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KOSS PRO 4AA Review (Headphone)

Robin L

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I wonder if pad aging has stiffened the interior foam? and is affecting fit and bass response
The original Pro 4AA didn't have foam in the earpads, it was gel of some sort and very good for a tight seal. Also sweaty ears.
 

phoenixsong

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The original Pro 4AA didn't have foam in the earpads, it was gel of some sort and very good for a tight seal. Also sweaty ears.
Now that is really interesting. I am not aware of any headphone that still uses the same gel pad design
 

solderdude

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pro4AA tyll.png

These are great for studio monitoring. They can take a beating, have a clean and articulate sound for voices only without male boominess and shrill highs, no compression and can handle a lot f power. Koss still sells them for $ 99.-
Not suited for anything else than that... listening to spoken word.
It's a specialty headphone, just like some Beyerdynamic DT48 models.
There are other Pro4 models that have a different response.

Below the old (original 4AA) that were fuller sounding
Pro4AA (1975).png

If you wanted a warm, bassy sound the Pro4AAA did just that.
See Pro4AAA below.
Pro4AAA.png

Or the Pro4S with its deep bass extension and better clarity.
See Pro4S below:
Pro4S.png

Form Tyll's archives.
Take into account: no Harman bass compensation and above 1kHz the level isn't correctly displayed due to wrong compensation (target to some) being used.

Folks remembering the Pro4AA to have bass most likely heard the pro4AAA.
This confirms Amirs measurements.

Some history (Pro4, Pro4A etc.)
 
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GWolfman

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What oddball cans, inside and out.
 

musicforcities

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View attachment 156143
These are great for studio monitoring. They can take a beating, have a clean and articulate sound for voices only without male boominess and shrill highs, no compression and can handle a lot f power. Koss still sells them for $ 99.-
Not suited for anything else than that... listening to spoken word.
It's a specialty headphone, just like some Beyerdynamic DT48 models.
There are other Pro4 models that have a different response.

Below the old (original 4AA) that were fuller sounding
View attachment 156145
If you wanted a warm, bassy sound the Pro4AAA did just that.
See Pro4AAA below.
View attachment 156146
Or the Pro4S with its deep bass extension and better clarity.
See Pro4S below:
View attachment 156147
Form Tyll's archives.
Take into account: no Harman bass compensation and above 1kHz the level isn't correctly displayed due to wrong compensation (target to some) being used.

Folks remembering the Pro4AA to have bass most likely heard the pro4AAA.
This confirms Amirs measurements.

Some history (Pro4, Pro4A etc.)
The gell filled pads also makes sense in that context of recording and mixing vocals. both in terms of isolation but also to reduce leakage of sound out to studio mics, etc

Thanks for the insight into These speciality cans. designed as tools as much as anything else.
 

Thomas_A

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This is a review and detailed measurements of the KOSS PRO 4AA headphone. It is on kind loan from a member. He bought it used for $10 but then sent it to KOSS and they sent him a new one. In researching it, I found a review (of a different revision) dating back to 1963 yet it is still on sale on Amazon for US $80!
So at least a 60 year old model? The Beyerdynamic DT-150 is from around 1960 as well. I wonder which headphone is the oldest and still in production today.
 

Thomas_A

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View attachment 156127
Speaking of uncomfortable and stiff cans…Anyone have a vintage Beyerdynamic dt 100 or dt108 to send into Amir? They were ubiquitous in recording studios throughout the 70s to mid 80s. Preferably in white as worn by Barry Gibb below. Not that the white plastic sounds different, just because they match white suits and bell bottoms better.

Seriously, I would bee curious to know how the phones and other equipment used to record and mix classic recordings would measure. The results may be a “tragedy”
I have sent the DT-150, a model from 1960 or so. The DT-100 is garbage by the way, no need to review. Unless you only use spoken words...
 
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solderdude

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DT48.... from 1937 ?
Just like the Pro4 there were several iterations.
 

Thomas_A

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sergeauckland

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I have a pair, bought them in around 2000, and recently asked Koss about new pads, which they sent me for free under their lifetime warranty. They certainly don't lack bass, but a good seal to the side of the head is essential. Even thin spectacle sidearms causes a complete collapse.
To me, sound isn't the problem, weight and sweaty ears much more so.

My other pair is the AKG K270P (same as the 270S, but without the microswitch that switches off the headphones unless on the head.) Much less bass than the Pro4AA, but more comfortable.

I regularly used Beyer DT100s when at work before I retired, didn't like them much either, but at least they were a known standard in the industry.

S
 

Thomas_A

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and sounds even worse than DT100 :)
Some say... [Jeremy Clarkson style] it is the best headphone ever made.
Perhaps a bunch of people said so in 1937? :)
 

Thomas_A

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Just read the review we made in 2003, the model "Koss Pro 4AA titanium" got poor listening verdict. "Very poor bass and treble, making it an uninteresting headphone."
 

don'ttrustauthority

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If I recall correctly the 4AA was a lower level than the 4AAA which was $80ish when I bought it in '81.
 

DSJR

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I remember the 4aa from the mid 70's and they didn't seem to lack bass at all back then. Incredibly heavy and uncomfortable though, but th emain alternatives we had were the DT100's which I found incredibly coloured sounding and the shrill HD414 Sennheisers (I still have a pair and the 2k impedance makes them useless unless fed straight from an amplifier).
 

Drengur

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The AKG k140 series were probably the most uncomfortable headphones ever made. I think they may have been designed by Dr. Mengele himself.

I still have a pair.
My first Grado 60s were a lot of fun, but I felt my ear's cartilage 24/7 even though I only had them on for a tens of minutes each day (for as long as the portable CD-player had juice). They were painful, but I still liked them.
 

nyxnyxnyx

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Great review Amir! I bet some of us always wondered how those ancient headphones would sound and measure like.

You measured a product from the Koss lineup, is there a chance you would do an evaluation of Koss ESP950/95X (massdrop)?
 
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