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Old 11th February 2013, 09:49 PM   #34831
RNMarsh is offline RNMarsh  United States
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Typically, common-mode signals are induced via field-coupling... usually means an HF/RF signal. Differential-mode signals are direct-coupled via conductors/wires, directly. Interference can be one or the other dominating or both. It isnt uncommon to have conversion of one to another within a system. Most trouble-some is C-M to Diff-mode conversion which then gets processed/amplified along with the desired signal.

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Old 11th February 2013, 10:05 PM   #34832
fas42 is offline fas42  Australia
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Originally Posted by qusp View Post
Whatever Frank, your full assessment without any first hand knowledge, or it would seem going by your take on a weekend with the HD650, without a proper headphone amp; doesnt hold much water as to your opinion on what myself and others are hearing. Continued theorizing by google does not strengthen your case.
Fair enough, qusp, not trying to have a go at you or anything ... like everyone else, just trying to get handles on why things are what they are, or more accurately, how various behaviours register in the hearing system.

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The first time I heard them I thought they were quite impressive, but over time with more experience with them, the overtly large stage along with the mind exploring mid/treble became apparent to me and now its all I hear. They are very picky as far as amplifier, most seem to enjoy them with tubes, probably due to having more damping in the electronics to offset some resonance in the driver, construction or impedance. Several mods have come about to battle the resonance I speak of, as well as a quite ridiculous one where a set of HD600 are worn at the same time as a set of HD800 over the top (both are open back) you should read Tyll's review of this hehe! hilarious!
That to me is saying that they're doing the job, which is revealing the weaknesses elsewhere in the chain.

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aside from soundstage size, my JH13 (custom in ears with passive 3 way 6 driver WW-MM-TT crossover) are better at everything they do for my taste. They are much more nimble, with STAX-like transient speed, more detail, nice tight and well extended bass, very good imaging, excellent and fairly neutral midrange, yet without the fatigue. they have a small bump at ~40-50hz (with extension down to 15-20Hz), but are otherwise quite neutral as are built to be Custom in ear stage monitors.

Each set of JH13 is equalized (to a target curve) due to every set and every ear cavity/'room' response being different. they use the ear impression used to create them, along with computer modelling and measured response to meet the curve for each set of headphones crossover. This is termed 'ear flat'
Impressive, shows what one can do to optimise the headphone experience. When I tried the HD650s the sound matched what reviews typically state of them, but this is not what I'm after ...

Frank
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Old 11th February 2013, 10:06 PM   #34833
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Old 11th February 2013, 10:23 PM   #34834
fas42 is offline fas42  Australia
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Originally Posted by gootee View Post
How often is it critical to use exactly the ferrite with certain characteristics? And how would we predict which ones would be suitable?

Can we model them as a series component with some impedance versus frequency curve? How would we calculate or simulate with them, and how would we design such that we arrived at the requirements for the bead? Or are they simpler to think of as just low-pass filters with a relatively-high cutoff frequencies? Or as tiny inductors?
For me, Tom, very critical ... a hint, precise modelling of the characteristics is extremely useful, this is something I've played quite a bit with recently to tame interference modulating voltage rails ...

IMO, adding ferrites slapdash around the place is like assembling a wristwatch with boxing gloves on ..

Frank

Last edited by fas42; 11th February 2013 at 10:26 PM.
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Old 11th February 2013, 10:40 PM   #34835
fas42 is offline fas42  Australia
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Originally Posted by Esperado View Post
May-be we can start a business of special audiophile ferrites, with rare earth, precious metal plated, with some nice wood cover to dump resonances (of course) witch will add purity to our music ?
With the advantage we could produce real impressive curves (in the Ghz range) to justify the amazing improvement, ( a little obscure technique help ), and nice poetic words to share comparative listening impressions, in the spatial area, separation, fluidity, easiness of transients and natural of the reproduction.
Of course, they will be VERY expensive, and w'll have to pretend their improvements only reach the top on HI-FI (not MID-FI) equipments around. While they will help any system, no way to lose a market.
The reason this nonsense goes on is the industry's fault: the "experts" can't explain in a straightforward way why various "things" do or don't make a difference; systems assembled by "experts" are usually very unconvincing to critical listeners; and if "experts" haven't got a ready answer they frequently disparage or show contempt for the consumer's listening capabilities.

If the car industry operated like this we still would have vehicles with a hundred levers and knobs on the dashboard, to allow for driver fine tuning of the performance ...

Frank
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Old 11th February 2013, 10:42 PM   #34836
qusp is offline qusp  Australia
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their job as a reference headphone is not reproducing a resonance or space that isnt there. did you look at the page I linked? you couldnt have, as youve just parroted the same thing you said before again in different words, my (headphone system) chain is not lacking, my (headphone) chain does not have a resonance centered at 6.5kHz, my chain does not normally sound like the space is expanded. it (the resonant mode at 6.5khz) sounds similar to the effect of really bad jitter to me, which makes some sense.

the link shows fairly clearly and objectively what i'm talking about. the measurements I linked are done by the same person who did the ones you are basing your 'opinions' on (Tyll, who founded headroom and sold it a few years ago, now runs innerfidelity) Tyll did the headroom measurements. but these are later, more closely and with better equipment after some people started all saying the same thing, they are not neutral.


removed part of this, its going nowhere, the opinion i'm arguing against is based on presumptions, not experience.

Last edited by qusp; 11th February 2013 at 10:58 PM.
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Old 11th February 2013, 11:00 PM   #34837
DF96 is offline DF96  England
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Originally Posted by fas42
IMO, adding ferrites slapdash around the place is like assembling a wristwatch with boxing gloves on ..
With the right ferrites used in common-mode form they can do little harm, and may be simpler to use than requiring all audio designers to be RF experts too.

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The reason this nonsense goes on is the industry's fault: the "experts" can't explain in a straightforward way why various "things" do or don't make a difference; systems assembled by "experts" are usually very unconvincing to critical listeners; and if "experts" haven't got a ready answer they frequently disparage or show contempt for the consumer's listening capabilities.
"Experts" often can explain, but they can find that some people either reject or simply don't understand their explanations. This can be due to stubborn preconceptions or simply lack of sufficient maths or physics. "Critical listeners" sometimes seem to need to augment their ears with eyes, or prefer low levels of distortion or frequency response modification while strenuously denying this. "Systems" don't have to convince anyone; just pass on the signal as unmolested as possible.

If the car industry was like this there would be people who buy expensive engine attachments guaranteed to improve performance, or who try to 'tune' their suspension without understanding damped harmonic oscillators, or who believe that 'go faster' stripes actually make their car go faster. Meanwhile real auto engineers will continue to design and build reliable cars, and tinkerers will continue to tinker (regarding reliability as almost a negative property of a car).
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Old 11th February 2013, 11:13 PM   #34838
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Originally Posted by fas42 View Post
The reason this nonsense goes on is the industry's fault: the "experts" can't explain in a straightforward way why various "things" do or don't make a difference;
I don't understand your point. By habit, engineers try their best to design the best things they can. And as opposite of what is often pretended, they CARE a lot of the sound quality, reason why they had chose this job rather than an other branch.
They are not so stupid to not being concerned by ergonomic. It is often their boss witch reduce the price/quality, ask for more gadgets etc...
I think it is not so complicated to explain the things in a comprehensive way. But audiophiles prefer to put their fear in somebody with a nice voice more than in a clear demonstration and logic demonstration.
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Old 11th February 2013, 11:29 PM   #34839
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Christophe, DF and Qusp,
The argument we are having here is somewhat like the difference between an evolutionist and a creationist. No matter how much evidence you have some will just choose to believe in fairy dust, they propose to be scientific but have some occult beliefs. Just add that Eye of Newt or find the Holy Grail and all will be right with their audio systems. You can never convince those who believe for no other reason but that they believe. I am not saying in any way that we know or understand every single detail down to the electron level of an electronic circuit but we strive to learn more all the time and fill in the details. Others would rather include some magical powers that just take care of the misunderstood. I place the Bybee device and many other audio tweaks in the latter camp.
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Old 11th February 2013, 11:33 PM   #34840
SY is offline SY  United States
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