AUX extension cable mod for Sony MH755

After having tried many different AUX extension cables, I really like this short 0.5m 3.5mm male to female AUX extension cable from DTECH. The TPE material is nice and soft and blends well with the MH755 cable unlike the fabric ones that sorely stand out.

Please note that this is a 3.5mm 3 pole (TRS) cable and doesn’t work with 3.5mm 4 pole microphone (TRRS) connectors.

Azla SednaEarfit XELASTEC – Initial Impressions

The Azla SednaEarfit XELASTEC are some of the grippiest wide-bore tips I’ve come across and as far as I know the only ones made of TPE (thermal plastic elastomer), which means they softens with body heat and change shape to fit your ears (unlike urethane foam tips that changes the shape of the ear canal).

I find, I need to choose a size smaller (MS) for these than the JVC Spiral Dots (M). I think this is because the Sprial Dots are spherical (hence wider) while the Azla’s are cylindrical.

Tyll would have loved the ER2XR

While reviewing the Etymotic ER4SR and ER4XR here is what Tyll had to say about bass response:

For me, the bass level on the ER4SR simply isn’t enough. Frankly, even the ER4XR doesn’t have enough bass for me, but it’s much better. I believe quite strongly that bass response on headphone should have about a 5dB bass boost below about 150Hz.

Tyll Hertsens in 25 Years of Making a Good Thing Better: The Etymotic ER4sr and ER4XR on Page 2

Tyll would have loved the ER2XR 🙂:

When the ER4XR was launched, Tyll applauded Etymotic for making the brave move of catering to user preferences and deviating from that they believed to be technically “accurate”. I think Etymotic went further with the ER2XR (and it’s almost like they took his feedback into account) and for that I am grateful as the ER2XR has just the right bass response for my preferences 🤗.

For me, having over 20 years of close experience interacting with Etymotic and the ER4 product evolution, I find it an interesting example of corporate learning at work. On the one hand, Etymotic has very strong reasons to believe they have a grip on what “accurate” means, on the other, they have 20 years of experience with customer feedback about the desire for more bass. Adding bass willy-nilly is simply not something this audiometry company would do; but having strong feedback that customers want more bass can’t be denied either. Making the corporate decision to deviate from technically accurate to cater to user preference is actually a pretty brave move from their point of view. I applaud this development!

Tyll Hertsens in 25 Years of Making a Good Thing Better: The Etymotic ER4sr and ER4XR on Page 2

Seekers vs. Tinkerers

You can judge IEMs/headphones on whether they sound good to you out of the box or also on their potential.

People from the former camp (seekers) might go down the path of finding the ones that perfectly match their preferences. IMO, the probability of this is so low that it seems futile to chase the perfect match. At best they might find something that is close to some of their preferences, but not others.

People from the latter camp (tinkeres) recognize they might not find the perfect match and are willing to put in the work to take advantage of potential. They do this either via EQ or modding. A prerequisite for this is potential. You might be able to fix tonality to some extent but you can’t fix things like technicalities, coherence, etc. if there isn’t a potential for it. Even tonality might not be fixable in some cases.

Some good example of tinkeres are james444 and the folks over at and a great example of an IEM being recognized for it’s potential is the JVC HA-FD01 which was modded by james444 and eventually resulted in the now legendary Drop+JVC HA-FDX1.

Of course there are many other dimensions along which to categories ourselves in the hobby but I think this is an interesting dichotomy to highlight.

So which are you, a seeker or a tinkerer? Are there better terms for these?

QKZ VK4 vs Sony MH755 (SBH56) – Measurements

So I took out the QKZ VK4 today to measure (using my DIY-tube rig) and I was pleasantly surprised to see why I remember liking them.

Note: The graphs don’t accurately represent what you might hear and are only representational. Improving them is an ongoing process.

Measurements taken using pre v0.1 of my DIY IEM measurement rig