Hi Koss.

We tried to talk to you, Koss. Now, we talk to the clouds.

As the title of this website says we exist somewhere within the city of Milwaukee Wisconsin and so does Koss! If you've been around for my dissection of Corsair Headsets you are very well aware that we are heavy users of headset/headphone technology.  When at home we sometimes jump on the ye'ol' telegram and talk to people for hours. Sometimes even get invited to events we cannot easily discuss, one part NDA, another part sexy robot time that would make most of the readers here uncomfortable!

This is my little diatribe of supporting a not-so-small local business and the trials that led us up to the point where it may be time we part ways from this company as a whole. It's very unlikely they'll even listen to us at this stage where I'm sitting on some lowly blog shouting into the clouds but it's better than leaving a bad review on Amazon only for manufactured positive reviews to overshadow the problems entirely. Understand Koss (and any other headset company that bothers to listen) that we don't hate you. We want you to get better. If possible, we'll even show you how. Because a blog is supposed to help.

First off, what the hell is a "Koss"

It's a headphone company that has existed since 1958 and has been one of the major businesses that existed within Milwaukee, WI. I'm not going to repeat everything that Wikipedia has already discussed. Long story short Koss has a bit of a record of not making good decisions in particular on the accounting front. What kept them alive is their technological achievements of making good headphones. In our early days back when radio was the only form of hearing new music there was NPR and College radio. We always kept hearing the DJs at WMSE get a donation of Koss headphones sent over to them and how much they legit liked them. We even remembered how there was such a beast as the "Koss Pavillion" at SummerFest which the company sponsored a stage for musicians to come to at the festival. We don't have many good memories of Summerfest as most of what we remember was excessive drinking and fights. So in a sense, it's probably best that Koss backed out of the whole ordeal.

Made in China. Printed in China.

We're going to be completely honest with everyone here. Koss does not really manufacture things in the States like they used to. Like the majority of electronics, it all goes off to China. Why? Try starting a capacitor company in the United States and watch the Environmental Protection Agency have an aneurysm over possible groundwater contamination. OOoo! Better yet! A lithium refinement plant! Nothing greener than refining lithium right?!? There's not even a path for a company to start production of this nature in America. This could very well be the intent given how corruption tends to run in most governments. It's better to say you're striving for a "greener world" by taking money from lobbyists to build bureaucratic walls for business instead of responsible pathways.

Back to the topic.

We know for a fact that Koss may still have their engineering and warranty processing department here in Milwaukee Wisconsin. Koss has a considerable warehouse space to maintain a distribution hub for the Midwest for all of the chain stores. But! That's really it. Like a lot of name-brand electronics, it's kind of a shell of what it once was.

Personal history time!

I've had previous headphones in the past. Most were hand-me-downs as we started as dirt-broken teenagers. However, my first set of headphones (and headset) was the following.

Koss Pro4AA TitaniumKoss Pro4AA Titanium series.

Originally purchased this set in 2005. We purchased this set of headphones BECAUSE of their lifetime warranty of standing behind the product. And process warranty we did!

Four times on these headphones and every time it was always the plastic hinges connecting the silver plastics with the black headband plastics and one time on the pivoting fork. Since there was a Koss office in the city I just had to follow procedure and call in advance so they have a set ready (Apparently these are out of stock a lot and realistically I probably should have just gone with the ole' reliable standard Pro 4AA's instead of "Titanium" edition. but eh) probably the best part of buying these was going to the Koss store and picking them out. Finding that sometimes the most expensive set isn't necessarily the best set for your ears.

I don't have any pictures of the breakage but if they do break after publishing this we'll be sure to take some pictures before sending them in.

The best times we had with this set were DJ'ing for a really-real DJ FM station that had a 10,000-watt transmitter and doing random DJ shit on Secondlife. We did some club DJ'ing but it kinda sucked because of pressure from the club owners to get people on the dance floor by playing the top 20 songs so they can work up a sweat and drink more. Again, fuck Milwaukee and its binge-drinking lifestyle.

Beyond those rare moments the headset never really left the house. I will say because of the size of the coils in his headset the music coming from my laptop or cellphone was always quiet. You almost need a pre-amp or go through a 1980s amplifier that has the larger headphone jacks to give it the power it needs.

A lot of people gave Koss shit because their bass line wasn't as intense as say, a Sony, or a Beats by Dr. Dre. But to us, the mid-tones stood out when listening to music on this set. We've grown to appreciate hearing instrumentals on a set like this.

We know a lot of the quality of the headphones comes down to the individual and how they wear their set. So, without sounding like some kind of audio snob. Let's just say we've enjoyed the warranty and we've enjoyed listening to these.

Koss CS-100Bonus get: Koss CS100 headset.

While at the Koss Store we also bought a pair of these bad boys for $21 which apparently even in the year 2023 you can still get! With good reason too!

Koss CS100 - Dual 3.5mm jacks for headset and microphone

Out of the nearly 20+ years of owning a pair, we've only had to process a warranty in the first year of these headphones. Hinge issue again, but this time around the upper head-band area is where the plastics began to shatter. Beyond that, we've had to replace the foam pads eight times. Which we don't consider really a part of the headphones. Frankly, we should just make our own set of leather cushions for the things and be done with it.

As for the Audio fidelity of the microphone on this headset. Well! For just over $20 it's not terrible. Back when we were doing helpdesk IT support we used adapters to convert the 2x 3.5mm jacks into an RJ11 so that we could answer the phone hands-free. It was however a little odd that they used a 3-pin barrel for their microphone side when the microphone was for the most part mono. It didn't hurt anything and most likely to keep the parts consistent to just recycle the same barrel plug for the microphone and call it a day.

Microphone test.


If the HTML5 audio player is not working above you can download the WAV and listen for yourself.

Is the audio the best we've ever heard out of a microphone? Nah! It's a little plosion happy and tinny. We go into detail during our audio testing. but overall it's 'okay' for $21 knowing Koss is a headphone company and not a microphone company.

Airport time!

2020 state of the blog in baggage - The title.


The work that we do involves being stuck inside airports for hours. A quality headset quickly becomes a requirement to keep oneself sane. After all, this is why in many terminals throughout the world electronics stores are selling the best of the worst in Bluetooth technology for travel. At the highest price point of course!

Hope you're ready to pay $30 for a USB-C charger!

When at an airport you're not a name but cattle. Er, customer!

Your job sends you to a place two states (about 550 miles)  in which if you factor arriving 2 hours early so the TSA can do their job(poorly), get you boarded onto a plane, only to let said plane taxi around the airfield for anywhere from a half hour to a full hour. Get taken to a 'connection flight' eight states away. Layover for three hours and fly you back to where you should be as if you're a DHL package. You'd realistically be better off just jumping in a car and driving for six to seven hours. But airport life is a lot of hurry up and wait. And thus, we needed headphones that could deal with the rigors of travel.


Koss-BT540I - Bluetooth headphones.Koss BT540i

Originally bought these in 2021 because we had friends that got these back in 2019. In the lifespan of Koss products having a 5-year run isn't a whole hell of a lot. The reason why we really liked this set is it folds flat and fits into a case which sits perfectly in my laptop bag next to my power supply and mouse so for travel's sake it was fantastic. The audio quality on the headset wasn't as perfect as my 4AA's but it was certainly better than the shitty corsairs we were traveling with. And, it's wireless. so bonus points there.


Microphone test.

If the HTML5 audio player is not working above you can download the WAV and listen for yourself.

The good news is it's not as "plosion" happy as the CS-100! However, the audio quality feels more muffled and worse than the CS-100's. This is actually understandable given how you're not necessarily speaking into the microphone like a normal headset. but it has to bounce around a little to pick out your voice from the ambiance. It was usable, but not great, and certainly a loss of fidelity in the grand scheme of microphone technology despite how Koss was trying to hype this. Then again, if you're running around airports having things in front of your face isn't really a great idea either so it's a trade-off.

3 and 4 pin audio diagram of common pinouts.

Another thing to keep in mind is the audio jack is only a 3-pin connector for the HEADPHONES and not for the microphone at all. You cannot bypass the microphone and hard-wire it into your laptop like you could with the CS-100. This seems like a missed opportunity because as you can see above, Koss could've provided a break-away 4-pin to 3-pin cable to use it classically while still maintaining general compatibility. With the microphone being Bluetooth only we will never really know how good the microphone quality truly was as for all we know it's getting mangled by the Bluetooth chip inside.

Bluetooth woes.

I will say that when listening to music it's totally fine. However, if you hook this headset up to a Windows laptop it gets a little weird because it takes up to half a second before Bluetooth engages the audio. As a result, you sometimes don't hear a ringtone of Discord/Teams/telegram for a little bit. This is probably a latency issue of Bluetooth 4.x and is out of the control of Koss.

As far as the distance goes. About 30 feet before Bluetooth drop off. If Bluetooth traffic is very dense like walking around the terminals of O'hare International Airport it starts to occasionally drop off. Again, excusable given how many hundreds of Bluetooth devices people have within the airport.

One-year warranty. WTF?

A lifetime warranty does not exist on Bluetooth series headphones. Only one year. The reasoning Koss gives is that lithium Ion batteries only have so much life to give. In which perhaps they should've taken some notes from Nokia:

Nokia cel-phone battery."Use a replaceable lithium battery."


Not entirely sure how hard it would've been to have a trap door on the side of the headphones to accept a battery. One could simply sell batteries instead of shortening the lifespan of a product warranty considerably. On top of all of this Koss would make the EU happy by separating hazardous materials away from their electronics for recycling.

Koss instead took the easy way out. Sealed everything up, threw the middle finger at serviceability, and just embraced warranty mediocrity offering a 1-year warranty just like every other low-end headphone company on the planet which we're sure will keep Koss competitive with Sony, Bose, etc!

Because of my previous history with Koss and knowing how lithium batteries tend to go. I picked up an insurance package for my headset. And after only two years we were totally glad we did but for old reasons. Not new.

I will have to give Koss Kudos on the charging circuit where you can still use the headphones in Bluetooth mode AND charge it at the same time as we've stayed overnight in strange places talking to randos online just to maintain sanity.

Damage report of the Koss BT540i

Keep in mind this is over the course of 2 years. where Monday through Friday we were on them a minimum of 2 hours talking to people.  In effect, These were our Daily Driver headsets.

Forward button failure.

Within the first few months of use the forward button broke immediately. These buttons near the top felt cheap and flimsy anyway. We could've processed a warranty on this alone but we kept going anyway. Too busy to sit around and visit a warranty office between 10 a.m. and 4 p.m. at this point in our lives.

Koss BT540i hinge crack.

You would think after 20+ years of making headphones Koss would try to avoid using plastics as a key resource for their hinge assemblies. Nope! This broke about 2 years in. So if we were to rely on Koss's new one-year warranty we would be screwed.

Koss BT540i microfactures all over the inside.

Microfractures on the other side of the plastics. Giving out both ways. Effectively it would be a matter of time before the whole headset would just burst ripping out any internal wiring holding it all together.

Insurance time!

Now this would usually be a part of the blog where we would rip apart the headphones and re-machine new metal pieces to unfuck the damage. But since I had 3-year insurance on it. Welp cashed that in and got an upgrade on my Koss. At least, we thought it was an upgrade.

New headphone time.

Koss bt740iqzKoss BT740IQZ


Here are some other comments we have about the BT740IQZ:

  • Better battery life than my BT540i. 30 hours of talk time. Nice.
  • Ovalistic speakers and padding which fit the ears.
  • Speaker coils in this sound very much like my Platinum Pro4AA's.
  • The buttons feel a little better. Like, they're not made from one stick of ABS plastic.

Koss bt740iqzWe do also like the fact that the LED is more low-key and not blast blue light everywhere as the BT540i did. We also sorely miss the latch that our bt540i's did to power on the headset as well as hold to reset the Bluetooth chip back into pairing mode again. Also, when using these on a plane the buttons kept getting pressed leaning against a window with these on. Thus, a 'lock' button would be nice as well.

Koss bt740iqx ports.

The headphone jack is just that. A headphone jack. Not a 4-pin headphone and microphone or "headset" jack like what was described above.

Also, USB-mini-B plugs in 2023 are a little out of fashion. Everyone has moved on to USB-C because it's stronger, you can charge faster, and it doesn't break if you look at it the wrong way. Modern standards are better Koss! Come join the rest of the world!

Microphone test:

If the HTML5 audio player is not working above you can download the WAV and listen for yourself.

Audacity preview of the microphone in the Koss bt740iqz

What the fuck was that Koss?!?!?

Not only is the microphone quiet as fuck with the volume at 100. There's a constant buzzing noise out of the microphone the moment it's activated. Now, for sanity's sake, we tried a lot of different things to ensure it's not just the 'source' hardware.

  • launched OBS an apple M1 - Same.
  • Plugged into a Bluetooth 5.0 dongle into a Windows 10 desktop. - Same.
  • Launched Ubuntu and paired with the Koss that way - Same.
  • Started Recorder on an iPhone 13 Pro - Same.
  • Launched recorder on a Samsung Galaxy 21  - Same.

Also keep in mind, that every single recording on this blog was done in the same room. So, we tried it outside of this room, as well as in another recording room, and get the same issue.

We even stopped by Koss headquarters just to exchange our headsets for another. Guess what? Same issue!

Possible causes of microphone buzz.

Without really voiding the warranty on the headset. There are a few things that could be at play.

  • Possible DC-DC circuit noise coming from the lithium battery when it needs to convert 3.7vdc to 1.5vdc to drive the rest of the amplifier circuits. I don't think this is likely because usually, you'd place filter caps at the beginning of your circuit.
  • 5.0vdc to 3.7vdc charge circuit for the lithium. Not likely considering it's unplugged during usage.
  • Coil noise coming off of the headset and interfering with the microphone. Although I don't think that's likely.
  • Because it starts off hard when you engage the microphone. possible bad filter capacitor within the microphone circuit itself.
  • circuit that produces the noise canceling is also interfering with it. Sometimes when you -really- crank up noise canceling on these things you just barely hear that buzz come across the speakers.

With the Koss BT740iqz, you're already starting off at a disadvantage with crippling microphone quality. By the time your voice makes it to another person on a phone line. You minus will be communicating halfway around the world relying on the NATO phonetic alphabet for anyone to even understand you!

Now, the inexperienced user who buys this set of headphones will dismiss this problem. Because to them it works perfectly fine in a corporate app such as Microsoft Teams or a gaming app like Discord.

What most take for granted is many of these conferencing programs have various forms of software-level noise canceling which can easily pick out that buzz and virtually eliminate it. But it doesn't come without a price!

That price is Microphone fidelity.

Your microphone will end up sounding very muddy. Or, if you had it hooked to an EQ someone just took the bass drive and cranked it to 11. That's effectively what is happening to the Koss bt740iqz  in these programs.

Koss support.

07/21/2023 - The first call was for warranty support for just exchanging the headset which that aspect went rather smoothly. Very nice people on the phone and at the warranty office. No problems there.

Now, the second time we had to contact support and not warranty because this is the second headset it's happened to.

07/28/2023 We've given them contact form requests several times. One representative (We will call him "M") asked us some technical questions about how we were troubleshooting this headset. We replied and "M" thanked us for the info and that he would speak with one of the engineers at Koss. Radio silence for 1 week and asked for an update now twice. requested status updates from "M" to which at the time of posting we have no comms to them.

There's a support system that looks like they're rocking lotus notes from the 1990s that we were filing out progress through. we requested an update about two times over two weeks. and nothing.

08/05/2023 - We've e-mailed them repeatedly asking for a response. Nothing.

08/11/2023 - Koss headset returned to Amazon. Referencing case number. The expiration window of return is 08/15/2023 and basically, there's no reason to wait until the end. Thankfully the Amazon return process was rather nice!

Koss case system.

08/28/2023 - We were wrong. It's Oracle, not Lotus Notes. Also, this is the final response from Koss. Delete the case. Pretend that the issue does not exist. Don't inform any of the upper board or management about this problem.  After all production lines from China are so short between models that if you manage to shut up a few buyers over the terrible microphone quality then you don't have to do a product recall. It's a really cute move. Don't worry Koss. We'll keep the e-mails just in case the lawyers get bored and throw some cease and desists around.

Final thoughts.

At this point. My return window is closing from Amazon. While we feel listening to these headphones is fun, especially with how good the bass drive is on these. Having a -30db noise floor is horrible for a headset. Especially one that is in the $100+ price range!

No one else gives a shit about quality.

Discord/Teams doesn't give a shit because they either want you to pay for a premium for 128kbs which was something they used to do and give away for free. Or in Mirosoft's case simply take high fidelity off of the table just to squeeze a few pennies.

Most Analog providers that work with people like Teams do not give a shit because the audio quality is already bit-crushed and now it's being fed into old POT lines to then go off to a cel-phone carrier which destroys the signal further with whatever carrier codecs they are using for compressing.

Koss stopped giving s shit 40+ years ago.

Koss Pro4AA 1970Because they already had a solution for breaking hinges on headphones. It's called "metal." and unless you were a complete monster it worked great (except for those plastic clips holding in the foam in those pro/AA's which didn't seem to matter really.) But no, Koss had to go down the road of mediocrity doing what every other headphone company was doing. Perhaps driven by cheapness, competition, and arrogance. Take your pick.

Koss, I guess what we're trying to say is:

Shame on us. - S

Should've learned from my first purchase with your company. But didn't; Because perhaps we were a little blinded by trying to support a theoretical local company.

Won't happen again. - S

Watching you release microphone after microphone only to see the nosedive in quality take hold is something we cannot stand anymore.

We keep taking massive steps backward in technology. the Koss BT740iqz is proof that you can't trust a company to deliver a good product. Perhaps it comes down to the DIY world to do something about it. But also, it's a societal issue:

  • We remember long-distance plans that offered 'pin-drop' quality.
  • We remember ISDN telephony which allows remote DJs to broadcast from an event right to the radio station as if they were still in the studio.
  • Heh, we even remember Skype and how 10 years ago it offered 3 times the audio quality of Discord and Teams.

But alas, here we are.

Everyone texts, watch videos, and e-mails. We are in a culture that has forgotten how to speak. Forgot how to enjoy talking to people. Most important. Forgot how to listen. Often you'll be downtown or on public transit only to hear someone's cellphone crackling with music at volume eleven because no fucks are given about even buying a pair of headphones. Assert your dominance over others and fight anyone who talks to you about manners or etiquette.

We stopped caring about not just a stupid headset. But communication as a whole. However, we hope we're dead wrong on this. Because fuck that's a bleak existence. And Koss, if you thought this was hurtful, at least you aren't Corsair.

If you made it to the end. Wow, thanks. If not, well. Shouting at the clouds was therapeutic for me at least!

Until next time!

Server protect you.


3 thoughts on “Hi Koss.

      • Not a problem. They're solid (made in USA) cans with great sound quality and decently flat frequency response (to me, some people have complained they're a little bright but my ears are kind of trashed anyways). I've had mine for probably about 20 years now.

        My bike wheel mechanic was also an helicopter pilot with Life Flight and is a stereo guy with a couple H10S-DC so he recommended it to me. I used to use Koss cans myself until about the late 2000s when their quality first started to slip. Though the classic Portapro is still a decent headset.

        Be aware that David Clark mainly make communications headsets that have limited-range drivers specifically tuned for good audio quality in the human speech range (typically ~100-~5000ish Hz). While they will nominally reproduce music they tend to be a bit lacking compared to an headset like the H10S-DC specifically designed with wide-range drivers for music listening.

        That, and you just have to love their classic aviation headset styling.


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