Slater
Headphoneus Supremus
So now that I made improvements to the ZS3, I thought I'd tackle the ZST.
It's one of my least favorite KZ IEMs, due to its shrill ear-piercing treble. It can actually get painful depending on the song I'm listening to, so they've sat unused pretty much since I got them. I figured I'd take a crack at modding them, since I really had nothing to lose.
I thought I would share my findings, since I know there are many others that also dislike the ZST due to its piercing highs.
It dawned on me while doing the ZS3 mod that I could possibly use foam to tune the ZST. However, I didn't want to block any sound from the dynamic driver, so I had to be careful how I went about making changes. I only wanted to address the treble, which meant only tinkering with the BA driver that's mounted right at the nozzle opening.
I stumbled upon a wonderful article from Tyll @ InnerFidelity (http://www.innerfidelity.com/content/how-balanced-armature-receiversdrivers-work). After getting an understanding of how BA drivers work, I saw that some BA drivers are fine tuned through the use of filter material in their tip. Eureka!
Since the foam was the easiest thing to try, I used that 1st. And low and behold it did the trick! The mod is simple, only takes a few minutes, and is completely reversible.
How does it affect the sound? There's still plenty of treble (but the treble is buttery smooth after the mod), and all of the shrillness that was present before is gone. I can listen to the ZST for hours now with no pain or fatigue. And there is no impact on the luscious bass and midrange that the ZST has. This thing went from my 2nd least-favorite KZ IEM to one of my top 5. So if you're one of those people like me that disliked their ZST, give this simple mod a try. You have nothing to lose.
1. You'll need a small piece of open-celled (acoustic) foam. You can get the foam from a number of places:
2. Now that you have your tiny piece of foam, it's time to cut it down into (2) near-microscopic sized pieces.
You know the writing on the side of the ZST that says "ZST - HIFI Armature"? Cut it to the exact same size as the word "HIFI" written on the side of the shell (same height, same length).
It's important to cut both pieces the same size, or else you may end up with a minor treble imbalance between the 2 sides.
You end up with a ridiculously small piece, like about 1/3 the size of a single grain of rice. Look at it in relationship to the date on a penny and a pencil lead:
3. Now that you have your foam pieces, take a sewing needle and CAREFULLY pop off the metal screen on the end of the ZST nozzle. Pry it up from an edge, but be very gentle, because the mesh could mangle and deform if you man-handle it with too much forceful poking from the needle. They're held on with a very weak gooey adhesive, and come off easily. Both of my mesh screens came off perfectly with no damage:
4. Now you'll be able to see the BA driver in the very end of the ZST's plastic nozzle.
At the very end of the BA driver itself is a little 'hole' - that's the BA driver's nozzle, which is where we'll be inserting the foam pieces. Just tuck a little bit of the foam inside the end of the BA driver nozzle using the tweezers (you're only trying to get it started in the hole). Next, take your sewing needle and carefully tuck the rest of the foam down inside of the tip of the BA driver. Don't jam the crap out of it in with the needle or you may damage the BA driver - just tuck it in (using the needle) with barely any pressure and to hardly any depth (we're talking 1-2 millimeters here folks).
It may take a few tries with the tweezers and needle, but it will go in no problem. It will be helpful to have really good eyes (or a magnifying glass) and bright light to illuminate everything. If you have poor close up vision, have someone with good eyes and steady hands help - the opening of the BA driver is barely larger than a "." on a piece of paper!
If you've done it correctly, here's what you'll end up with:
Partially Inserted:
Partially Inserted Closeup:
Fully Inserted:
Fully Inserted Closeup:
5. Once the foam is fully inserted inside the tip of both BA drivers, take your tweezers & replace the mesh nozzle screens back into the ZST nozzle. The gooey adhesive around the inside edge will keep the mesh screen in place with no additional glue needed. All you have to do is lay the mesh inside the end, make sure it's centered & doesn't overhang any part of the rim of the nozzle, and then gently push on it with your finger to get it to stick securely.
6. Put your ear tips back on, and reinstall the cables (making sure to insert them in the proper direction by paying attention to the rounded vs flat keyway of the plug and socket). If you insert one of both backwards you will end up with phasing issues and/or the plugs be loose and fall off during use. Here's a photo illustrating the correct orientation:
That's it; you're all done!
Total time from start to finish is under 10 minutes.
If for whatever reason you don't like the mod, you can easily remove the foam from the BA driver by plucking the foam with the sewing needle and removing it completely with the tweezers.
Let me know if you have any questions.
- Slater
It's one of my least favorite KZ IEMs, due to its shrill ear-piercing treble. It can actually get painful depending on the song I'm listening to, so they've sat unused pretty much since I got them. I figured I'd take a crack at modding them, since I really had nothing to lose.
I thought I would share my findings, since I know there are many others that also dislike the ZST due to its piercing highs.
It dawned on me while doing the ZS3 mod that I could possibly use foam to tune the ZST. However, I didn't want to block any sound from the dynamic driver, so I had to be careful how I went about making changes. I only wanted to address the treble, which meant only tinkering with the BA driver that's mounted right at the nozzle opening.
I stumbled upon a wonderful article from Tyll @ InnerFidelity (http://www.innerfidelity.com/content/how-balanced-armature-receiversdrivers-work). After getting an understanding of how BA drivers work, I saw that some BA drivers are fine tuned through the use of filter material in their tip. Eureka!
Since the foam was the easiest thing to try, I used that 1st. And low and behold it did the trick! The mod is simple, only takes a few minutes, and is completely reversible.
How does it affect the sound? There's still plenty of treble (but the treble is buttery smooth after the mod), and all of the shrillness that was present before is gone. I can listen to the ZST for hours now with no pain or fatigue. And there is no impact on the luscious bass and midrange that the ZST has. This thing went from my 2nd least-favorite KZ IEM to one of my top 5. So if you're one of those people like me that disliked their ZST, give this simple mod a try. You have nothing to lose.
1. You'll need a small piece of open-celled (acoustic) foam. You can get the foam from a number of places:
- An old foam earbud cover (new is best, not used and crusty)
- From the inside of an old full-size headphone earpad
- The foam that protects a lot of items during shipping (mostly electronic and computer products). It's got peaks and valleys arranged like a bunch of pyramids.
- The "tear off foam cubes" inside of Pelican and other hard cases
- The foam used for acoustic soundproofing tiles used in sound rooms, recording studios, etc (usually has peaks and valleys arranged like a bunch of pyramids, or sometimes alternating grids of long triangular tube shapes).
- The small pieces of foam you removed from the plastic tube of the ZS3's nozzle for the "ZS3 Slater Mod"
- The inside foam from the KZ headphone hard case (which incidentally is the EXACT same foam KZ used inside of the ZS3 LOL). <<This is the foam I used as seen below>>.
2. Now that you have your tiny piece of foam, it's time to cut it down into (2) near-microscopic sized pieces.
You know the writing on the side of the ZST that says "ZST - HIFI Armature"? Cut it to the exact same size as the word "HIFI" written on the side of the shell (same height, same length).
It's important to cut both pieces the same size, or else you may end up with a minor treble imbalance between the 2 sides.
You end up with a ridiculously small piece, like about 1/3 the size of a single grain of rice. Look at it in relationship to the date on a penny and a pencil lead:
3. Now that you have your foam pieces, take a sewing needle and CAREFULLY pop off the metal screen on the end of the ZST nozzle. Pry it up from an edge, but be very gentle, because the mesh could mangle and deform if you man-handle it with too much forceful poking from the needle. They're held on with a very weak gooey adhesive, and come off easily. Both of my mesh screens came off perfectly with no damage:
4. Now you'll be able to see the BA driver in the very end of the ZST's plastic nozzle.
At the very end of the BA driver itself is a little 'hole' - that's the BA driver's nozzle, which is where we'll be inserting the foam pieces. Just tuck a little bit of the foam inside the end of the BA driver nozzle using the tweezers (you're only trying to get it started in the hole). Next, take your sewing needle and carefully tuck the rest of the foam down inside of the tip of the BA driver. Don't jam the crap out of it in with the needle or you may damage the BA driver - just tuck it in (using the needle) with barely any pressure and to hardly any depth (we're talking 1-2 millimeters here folks).
It may take a few tries with the tweezers and needle, but it will go in no problem. It will be helpful to have really good eyes (or a magnifying glass) and bright light to illuminate everything. If you have poor close up vision, have someone with good eyes and steady hands help - the opening of the BA driver is barely larger than a "." on a piece of paper!
If you've done it correctly, here's what you'll end up with:
Partially Inserted:
Partially Inserted Closeup:
Fully Inserted:
Fully Inserted Closeup:
5. Once the foam is fully inserted inside the tip of both BA drivers, take your tweezers & replace the mesh nozzle screens back into the ZST nozzle. The gooey adhesive around the inside edge will keep the mesh screen in place with no additional glue needed. All you have to do is lay the mesh inside the end, make sure it's centered & doesn't overhang any part of the rim of the nozzle, and then gently push on it with your finger to get it to stick securely.
6. Put your ear tips back on, and reinstall the cables (making sure to insert them in the proper direction by paying attention to the rounded vs flat keyway of the plug and socket). If you insert one of both backwards you will end up with phasing issues and/or the plugs be loose and fall off during use. Here's a photo illustrating the correct orientation:
That's it; you're all done!
Total time from start to finish is under 10 minutes.
If for whatever reason you don't like the mod, you can easily remove the foam from the BA driver by plucking the foam with the sewing needle and removing it completely with the tweezers.
Let me know if you have any questions.
- Slater
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