isn't definitive enough. And maybe Harman has tested that with the panel also. I know one thing that worries me is that the low end and lower midrange of panels is much more effected by spacing from the backwall. Done correctly it is enhancing to overall balance. Anywhere else is not using the panel speaker at its best. I don't see that Harman addressed that in the stuff I have read about it.
Perhaps, but I think there is an easier explanation as to the poor score, something I notice when I switch back and forth between panels and dynamic speakers in the same room:

Panel speakers sound weird for just a little bit, until my ear/brain interface recalibrates itself.

I think it's entirely possible after listening to several dynamic speakers in a row, when they get to the panel (especially if blind and they can't see that it looks different) they go 'EWW' because to them it sounds like a dynamic speaker with 'something wrong' (as opposed to a different genus entirely).
 

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