Moondrop Para - very not bad!

My dmm says 8.8ohms...

 

Verum One is rated 8 ohms by the manufacturer, but the sensitivity is 96dB/mW.

 

I have the Moondrop Venus and "very not bad" is a great way to describe them. They're really competent and carry the Moondrop house sound... very enjoyable. Sort of a "jack of all trades, master of none" thing. I travel with them and listen to them out of a Shanling M8. My main nitpick is that they don't handle chaos like the HD800 or Atticus, so separation suffers a bit, but that's an unfair comparison to begin with.

I actually picked them up in Moondrop's hometown of Chengdu, in a fantastic slice of heaven called Gotham Pro Audio, also owned by the same guy as Moondrop. I didn't know at the time but when I bought them, they had been available to the public for all of two days. The price was right, too: about 33% off the US MSRP, and they threw in a free cable upgrade to boot.

EDIT: Would people be interested in a Venus loaner? I could travel with the ZMF Blackwoods for a while instead.

 

My full review is up at Headphonesty - https://www.headphonesty.com/2023/11/review-moondrop-para/

There are some extra sound impressions and comments regarding build/ergo.

 

Hm, that extra 3k peak doesn't look that appealing to me. Still, I hope this improves on the overall haze and treble resonance of Sundara/400se at a comparable price. I also love the pad mount, and this makes a real good case for buying a Rekkr to amp it too.

 

The peak isn't too bad. It's a +1-2dB over neutral.

 

It's just a sliver over the HD6XX, but fair enough the upper mids on the Sennheiser kids aren't sedate by any means IMO (much the opposite).

 

Kind of looks like Twiki too

 

Then I must admit I don't know what's flat these days. My reference was using the HD6XX as a baseline. As for what Harman is peddling these days - I'm sort of okay with the over-ear target (depends on the LF shelf) but for IEMs Crin's target is more my jam.

 

All right, this has happened to me a couple of times now, so I'm making a post - the Para starts to make strange sounds after a few hours of loud listening. Remember that scene in Saving Private Ryan where the squad defeats the MG42 nest and the MG cools off making those ping-ping sounds? That's what it sounds like. And yes - the sounds persist with the headphones plugged off and I can hear them from the other side of the earcup as well.

I have no other theory than the diaphragm getting heat expanded and crinkling from cooling. Remember - this headphone needs actual power to run - 80dB/mW is very low. With acoustic transducers having less than 10% efficiency the rest of the power is turned into heat.

 

Just got my Para delivered a few hours ago, and liked the drivers quite a lot. I bought it for the sole purpose with its silver traced diaphragm. Aluminum traced diaphragm just isn't my thing unless the trace is significantly thinner than the plasic film. If possible I would rather have the trace made in copper, silver, gold, or heck even lead.

8 ohm loads, magnetic earpads mount, cheapish build quality, just reminds me too much about Verum One. Not sure how much plagiarism is going on here without taking both of them apart...

Welp first thing I did was pad rolling. The stock velour pads sounds a but mushy, and the stock perforated pleather pad lacks punchy bass. This set of drivers do like sealed pads, or else the bass would leak out easily. First I tried the AHG pads, which brought the FR fairly neutral till 4kHz. However this driver seems to resonate at 8kHz and 15kHz, and the AHG pads failed to damp them out much.


Then I dig through my stash of pads, and found the MrSpeakers angled Ether pads to yield the best result:

Fairly neutral now and sounds great. It's like the AHG pads but without the hot treble and with better staging. My Ether pads were from years ago when they were still branded as MrSpeakers. I also spilled milk onto it and rinsed it with tap water once, so I'm not sure if it's still sound the same as the DCA angled Ether pads in stock now... I haven't been following up with orthos much the past couple years, so maybe you guys can find even better pads for the Para. The calibration target was SBAF v3.2. My MiniDSP EARS is not very well matched, so maybe take the measurement with a grain of salt. Should still be in the ball park though.

Here's what my pads looks like:

I haven't heard any Ether series from DCA, but I guess this para is like a poor man's Ether now, or a bit less poor man's Verum One. Note I used HE6SE's jellyfish cable too. It just sounds great on any of my 3.5mm headphones. HE6SE was such a steal that I feel like the cable alone is worth $200+ at audiophile gear's price. Maybe they made this cable with lizard people's skin or something. Para's stock cable wasn't bad, but it just sounds like a typical purity copper cable. The HE6SE cable just clears things up without making things sound cold and harsh like some silver cables. I'm now curious about how would Moondrop Venus sound like with these cable and pads.

Sound wise I like it a lot after the mod. Doesn't sound as cuppy as my HE6SE. Kinda sounds like Verum One now but with finer sound like HE6SE. Verum One could sound a bit gritty when playing loud. I guess it has something to do with distortion. With the mod, my Para is pretty on par with my pad swapped LCD2 if not slightly beyond. Can't be sure untill my FOTM syndrome wears out.

Comfort wise this is the best ortho I've ever tried. Despite weighing 550ish grams, the center of gravity is very close to the inside, so it doesn't feel very heavy. Clamping force is pretty light for my wwiiddee head. Seals just alright to keep the bass in the chamber.

Despite 8 ohm impedance, it doesn't seem to be too current hungury. My amp's output impedance is on the high side, and it has no effect on the sound. My amp is very discrete, so not sure about how the chip amps would handle it.

I had the thermal expansion crackle happen on my left driver when I was doing the pad swaps. Not sure what caused it. It went out pretty quickly after a pad swap, and haven't come back yet. I hope it won't ever come back to ruin this great setup.

 

Just did a waterfall plot with miniDSP EARS, probably not as reliable as FPC measurements, but should tell the idea. It look like there's some contour but not a huge wall at 4k-5k. There are some ringing around 1.3k, 2.5k, 8k and 16k. They all seem well controlled except the 16k one. Probably explains why I still notice a little tiny bit of sibilant even with the Ether pads. These aren't the worst "ortho-wall" likely thanks to the silver traced diaphragms. I could write a whole rant plus simulation bitching about aluminum traces and the thinness war, but my thoughts aren't fully flushed out yet.

 

Holy f**k, all the dots just connected in my mind tonight. What Moondrop did in the Para was actual innovation. Kinda like what Fostex did in T50RP with zigzag traces, but I don't know if any other modern orthos did these things before Moondrop, let me know if you have clues.

I was going to post this rant in a separate thread, but since Moondrop is actively solving the problem, I'm just gonna post it here. I learned the problem last year with my failed ortho experiment, but didn't figure out how to solve it. Don't read if you don't know/don't care about driver breakup and ortho wall.

spolier: planer diaphragm doesn't always move like a plane

The problem: the diaphragm doesn't vibrate uniformly at high frequencies. It breaks up into segments that each of them rings like a bell at certain frequencies, and cause the "ortho wall" effect. The more brittle the metal traces are, the more violently they ring, so oxidized aluminum hardens the traces and exacerbates this problem. The plastic membrane could dampen it a bit, but it has to be significantly thicker than the metal traces to be useful. The thinnest diaphragm war did the completely opposite of helpful. Here's an example of what the break up looks like:

This is what happens when you have bunch of solid horizontal metal traces in typical modern orthos. The diaphragm is extremely stiff and metallic in the horizontal direction, but very soft vertically. Hence each trace acts like a metal cone driver and celebrate the ringing party together. The plastic membranes aren't invited to dampen the party cuz they are way softer than metal.

Here's what Moondrop did to solve the problem. They punched holes in the metal traces to soften the metal up. At first I thought this metal mesh was a seperate piece of screen to protect the diaphragm, but they are actually the diaphragm itself. Here's how Moondrop described it:

Basically they perforated the traces to soften out the metal layer. They also added the metal islands to stiffen up the plastic bridges. As a result the diaphragm is more evenly stiff and damped in all directions. Hence the waterfall chart looks pretty evenly damped in across frequencies. It's similar to what Fostex did in the T50RP's zigzag trace diaphragm, but in the modern style. I'd bet they are the only ortho engineers who actually looked into how the diaphragm breaks up.

I hope Moondrop patented this technology. I'd imagine every well designed ortho brands will adopt similar technologies to address this problem in a few years. Para still feels like an engineering prototype to test out the concept. So far it's doing good. I guess it could actually have better drivers than the Venus. I'd expect Moondrop to come up a next iteration more premium version of this concept in a year or two. Here's my wishlist of what they could do:
1. Tune it better like with the Ether pads. Find the most optimum pantyhose and foam to dampen at the back of the driver, which we can't reach without taking the whole assembly apart.
2. Keep doing great experiments with the diaphragm. Maybe do FEM simulations to figure out where to punch holes and add metal islands to completely even out the stiffness and dampeness in the polar coordinate.
3. Try to eliminate the 16kHz ringing perhaps with more tensioning or dampening.
4. Maybe consider gold or gold coated traces too, so we won't worry about silver getting oxidized in humid environments.
5. Draw denser traces or thin down the metal layer to bring up the impedance around 50 ohms. Some amps could have stability issue with 8 ohm loads.
6. Pair with better sounding cables out of stock. Purer copper ones would be great, and maybe offer 4pin XLR too.
7. Solve the thermal expansion rattling issue. Seems to be a QC problem that should get solved with better build quality.

Anyway 2024 should be an interesting year. Going by chinese zodiac signs, it's the best year to start doing big things (both for good and for evil). I wish solving the ortho wall problem is one of them. 2024 probably wouldn't be a boring year in many fields. Let's just pray for all those things that's going to happen will be serving for the greater good.

 

Crap, that's hella flat! I might have to try the angled Ether pads as well. I didn't like the alternative bundled pads as well, made the sound too bright. Do the Ether pads mount easily on the perforated steel plates?

Silver doesn't really oxidize per se, it reacts with air pollution and goes green. Silver jewelry usually reacts with ammonia in our sweat.

Only after they solve the low impedance/low sensitivity issue. BAL won't do much if your amp is current starved. Extra gain will make it even more easier to cook it.

 

Yeah it takes a little strecth, but still quite easy. Most 10cm pads should have no problem mounting on it.

It could get a little sweaty in the earcup especially with sealed leather pads. I have no idea if evaporated ammonia from sweat will get onto the diaphragm. I guess the only way to findout is to wear it long term.

Ha I just came up with an amp idea recently that has no gain and has plenty of current for these loads. Minimally it only takes 8 transistors and 8 resistors to make a fully balanced amp as such

 

Are we sure that 'therm

I thought it was hydrogen sulfide. Either way, silver doesn't get eaten away by tarnish and oxidation the same way copper can, so I wouldn't be too worried about this.

Anyway, the 'crinkling' that is being heard... Is that analogous to the Stax fart, or is it something different?

 

My concern isn't the silver gets eaten away, but the oxidation hardening effect like aluminum. There's finally a solution for orthos to break up like paper cone drivers and distorts low like the metal cone drivers, so I don't want the hard oxidation layer to ruin the break up characteristics. I don't know enough about physics and chemistry of silver to be sure if there's such effect. My left driver actually rings much less than the right driver at 16kHz. I wonder if this has something to do with it or it's just tensioning variation or something else.

I haven't heard any Stax, so I looked it up from the web. I don't think they are the same. My Para crackled when the music was not playing, and I wasn't wearing it. I feel like it comes from the mounting assembly rather than the diaphragm, but I could be wrong. Haven't got it to crackle again yet.

 

I believe silver sulfide has quite different materials properties to aluminium oxide. Silver sulfide forms tiny nanocrystals, whereas aluminium oxide is a much larger continuous lattice-like ceramic layer.

But man, this is going back to chemistry from over 25 years ago......