[Knee Deep In Epoxy]

Had some fun messing with a stash of Koss headphones, KPH40, Porta Pro Utility, original Porta Pro, Kph30i and KSC75.

Kph40 Vs Porta Pro Utility driver comparison
I put the Porta Pro Utility driver on the KPH40 headband and compared them to the stock KPH40. They sounded different. However I've come to the conclusion (and I could be wrong so don't fight me) that that the difference is in the PPU and KPH40 pads. The PPU pads are thinners and probably less of an obstruction to the sound.

In that comparison, I preferred the PPU driver sound over the stock KPH40. It seems to have more presence and resolution and air across the spectrum.

To Yaxi or not to Yaxi

IMHO... to Yaxi

Spoiler alert: My favourite combination in terms of sound quality of everything I tried yesterday was the KSC75 on Retrospekt headband with Yaxi pads with a hole cut out in of the centre of the pads. More on that below, but that became my target sound for this experiment.

Disclaimer: My preference is for clarity, width, resolution over warmth and punchy dynamics. When I say something is good or best it means it leans towards my sonic preferences. You may be the complete opposite.

So...

I added Yaxi pads to all of the drivers Kph40, Ksc75, PPU and PP (all except the KPH30i) and used them all with Retrospekt/KPH40 headbands. In that configuration the Kph40, PPU and PP all sounded identical to me, and they all sounded best with stock Yaxi pads. They lost a some bass presence and impact but gained space, stage and treble resolution. The mids were also slightly clearer with the Yaxi pads. I didn't mind the loss in the low end because the drives naturally lean warm

(Sidenote: The KSC75 with stock Yaxis was far too bass light)

Without Yaxi pads, my favourite (non-KSC75) combination was the to use the PPU pads (which may be the same as original PP pads, I don't know as I've lost mine) on the KPH40/PPU/PP drivers with the KPH40/Retrospekt headband.

Holey Yaxi?

Next up tried Yaxis with a centre hole cut out.

The hole allows the bass to come through and feel more punchy and dynamic. Meanwhile the thickness of the Yaxi pads creates a little extra distance between the ears and the driver which broadens the soundstage a little. This is perfect for the KSC75 which retains its crispy mids and sparkly treble.

However on the KPH40/PPU/PP drivers the holey Yaxis increased the low end compared to stock Yaxis, but the low end was still less than the drivers with their stock pads. The Yaxis (with and without hole) also widen the soundstage a little. But the drawback of the holey Yaxis on KPH40/PPU/PP drivers was loss of treble resolution and detail retrieval. So I settled on stock Yaxis being the best sound could get out of the (without EQ of course)

Conclusions:

1. I had fun.

2. The KSC75 on KPH40/Retrospekt band with Yaxi with holes combo takes gold.

3. Silver goes to the KPH40/PPU/PP drivers on KPH40/Retrospekt band with stock Yaxi pads without holes

4. The PPU driver (or KPH40/PP with PPU) pads takes bronze

5. Keep in mind, the stock KPH40 with no modifications at all is an awesome package as is (if you can't be bothered with all the mad science). I've been happily walking around with mine for a few months and I love them.

To be continued?...
Mad science part 2 using the porta pro headband?

 

[jmwant]

Looks like attaching the Yaxipads will be a lot easier on these one.

 

[Querkle]

quote "I doubt many people will complain about the bass representation on the KPH40."

i am here to complain about the bass representation, which in my opinion is not very good and missing detail

 

[Knee Deep In Epoxy]

quote "I doubt many people will complain about the bass representation on the KPH40."

i am here to complain about the bass representation, which in my opinion is not very good and missing detail

"Not very good and missing detail" in comparison to which other headphones?

Not trying to pick a fight, just curious about what your reference is for good bass and what price bracket it/they sit in compared to the KPH40?

 

[squyzz]

Has anyone tries If the kph40 can be run balanced since the Jack of the cable IS a 4 pole ?

I've come across a 2.5mm trrs male to 2.5mm trrs male cable on Amazon, but before ordering wich IS expensive and take time to deliver to the EU i'd likebto knowif it works
https://www.amazon.com/2-5mm-Balanc...?dplnkId=1494212a-4c03-414a-b6bd-afdb62ff9fe6

 

[Knee Deep In Epoxy]

Has anyone tries If the kph40 can be run balanced since the Jack of the cable IS a 4 pole ?

I've come across a 2.5mm trrs male to 2.5mm trrs male cable on Amazon, but before ordering wich IS expensive and take time to deliver to the EU i'd likebto knowif it works
https://www.amazon.com/2-5mm-Balanc...?dplnkId=1494212a-4c03-414a-b6bd-afdb62ff9fe6

My guess is it won't work. The connector on the KPH40 has an oval shaped housing that may clash with the housing of the cable preventing the jack from connecting properly.

On the flip side, Amazon is normally good with returns so you could always take the risk in the name of science and return if it doesn't work

 

[Somefears]

Has anyone tries If the kph40 can be run balanced since the Jack of the cable IS a 4 pole ?

I've come across a 2.5mm trrs male to 2.5mm trrs male cable on Amazon, but before ordering wich IS expensive and take time to deliver to the EU i'd likebto knowif it works
https://www.amazon.com/2-5mm-Balanc...?dplnkId=1494212a-4c03-414a-b6bd-afdb62ff9fe6

I've recently successfully used a balanced cable with the KPH40. I bought a very short 2.5 to 2.5 trrs from ebay to use with my Qudelix 5k. I didn't have any issues with the connection being blocked by the rubber shroud over the headphone side connector, but I think it will depend on which cable you get. There IS a rub to the issue though, and that is the pinout for the female TRRS connection on the headphone may be different than your source. In my case, the Qudelix expects R-,R+,L+,L- for the TRRS respectively.

Whereas the female TRRS connector for the KPH40 is wired for L+,R+,L-,R- for the TRRS respectively (and I have verified this through Koss customer support).

The takeaway is that the balanced cable may work, but you need to be mindful of how your source/amp is using the TRRS connection. I had to rewire my balanced cable to match the connections properly.

 

[Elegiac]

I don't have golden ears. Just big ol' bronze ones. But I can hear that the KPH40 is a cut above the KPH30i.
More clarity, more detail. The bass goes deeper. Better treble. A slight sacrifice in mid-range capacity/quantity (vs KPH30i) in exchange for overall sound quality, imo.
They can do a lot more justice to a higher quality source than the 30i's, that was my biggest confirmation.

 

[AlexxxAA85]

I've recently successfully used a balanced cable with the KPH40. I bought a very short 2.5 to 2.5 trrs from ebay to use with my Qudelix 5k. I didn't have any issues with the connection being blocked by the rubber shroud over the headphone side connector, but I think it will depend on which cable you get. There IS a rub to the issue though, and that is the pinout for the female TRRS connection on the headphone may be different than your source. In my case, the Qudelix expects R-,R+,L+,L- for the TRRS respectively.

Whereas the female TRRS connector for the KPH40 is wired for L+,R+,L-,R- for the TRRS respectively (and I have verified this through Koss customer support).


The takeaway is that the balanced cable may work, but you need to be mindful of how your source/amp is using the TRRS connection. I had to rewire my balanced cable to match the connections properly.

welp... there goes my dream of running a balanced cable for these on my 5K or the DX240. Its probably not worth the risk. And I've never messed around modding cables/connections, so theres no hope for that lol

What is the risk of using a cable like the one you purchased just like that unmodified on the Qudelix?

 

[Somefears]

welp... there goes my dream of running a balanced cable for these on my 5K or the DX240. Its probably not worth the risk. And I've never messed around modding cables/connections, so theres no hope for that lol

What is the risk of using a cable like the one you purchased just like that unmodified on the Qudelix?

Sorry for the late response, but if you're still in need of info, you really shouldn't even try to use it. I'm not sure if there's any risk of damaging your amp or your headphones, but I initially tried it unmodified because I didn't know the wiring was different, and they sounded terrible. Just dull and flat like something out of earbuds you'd get for free with a phone. I ended up thinking the cable must be bad before I did a little digging on the wiring. So yeah, hopefully you didn't sink money into a balanced cable just for this purpose. For what it's worth, modifying the cable wasn't TOO bad. The connections were a tad finicky, but if you have a soldering iron and some patience, it's doable.

 

[AlexxxAA85]

Sorry for the late response, but if you're still in need of info, you really shouldn't even try to use it. I'm not sure if there's any risk of damaging your amp or your headphones, but I initially tried it unmodified because I didn't know the wiring was different, and they sounded terrible. Just dull and flat like something out of earbuds you'd get for free with a phone. I ended up thinking the cable must be bad before I did a little digging on the wiring. So yeah, hopefully you didn't sink money into a balanced cable just for this purpose. For what it's worth, modifying the cable wasn't TOO bad. The connections were a tad finicky, but if you have a soldering iron and some patience, it's doable.

No worries! Thanks for the response. And i definitely haven't tried to modify anything. I don't have any electrical soldering experience so why risk it lol. I'll just keep enjoying my set how it came out of the box.

 

[Jefffeith]

Well, the KPH40 sounds different than my PortaPro. My PortaPro was purchased several months ago from Drop (thicker wires and a mic, thank you). I also have a ’regular‘ PortaPro and the KPH30i. I enjoy them all! So the question I have is if the KPH40 and new Utility Series PortaPro use the same drivers? Certainly the new KPH40 sounds different enough than the older PortaPro to warrant the question. Or perhaps Koss just modified the tuning a little to give their new products a bit of a brighter sound? I feel the new KPH40 doesn’t sound as ‘dark’ and mellow as the PortaPro I own.

 

[Mad Lust Envy]

Apparently the sound change can be attributed to different foam pads.

There is no way in any world that the PortaPro and KPH40 sound the same without some external influence.

I haven't swapped out the foams to verify, but yeah. The website does have different foam options per these models, so this is a large possibility. I'll leave it to someone else to verify. My initial error was thinking it was the same foam, with only the KSC75 having a more coarse/scratchy foam.

I'm sure to those that use those Yaxi pads or whatever can verify if they sound the same after using those pads betwen the two models. I personally don't like the pads, but it's also because I use the KSC75 malleable clips with all these models, and not their headbands. After adjusting the clips to put the drivers close to my ears, the yaxi pads just aren't comfortable with these. I'm sure they're good with the KPH40 headband though, but it's not my preferred way to use them.

 

[Knee Deep In Epoxy]

If I recall correctly the foams are different across models. I'd say the differences are attributed more to a combination of the foam type and headband type (especially the resulting clamp force) that results in different sound. the drivers themselves seem identical otherwise.

I've put yaxi pads on all. That alone doesn't make porta pros and KPH40 sound the same. But put yaxis on all and then test them on the same headband, they'll sound the same. Of course, this doesn't apply to the KSC75 which is a different beast.

 

[Elegiac]

Jeez. I find this a bit depressing. Any monkey can tune by headband/foam, surely. I thought I was buying fundamentally different things.