An idea for audiophile system

I guess so - but usually you don't want to wake up the neighbors (or your significant other) when listening to headphones.
 

Have you actually heard a set of Stax?  Unless you're used to the TH900 and will accept no substitute, you're never going feel like youre missing out on bass extension.  If you actually want the physical feel of rumbling bass, then any headphone setup would disappoint you, even with a sub - it would feel very disjointed without a speaker's soundstage. 

 

If you want electrostatic detail, get electrostatic speakers :D 

"I'm Doug, I have Quads. Neenerneenerneener."

 

...or something like that. :D

 

Back when I owned a pair of AKG K1000s I remember a member telling me about running a sub along with them. So while the idea seems a tad counter intuitive to me, someone else put their has done it. I think the main problem would be finding a suitably fast sub to pair with the Stax.

you know it, my friend! 

 

 

May not work. how to synchronize the speed of dynamic with stats which is way faster ? The bass extension will arrive after the other elements in the same note left.......

You'd have to get a sub the same way people with electrostatic speakers do. 

 

You get a smaller, faster sub that can keep up. Unfortunately this means overall extension hurts. 

 

The other issue with this plan is the fact that honestly the higher end stats go deeper than any sub that will keep up with them. 
 

 

The "smaller faster sub" is a myth. When people suggest this, it usually means the larger sub was improperly designed, underamped, or "sloppy" due to faulty construction/design.

 

A 15" driver can't play a 25 Hz note "slower" than a 12" driver. A 25 Hz note is a wave that oscillates at the rate of 25 cycles per second. If the the 15" driver is oscillating at a "slower" rate, say 23 times per second, it's reproducing a different note. If the 12" driver is oscillating "faster" than 25 Hz, it's also playing a different note.

 

Any of the competently designed larger subs out there will be as "fast" as a smaller sub, and you don't have to sacrifice extension to get there.  You do have to make a wallet sacrifice though...

 

For the OP - it's really difficult to get the synchronization of the phones and the subs nailed.  I tried this a while ago with my JL F113s and quickly gave up on it.  Then bought LCD-3's to get the bass I was looking for.  Of course, it doesn't have the tactile feel of a sub, but it also doesn't disturb the rest of the house.

I'm operating on 'general' things here. Unfortunately this has been my experience. 

 

You're absolutely right that when you get a proper large sub it'll be just as good, but more often than not when you buy a larger sub you're getting a 'slower' sub.

 

There are always exceptions, but if went out and bought a 8" and 12" sub off the shelf chances are the 8" one will keep up better.

 

 

While there are certainly bad subs out there, fortunately, not nearly as many as there were before.  In fact, there aren't many quality 8" subs out there anymore as they really can't produce much of value below 35-40hz, so what's left in the 8" market is generally pretty weak.  There's probably been more development in the subs than anything else in audio over the last decade, other than perhaps headphones, so lots of good choices now for reasonably priced 12" and up subwoofers.

 

If my only choice was to go for an 8" sub, I wouldn't bother - it's really too small to be effective.  The only reason I could see to go that small would be if your mains were in a poor acoustical location for bass reproduction and you needed a sub in a better in room location.

 

Either way, I don't think the OP will find joy in a phone/sub combo due to the integration challenge.

In this case I really think it's the best option due to the fact that I assume we're not going for extension overall we're going for physicality. 

 

Either way I think it's bad idea, but your headphones will probably go deeper than most subs anyway (again unless you pay a pretty penny for them) and 8" subs do physicality of sound really well.