[kartik]

Interesting. Sounds plausible. The way the brain works it amplifies the stereo effect at multiple levels by a phenomenon known as afferent inhibition. i.e. when faced with two stimuli of different intensity form opposite sides, it negates the weaker one and accepts only the stronger one. This is why you differentiate sounds as emanating from the left or right. The placement of the human ear although better for stereophonic hearing is really hearing mono with slightly different sonic pictures. What the brain does is to inhibit the weaker signal thus giving much clearer resolution to the "sideness" of the sound.

 

[PinkFloyd]

Quote:

Originally posted by tortie I used to have an xfeed without the switch. I sold it & got an Xfeed circuit. I now have that circuit built-in my switchbox with its own switch. Actually my xfeed is never turned off But when I tested it to see if I can hear some sonic differences, I noticed the slight decrease in volume.

Sorry Tortie,

I forgot I sent you a circuit

I haven't got a clue what the guy who built your switchbox did with it but it "shouldn't" be giving you a "noticeable" drop in volume.

Mike.

 

[tortie]

The funny thing is that this drop in volume is more evident in some recordings and not noticable in some.

It doesn't bother me that much though, cause as I said, I always listen to music with it on.

 

[PinkFloyd]

Quote:

Originally posted by kartik Interesting. Sounds plausible. The way the brain works it amplifies the stereo effect at multiple levels by a phenomenon known as afferent inhibition. i.e. when faced with two stimuli of different intensity form opposite sides, it negates the weaker one and accepts only the stronger one. This is why you differentiate sounds as emanating from the left or right. The placement of the human ear although better for stereophonic hearing is really hearing mono with slightly different sonic pictures. What the brain does is to inhibit the weaker signal thus giving much clearer resolution to the "sideness" of the sound.

In natural surroundings you hear sounds in both ears... fact. Headphone listening confuses our natural perception of sound...... bass being heard by one ear only throws our creative sub conscience out of synch and outwith it's comfort zone....... this is where "listener fatigue" enters the equation.

The creative sub conscience rebels against this unnatural presentation of sound as our sub conscience has been used to hearing sounds in both ears since birth..... suddenly it's faced with a total reversal of what it perceives as natural and comforable and a creative sub conscience / sub conscience battle ensues making "you" the listener suffer fatigue. If you listened to headphones from birth and were suddenly exposed to the outside (real) world sounds you'd be equally agitated and outwith your creative sub conscience comfort zone and would be equally agitated.

It's heavy stuff but Lou Tice of the Pacific Institute makes it easy to understand........If you ever get the opportunity, attend one of his lectures.. they rock! Nothing worse than secondhand information...... he's not an audiophile but he explains "why" we get fatigued, stressed and uncomfortable.

Pinkie.

 

[kartik]

Hey Mike,
The psychoacoustic stuff is kinda derived from the inbuilt neurophysiology I was talking about. There is a crossing of tracts at multiple levels in the brain, right from the sensory afferents of the auditory nerve, the nucleus of the VIII N in the medulla, the efferents via the midbrain, the cortical tracts and even from one audiotry cortex to the other. The brain then goes through a whole set of calculations based on the sounds from each ear as well as the sidedness it assigns to a given sound. It is thus conceivable that the extreme sonic isolation from most truly stereophonic recordings, the brain is not able to place sounds in front, but on both sides of the listener. This probably gives rise to fatigue.

 

[PinkFloyd]

Quote:

Originally posted by kartik Hey Mike, The psychoacoustic stuff is kinda derived from the inbuilt neurophysiology I was talking about. There is a crossing of tracts at multiple levels in the brain, right from the sensory afferents of the auditory nerve, the nucleus of the VIII N in the medulla, the efferents via the midbrain, the cortical tracts and even from one audiotry cortex to the other. The brain then goes through a whole set of calculations based on the sounds from each ear as well as the sidedness it assigns to a given sound. It is thus conceivable that the extreme sonic isolation from most truly stereophonic recordings, the brain is not able to place sounds in front, but on both sides of the listener. This probably gives rise to fatigue.

This is more like it The headphone scenario is much like our eyes. If one eye only saw blue and the other only saw yellow when we wore sunglasses we would panic thinking there was something wrong with our eyes and would rip the sunglasses off immediately. Same goes for headphone listening..... hearing bass in the left ear is extremely strange... our SC is saying "hold on, have we gone deaf?" creative Sub conscience battle ensues resulting in fatigue. X-Feed addresses the balance which is why people comment on fatigue free listening...... it's not rocket science it simply feeds our sub conscience with the sound it expects.

Much like a scotoma (blind spot) headphone listening is either a matter of reading the word in white instead of black or employing a translator to do the hard work for you...... X-Feed is a scotoma converter and saves your mind struggling to find the reverse image.

Pinkie.

 

[kartik]

Mike, I have an idea. If you look at the design of the human ear, you can divide it broadly into the outer sound collection or analog unit, the middle or trandsuction system and the inner or analog to digital conversion system. The interfaces between each of these systems is a single membrane. It is the post processing of this sound by the brain that decides the sonic picture. However this sonic picture is greatly reflective of the primary image generated in the inner ear's digital signal. Rather than designing a 24.1 system which places different instruments at different parts of the room and thus tells the ear the sonic image of the recording, how about figuring out the vibration pattern and the encoding of the basilar membrane in the cochlea. Once we figure that out, we could design a device that recreates sound based on its perceptions of the primary recording, including placement of instruments and vocals. The algorithms would need to include the nuances of the external ear and the mechanical characteristics of the middle ear conduction system. It is worthwhile remember that although you could have an unlimited set of sources, the ultimate perception of the sound is based on an A/D conversion based on two relatively simple diaphragms.

 

[Nigel]

I always considered my X-Feed mk3. to be a very neutral sounding accessory, bass performance didn't seem to be adversely compromised. However, recently I've been listening to headphones a lot more than loudspeakers & don't seem to need the crossfeed insertion. Maybe I've just become more acclimatised
to the sound. Up until a few months ago I couldn't live without the X-Feed though & Pinkie's was the best I'd heard & that was a mk3 model. Knowing Mike, & being the perfectionist that he is, I'm sure later models are even better value. The switched model will give the added benefit of not having to mess with interconnects every time you want it in or out of the system. Mighty fine looking case as well.

 

[darkclouds]

Funny thing, I was about to dig up that old xfeed thread to comment on xfeed after having it for sometime now.

As I was listening to my HD650 it occured to me that I really dig Mike's xfeed. It's very shuttle at first, until you get used to it or rather used to having it. The big thing for me is how it helps focus the center image better, giving you a sense that the source is coming from outside of your head, just in front of you. Like I said, it grows on you, or at least on me. This phenomenon seems to work much better with my HD650 than SR300. Of course, YMMV.

The question for me is, am I supposed to stick this between my SCD1 and Ray Samuel's Stealth? Hmmm... will see.

Quote:

Originally posted by PinkFloyd Sorry Tortie, I forgot I sent you a circuit I haven't got a clue what the guy who built your switchbox did with it but it "shouldn't" be giving you a "noticeable" drop in volume. Mike.

You know Mike, I think I've noted this also. There is a drop in volume slightly. But it doesn't bother me as my amp has plenty of gain to spare. I think I may have mentioned this in my original comments as well.

The only real gripe is the extra IC. That could get costly if you want to stay consistent within your system.

Final verdict... DC likes it!!!

Great job Mike.

 

[Edwood]

I've noticed no change in tone or any any other coloration with the X-Feed (non-switched).

It is very subtle. I simply blends the sound directly between my two ears. It's a little weird. I guess I prefer the Headroom "shape" of their cross feed. I like the imaging to sound more like an "arc" in front of my face. That's what it sounds like with my K1000's. (with their own natural cross feed). I like cross feeds that "shape" the sound, but without adding coloration. I guess the K1000 is the only crossfeed that does that.

I really think that Pinky's X-Feed would appeal the most to headphone purists that want a less fatiguing sound.

Now if only there was an X-Feed that could be put inline with the output of an amp's 1/4" jack. Basically a breakout box. You would plug your headphones into the X-Feed O (Output Version) Or you could call it the X-Feed E (External or Edwood)

-Ed

 

[darkclouds]

Quote:

Originally posted by Edwood I really think that Pinky's X-Feed would appeal the most to headphone purists that want a less fatiguing sound. -Ed

You know, I didn't have any problem of listening fatique at all. Hence I never thought of getting some sort of crossfeed.
Surprisingly, as I've said earlier, there are other benefits to gain beyond the alleviation of listening fatique. I'm simply using it to focus the center image.

 

[Ticky]

Talk about good timing! I'm in the market for a new amp... unfortunately several prospective ones don't have crossfeed. Pinkfloyd, are you taking orders for your new x-feed at this time?

 

[PinkFloyd]

Quote:

Originally posted by Ticky Talk about good timing! I'm in the market for a new amp... unfortunately several prospective ones don't have crossfeed. Pinkfloyd, are you taking orders for your new x-feed at this time?

Hi Ticky,

You've got PM

Mike.

 

[Sovkiller]

Quote:

Originally posted by Edwood Now if only there was an X-Feed that could be put inline with the output of an amp's 1/4" jack. Basically a breakout box. You would plug your headphones into the X-Feed O (Output Version) Or you could call it the X-Feed E (External or Edwood) -Ed

This device already exists, is called X-feed Xin, yes xin the guy that made the mini/micro amps have one for 1/8" mini jacks and plugs, that was design for the output of any amp, and is sold like an adaptor, tiny as usual, unfortunately I want 1/4" not 1/8" and he never answered the emails I sent him, so I opted for the Pink version, I would like it also on the output though...

 

[PinkFloyd]

Ahhhhh nothing better than spending cold winter nights armed with a soldering iron and an array of components at my disposal.... Let me explain

I was conversing at great length via e-mail with Sovkiller explaining that "exotic" components didn't make any difference to the X-Feed..... I had tried the "Wima" metallised polypropelyne caps and the "Vishay" precision resistors in the circuit ages ago and found they didn't do anything to the sound quality so adopted the stance that exotic componets (read expensive) were a waste of time in the X-Feed until........................

I noticed these new capacitors on the site I order from which were classed as "polypropylene 1% film capacitors specially designed for audio applications possessing very low dissipation factor at high frequencies" I couldn't resist so ordered some. They were also described as " particularly suitable for use in Valve amplifiers"

Whilst I was at it I ordered some Welwyn 0.01% precision resistors (costing £1.09 each!!!!) and some EVOX 1% metallised polypropylene 105c caps. In for a penny in for a pound I thought at the time.......

Well, I eat my words Sovkiller........ These components have added energy, attack and "sparkle" to the sound or, should I say, they have ensured that the energy, attack and sparkle has remained in the signal path. The X-Feed had a pretty low insertion loss in its previous incarnation, the only negative comments being that there was a slight decrease in "volume" with the X-Feed in the circuit, I would honestly say that my ears hear no insertion loss "whatsoever" with the different components in the circuit.


The better quality (different) components have improved the quality, across the board, as has the thicker guage of OFC hookup wire and gold plated teflon insulated RCA's......... The attention to small detail has totally transformed the X-Feed.

Sovkiller......... I eat my words regarding "exotic components" they work in the X-Feed!

The X-Feeds that have been sent out in the past 2 weeks (all one of them!) have the latest components in place.

Pinkie.