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Audeze LCD-X Over Ear Open Back Headphone Review

BYRTT

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Sure, there's no problem in trying them, but the research is there to show that there's no point (& detrimental by extension I suppose) making fine corrections above 10kHz, and also filling in all those sharp peaks in the treble I also don't agree with, but no harm in trying it of course.....
First reason suggest a precision filter was because of the unique low AP benchmarked distortion for LCD-X verse HD650, next reason is in support files method can save Amir some research time well other for case than he had to send me the real files all he need to do now is a listening test and even if it fails or succeed its probably also interesting stuff for him in process can probably also hint a bit about his loaned lab gear and used methods, for example about dedicated correction myself had very positive experience order head phones with a dedicated correction from Sonarworks even those set of cans was low cost compared to for example HD650, that said i try hold bit back comment on your personal Q rules and to other user comments never boost only do cuts because there is so much into EQ in modern days where real many system chains has excess phase verse in the past using pure analog circuits plus its not always sure a digital equalizer claimed or suspected to be of minumum phase is performing 100% minimum phase, and yes acoustic EQ is hard to execute right because most often measurements are executed with less precision than in a electric domain but if we up that and magnitude deviations are linear then EQ in acoustic domain is as precise as in electric or digital domain. It was not my meaning get started on EQ subject but i did a bit long story there sorry and now cant stop hang on below dedicated corrections for those low cost cans below and notice there is didicated corrections L verse R channel in all audioband including above 10kHz area :) its the upper one that is the dedicated to my serial number and the lower one is their avarage profile, these cans for me are unlisteable raw and think most will agree, they okay listenable using avarage profile and they shine using the dedicated..
SW_HP_compare_DT-770_Pro_250_AB192G_v4.4.png

SW_HP_compare_DT-770_Pro_250_v4.4.png


.....What are the advantages of convolution vs regular parametric EQ filters?
Most normal advantage is we can do whatever FIR filter there but for this case advantage is it takes less than five minuttes create precise inverse Harman target verse the raw LCD-X curve and doing same precision curve using PEQs would probably take hours and maybe use numbers of PEQs up in three digit area.
 
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amirm

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What are the advantages of convolution vs regular parametric EQ filters?
@BYRTT explained the benefit. The drawback is that it is all or nothing. With PEQ, you can turn each one on and off and see if you like the effect or not.
 

Jimbob54

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Sure, there's no problem in trying them, but the research is there to show that there's no point (& detrimental by extension I suppose) making fine corrections above 10kHz, and also filling in all those sharp peaks in the treble I also don't agree with, but no harm in trying it of course.

What are the advantages of convolution vs regular parametric EQ filters?

One click. As a user obv.
 

Robbo99999

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First reason suggest a precision filter was because of the unique low AP benchmarked distortion for LCD-X verse HD650, next reason is in support files method can save Amir some research time well other for case than he had to send me the real files all he need to do now is a listening test and even if it fails or succeed its probably also interesting stuff for him in process can probably also hint a bit about his loaned lab gear and used methods, for example about dedicated correction myself had very positive experience order head phones with a dedicated correction from Sonarworks even those set of cans was low cost compared to for example HD650, that said i try hold bit back comment on your personal Q rules and to other user comments never boost only do cuts because there is so much into EQ in modern days where real many system chains has excess phase verse in the past using pure analog circuits plus its not always sure a digital equalizer claimed or suspected to be of minumum phase is performing 100% minimum phase, and yes acoustic EQ is hard to execute right because most often measurements are executed with less precision than in a electric domain but if we up that and magnitude deviations are linear then EQ in acoustic domain is as precise as in electric or digital domain. It was not my meaning get started on EQ subject but i did a bit long story there sorry and now cant stop hang on below dedicated corrections for those low cost cans below and notice there is didicated corrections L verse R channel in all audioband including above 10kHz area :) its the upper one that is the dedicated to my serial number and the lower one is their avarage profile, these cans for me are unlisteable raw and think most will agree, they okay listenable using avarage profile and they shine using the dedicated..
View attachment 88407
View attachment 88408


Most normal advantage is we can do whatever FIR filter there but for this case advantage is it takes less than five minuttes create precise inverse Harman target verse the raw LCD-X curve and doing same precision curve using PEQs would probably take hours and maybe use numbers of PEQs up in three digit area.
Well thanks for replying to my post and taking the time to explain your angle, I got most of the gist of what you are saying, and even more thanks that I know it's not your native language. Yes, well it's cool that it only takes 5 mins for you to come up with the automatic convolution, but my opinions still stand. Currently I think taking the time to do PEQs manually is a better solution for all the reasons previously discussed. I think I could probably agree with automatic convolution up to say 1kHz, but then I'd want to do normal manual parametric filter equalisation for everything above 1kHz. I don't know if it's possible to use both convolution filters & normal parametric filters together? However, when I EQ headphones the EQ'ing of the area up to 1kHz is not problematical using manual parametric filters in REW anyway, probably takes me 10 mins to do up to 1kHz, the treble is normally the bit I have to think about & make value judgements about where to place filters whilst trying to keep Q values relatively low. I can normally do a manual EQ for a headphone within an hour easily (and I enjoy the process), and I've found part of the most important decision is how to align the Target Curve on the measurement before even starting to create the EQ filters, in terms of shifting the Target Curve up & down on the measurement to see where the most efficient EQ can be done - often times I find aligning the Target Curve on the treble hump at 1.5kHz to 4kHz area is quite an efficient place to line it up as the treble is often the hardest part to EQ, but it depends on the frequency response.
@BYRTT explained the benefit. The drawback is that it is all or nothing. With PEQ, you can turn each one on and off and see if you like the effect or not.
Yes, often times I've switched off a few filters to see the effect. I don't think the automated precision of convolution is required if it's only about ease of implementation, then that doesn't matter if you don't mind taking a bit of extra creative time to manually create the filters yourself (like I do using REW) - giving extra flexibility in implementation & creation.

EDIT: I don't mind taking the time when I can to create a few EQ's for headphones that are reviewed here if people think that would be helpful. I mean I'm not gonna commit to doing it for each headphone or within X number of days, but I can casually create an EQ here & there if people are interested. I've done them for other folks privately here, and a few in some random headphone threads.

EDIT #2: in context to my EDIT above, here's a few of my own & others headphones I've EQ'd, just so you can see the flavour of my approach so to speak, the first two are a couple of my own headphones (these are all done from Oratory1990 measurements, but my own EQ, all to the Harman Curve):
Sennheiser HD600:
HD600 Oratory My EQ.jpg

NAD HP50:
NAD HP50 Oratory my own EQ.jpg

Sony WH1000 XM3 (10 filters):
Sony WH1000 XM3 10 filters.jpg

AKG K371:
K371 Oratory My EQ.jpg

Sennheiser HD650:
Sennheisser HD650 Oratory My EQ.jpg

Neumann NDH 20 (for RME ADI-2 which has limitation to only a few filters):
Neumann NDH 20 Oratory Measurement, My EQ.jpg
 
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bobbooo

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The one problem I see with these "automated" convolution files is that you are correcting for every little deviation in the measurement, and given the measurement above 10kHz is unreliable in both measurement terms (headphone position impacts over 10kHz greatly) and also in translation to how it would fit an individual (as individuals have wildly different responses above 10kHz) - then I see large & high Q corrections above 10kHz as likely to be doing more harm than good in terms of improving the sound. I think you'd want to limit above 10kHz changes to something similar to High Shelf Filters or broad peak filters eg Q1-2. I also feel a bit uncomfortable about (completely) filling in massive sharp dips as seen at 4kHz, I feel that this could be detrimental to the sound, I don't think high Q filters should be used if possible and even more so in the treble region.

Yep, EQing above 10 kHz is fraught with potential error, and sharp, deep dips in a headphone's frequency response (like the LCD-X's notch at 4 kHz) are often due to destructive interference in the earcup that won't be able to be fully remedied with EQ due to excess group delay in that frequency region. Oratory gives a good summary of what makes a headphone well suited to EQ:
  • perform reliably, with repeatable seal across multiple users
  • easily obtain the amount of seal that it was designed for
  • have good QC = little unit variation and no channel imbalance
  • have a relatively smooth frequency response free from high-q artifacts
  • deform the pinna as little as possible
  • have little reflections inside the earcup, especially those that lead to destructive interference. You can't fix a notch in the frequency response with EQ (non-flat excess group delay).
  • have suitably low distortion. That doesn't mean it needs to have <0.001% THD, but a headphone that has 10 % THD at 90 dB at low frequencies together with not enough bass can't be made to fit even a linear-bass target curve. Well it can, but the distortion would be so high that the sound quality would suffer a lot
Many of these features depend on each other. E.g. a headphone that deforms the pinna will not have a smooth frequency response, and will also not have a repeatable seal across multiple users, because of it deforming the pinna.

The LCD-X seems to fail on at least three of those criteria. I think much of the pitfalls of speaker EQing translate to headphone EQing actually, such as the various considerations of minimum phase (and deviations from it), as explained by John Mulcahy of REW here. Headphone excess group delay measurements and plots would be very useful here (and I haven't seen any other sites publishing them really) for knowing at which points the response is non-minimum phase and so where EQing is unlikely to work well. And then there's the fact that multiple seater positions result in high-frequency response variation that is difficult to EQ for, which has a direct analogue in headphone position on the head, which can also cause a significant change in high-frequencies (plus PRTF differences of course as you mention).
 
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Belgarathian

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Oof... Oh no.
 

Robbo99999

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Yep, EQing above 10 kHz is fraught with potential error, and sharp, deep dips in a headphone's frequency response (like the LCD-X's notch at 4 kHz) are often due to destructive interference in the earcup that won't be able to be fully remedied with EQ due to excess group delay in that frequency region. Oratory gives a good summary of what makes a headphone well suited to EQ:


I think much of the pitfalls of speaker EQing translate to headphone EQing actually, such as the various considerations of minimum phase (and deviations from it), as explained by John Mulcahy of REW here. I think headphone excess group delay measurements and plots would be very useful here (and I haven't seen any other sites publishing them really) for knowing at which points the response is non-minimum phase and so where EQing is unlikely to work well. And then there's the fact that multiple seater positions result in high-frequency response variation that is difficult to EQ for, which has a direct analogue in headphone position on the head, which can also cause a significant change in high-frequencies (plus PRTF differences of course as you mention).
Yes, all of that stuff that Oratory mentions makes sense to me. I don't really understand the phase related stuff as much, but I can broadly/loosely understand the idea of "destructive interference", but I can appreciate that dips like the headphone in this review has around 4kHz is pretty much un'EQable in terms of reaching perfection ....it can't be expected to achieve a smooth response in that treble area for this headphone.
 
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amirm

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I think headphone excess group delay measurements and plots would be very useful here (and I haven't seen any other sites publishing them really) for knowing at which points the response is non-minimum phase and so where EQing is unlikely to work well.
AP software can't generate excess group delay but can give you the absolute value:
Audeze LCD-X Headphone Group Delay Audio Measurements.png


You can visually eyeball what would be excess delay. Note that there can be some signal processing errors in the way this is computed so don't 100% rely on it.
 
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amirm

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Yes, all of that stuff that Oratory mentions makes sense to me. I don't really understand the phase related stuff as much, but I can broadly/loosely understand the idea of "destructive interference", but I can appreciate that dips like the headphone in this review has around 4kHz is pretty much un'EQable in terms of reaching perfection ....it can't be expected to achieve a smooth response in that treble area for this headphone.
In much simpler terms, anytime there are cancellations, EQ can't help so all those deep notches should not be touched in general. In practice, I have fund that EQ can help partially. Care must be exercised in doing so. You will need a lot of headroom both in the amp and headphone for this to work at all.
 

Robbo99999

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In much simpler terms, anytime there are cancellations, EQ can't help so all those deep notches should not be touched in general. In practice, I have fund that EQ can help partially. Care must be exercised in doing so. You will need a lot of headroom both in the amp and headphone for this to work at all.
Indeed, if you're boosting heavily then you're gonna need a large negative preamp and therefore lots of extra spare volume capacity in your amp to drive that boosted part of the frequency response to such levels (and as you say the headphone has to be able to handle that boosted section without issue too). Yeah, thanks, that makes sense in terms of cancellations, it can happen in speaker/room environments too.....I suppose the speaker cup & ear is like a mini room in which the acoustic relationships happen!
 

bobbooo

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AP software can't generate excess group delay but can give you the absolute value:
View attachment 88444

You can visually eyeball what would be excess delay. Note that there can be some signal processing errors in the way this is computed so don't 100% rely on it.

Looks like the 4 kHz notch in frequency response is likely due to an earcup cancellation as suspected then, as seen by the large swing in group delay at that frequency, and so is not amenable to being effectively EQed out well.
 
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amirm

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Looks like the 4 kHz notch in frequency response is likely due to an earcup cancellation as suspected then, as seen by the large swing in group delay at that frequency, and so is not amenable to being effectively EQed out well.
Yup. As I explained in my last post, it is easy to spot these from frequency response without looking at phase.
 

BYRTT

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AP software can't generate excess group delay but can give you the absolute value:
View attachment 88444

You can visually eyeball what would be excess delay. Note that there can be some signal processing errors in the way this is computed so don't 100% rely on it.

Thanks managed get REW create a kind of GD minimum phase reference on some homebrew wav-files @48kHz that is overlaid to AP curve below as animation, as you prepared us in general there looks be some propagation delay covering full bandwidth so probably more or less a linear system flow delay, something looks happen in 4-5kHz area including impedance and isolation charts from Innerfidelity pdf-file..

GD_x1x1_1500mS.gif
 

Martin

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Audeze LCD headphones non-EQed preference scores:
81 - LCD-2 Closed (crinacle)​
76 - LCD-2 Closed (oratory1990)​
74 - LCD-1 (oratory1990)​
71 - LCD-XC (crinacle)​
70 - LCD-2 (oratory1990)​
70 - LCD-2 Fazor (oratory1990)​
65 - LCD-1 (crinacle)​
52 - LCD-4 (oratory1990)​
51 - LCD-2 Classic (oratory1990)​
50 - LCD-X (oratory1990)​
48 - LCD-2 Classic (crinacle)​
40 - LCD-X (crinacle)​
31 - LCD-3 (crinacle) :facepalm: I have these... and rather like them.​

Scores: https://github.com/jaakkopasanen/AutoEq/blob/master/results/RANKING.md

Martin
 

solderdude

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31 - LCD-3 (crinacle) :facepalm: I have these... and rather like them.

LCD-3, Excellent lows and mids, very 'laid-back' and smooth sound (as further seated in a nice venue) with smooth and clear treble.
Sometimes preference scores do not represent someone's taste.
There is nothing wrong with liking this sound and what it does with poorer too midrangy/shouty recordings.
Add some of the missing lower treble and the 'laid-back' becomes forward and realistic.
Heavy headphone, don't like the sticky leather on warmer days and the 'suck' you get removing them. Glasses help a bit with the last issue.
 
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KeithPhantom

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I have a pair of these. This review might start to explain why I grab my Focal Clear 8 out of 10 times whenever I want to listen to headphones.
So now who is going to send Amir the Clear? I am not letting my Clear Pro go away from me for one second.
 
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