[Mad Lust Envy]

As I mentioned in the last sentence, the test is to try both. I have not. It's up to someone else to try both the KPH40 and PortaPro utility and compare both to the old Porta Pro (non-utility).

And yeah, that's why I said this. The new Porta Pro utility has the housing of the KPH40, so it may be they updated the driver to sound like the KPH40, or it's just cosmetic and it will sound like non-utility Portas.

I'll leave that for someone else to answer. I'm done buying Koss until they add MMCX connectors. My KPH40 is useless atm now that the cable has gone bad and I'm not one to solder. I shouldn't have to. Koss should've done this decades ago. They waste their RND with detachable cables that are still as bad as their old cables. It's frustrating.

 

[Philimon]

Except as I stated, none of the Portapro, KSC35, and Sportapro sound different. Like, AT ALL, if you put them on the same mount. By mount, I mean put them on the same headband, or on the same clip. They will sound essentially the same (give or take some minor driver to driver variation). This proves they are the same drivers with different headbands, clips, etc. The KSC75 sounds different because it IS different, and that's pretty well known.

The KPH40 sounds different, period. Nothing about them will lead anyone with decent ears to conclude they use the same drivers. It falls well outside driver variation.

So your argument does not correlate. Sound-wise, they share nothing in common with the others, other than being budget bangers.

They are more reference sounding, and less skewed towards the low end. Not that it's lacking in bass.

Believe me, I WISH they were just Portapro drivers again, because that would've justified me having modded my other two Portapro driver headphones.

But now, I HAVE to mod the KPH40 with MMCX connectors, because it's simply the best headphone of these yet.

Now, CAN Koss have updated ALL the drivers to sound like this from this point on? That MAY be true, in which case you would be correct at least NOW. The test is to buy the new Portapro Utility and KPH40 and compare to an old set of Portapros. The new Portapro Utility will either sound like the old Portapro, or it will sound like the KPH40. This will ensure which direction Koss is going.

I still dont buy your argument that because KPH40 sounds a little different means that the driver is different. There are physical differences that account for sound differences such as pads, cups, headband, and driver baffle. Far more likely to be the case than quality control driver variance. And more likely the case than different drivers.

Stock pads are different between models. Some are denser, some thicker. Porta Pro has had stock pad changes over its long production and the differences in frequency response have been noted subjectively and by measurement. Padrolling differences are obvious amongst headphones.

Headband clamp is going to determine driver distance from ears, and seal quality especially with open foam pads. Porta Pro has the strongest clamp among the KOSS variants. Headband clamp will squish the open foam pads causing them to become more dense and have a stronger seal.

Driver baffle dimensions example is most obvious between Porta Pro and KPH30i. The Porta Pro small baffle combined with clamp causes the driver to sit very deep in your ear compared to KPH30i which again effects seal. Driver distance has its own effect on sound qualities…

The cup differences in this case are probably much less effecting than the aforementioned variables.

 

[Mad Lust Envy]

We're talking about a driver that is literally attach to a plastic cover. These are not like other headphones with damping foam, and a bunch of other factors that WOULD alter sound.

I mean, do you EVEN have the KPH40?

Because if you had them and compared them to literally every other Koss headphone you keep thinking is the same driver, well, I'm sorry, but the chance of that is next to none based off sound alone. You'd have to be deaf to think they're remotely the same sound, altered slightly. They sound like two different headphones. Same house, but different headphones. Think DT880s to DT990s, or HD600s to HD650s.

Put them in the same control group, (i.e. same headband or clip, or foam), and you'd see their sound falls WELL outside of variation. You can even check out actual reviews where people with experience will tell you... they sound different./ So unless you're telling me every KPH40 has some inconsistency... I don't buy it. But hey, that's really not my concern.

You keep talking about clamp etc, when I continuously keep telling you that if you mount them on the same exact headband or ear clip, they will still sound different.

Let me spell it out for you.

Put KPH40 on KSC35 clips (where clamp factors will not change between the KPH40 or Sporta/Porta/35s). They will sound different. The others will all sound the same.

Put KPH40 on KSC75 clips and compared. It will sound different from the others. The others will all sound the same.

Put KPH40 on PortaPro headband. It will sound different from the others. The others will all sound the same.

Put KPH40 on SportaPro headband. It will sound different from the others. The others will all sound the same.

Puit KPH40 on KPH40 headband. It will sound different from the others. The others will all sound the same.

So all your talk about clamp factors is absolutely moot, when you're literally using the same mounts.

The best device to control testing is the KSC35 clips. Those clips clamp the same with any of these drivers everytime. You can't change their clamp on those clips as they are plastc and rigid. They will always fit the same, unless you literally break the clips.

As for the foam pads, there is not enough of a difference to consider them affecting the sound to this degree. Sure the KSC75 pads are CONSIDERABLY different from the Portas and KPH40. However the KPH40 and Portas, 35s, Sportas do NOT have enough variability to change the sound between them. Removed the pads on the KPH40 and my two others, and guess what? No change. Not enough to account for the change in sound.

But I'm done arguing this. If you think they're the same driver, enjoy. Go buy some Sportapros, which are the cheapest option, use with whatever parts express headband, and be happy that you saved a few dollars.

For everyone else: The KPH40 is a more neutral sounding headphone than the non-Utility Koss stuff, regardless of headband, or clip used.

Now is there a chance that it's the same exact driver as used for decades? Hey, it's possible. But what I'm saying is that all signs lead to: NO. It's my firm belief that they have updated to drivers with new tuning, which is not the same as before.

I can't say this is the case with the Porta Pro utility as I have zero experience with those. That's for someone else to test and answer.

 

[Philimon]

We're talking about a driver that is literally attach to a plastic cover. These are not like other headphones with damping foam, and a bunch of other factors that WOULD alter sound.

I mean, do you EVEN have the KPH40?

Because if you had them and compared them to literally every other Koss headphone you keep thinking is the same driver, well, I'm sorry, but the chance of that is next to none based off sound alone. You'd have to be deaf to think they're remotely the same sound, altered slightly. They sound like two different headphones. Same house, but different headphones. Think DT880s to DT990s, or HD600s to HD650s.

Put them in the same control group, (i.e. same headband or clip, or foam), and you'd see their sound falls WELL outside of variation. You can even check out actual reviews where people with experience will tell you... they sound different./ So unless you're telling me every KPH40 has some inconsistency... I don't buy it. But hey, that's really not my concern.

You keep talking about clamp etc, when I continuously keep telling you that if you mount them on the same exact headband or ear clip, they will still sound different.

Let me spell it out for you.

Put KPH40 on KSC35 clips (where clamp factors will not change between the KPH40 or Sporta/Porta/35s). They will sound different. The others will all sound the same.

Put KPH40 on KSC75 clips and compared. It will sound different from the others. The others will all sound the same.

Put KPH40 on PortaPro headband. It will sound different from the others. The others will all sound the same.

Put KPH40 on SportaPro headband. It will sound different from the others. The others will all sound the same.

Puit KPH40 on KPH40 headband. It will sound different from the others. The others will all sound the same.

So all your talk about clamp factors is absolutely moot, when you're literally using the same mounts.

The best device to control testing is the KSC35 clips. Those clips clamp the same with any of these drivers everytime. You can't change their clamp on those clips as they are plastc and rigid. They will always fit the same, unless you literally break the clips.

As for the foam pads, there is not enough of a difference to consider them affecting the sound to this degree. Sure the KSC75 pads are CONSIDERABLY different from the Portas and KPH40. However the KPH40 and Portas, 35s, Sportas do NOT have enough variability to change the sound between them. Removed the pads on the KPH40 and my two others, and guess what? No change. Not enough to account for the change in sound.

But I'm done arguing this. If you think they're the same driver, enjoy. Go buy some Sportapros, which are the cheapest option, use with whatever parts express headband, and be happy that you saved a few dollars.

For everyone else: The KPH40 is a more neutral sounding headphone than the non-Utility Koss stuff, regardless of headband, or clip used.

Now is there a chance that it's the same exact driver as used for decades? Hey, it's possible. But what I'm saying is that all signs lead to: NO. It's my firm belief that they have updated to drivers with new tuning, which is not the same as before.

I can't say this is the case with the Porta Pro utility as I have zero experience with those. That's for someone else to test and answer.

Im sorry. I didnt read all of your original post. Way too long for headphones that are not that interesting and not all too different from the other KOSS. Shortening your review to the most important bits would make it a lot more digestable.

Do you have pics of the pads used on your other KOSS? That could explain the difference other than different driver.

Are your other KOSS genuine? Did you do the quick disconnect cable installs yourself? I saw aliexpress or alibaba sells those “KOSS” with quick disconnects (mmcx) pre-installed…

@Audeze

 

[Philimon]

The differences in sound between the three KOSS I own is mainly in tonality. The small differences in tonality and other sound characteristics could easily be accounted for by different pads and clamp. Its easily possible that KPH40 is using the same driver as Porta Pro and KPH30i. If headband / clamp variable is removed, then that leaves pads, cups, and driver baffle as next known different variables. You could put all the same pads on each then compare but then any small difference thereafter could be in the cups or driver baffle.

Ill try some measurements soon but am not that motivated. We are talking small sound differences on lofi cheap headphones. To me more important is form considering the use case.

 

[Mad Lust Envy]

KPH30i, PortaPro, and KPH40.

There are significant differences here.

KPH30i, has a blatantly obvious design difference, where not only is the driver enclosed in the headband design, but the front side is also supplanted with more padding and structural design. This is magnitudes different to the Porta and KPH40 which are NOT different in driver enclosures and pad design. So yes, your argument is COMPLETELY valid when speaking about the KPH30i.

However, that is ONLY for the KPH30i.

There is nothing to take pictures of on the KPH40 and Portapros. They look indetical in all but the rear cover, which I outlined in my review. So the sound changes would have to be INTERNAL, and not due to external factors like those found on the KPH30i, which makes them drastically different in implemetation, in the same way the UR40 (a headphone I have left out sue to how utterly different in design it is) sounds completely different despite similar drivers.

I am not disagreeing with you that enclosements and pads will drastically alter the sound of a driver. I'm merely pointing out that that logic does NOT apply to the KPH40 which sounds different despite sharing the same design and enclosure as the Portapro, 35, and Sportapro which all, under the same conditions sound the same to one another.

 

[Philimon]

KPH30i, PortaPro, and KPH40.

There are significant differences here.

KPH30i, has a blatantly obvious design difference, where not only is the driver enclosed in the headband design, but the front side is also supplanted with more padding and structural design. This is magnitudes different to the Porta and KPH40 which are NOT different in driver enclosures and pad design. So yes, your argument is COMPLETELY valid when speaking about the KPH30i.

However, that is ONLY for the KPH30i.

There is nothing to take pictures of on the KPH40 and Portapros. They look indetical in all but the rear cover, which I outlined in my review. So the sound changes would have to be INTERNAL, and not due to external factors like those found on the KPH30i, which makes them drastically different in implemetation, in the same way the UR40 (a headphone I have left out sue to how utterly different in design it is) sounds completely different despite similar drivers.

I am not disagreeing with you that enclosements and pads will drastically alter the sound of a driver. I'm merely pointing out that that logic does NOT apply to the KPH40 which sounds different despite sharing the same design and enclosure as the Portapro, 35, and Sportapro which all, under the same conditions sound the same to one another.

So you are comparing to non-genuine KOSS? Maybe KOSS updated the cup design to temporarily throw off counterfeiters.

Basically the dimensions of the cups+baffle are about the same. The pads on my Drop Porta are a little thicker around edges but that could just be quality control since they look hand cut (not uniform) on the inner edges. I noticed a slight difference in color and density of the foams, but who knows maybe my Porta Pro pads are crusty from occasional use. My phone camera lens is cracked so photos are not that good but when held up to the light you can see the difference in pads but whether that amounts to any sound difference could be negligible. I could try measurements of each set of drivers using the same headband …

Edit: When reinstalling pads I determined that the Porta pads are a little firmer. The sound difference between old style PP pads and new style PP pads have been recorded. Older style PP pads were a bit thinner and less firm…

 

[Mad Lust Envy]

What are you even talking about? Where do you get the notion that I have non-genuine Koss? You're starting to lose me. My modded Koss were units I bought new and untouched, in which I had MMCX connectors attached. Nothing else was done.

I'm basically over this discussion. I've made me thoughts known. You can agree or disagree, really it doesn't matter to me. My data points have been made.

 

[Philimon]

What are you even talking about? Where do you get the notion that I have non-genuine Koss? You're starting to lose me. My modded Koss were units I bought new and untouched, in which I had MMCX connectors attached. Nothing else was done.

I'm basically over this discussion. I've made me thoughts known. You can agree or disagree, really it doesn't matter to me. My data points have been made.

You installed the mmcx connectors yourself?

 

[Mad Lust Envy]

You installed the mmcx connectors yourself?

No, I had a friend do it.

 

[Philimon]

^ KPH40 (pphb) = KPH40 driver / capsules / pads on a Porta Pro headband. Porta Pro = Drop version

As you can see the measured difference is minimal. The differences could be due to the observed difference in the rear cup, pads, or just positioning upon measurement rig coupler variance.

Compare to solderdude's measurements. He also demonstrates the differences of current pads VS old style Porta pads.

@Audeze If you need a replacement Ill shill for an LCD5.

 

[Philimon]

Here is link to aliexpress KOSS parts with MMCX preinstalled. You can find more examples.
edit: link not working. Just google aliexpress and KOSS parts or KOSS mmcx
edit2: @Audeze I'll stop refuting @Mad Lust Envy for an LCD2C.

 

[Mad Lust Envy]

Not sure what to tell you. I and other people with the KPH40 and what Ive seen on their impressions is that they do not sound like Portas. There is no way in any universe, anyone would sit here and say they sound alike.

As for the aliexpress Koss, not sure what to do with that info, as I didn't buy those, so they have zero relevance to this discussion whatsoever.

edit: regurgitating the same things over and over, so I'm gonna omit the same things I've already mentioned.

For those measurements, it'd help to know how close in manufacturing date were those Portapros were to the KPH40. Because as I have said before, it could very well be that Koss has updated their drivers to whatever the KPH40 uses (I said as a such in my review) recently. My Portas and KSC35s used to test were closer to one to two years apart from my KPH40. One of them is from January 2020 (Koss's Amazon page), the other I bought directly from Koss about half a year later.

Excerpt from my review:

Warning: The PortaPro Utility has also received an update in its rear housing design. Does it stop there, or did Koss ALSO use whatever drivers are in the KPH40 with the PortaPro utility? That's a question someone else will have to answer. For now, I'm under the assumption that the KPH40 and PortaPro sound different, simply because all the PortaPros I have owned all sounded like all my previous KSC35 and SportaPros. There is a distinction of those units being darker and more bass prominent than the KPH40 I have. IF Koss updated the PortaPro Utility to use the same drivers as the KPH40, then the tonal balance has shifted a bit towards more neutral, and not AS bass-centric and laid back. Perhaps in the future I'll try out the PortaPro utility to confirm whether they retain the old sound, or have changed. So just a word of warning. Any comparisons I make are with the KPH40 and OLDER PortaPros and its brethren. I know nothing of the new PortaPro Utility sound.

I highly doubt Koss will give anyone a solid, firm answer on whether they use the same drivers or not. So I leave it for others to measure the KPH40 and PortaPro Utility (on the same headband/mounts for proper 1:1 comparison). Though it may be the PortaPro utility still has the old sound which (to me) is obviously different. Time will tell.

 

[Philimon]

Not sure what to tell you. I and other people with the KPH40 and what Ive seen on their impressions is that they do not sound like Portas. There is no way in any universe, anyone would sit here and say they sound alike. I have purchased multiple headphones of other companies of same model which had subtle driver variation, and I could tell. The KPH40 sound is nothing like that. It may as well be a different headphone.

As for the aliexpress Koss, not sure what to do with that info, as I didn't buy those, so they have zero relevance to this discussion whatsoever.

I've been accustomed to official Porta/Sporta/KSC35 for over a decade now. Pre and post mod, they sound as I have always heard them. In a decade, and with literally 25+ or so variants I've purchased, there has never, ever been this change in sound balancing.

They sound different regardless of headband used. And I tested with Portapro headband, Sportapro headband, KSC35 clips, and KSC75 clips.

For those measurements, it'd help to know how close in manufacturing date were those Portapros were to the KPH40. Because as I have said before, it could very well be that Koss has updated their drivers to all sound like the KPH40 (I said as a such in my review) recently.

I didn't know you tried KPH40 with Porta Pro headband. You didn't mention that earlier, you only said you tried with "clips". And you still thought it sounded different from a Porta Pro? I don't refute there could be a difference but would say it's very small. I acknowledge that my ears are not as good as yours.

The aliexpress KOSS serve to show "custom" mmcx KOSS may be ordered pre-customed from aliexpress. Are they identical otherwise? Who knows.

Same, KOSS is my longest tenured headphone. Also over a decade. I like your style.

Most people don't have measurement rigs to keep their easily influenced biases in check. KPH40 with its stock light clamp headband does not sound like Porta Pro with its stock high clamp headband even though they appear to use the same drivers. Who knows.

No. I've owned old versions of Porta Pro too. I used to have to buy a set every few years when I was younger and more active. I didn't notice a difference in sound until the Massdrop versions launched. The Massdrop version used a thicker and denser set of pads which as far I could tell was the only reason for difference in sound. I had tried padrolling previously with HD414 pads and Yaxi pads. When you buy a pack of replacement KOSS pads from Amazon now they are the same as the ones from Massdrop. See the solderdude link for more info.

 

[SenyorC]

As I don't see a main showcase for the KPH40, I will leave my review of them here in this thread as it seems to be the most active/relevant.

The KPH40 have been very kindly sent to me by Koss, along with the KEB90 and the utility cables. Today's review is going to focus on the KPH40, both with and without the utility cable, and I will mention the IEMs in another independent review.


Koss have not requested anything specific, not even that I publish links. In fact, the utility series is not available yet in Europe, although Koss inform me that they will be available in the very near future and will be priced at 64.99€ for the KPH40, 89.99€ for the KEB90 and 69.99€ for the PortaPro Utility (which I don’t have at present).

The utility cables, which I will talk about also in this review, work with all the models and are available with both USB-C and Lightning connectors. These will be available at 49.99€.

More information about all of these can be found on the official Koss site here: https://koss.com/collections/utility-series

Intro…

I don’t think anyone who has spent any kind of time around headphones and earphones can have done so without the brand Koss appearing on the radar. Even my father, who is not a headphone fan, had a set of PortaPros for a long time, long before I became seriously interested in headphones.

In my case, although I have many options to choose from, I have to say that Koss are still the brand that sees the most ear time. I basically have a set of PortaPro’s, KSC75’s (with PP headband) or KPH30i at each position where I spend any amount of time. Most of them are connected to Apple dongles, making them my “quick grab” headphones for simple media consumption and, more importantly, long conference calls where I need to wear them for hours and hours without a break.

They also spend a lot of time on my head between calls, just for listening to music without having to swap headphones, offering a very enjoyable sound that I would say is very impressive for their price range.

Anyway, you can see my full reviews of the PortaPro, KSC75 & KPH30i (by clicking on any of them). The focus today is on the KPH40, part of the new “Utility” series, which I find is quite an announcement as it is a new addition to this style of headphones from Koss, joining the other models that have been around for 5 years, in the case of the KPH30i, or decades in the case of the PortaPro.

Presentation…

The presentation has not changed, it still follows the simple packaging that Koss uses on most (all?) of their headphones/earphones. It is a simple white box, with an image of the KPH40 shown on the cover, with some other basic info distributed around the box.

Inside we receive the KPH40 well fixed in place and well protected for shipping, along with the normal 3.5mm cable. Yes, Koss have actually added detachable cables to the “utility” series, which is great, even if it is a little different to what people may expect when they hear “detachable cable”, but then again, Koss have proved continuously over the years that they like to do things their own way.

The Utility cable is shipped separately as it is a separate purchase. This is again packed in a similar fashion, with simple packaging and good shipping protection.

Basically, Koss ships their Utility series (as with other series headphones) in packaging that is meant to protect the item during shipping and then be recycled as soon as they have been opened. This is great in my opinion, keeping the packaging costs down, along with reducing the use of plastics in the packaging.

Build and aesthetics…

I also leave my impressions of comfort under the “Build and aesthetics” section and this time I just need to say one thing…

These are the most comfortable headphones/earphones I have ever worn!

Yes, they are that comfortable.

The minimalist headband is extremely lightweight, the drivers are small and there is plenty of adjustment for each person's ears. I sometimes forget I am wearing PortaPros and sit with them on my head for extended periods without anything playing, that is how comfortable the PortaPros are, well the KPH40 just increased the comfort level by quite a significant amount.

I know that comfort is a very personal thing but I have actually put the KPH40 on the heads of multiple people and every one of them said “it’s like wearing nothing”.

As far as build quality, I have never been very inspired by Koss build, yet I have never had an issue either, so I cannot complain about them. In the case of the KPH40, the build is still very simple but the headband is a definite step up, at least it seems to be. A very simple metal band has been used, with an adjustment system on the sides, similar to the KPH30i system but with metal parts that inspire far more confidence.

The look of the headband is also great in my opinion. I mean, it is difficult to make a thin metal band into anything interesting but the colour used and the logos etc. do a good job of giving it a bit more of a well built and modern style.

The pads are also a step up from previous models, being slightly thicker and more comfortable. The only other Koss model I have that still wears stock pads is a set of KSC75’s that I have for reference and I find that the KPH40 pads are much nicer.

The cable, which is detachable from the point where the cable splits, is a flat cable and I actually quite like it. It feels good, is not microphonic and it works as its intended. Ok, it is not a boutique cable, but I would say it is certainly a huge step above the older series cables.

I will talk more about the cable in the functionality section but just so we are clear, the KPH40 has a cable that is fixed at each driver (non-removable) but then has a female connector where the split would be on a normal cable. Included in the box is a simple 3.5mm TRS to 2.5mm TRRS cable, this cable can be swapped out for the Utility cable, but again, I will discuss this more in a second.

Functionality…

I know that a “functionality” section in a simple headphone review is not a usual occurrence, but I need to mention a little about the Utility cable, which is a very important aspect of this series, in my opinion.

As I just mentioned, Koss have used a system that allows the bottom half of the cable to be swapped out. This allows the included 3.5mm terminated cable to be swapped out for a Utility cable, terminated in USB-C or Lightning, which contains a microphone and a DAC inside the cable.

As I also mentioned, I keep quite a few pairs of Koss around with Apple dongles on them, allowing me to plug them into almost anything, giving me a decent listening and communication headset. The addition of the Utility cable basically does the same thing.

Where the Utility cable differs from something like the Apple dongle is that it has an inline microphone built in, along with some basic controls like vol+/vol-, play/pause etc. These controls are simple rubber rockers that have a robust feeling to them and work fine on both Android and PC. The inline microphone is also of good enough quality to be used for calls without any complaints. I spend quite a bit of time on calls and using the KHP40 during the past week or so has not brought me any complaints from others at all.

The female connector that is mounted on the fixed part of the KPH40 cable is a female TRRS, which actually allows the headphones to be run balanced. However, the pinout is not a standard pinout, so anyone making DIY cables for this will need to do some investigation first. I have no idea if Koss plans to release a balanced cable for the Utility series but to be totally honest, I can’t see the need for running these headphones balanced (although that doesn’t mean that a bunch of people wouldn’t buy a balanced cable if available).

Sound…

(*note that any songs that I mention in this review are clickable links, as always, which allow you to listen to the song on the streaming platform of your choice)

Let me start by saying that I have done some A/B testing back and forth between using the Koss Utility (USB-C) cable and the normal 3.5mm included cable with the Apple dongle, and I really can’t tell the difference. There are occasions when I think I do but then I swap over and I am no longer convinced. There is no way that I would differentiate between them in a blind test.

This is a high compliment in my opinion as the Apple dongle is a pretty good DAC and rivals other dongles costing 10 times as much. The Utility cable not being a step down means that it is also a decent sounding DAC and does justice to the headphones. Also, the fact that I can’t tell the difference is a sign that no DSP correction has been used in the Utility cable, so it is not an “obligatory” purchase like it is with some other brands that I won’t name.

So, my impressions have been with both setups, along with running it from my usual set ups, although the majority of use has been with the Utility cable.

I will also mention that all of my Koss models are currently wearing Yaxi Pads and have been for quite some time. This means that my current impressions of those models are using Yaxi pads, which is maybe not an apples to apples comparison. However, all of my reviews have been with stock pads, before trying out the Yaxi pads, so it is only fair that the KPH40 gets reviewed in the same way. I will be giving the Yaxi pads a try once I have finished this review and will post a quick update in the near future if I feel that they change things enough to be relevant (which they did on all the previous models I have tried them on).

Anyway, on to the sound…

The subbass region is rolled off, as is to be expected. These are small on-ear headphones, it would be quite a feat if they pulled off a huge amount of subbass. Putting them through the usual subbass stress test, they do sound noticeably rolled off but I will say that they still manage to sound clean. Many times, when pushing a driver to reproduce frequencies that are not in the zone that it is designed to reproduce, will result in a sound that is stressed and will cause no end of distortions and issues. Just try boosting 40Hz on a normal bookshelf speaker and then turn it up, it won’t sound good. However, the KPH don’t fall apart even when pushed. I turned the volume way above my usual listening levels and was surprised that “Chameleon” didn’t make them suffer.

The midbass is more present and actually is partly responsible for the warmth that the general sound signature presents. I would definitely say that the general signature is aimed more towards the PortaPro than the KSC75, with more warmth and less upper registry focus. This works well with a lot of electric bass and guitar, giving a nice warm low end to rock and other electric focused styles.

However, the bass does not seem to be as detailed or as focused in relation to other mentioned Koss models. The bass seems to be a little smoothed over and while this can work well for BGM listening, I found that I was missing detail once I paid attention.

The transition into the lower mids is not bloaty or muddy, but it does follow that slight warm sound with a little lack of detail. For example, “Give Me One Reason” by Tracy Chapman, sounds great while listening to her on the KPH40, with a nice timbre to the guitar, however, “Killing in the Name” doesn’t fare so well.

The midrange is fairly balanced but I do find that on certain songs, vocals can take a step back when there is a lot going on. This is not a regular occurrence but I have noticed it on certain songs, such as “Killing in the Name” I just mentioned.

For the majority of simple acoustic & vocal based music I listen to, I can not complain, the KPH40 do a nice job of presenting the music in a relaxed and smooth manner, yet there are certain songs that just sound a little muffled to me in the vocal range, “Whole Lotta Love” being an example.

Moving into the higher end of the midrange, again, the presence is good on a great majority of music, but I do find certain songs, or certain artists, getting a little lost in the mix. This is something that seemed to stand out more on tracks that have multiple electric guitars, it seems that the guitars just get pushed forwards a little bit more than the vocals.

Heading up into the higher registries, there is no sibilance to speak of when using the usual “Code Cool” test, however, there is a peak somewhere around the 5kHz mark that can sometimes come across a little harsh. I am wondering if this frequency peak has anything to do with the additional presence of guitars vs vocals, however, without some exact measurements and EQ, I will continue to wonder for now.

The highest frequencies do not extend as far as they could, or rather, I feel that the sound signature of the KPH40 takes away from the sensation of air and extension. It's not that there is no treble, the treble is there, it is just masked slightly by the overall tuning.

Soundstage is as good as it is on any of the other Koss models I have had the pleasure of trying. It is not the widest soundstage in the world but does have enough space to breathe and while I would consider it more on the “intimate” side of things, it does not feel closed in. The placement of images inside the stage is also acceptable. Layers are nicely identifiable if paying attention but the details do not jump out and grab you, they are not attention seekers.

Conclusion…

I feel there is a lot of good in the KPH40, although there are also a couple of things that don’t quite convince me, mostly in regards to sound, more specifically, sound with certain music.

As far as build, these actually feel like a step up from other models, with a comfort that really is second to none. I would not complain if I had to wear these on my head for 16 hours per day. They are a great set of headphones for the office and I would highly recommend them to anyone needing to wear headphones all day (such as call centres). The mic is also decent. I thought it might suffer by being further away from the mouth than on other models, but that has not been the case.

The utility cable is a very good idea and while it may not be the way that we would have expected, I have no complaints about the quality or functionality of the system. In fact, I have no complaints about the KPH40 with regards to quality.

If there is anywhere that I am not 100% sold, it is in the sound category. Now, I am not saying that the KPH40 are not a good set of headphones for the price, they most certainly are, however, they are up against some tough competition from themselves.

In regards to my favourite sound from the Koss models I have been mentioning throughout the review, my ranking is KSC75 (on PortaPro headband) > KPH30i > PortaPro.

That is obviously a very subjective opinion, one that is not shared by a huge amount of people who would probably rank them the other way, but that is how my preferences go.

In the case of the KPH40, I would place them between the KPH30i and the PortaPro, strictly on sound terms only. This is also very dependent on music, where some heavy rock will drop my preference for them, some acoustic & vocal music will quickly bring them back up.

If talking about build, comfort, etc., then I would easily rank the KPH40 above any of those three.

I have no doubt that the KPH40 will see a lot of use, as with all the Koss models I own, and I am now excited to see what changes Yaxi may bring.

As with all my reviews, this is also available in Spanish on my blog (here) and on Youtube (here).