[takato14]

A bit of an introduction, I'm kind of a vintage headphone nut and I've been using the KOSS PRO/4AAA (original, 1976) for quite some time now, a headphone I still believe trumps most modern options in the $1-200 range effortlessly, and can get even better with modifications.
 
The 4AAA has been out of production for quite some time, but KOSS made a successor, the 4AAA Titanium or 4AAAT, and it's been on the market for a good 6.5 years now at a price of $150. It features the same driver topology as the original PRO model drivers, with better magnets and a titanium coating on the diaphragm (unlike the 4AAT, which uses a different driver entirely). Most people cite it as being nothing like its grandfather, and go as far to call it harsh and bassless. The general consensus is that they're simply bad. Very bad.
 
   
 
Since the shell is fully open I decided to ask my friend for one for Christmas, for a DiY project. He apparently found one for dirt cheap on eBay and I just got it. I have been listening to it all day.
 
... Exactly why do people say these are terrible? They're a lot harder to drive than the original but they sound almost completely identical in frequency response, except the bass and treble extend farther. The transients are drastically improved and they're far clearer and more controlled. The 4AAA has more aggressive and out of control highs, the 4AAAT is far more mature sounding and the actual detail and clarity is superior even though the 4AAA may seem to have the upper hand at first listen. Furthermore, the 4AAAT is unique in that its the only sealed AND open design in existence, so essentially it has the same speaker-like bass heft and impact of the original 4AAA (which it was renowned for) with a very open sounding soundstage to boot. They're literally a straight up improvement, and this is comparing them to a <HEAVILY> modified 4AAA that has the rarer series 2 drivers (which are slightly better than the much more common series 1) and have every singe shred of performance squeezed out of them as possible. 
 
They aren't end-all be-all, but come on, this is a $150 headphone we're talking about. Are they colored? Yes, heavily. Are they easy to drive? Hell no. Are they built as well? Not even close. But they are most certainly not terrible. I can understand not liking their colorations, but if you already DO like the 4AAA (which many people do), hating the 4AAAT makes absolutely no sense to me. The original is like a spunky, bombastic, out of control kid and the Titanium is like the same kid, all grown up and more proper sounding. It's the same classic KOSS coloration with modern technicalities and refinement. 
 
These cans are great, especially at the price range, and it really irks me to see them get tossed to the dirt like this seemingly without rhyme or reason.
 
EDIT: After spending a significant amount of time with these I'm noticing a very odd sounding veil on the midrange that makes them a chore to listen to. It's not fixable with EQ so it's not related to the headphone's frequency response. I believe the diaphragm is so heavy that it's causing the attack speed of the driver to suffer in the 800-3000 Hz area. It seems that either titanium wasn't a good metal choice, or they just crammed way too much of it onto the diaphragm... 
 
Oh well, they've still got decay that's competitive way above their price bracket, and they isolate better than anything I've ever used so they're my portables for now. Perhaps a transplant with my series 2 4AAA drivers is in order...

 

[takato14]

No interest? I mean, after hearing these I have absolutely no desire to mod them anymore, they're too good to defile, and I'm not exactly easy to please.

Maybe people are underpowering them? Or perhaps it's expectation bias; ie metal plated headphones must sound metallic and bright just like wood headlines must sound organic? Maybe it's just because they're not a mainstream audiophile brand?

 

[tdockweiler]

Koss stuff always falls under the radar unless it's a Porta Pro or KSC75 it seems like.
 
I've had the Pro4AAAT before and i'll assume mine was a lemon or something because I hated it. It had this weird plasticy haze to the sound and I had it extremely well amped.
 
IMO some of the best stuff Koss has made was released not too long ago.
 
There is the UR-55 and DJ100. DJ100 isn't very colored and to my ears requires a full desktop setup to be at it's best. To me it's more balanced than the M50, V6, DT-880 and most everything else labeled as "neutral".
 
UR-55 is a fun headphone but it's pads are too small.
 
I do want to try the old PRo4AA which is the version which weighs a ton..
 
One headphone that WOWed me for the price is the Koss UR-22v with upgraded pads. One of the few $15 headphones that isn't a piece of junk and actually has decent treble!
 
Wish Koss would released a larger open version of the DJ100 with better comfort. The DJ100 is held back by it's pads IMO.

 

[takato14]

  Koss stuff always falls under the radar unless it's a Porta Pro or KSC75 it seems like.
 
I've had the Pro4AAAT before and i'll assume mine was a lemon or something because I hated it. It had this weird plasticy haze to the sound and I had it extremely well amped.

Explain this. Where is said haze? To my ears the headphones sound slightly veiled up top because of the lack of treble extension but that's about it. They did sound exceptionally strange at first listen but once my ears adjusted to the colorations it was a very enjoyable sound. 
 
As much as KOSS and their consumers didn't like to admit it, the 4AA and thus the 4AAA (same drivers) were designed for one thing, and that's vocal monitoring. They were originally headsets, after all. That's why they're colored the way they are. The 4AAAT has the same driver design as its grandfather, just with a titanium coating and a better magnet, so the colorations persist. This might be the "haze" you're talking about, I don't know what else it could be because the headphones have shockingly good control and detail retrieval; definitely uncharacteristic of the standards KOSS upholds. The colorations are less apparent on the original however, due to the more aggressive highs. Perhaps this is why people prefer the original?
 
The 4AAA (original) sounded more like the DJ200 to my ears, the DJs had a bit less bass and sharper treble. Same sound, but a tiny bit better on the 4AAA... might be my own expectation bias though. Also yeah, the UR-22v/i are quite good sounding, especially for $15!
 
What amp did you use, because these things seem to crave a LOT of juice, much like their predecessor.

 

[Slygon]

Just to chime in here.... I am a huge KOSS fan... sure, not all of their products are audiophile quality, and while I have been a music collector for many years, I am just starting to experiment with more entry level audiophile equipment (speakers, turntables, etc...)  I have about 5 sets of KOSS headphones, from vintage PRO 4AA's, to newer 4AAT's, DJPRO 100's, and the MV1's.... I also own Grado's and a few others now....
 
What MAY be happening with many reviewers is that some of these newer KOSS full size headphones require a LOT of break-in time.... my MV1's sounded downright muddy when I first got them... most reviews were bad... and KOSS does not even make them anymore... but once you get a couple hundred hours into them, and give them plenty of power, they now sound downright fantastic....
 
I have been wanting a pair of 4AAAT's.... I may just have to order some....
 
Yes, you can buy better headphones... but their prices are decent, their sound is actually quite good, and their service/support is wonderful.  Some of their full size headphones are American made too.

 

[trellus]

I'm resuscitating this dead thread because I've just purchased these on Amazon for $40 brand new, and I figure at that price it's worth satisfying my curiousity over this discarded model which at least in pictures looks very appealing - and it comes with a nice case I can pilfer for other cans should I decide the 'phones themselves are a disaster.

My guess is that they failed because of some build issues, judging from the reviews on Amazon, and poor timing of the market.

Probably, people who appreciated the vintage 4AAA can excuse the limitations of those because, well, they're vintage, but this later variant (as old as they are now) faced a lot stiffer competition at the time of their release, so the competition wasn't their vintage predecessor, but their contemporaries.

Oh, and this video of them helped spur me to pull the trigger on the purchase; they just look so interesting to me:

https://youtu.be/SHUxIOR4OYo

 

[Neighbour]

You should better save your Money an not waste it.
Even 40$ is to much.
 
The Headband Design is a totally disaster. Only Koss Designers have an idea how torturing the Costumers with an air filled headband in professional Recording. Come on, On-Air Torturing by Design.
 
The Vinyl Cushions are crap too. Within of few weeks hardened with skin contact.
 
The Titanium Coating is truly micro breaking in on Flanks and Surface. The anemic and bad Response with the really low THD comes from the stiffness of the diapghram. Every better Studio Monitor has reliability in it Sound Signature.
 
So I'm not going deeper into a budget painted studio professional for 150$ with no spare parts.
 
The pro4AAAT shares the same Capsules from the pro4AAT with a different Enclosure Design ,I have had 4 of them and it is the same bad Design with the same Sound Signature, You need to burn-in on high Levels for about 50 hours but at least i prefer the far better pro4AA Design and capsule without the Magic of Titanium Coating.
 
Even one Capsule Housing of the pro4AAAT has broken in to two parts.

 

[trellus]

  You should better save your Money an not waste it.
Even 40$ is to much.
 
The Headband Design is a totally disaster. Only Koss Designers have an idea how torturing the Costumers with an air filled headband in professional Recording. Come on, On-Air Torturing by Design.
 
The Vinyl Cushions are crap too. Within of few weeks hardened with skin contact.
 
The Titanium Coating is truly micro breaking in on Flanks and Surface. The anemic and bad Response with the really low THD comes from the stiffness of the diapghram. Every better Studio Monitor has reliability in it Sound Signature.
 
So I'm not going deeper into a budget painted studio professional for 150$ with no spare parts.
 
The pro4AAAT shares the same Capsules from the pro4AAT with a different Enclosure Design ,I have had 4 of them and it is the same bad Design with the same Sound Signature, You need to burn-in on high Levels for about 50 hours but at least i prefer the far better pro4AA Design and capsule without the Magic of Titanium Coating.
 
Even one Capsule Housing of the pro4AAAT has broken in to two parts.

Interesting, thanks for the heads up.
 
I bought it already and it has already shipped.  In a way, I'm also using this as a way to test the famed Koss Limited Lifetime Warranty. 
 
It comes with a case, and that's easily worth $20 to me alone, so I'm willing to gamble.  

 

[trellus]

Well, color me crazy, but I like these. Wouldn't pay $150 because I think the build quality isn't $150-worthy, but I paid $40.

They sound like "fast" headphones to me, treble was somewhat piercing at first but even after just an hour of play time seems (to my brain) less so.

Oh, and yes, I sweat within 20 minutes with these cushions. But a rather good sound to my ears and except for the heat trap aspect of the ear pads, comfort is really good for me.

 

[trellus]

Pulled these out again just out of curiosity. They definitely have a strange sound signature, but once my brain adjusts to them, they are nonetheless pleasing.