[nehcrow]

   
Well, first of all I'd like to quote Dopaminer on the SpinFits... 

 
 
That being said, personally I think rotating tips are a bit of a gimmick - why would we need them to rotate anyway?
 
On the other hand, the ability to curve and adapt to the shape of your ear canal seems more useful, but in my experience it comes at a price. Like I said, the silicone used is very thin (similar to the Philips SHE3590 tips). On the plus side, that makes the tips very comfortable and easier to fit deeply. However, it also offers less support than regular tips and is prone to warping, which may result in tiny leaks. Hence you may end up with a deeper seal and more bass, or a leaky seal and less bass, depending on the shape of your ear canals and nature of your fit. 
 
Another reason for concern is that the SpinFits' opening is narrower than the JVC's nozzle opening, and due to their soft / flexible nature they may become even narrower as they adapt to your ear canal. This creates a (slight) reverse-horn, which may reduce treble extension and make them sound bassier and somewhat congested, depending on the severity of the effect.
 
Most of the above is pretty individual though, so what works for you may not work for someone else and vice versa.
 
Last not least, the front-mod should work well for those who're getting a secure seal with SpinFits, but others with an already leaky seal may find little or no difference after the mod.

I'd say they operate in the same way the GR07 nozzles, they allow for that perfect fit
I do hear a bassier sound with a lot of earphones, so maybe I am getting that reverse horn effect. I don't mind it actually since I dig a warm sound on public transport
It's weird how the Ortofon tips are so popular yet they have a similar opening diameter and silicone firmness... I actually think of the SpinFits as a bassier Ortofon with insane comfort

 

[nehcrow]

I also thought the rotation thing was supposed to get RID of the reverse horn effect that a lot of Silicone tips have

 

[james444]

  I also thought the rotation thing was supposed to get RID of the reverse horn effect that a lot of Silicone tips have

 
Nope, the effect has nothing to do with rotation or material, it's simply the result of sound waves "squeezing" through a tapered tube.
 
For example, the TF10 tips are also made of silicone, but because of their wider tube you won't get that effect.

 

[quartertone]

I couldn't do the front mod with the TF10 tips when I tried - they're not as elastic as the spiral dots. 

 

[james444]

  I couldn't do the front mod with the TF10 tips when I tried - they're not as elastic as the spiral dots. 

 
It's easier if you reverse the tips and stretch them over a pen, to widen them a bit before you put them on.

 

[smithamb]

Edit: question already answered.

Apologies

 

[quartertone]

 

  I couldn't do the front mod with the TF10 tips when I tried - they're not as elastic as the spiral dots. 

 
It's easier if you reverse the tips and stretch them over a pen, to widen them a bit before you put them on.

 
Did it and it worked. The result strikes me as a little smoother, more balanced than with the original tips. Admittedly I didn't go back and forth with the spirals once I'd changed, too much hassle with the mod! Also, I got a nice remote cable from sunricky on eBay. Really soft and light, with three buttons. Even works (minus the volume function) on the X1. And finally smaller connectors! Clunk factor noticeably reduced. 

 

[james444]

  Did it and it worked. The result strikes me as a little smoother, more balanced than with the original tips. Admittedly I didn't go back and forth with the spirals once I'd changed, too much hassle with the mod! Also, I got a nice remote cable from sunricky on eBay. Really soft and light, with three buttons. Even works (minus the volume function) on the X1. And finally smaller connectors! Clunk factor noticeably reduced. 

 
Congrats! To me, the TF10 tips sound a tad clearer than stock and I guess it's because they're less soft than the Spiral Dots. The difference is rather subtle though and I had to go back and forth several times to be sure.
 
Anyway, I'd think the most important improvement are smaller cable connectors, especially if you wear your JVCs over the ears.

 

[Ben Dover]

I ended up with Sony Hybrid tips. The others I tried would not sit well in my ear. 

 

[Dopaminer]

If a tip is hard to get on a nozzle, just soak it in hot water (near boiling) for a minute : it will loosen up significantly and go on easily, probably (and maybe never come off).  It`s how I got the tiny rubber 0-ring on my AK120ii volume knob - this sucker is never coming off.  Cold, it was about 1/3 the diameter of the volume knob but after the water-torture it rolled right on, then cooled and tightened up:
 


Regarding the size of a tip`s bore-hole, I agree it seems intuitive that the larger the bore, the less `restricted` or `constricted` the sound is.  However, we need only to look at the pin-sized holes in the Shure SE tips, or the teeny-tiny holes in custom IEMs like JH Harvey and all the others, to see that it can`t matter all that much.  
 
For anyone who feels they are getting a lowering of bass quality with the FX850+Spinfit combo, I can only assume it is due to either: 
 
A) the inherent individual-specific variation in ears and brains, or
B) you are using the Muse Spinfits, and not the Japanese Sarounbi Spinfits, which despite looking similar, differ substantially quality, in my and many other`s opinions. 
 
The purpose of the Spinfit tip-head rotation is to prevent the sound tube from collapsing as it pushes against the inner ear canal.  It is not a gimmick. Becaue the tip head can bend and follow the curve of the canal, the tip can insert slightly deeper without de-forming, the higher-quality silicon grips more completely, a better seal is achieved and therefor more subtle details can be heard, especially in the low frequencies.  Which is why the FX850-spinfit combo is sooo good: that huge extended bass becomes more detailed, more complex, more complete, in my ears.  
 
Another technique to achieve this is what Ostry are doing - these tips actually have a metal gasket inside.  There is no way to collapse these sound tubes !
 

 
d

 

[richbass]

  If a tip is hard to get on a nozzle, just soak it in hot water (near boiling) for a minute : it will loosen up significantly and go on easily, probably (and maybe never come off).  It`s how I got the tiny rubber 0-ring on my AK120ii volume knob - this sucker is never coming off.  Cold, it was about 1/3 the diameter of the volume knob but after the water-torture it rolled right on, then cooled and tightened up:
 


Regarding the size of a tip`s bore-hole, I agree it seems intuitive that the larger the bore, the less `restricted` or `constricted` the sound is.  However, we need only to look at the pin-sized holes in the Shure SE tips, or the teeny-tiny holes in custom IEMs like JH Harvey and all the others, to see that it can`t matter all that much.  
 
For anyone who feels they are getting a lowering of bass quality with the FX850+Spinfit combo, I can only assume it is due to either: 
 
A) the inherent individual-specific variation in ears and brains, or
B) you are using the Muse Spinfits, and not the Japanese Sarounbi Spinfits, which despite looking similar, differ substantially quality, in my and many other`s opinions. 
 
The purpose of the Spinfit tip-head rotation is to prevent the sound tube from collapsing as it pushes against the inner ear canal.  It is not a gimmick. Becaue the tip head can bend and follow the curve of the canal, the tip can insert slightly deeper without de-forming, the higher-quality silicon grips more completely, a better seal is achieved and therefor more subtle details can be heard, especially in the low frequencies.  Which is why the FX850-spinfit combo is sooo good: that huge extended bass becomes more detailed, more complex, more complete, in my ears.  
 
Another technique to achieve this is what Ostry are doing - these tips actually have a metal gasket inside.  There is no way to collapse these sound tubes !
 

 
d

Where to get these lovely tips ?

 

[Whaleshark12]

 
Where to get these lovely tips ?

Pm @Dopaminer  XD

 

[james444]

 
Regarding the size of a tip`s bore-hole, I agree it seems intuitive that the larger the bore, the less `restricted` or `constricted` the sound is.  However, we need only to look at the pin-sized holes in the Shure SE tips, or the teeny-tiny holes in custom IEMs like JH Harvey and all the others, to see that it can`t matter all that much.  
 
For anyone who feels they are getting a lowering of bass quality with the FX850+Spinfit combo, I can only assume it is due to either: 
 
A) the inherent individual-specific variation in ears and brains, or
B) you are using the Muse Spinfits, and not the Japanese Sarounbi Spinfits, which despite looking similar, differ substantially quality, in my and many other`s opinions. 

 
Sorry to say, the bolded part is a misconception. Shure tips don't impair sound quality on Shure IEMs, because their bore size is equal to Shure's nozzle bore. But stretch a Shure tip over the FX850's nozzle and it will render the JVCs unlistenable.
 
The reverse-horn effect is for real, and while it's only mild with Spinfit tips on the JVCs, it inevitably affects sound signature. Always consider nozzle bore vs. tip bore, here's a quote from another thread where I've tried to illustrate it:
 

 
Sony Hybrids are very comfortable and among my favorite tips. However, their inner diameter is smaller than the RE400/600's nozzle, that's why one needs to stretch the core to fit.
 
Now, what happens in that case is that the Hybrids' tube acts like a reducer (D = nozzle diameter, D2 = exit diameter), which decreases treble energy and makes the overall sound slightly more bassy and veiled:
 

 
While this can be a handy trick to tame treble on too bright sounding IEMs, I don't think that it's desirable for the RE400/600. Imo the only suitable way of using Hybrids with them would be to cut off about half of the tip stem, so that the remaining stem stretches almost full-length over the nozzle.

 

[Koolpep]

I am as well interested in the tips - though I don't think there is anything wrong with the stock tips. I use the Sony hybrids sometimes because they are for me a bit comfier and only affect the sound quality slightly. 
 
After months without them, I just listened a bit with the FX850 again and my god, always good to be wowed again Love these earphones.
 
Cheers,
K

 

[7S Cameron]

I completely agree with James. To be honest I haven't found any positive gains from tip rolling. I always find myself coming back to the stock tips when it comes to all of my earphones. I haven't tried any other tips with my FX850 though...