[Gclef]

If my definitions of these bass terms are correct:
 
Punchy = quick, sharp, tight (as in no reverb) bass notes
Impact = high level of force or great weight in delivery (like the thumping of a subwoofer)
 
I have to ask, can you have impact without punch or punch without impact?  How so?  I read a lot of posts about the Sony Z1000 headphones being punchy, but lacking impact.  In my simple noob (yet logical world), these two characteristics are associated.  Can someone help me better understand this phenomena?

 

[TMRaven]

To me punchy is more about the recording of a song than the actual headphone.  I'm not saying my personal definition is the right definition, but everybody will use different terms slightly differently and there will always be overlap of said terms too.  So in a way every answer is the right answer for what you're asking.

 

[Head Injury]

With headphones, I'd say impact is usually in the mid-bass (exception being headphones that extend flat and deep, like planars and electrostatics, etc.) Headphone drivers don't usually push enough air to impact with sub-bass like a subwoofer, only rumble.
 
It depends on the recording and the headphones. With the planars I mentioned and any other headphone with neutral and extended bass, punchy recordings will sound punchy and not-so punchy recordings won't, because the impact is balanced between sub- and mid-bass. So if there's sub-bass to play, it'll play. Headphones with big mid-bass humps will make everything sound punchy (Grados), unless it has no mid-bass (which is rare).
 
Headphone construction matters too. Closed headphones are punchier, perhaps because of increased reverberation and lower ambient volume. Bass is the first thing to fall prey to ambient noise.

 

[Mad Lust Envy]

I associate punchy and impact generally to the mid bass section.

The most easy to identify sub bass term for me would be deep or rumble, lol.

 

[Gclef]

I'm guessing they chose the term "punchy" in relation to the snappiness of a punch.  And to me, that equates to sharp, crisp and dart-like musical notes - no lingering reverb or bleeding of sound.  It just seems to me that that type of action would naturally transition to impact.  Those terms seem relative to me, I just can't get my head around one without the other.
 
Edit:  after re-reading these replies, something clicked.  I can see how sub-bass would lack impact considering the size and space we're dealing with with headphones/drivers.  And I can see how punchy applies to mid-bass.  So, I guess my only other question would be...what exactly is non-punchy mid-bass?  Wouldn't that bleed into the sub-bass and get lost?  Does that mean that headphones that lack punchy midbass won't sound very good?

 

[TMRaven]

Although I can't say it's impact at its truest, but a couple headphones like the Denons for me offer more pressure with low bass than mid-bass impact, so it's possible to have visceral properties from it.  Of course it's not the same as your average chest-thump you get from the pounding of lower bass reverberations that a full-sized woofer can provide.  If the headphone is open at all though, you lose all that pressure-build up and lose the visceral properties of the sub-bass.
 
I've never personally found mid-bass to be more visceral than sub-bass on headphones either.  
 
 

 

[Chris_Himself]

To me (I don't have the best understanding of audiophile terms)
 
Punchy: Quick and responsive bass with lots of power behind it
Impact: Same thing but applicable to mids.
 
I'm probably very wrong.