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Is the LXmini by Siegfried Linkwitz the answer for home audio?

Shazb0t

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No, that's a straw man.
Rather, it's the interpretation of the results where discussion is appropriate. (I would think that should be obvious by now.)

And all of this assumes that multiple NFS testers would achieve the same objective measurements to begin with.

Dave.
Okay, so then we're clear that your problem is with Amir and not with the beneficial objective data we would all be privy to from Klippel NFS measurements. It makes one wonder why you chose, unprompted, to mention that you own the speakers and are physically close to Amir just to insinuate that he's not capable of measuring the speakers on a forum devoted to doing that exact thing though doesn't it? I think there's a word for people who do things like that?
I would not have any issue if some other LXmini owner decided to contribute a speaker to Amir for NFS testing. It won't be me though. :)
You can beat me up for my stance on this. I'm totally fine with that.

Dave.
Okay, I believe that you made it pretty easy to do just that. Happily obliged.
Measurement is not the problem. Interpretation of the data is.

In section 10 of Dr. Olive's paper on the preference score model, he discussed its limitation. There isn't a good model to relate the perceived spatial attributes of a speaker with its measurements. Listeners have strong preference to perceived SPACIOUSNESS...
I'm sure that you're aware that what interests people about Amir's reviews is the use of the Klippel NFS to measure the complete sound field of a speaker. Olive's preference formula, which has been hashed out over and over and over and over (get it?) again despite not being an official part of the "review", as a means to discourage or cast doubt on the validity of the speaker reviews is not helpful. Regardless of how anyone feels about the subjective part of the review, more reviews which contain the objective measurements should be encouraged.
I doubt that the NFS will provide any additional insight but as Dave said if someone wants to build / donate a LXmini for NFS testing I wouldn’t mind the additional data. However, the lack of a NFS test is not going to keep me from enjoying the LXminis, YMMV.

Michael
You doubt that a full measurement of the speakers sound field, reflections, and distortion measurements would add any value to this speakers discussion? I doubt that you're correct. Guess where the smart money is?
The fear is not of the measurements, the objection is to the rigid interpretation of Harmon/Toole/Olive, i.e. anything that falls outside of a singular model of directivity is automatically frowned upon.

My pair is not in current use, but my build is much too shoddy to withstand shipping.
This is more Olive's Preference score strawmaning. See? I wasn't lying about it being a bad repetitive argument! The Klippel NFS doesn't rigidly define anything. You know that, I know that, everyone in this forum knows that. Measuring this speaker on the Klippel NFS would pose no special sound field challenge. And yes, you and others here are clearly afraid that the measurements may show it to have directivity or other issues which you would have no rational way to defend. So don't measure one! I totally get it. Ignorance is bliss.
 
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ooheadsoo

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Okay, so then we're clear that your problem is with Amir and not with the beneficial objective data we would all be privy to from Klippel NFS measurements. It makes one wonder why you chose, unprompted, to mention that you own the speakers and are physically close to Amir just to insinuate that he's not capable of measuring the speakers on a forum devoted to doing that exact thing though doesn't it? I think there's a word for people who do things like that?

Okay, I believe that you made it pretty easy to do just that. Happily obliged.

I'm sure that you're aware that what interests people about Amir's reviews is the use of the Klippel NFS to measure the complete sound field of a speaker. Strawmaning Olive's preference formula, which has been done over and over and over and over (get it?) again despite not being an official part of the "review", as a reason that the Klippel measurements aren't valid is not a rationale argument. Please stop doing it.

You doubt that a full measurement of the speakers sound field, reflections, and distortion measurements would add any value to this speakers discussion? I doubt that you're correct. Guess where the smart money is?
This is more Olive's Preference score strawmaning. See? I wasn't lying about it being a bad repetitive argument! The Klippel NFS doesn't rigidly define anything. You know that, I know that, everyone in this forum knows that. Measuring this speaker on the Klippel NFS would pose no special sound field challenge. And yes, you and others here are clearly afraid that the measurements may show it to have directivity or other issues which you would have no rationale way to defend. So don't measure one! I totally get it. Ignorance is bliss.
Offensive responses like yours don't help encourage anyone to send it in. The directivity is part of the design. I'd love to see measurements and some open minded subjective impressions.
 

richard12511

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I live really close and considered taking my spare LXmini pair to Amir for NFS testing, but based on the speaker reviews from Amir I've seen so far, I don't see any point in it. These speakers are outside his understanding of what a speaker radiation pattern objective might be.
.

They may not look great by CEA2034 standards(though I'm not totally convinced that they won't), but why does that matter? If Amir doesn't like them, who cares? The data will still be very valuable for the rest of us, especially those like me who are looking to build a set someday, so I have to disagree that there's "no point". These unique out of the box speakers like this are exactly the ones who's measurements will teach us the most. With enough of them, maybe we can start to develop a different model(ie not Olive score) to predict their performance.

The only other omni tested here actually did really well, and Amir liked the sound, despite it being the worst measuring speaker so far. I have a feeling he'd like this one quite a bit more ;), and this speaker should do especially well in mono. Opposite of something like the LRS, which (imo) really needs stereo to show it's strengths.
 

richard12511

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At the base level the electronics are very simple, $95 miniDSP 2X4 and 4 channels of amplification. Adding subs can be as simple as adding another miniDSP 2X4 and 2 more channels of amplification. Of course if you want more input options the 2X4HD or the 4X10HD are great choices.

The nice thing to me is that the DSP and amplifiers can be repurposed for something else down the line. When I built these I already had DSP and amplifiers from past projects so it was literally just the cost of the speakers themselves.

Michael

Is that 4 channels per speaker? or 4 total?
 

mdsimon2

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Okay, so then we're clear that your problem is with Amir and not with the beneficial objective data we would all be privy to from Klippel NFS measurements. It makes one wonder why you chose, unprompted, to mention that you own the speakers and are physically close to Amir just to insinuate that he's not capable of measuring the speakers on a forum devoted to doing that exact thing though doesn't it? I think there's a word for people who do things like that?

Okay, I believe that you made it pretty easy to do just that. Happily obliged.

I'm sure that you're aware that what interests people about Amir's reviews is the use of the Klippel NFS to measure the complete sound field of a speaker. Strawmaning Olive's preference formula, which has been done over and over and over and over (get it?) again despite not being an official part of the "review", as a reason that the Klippel measurements aren't valid is not a rationale argument. Please stop doing it.

You doubt that a full measurement of the speakers sound field, reflections, and distortion measurements would add any value to this speakers discussion? I doubt that you're correct. Guess where the smart money is?
This is more Olive's Preference score strawmaning. See? I wasn't lying about it being a bad repetitive argument! The Klippel NFS doesn't rigidly define anything. You know that, I know that, everyone in this forum knows that. Measuring this speaker on the Klippel NFS would pose no special sound field challenge. And yes, you and others here are clearly afraid that the measurements may show it to have directivity or other issues which you would have no rationale way to defend. So don't measure one! I totally get it. Ignorance is bliss.

Not sure how making inflammatory posts like this helps progress the discussion.

My comments on the value of NFS measurements were specifically in response abdo123 and potential design modifications.

Like others I would be more than happy to see additional data from the NFS and have never said otherwise. That being said given the low cost and ease of construction I wouldn't hesitate on building a pair without NFS measurements.

Michael
 

richard12511

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ASR can be an odd place sometimes.

For those insisting on a NFS test, what do you think that this test will show that is not already known from SL’s outdoor measurement and significant explanation of the design on his website?

Michael

Anechoic horizontal and vertical off axis measurements would be hugely useful for designing PEQs to eliminate the room problems and fully reveal the speakers themselves and make them sound even better than already do.

With typical in room measurements, it's very difficult(or impossible) to fully remove the room with PEQ, since you have no idea if deviations are due to the room or the speaker itself. All of my speakers that Amir has measured sound better now that I can EQ based on anechoic measurements.

BTW, I'd be willing to chip in for shipping for anyone that does send them in, and I bet others would be to. We've seen enough box speaker measurements, and we already know what measurements to look for there, but we still have a lot more to learn when it comes to measurements of speakers like this.
 

Shazb0t

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Offensive responses like yours don't help encourage anyone to send it in. The directivity is part of the design. I'd love to see measurements and some open minded subjective impressions.
My "offensive" response was literally in opposition to your post which was defending why these speakers shouldn't be sent in for measurement. What mental gymnastics are you doing to flip it around and make out like I'm the one discouraging people from sending speakers in? No sarcasm this time, I really don't understand.
Not sure how making inflammatory posts like this helps progress the discussion.

My comments on the value of NFS measurements were specifically in response abdo123 and potential design modifications.

Like others I would be more than happy to see additional data from the NFS and have never said otherwise. That being said given the low cost and ease of construction I wouldn't hesitate on building a pair without NFS measurements.

Michael
Inflammatory and offensive? I've clearly touched a nerve. In my experience, if you're going to play the high ground card it had better be against something pretty awful. I'm not seeing it here.

So now we're all on the same page about the value of the Klippel NFS data? That's great! I guess my reading comprehension is horrible because I still find it hard to take statements like "I doubt that the NFS will provide any additional insight" and "The fear is not of the measurements, the objection is to the rigid interpretation of Harmon/Toole/Olive, i.e. anything that falls outside of a singular model of directivity is automatically frowned upon" as a call to encourage the gathering of additional data using the Klippel NFS. It almost reads like people making those statements don't believe there is value to gathering the data. I'm glad it's just my incorrect interpretation.

I think that it's important to make it clear that the way the Klippel NFS measures a speaker is not unique to a standard box speaker. It is just as valid for a speaker like these LXminis and we can all learn from reviewing the sound field data. If you don't like the Olive preference score or the Spinorama "summary" it doesn't change this fact. Measuring these on the Klippel NFS is only beneficial for more objective data. More objective data is never a bad thing. My whole point is the gathering of said data should be encouraged. Especially in this forum. If that's offensive and inflammatory to you then I don't know what else to say.
 
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mdsimon2

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Anechoic horizontal and vertical off axis measurements would be hugely useful for designing PEQs to eliminate the room problems and fully reveal the speakers themselves and make them sound even better than already do.

With typical in room measurements, it's very difficult(or impossible) to fully remove the room with PEQ, since you have no idea if deviations are due to the room or the speaker itself. All of my speakers that Amir has measured sound better now that I can EQ based on anechoic measurements.

BTW, I'd be willing to chip in for shipping for anyone that does send them in, and I bet others would be to. We've seen enough box speaker measurements, and we already know what measurements to look for there, but we still have a lot more to learn when it comes to measurements of speakers like this.

As was discussed earlier in this thread Linkwitz designed these using outdoor measurements which outside of anechoic chamber or a NFS are about as good as you can do. These have extensive equalization in the miniDSP based on these measurements.

Will the NFS be more accurate? Probably.

Will this allow someone to improve the design? Ehh, that is questionable to me given that Linkwitz brought a lot of experience to the table. I've played around with some of the other designs from OPLUG and so far I find the original design the most pleasing.

Michael
 

richard12511

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I dont get why people are so scared of measurements?
If it measures "poorly" it wont effect your enjoyment, just more data for everyone.
I am on my 3rd Linkwitz design.....

This! Or scared of Amir not liking them or saying bad things about them. The review shouldn't affect your enjoyment of the speakers. If they sounded great before the review, they'll sound just as great after the review, regardless of what Amir thinks :). The data would be very useful for owners.

I'm looking to build a set for my home gym, so if I do, I'll definitely find a way to ship them.
 

richard12511

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Sometimes measurements can be a deal breaker. I very much doubt any listeners on this forum will be auditioning any Zu's anytime soon. :p

Maybe for more traditional speakers. For non box speakers like this, I don't think we know enough about how to interpret the measurements to make that kind of judgment. The problem is, that's never gonna change until we start measuring a bunch of these to see what they "should" look like. The Canon omni speaker measured here was terrible(negative Olive score :D) by traditional interpretations, and yet Amir still enjoyed the sound. It's obvious that traditional interpretations aren't fully appropriate.
 

richard12511

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Will this allow someone to improve the design? Ehh, that is questionable to me given that Linkwitz brought a lot of experience to the table. I've played around with some of the other designs from OPLUG and so far I find the original design the most pleasing.

Michael

To me as a consumer, it's not about improving the design of the speaker, it's about improving the design of the PEQ that I make to fix the room. Having anechoic measurements may not lead to any design improvements, but they definitely will lead to them sounding better in my room.
 

MrPeabody

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The 2" driver in the Pluto is monopole, not dipole.

That's correct in that it is mounted in a way that makes this true, however the driver itself does not have a chamber like a tweeter does.

The crossover between woofer and full range also provides an overlap of cardioid dispersion, which is what provides extra rear wave cancellation below the dipole region.

I think it all but certain that what you're attempting to say is that in the frequency overlap between the woofer and the full-range driver, the radiation pattern is quasi-cardioid, due to the rear-directed radiation from the full-range driver being opposite in phase to the woofer's rear-directed radiation.

The obvious question that this raises is why it is desirable for the rear-directed radiation to have such a ginormous response dip in that overlap region, in the upper midrange. The dip is 15 dB at 180 degrees, and while it is milder at angles not directly at the rear, it is still very evident most everywhere in the rear hemisphere. The power response for the rear hemisphere has a huge, huge dip in the upper midrange, owing to the cancellation in the overlap region. This certainly does not synch up with the concept of constant directivity, and I can't imagine how this could be thought desirable.

Oh, and the mini's woofer was built, by SEAS, to Linkwitz's spec originally for the Pluto to be crossed at 1khz. You're suggesting that it's good enough for the Pluto but not for the Mini.

I made no such suggestion, and I have no interest in trying to understand how you managed to arrive at a conclusion that strange. Certainly not by any normal reasoning.

After looking at those response graphs again and thinking about it a bit more, I am more convinced than before that the Pluto is the more desirable speaker. If the rear-directed radiation is reasonably flat in frequency response, it may be desirable in a subjective way, but when it is as ragged and ugly as it is with the LXmini, I cannot fathom how it would be an improvement to the sound of the speaker. And even if the ugly rear-directed radiation is given a free pass, there is still the fact that the treble response is very uneven at modest angles horizontally off axis. The Pluto did not have these warts.
 

mdsimon2

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To me as a consumer, it's not about improving the design of the speaker, it's about improving the design of the PEQ that I make to fix the room. Having anechoic measurements may not lead to any design improvements, but they definitely will lead to them sounding better in my room.

Interesting, I am honestly a bit skeptical of room correction but I understand this perspective. Certainly anything that helps you differentiate between room response and speaker response is helpful.

Michael
 
D

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After looking at those response graphs again and thinking about it a bit more, I am more convinced than before that the Pluto is the more desirable speaker. If the rear-directed radiation is reasonably flat in frequency response, it may be desirable in a subjective way, but when it is as ragged and ugly as it is with the LXmini, I cannot fathom how it would be an improvement to the sound of the speaker. And even if the ugly rear-directed radiation is given a free pass, there is still the fact that the treble response is very uneven at modest angles horizontally off axis. The Pluto did not have these warts.
You're in luck. The drivers for the Pluto 2 system are still available. And the system can be built for not much money! :)
https://www.madisoundspeakerstore.c...o-speaker-kit-pair-drive-units-stuffing-only/

Dave.
 

ooheadsoo

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He also switched to a different woofer, and moved the crossover point lower. I can't help but wonder if the lower crossover point was made necessary by the behavior of the metal cone woofer, and if the lower crossover point is what drove the decision to switch from the 2" Aura driver to the larger full-range used in the LXmini. The true answer will never be known.
I think the mini uses the same woofer.

I don't have space for my lx minis but I see nothing personal to gain by shipping one of my poorly assembled speakers. I suppose if there were enough interest for other members to pay for dropping a speaker off at UPS for their packing and shipping service - to be sent to Dave if he were willing to verify that it is within spec, and then somehow get it to Amir, I guess I would be open to it. I don't trust my craftsmanship. But everything would have to line up because I've got a toddler and an infant draining my resources.
 
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abdo123

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I did not quite follow your reasoning for why the LXmini would be ideally suited for mitigating this conflict. Perhaps it is, but I didn't understand why you were saying that it is. This may be a very complex thing that would require an inordinately complex analysis, to do justice to the question. I'm not sure.

The LXmini design appears to solve the compromise i described, yet Siegfried never really went into detail why his design works. thus the question/discussion format.

I'm not providing reasoning for why the LXmini solves these issues, i'm just saying that it does by the testimony of their users and the designer (Wide directivity + little collapse) and i infer that its unique design that might facilitate this. The little collapse claim doesn't require a person to be a trained ear as it is noticeable to anyone with adequate hearing. However, The tonal balance claim indeed requires much more scrutiny specially since his own measurements are available.

Maybe this works in a room that is very wide and short, but then only if the listeners don't object to the exaggerated stereo effect you get with one speaker located way over to one side and the other speaker located way over to the other side. Personally, I would not like this.

This is a very controversial opinion tbh, most people i know would very much rather have the entire wall behind their speakers as the canvas for the stereo image, instead of it being a small patch in the middle of the wall. Specially for a sofa in a living room with multiple people.

I think this is also one of the strengths of the LXmini, as the sound image is not hardbound by the speakers (omni and cardioid range) and you can 'draw' on the entire wall without having the speakers at the edges of the room.


When I look at the off-axis response plots of the LXmini, one thing that gives me some concern is the way the high-frequency response becomes unusually erratic when just modestly off axis, i.e., by thirty degrees, and then worsens as you move further off axis. The presumptive explanation for this is that the driver used for the high frequencies is too large. It may have an adequately flat on-axis response, but off axis, the difference in the distance, from the listener to the near edge of the cone vs. the far edge of the cone, is well in excess of the wavelength. As such, it is to be expected that this full-range or mid-range driver would exhibit erratic off-axis response in higher frequencies. If I intended to place this speaker near a side wall, or for anyone to listen to it while located off to one side, I would possibly have some concern about this.

Acording to Siegfried:

"Thus a listener's ears should be on the dipole axis. Standing upright close to the speakers definitely darkens the timbre. "

He never claimed that he created the perfect wide directivity speaker, I think his design entertains the concept of wide directivity up until the point of where are hearing is most sensitive to spatial cues (1k to 5k Hz). From there, your speakers has to have narrow directivity or your stereo image will inevitably collapse as i mentioned in part 1.

So when you position these speakers in your room, you have to pay attention greatly to how they work over the entire range.
 
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D

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abdo123, I would suggest you search out somebody who has LXmini speakers and audition for yourself. Listen to various types of music, move left/right from the listening position, walk around the room while listening, etc, etc.

I see on the OPLUG you're interested in using a Hypex Fusion setup to implement the setup. (That should be fine.)

That said, and based on system photographs I've seen, and a few of those I've listened to, a number of owners don't have their speakers located optimally. However, the speakers are very portable and can be moved from a storage position to a listening position very easily when the wife is gone.......which is the procedure followed by some owners. :)

Dave.
 

MrPeabody

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I hadn't thought much about the LXmini vs. the Pluto until this thread came along. I thought about it some more last night and again this morning. It is not difficult to understand why Linkwitz grew dissatisfied with Pluto (even though he was obviously fond of the Aura 2" full-range driver), because as frequency increases, the directivity pattern becomes increasingly mono-directional, just like any tweeter. But at least the pattern transition from the woofer to the tweeter was smooth. At the 1 kHz crossover point, the wavelength is almost 7x greater than the diaphragm diameter. This is similar to a 12" woofer at 167 Hz. In other words, at the crossover point, the radiation pattern for the small midrange is essentially the same as it is with the woofer, in the horizontal plane at least. Of course it eventually becomes directional as it does with any tweeter, and this is what Linkwitz decided that he didn't like. So he decided to go dipole for the upper driver, to fix what he had decided was something that needed fixing. Given that the woofer isn't dipole, this seems a curious choice. Given that the woofer is omnidirectional, it seems that the obvious solution to the ostensible problem would have been to add a smaller tweeter or midrange, such as the similar 1" made by Aura, facing to the rear, in the same polarity as the 2", to achieve a bipolar pattern for treble. The bipolar pattern wouldn't be a perfect match to the omnidirectional pattern at lower frequency, but it would have been effective in addressing the ostensible problem, and it wouldn't have created the very unmistakable directivity mismatch that resulted when he replaced the 2" driver with that larger driver mounted for dipole operation. It leaves me scratching my head. I can't help but think that he liked it simply because it gave the LXmini something in common with the LX521. Or maybe not exactly that, but rather because he simply wanted for it to be a dipole speaker in some way. Whatever.
 
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