I have a peculiar problem with my Audeze LCD-2 Closed-back headphones.
This is an old apartment building with partial/poor grounding and there’s crappy old antenna wiring running alongside the mains in the wall, so my living room is somewhat RFI polluted.
It only affects the Audezes, though. I’ve tried all available sources (all single-ended), with a premium double-shielded cable, cleaned all contacts, etc, so there should be no rectification happening in the chain.
There’s very often a faintly but clearly audible interference that seems to be a TV channel’s audio track. Its volume is independent of adjusting the gain, so it doesn’t really impose itself on music but is bugging me at silent passages or when nothing playing.
None of my other headphones (dynamic ones) suffer from any audible interference.
Since this happens with any source and any cable, it leads me to believe that this phenomenon is internal to the headphones. Now, how could this be?
Could a relatively high-impedance (70 ohms) planar diaphragm with near-null mass really react to RFI enough to audibly move air, as in, act as an antenna in itself?
Would I most likely get rid of this problem by getting a balanced headphone amp? (If this nuisance ain’t gone after that I’ll lose my temper, haha)
Obviously this constant talk show in the background makes these expensive headphones pretty much unusable.
Seriously. Is this as hard a problem to solve as it seems? I’ve asked Paul, I’ve asked Chris (waiting for his expertise as he’s the definitive planar expert), I’m considering asking Audeze. But is this really such a mystery?
Okay, let’s consider the frequency bandgap of a TV channel’s audio track, well, its mid-high portion. In an antenna based network. Not satellite.
Please continue from here… Why would the Audezes be so selective on what channel and what bandgap of it they pick up? Is this maybe proportional to the planar driver size, the geometry of its magnetic circuit, etc? Is there something happening at the diaphragm level that amplifies a “resonant” bandgap?
If so…
How many layers of aluminium foil should I wrap around the headphones’ cups? Will 5 do?
Contacting Audeze is a good idea. Also try Moon Audio (not the electronics manufacturer)
They know cables, have their own line and have a lot of experience with different
headphone manufacturers. I use their Silver Dragon cable for my LCD-3. Just email
them. Good luck.
I had the Silver Dragon Premium V3 in use, until it broke down.
Switching to it did not attenuate the interference at all. Well, it did make it a bit clearer though!
Great cable soundwise, but didn’t expect the Furutech mini-XLRs to be so fragile. Well, gotta send it for maintenance and have it terminated with 4-pin XLR and invest in a balanced amp. Maybe, maybe the balancing might help… Even if the RFI was happening “inside” the headphones, wouldn’t it go to ground?
My Silver Dragon balanced is still good after 3 years or so.
I have a Bryston headphone amp, totally balanced, dead quiet even
when I turn up volume all the way with no signal.
Well surely. I think having such antenna pollution as here is rare. These mains and antenna wirings that run through the walls are untouched since 1970, I think.
Technically, can the magnetic circuits embedded on the diaphragms be suspectible to a certain bandgap of interference? If so, can we now call this a form of resonance?
Or do I have DC on the drivers somehow? As I said the RFI does not respond to turning up the volume. It’s a constant volume pickup.
Okay, I got some should-be-obvious things confirmed by Audeze.
Their drivers are very efficient, but they can’t drive themselves just by induction, some driving current is required - so in my case, there is a tiny current being induced into them with any source in the room. Including my phone.
Could it be that the interference isn’t picked up internally in the headphones but rather by the contacts of every source or simply the cable’s terminations? It can’t be happening along the length of the cable, as is obvious from Moon Audio premium shielded cables not mitigating this. Just how strong are the fields here, am I in risk of cancer?