Stax SR-X9000

[Svperstar]

I have the HD800, both it and the X9000 are great end game headphones. I thought when I got my HD800 I was done buying new headphones, it sounds premium. The only thing it doesn't do is have really subwoofer quality bass.

On my quest for the perfect pads for the X9000 looks like the Zmf Caldera open pads might fit perfect. I ordered some. Turns out ZMF is only 7 hours from me. I had no idea.

 

[alota]

I had two hd-800 in the past with otl balanced amp ad beta-22 amp. From my memory x9000 is better without any doubts

 

[hutzelmeier]

The HD800S is like that where by clustering all of the sounds together in terms of distance, I was acutely aware of the boundaries of the soundstage similar to how city lights frame bodies of water. The X9000, by spreading out elements at different depths within the soundstage, made it harder for me to judge the exact boundaries of the soundstage. It's a trick that I called "the illusion of boundless soundstage" in my impressions from 2023.

Good point – maybe I’d say that the HD800S has a large soundstage, while with the X9000 the width of the soundstage does not matter to me because I’m *in the room* where the music happens.

 

[Svperstar]

So I finally took the time to swap my ZMF Caledra pads onto my X9000. Sadly the inner diameter is just a bit smaller then I would have liked, 5mm more would have been perfect. Compared to the stock X9000 pad:

Here we see the .4 inch glue dots I used. Didn't take as long to put on as it looks, but peeling the top layer off....

Here is the aftermarket eBay pads made for the Sundara/others of similar size. From the back they look similar:

But from the front you can see the ZMF pads aren't symmetrical and tapper off in the front, just like the stock X9000 pads:

Here we go completed. I may be the only person in the world using an X9000 with ZMF Caledra pads:

 

[RagnarAyn]

You have probably tried more earpads than anyone has for this headphone. Do you like this one? I'm happy with stock. My biggest upgrade came from replacing my eyeglass frames for a new prescription. My old frames were thicker and caused annoying squeaks against the leather. My new ones don't.

 

[Svperstar]

You have probably tried more earpads than anyone has for this headphone. Do you like this one? I'm happy with stock. My biggest upgrade came from replacing my eyeglass frames for a new prescription. My old frames were thicker and caused annoying squeaks against the leather. My new ones don't.

Yes I like it, the drivers are closer to your ears then the eBay pads I was using so it sounds more detailed. Unfortunately on first listen it appears that compared to the eBay pads the bass while strong is lessened a bit. Not a huge difference but its there. Maybe because they are perforated and there is less cavity to reverb? Not sure.

Debating leaving these on till the meetup.

 

[LarsHP]

Yes I like it, the drivers are closer to your ears then the eBay pads I was using so it sounds more detailed. Unfortunately on first listen it appears that compared to the eBay pads the bass while strong is lessened a bit. Not a huge difference but its there. Maybe because they are perforated and there is less cavity to reverb? Not sure.

Debating leaving these on till the meetup.

The perforations reduce sub-bass, IIRC reading the description. In addition, there are small air leaks between the glue dots which also contributes to leakage. In order to maximize sub-bass extension, a complete seal is needed. That's the reason Audeze insist gluing pads to the cups.

Tyll Hertsens said that when he measured the LCD-2.2, the response was flat down to 5Hz! When I had that model, I could feel the air pressure in my eardrums when pressing on the cups as well as suction when pulling the cups away again. That was of course with leather pads.

 

[Svperstar]

The perforations reduce sub-bass, IIRC reading the description. In addition, there are small air leaks between the glue dots which also contributes to leakage. In order to maximize sub-bass extension, a complete seal is needed. That's the reason Audeze insist gluing pads to the cups.

I have vinyl tape wrapped around it. Wasn't done when I took the pictures, but yes that is a benefit of using regular tape over the dots. I have the exact tape Audeze uses but not in the ring format. Saving the few Audeze glue rings I have left.

Wonder if the Caldera Thick pads would have better bass?

 

[LarsHP]

I have vinyl tape wrapped around it. Wasn't done when I took the pictures, but yes that is a benefit of using regular tape over the dots. I have the exact tape Audeze uses but not in the ring format. Saving the few Audeze glue rings I have left.

Wonder if the Caldera Thick pads would have better bass?

Leather pads with memory foam are my favorites for best possible bass.

My understanding is also that a smaller inner opening will work like what is commonly called a "bass lens" (a piece of thick cloth with a hole in the middle), but even more: A pad covering a significant part of the driver will reduce all frequencies except the very lowest. However, this of course comes at the expense of soundstage and openness, so overdoing it is certainly possible.

 

[Svperstar]

The Caldera pads form a seal, can feel the air when pressing and makes a noise when you press on the side on your head.

I tried pads that don't form a seal on my 007, the difference wasn't subtle at all

 

[MrHaelscheir]

Leather pads with memory foam are my favorites for best possible bass.

My understanding is also that a smaller inner opening will work like what is commonly called a "bass lens" (a piece of thick cloth with a hole in the middle), but even more: A pad covering a significant part of the driver will reduce all frequencies except the very lowest. However, this of course comes at the expense of soundstage and openness, so overdoing it is certainly possible.

I've actually measured with multiple custom HE1000se pads (made by Ntrax Mod Design) that decreasing the internal volume mainly fills the upper midrange while increasing it deepens the HiFiMan dip, the upper treble and top octave not being affected that much, though I haven't and don't intend on testing a substantial decreasing of the HiFiMan pads' internal aperture to cover more of the driver. Sub-bass extension is mainly affected by seal, in this case, memory foam additionally sealing better than the stock foam.

The stock pad (red trace) has the normal level of covering the outer perimeter of the driver. The rest leave the driver almost completely uncovered and use memory foam, thus incurring a similar improvement in sub-bass extension and commensurate decrease or flattening of mid-bass. For the "A6" pad in azure. The "A6+" pad in blue is comically deeper and mainly further deepens the upper midrange while having some interesting decreases in some treble peaks perhaps due to internal pad geometry or absorptive surface area. Pads F1 to F5 have the same aperture as A6 and A6+, but are much shorter and are ordered in terms of increasing internal pad lining reflectivity from fabric to solid leather. For those ones, it was probably the decreased distance from the ears among other factors that eliminated the 11 kHz peak for my ears, but the 6.5 kHz peak was largely unaffected.

As for Audeze pads on the X9000, I would predict the existing upper midrange boost to be made even larger, though I forget whether @Svperstar had ever reported something like that.

Type A6 pads:

Really comfortable and open, but the HiFiMan dip gets unacceptably deepened which I would need to EQ up by even more when that region is already high in (measurable but barely audible) distortion.

Type A6+ pads:

If ever it sounded "wider", without how I hear imaging, it's literally by only the few more centimeters that the drivers were moved out, after which the upper midrange disappears.

 

[Svperstar]

As for Audeze pads on the X9000, I would predict the existing upper midrange boost to be made even larger, though I forget whether @Svperstar had ever reported something like that.

The biggest issue with the Audeze pads is unlike the rectangular driver in Audeze the X9000 driver is circular so it attenuates the sound. I'm trying to only go with circular pads from now on. I don't have any measurement gear. If I get some I want to invest in a nice setup nothing entry level and so far haven't taken the plunge.

The X9000 "field of sound" and soundstage is changed by pads somewhat, and bass response for sure. I had high hops for the ZMF Caledera pads and they sound good but a very "side grade" from stock.

Curious what pads are you using on the X9000? These actually look like they might work well:

Ntrax quoted me something like $160 shipped for custom X9000 pads. Didn't buy them yet still on the fence.

What pads are you currently using with the X9000?

 

[MrHaelscheir]

The biggest issue with the Audeze pads is unlike the rectangular driver in Audeze the X9000 driver is circular so it attenuates the sound. I'm trying to only go with circular pads from now on. I don't have any measurement gear. If I get some I want to invest in a nice setup nothing entry level and so far haven't taken the plunge.

The X9000 "field of sound" and soundstage is changed by pads somewhat, and bass response for sure. I had high hops for the ZMF Caledera pads and they sound good but a very "side grade" from stock.

Curious what pads are you using on the X9000? These actually look like they might work well:

Ntrax quoted me something like $160 shipped for custom X9000 pads. Didn't buy them yet still on the fence.

What pads are you currently using with the X9000?

Mine are completely bespoke based on my own CAD and materials recommendations. I'll report on those once they arrive, but there are still some delays in delivering that project. Right now, the X9000 just has to rest under its dust cover. Those custom pads will use memory foam and will have compound contours to seal best around my head. The focus of this project is on bass seal and comfort.

 

[Svperstar]

Mine are completely bespoke based on my own CAD and materials recommendations. I'll report on those once they arrive, but there are still some delays in delivering that project. Right now, the X9000 just has to rest under its dust cover. Those custom pads will use memory foam and will have compound contours to seal best around my head. The focus of this project is on bass seal and comfort.

Can't wait to see pictures of that, NTRAX pads or you making them yourself?

 

[MrHaelscheir]

Can't wait to see pictures of that, NTRAX pads or you making them yourself?

Ntrax's team will be making the pads per my spec and some experimental materials I sponsored. I'm of the stance of not sharing the full details until it has been deemed whether it was a success.