[wmedrz]

My loaner unit Venus arrived yesterday and the left driver is winkled. The right driver looks fine. The wrinkled driver has better bass output. I tried swapping the L/R channel and result is consistent: every time I hear more bass from the wrinkled driver.

Is that part of a loaner tour?

Trying to assess if QC issue or abuse from multiple people.

 

[wmedrz]

Is it a diaphragm damaged during a loan (since it's a loan headphone); or is it a construction defect that wasn't seen during quality control?

You beat me to it Eric.

I'm wondering how many had it prior to him receiving it.

 

[lambdastorm]

Thanks for the photos, which speak for themselves.

What you describe (more bass on the crumpled (damaged) driver) is possible, but not normal.

It's not normal to have a VENUS planar driver with a crumpled diaphragm like that in an accordion (loose diaphragm?).

Is it a diaphragm damaged during a loan (since it's a loan headphone); or is it a construction defect that wasn't seen during quality control?

In any case, this is the first VENUS planar headphone I've seen in this condition, for one of its drivers. Quality control is usually good, and driver matching (right channel - left channel) is excellent to within 1 dB.

Spoiler

Driver matching (right channel - left channel)

The first sample of the VENUS, measured by Crinacle, seems to have a poorer matching of right/left drivers at 14 KHz (unless it's a measurement artifact and/or a failure to place the drivers rigorously on the measurement platform, with poor driver centering?).
Anyway, my old ears can't hear anything at 14-15 KHz...

The second sample of the VENUS, measured by TechPowerUp (more rigorously than Crinacle?), is exemplary for the matching of right/left drivers, to within 1 dB over the whole FR range; it's remarkable!

First sample VENUS (planar) driver matching (right channel - left channel).

Second sample VENUS (planar) driver matching (right channel - left channel).


Below you'll find four more examples of right/left driver pairing, for four headphones with three different technologies (electrostatic, orthodynamic (planar) and electrodynamic).

For first comparison. Sennheiser HE-1 (electrostatic) driver matching (right channel - left channel).

For second comparison. Abyss AB-1266 Phi CC (planar) driver matching (right channel - left channel).

For third comparison. Kennerton Odin (planar) driver matching (right channel - left channel).

For fourth comparison. Sennheiser HD-600 (2020) (electrodynamic) driver matching (right channel - left channel).

If you buy the VENUS, make sure both drivers have a well-tensioned membrane (not wrinkled).

As for getting more bass level (+3 to +4 dB between 30 and 70 Hz) with the VENUS and increasing their snap and impact, without changing the pads or using an equalizer, it's very easy to achieve: simply break the pads' seal slightly on their front, as described here: https://www.head-fi.org/threads/moo...reasonable-price.970569/page-13#post-17904176

Is that part of a loaner tour?

Trying to assess if QC issue or abuse from multiple people.

Thanks for the replies guys. I'm leaning towards it being more of a QC issue rather than rough handling. The driver housing of this headphone is very sturdy. Quite unlikely that someone before me puts enough pressure on the housing to actually deform the driver. On the other hand if you drop the headphones they just break.

 

[eric65]

Thanks for the replies guys. I'm leaning towards it being more of a QC issue rather than rough handling. The driver housing of this headphone is very sturdy. Quite unlikely that someone before me puts enough pressure on the housing to actually deform the driver. On the other hand if you drop the headphones they just break.

Probably.

Your testimony is valuable, and I am sure that Moondrop who is most likely following this thread on head-fi about its full-size planar helmets is now aware of this quality control "bug" of this driver of this planar headphone VENUS on loan.

This is perhaps a procedural error during the manufacturing of the VENUS planar drivers as described below (last step not carried out which would have gone unnoticed?)

Quote (Moondrop) about the manufacturing process of the VENUS planar driver:

" Secondary Diaphragm Stress Balance Technology​

After the diaphragm has been molded, the stress on it is released and then equalized a second time. As a result of this additional process, the non-linear of the diaphragm under loud pressure is reduced at least 95 %."

 

[lambdastorm]

Probably.

Your testimony is valuable, and I am sure that Moondrop who is most likely following this thread on head-fi about its full-size planar helmets is now aware of this quality control "bug" of this driver of this planar headphone VENUS on loan.

This is perhaps a procedural error during the manufacturing of the VENUS planar drivers as described below (last step not carried out which would have gone unnoticed?)

Quote (Moondrop) about the manufacturing process of the VENUS planar driver:

" Dual equalization​

After the diaphragm is molded, the stress on it is released and then equalized a second time. This additional process reduces the non-linear distortion of the diaphragm at high pressure by at least 95%. "

It's not a one-off issue though. Ever since I posted the driver pictures 3 users in the loaner group have told me that they've faced the same issue on their own units, 2 Para and 1 Venus. One member sent me this picture and it's the Para they just bought last month. They sent the headphones back and the dealer offered a replacement.

 

[psy472]

Uggg this is why I get nervous buying Chi-fi stuff. At least my para is safe for now.

 

[eric65]

It's not a one-off issue though. Ever since I posted the driver pictures 3 users in the loaner group have told me that they've faced the same issue on their own units, 2 Para and 1 Venus. One member sent me this picture and it's the Para they just bought last month. They sent the headphones back and the dealer offered a replacement.

Hi.

Your words are worrying.

A bad series, or "very tired", damaged drive loan headphones?

Concerning the two VENUS headphones in France that I know.

My friend René K's drivers are perfect without any suspicious membrane folds.

It is the same with my two planar drivers of my VENUS that I have just inspected: apart from a dust or two introduced during the inspection of the headphones, not the shadow of a wrinkle of the two membranes; they are real silver mirrors, perfectly stretched evenly.

 

[wmedrz]

Uggg this is why I get nervous buying Chi-fi stuff. At least my para is safe for now.

My thoughts exactly. And here I was hoping quality was going to be better than some others...

 

[wmedrz]

Hi.

Your words are worrying.

A bad series, or "very tired", damaged drive loan headphones?

Concerning the two VENUS headphones in France that I know.

My friend René K's drivers are perfect without any suspicious membrane folds.

It is the same with my two planar drivers of my VENUS that I have just inspected: apart from a dust or two introduced during the inspection of the headphones, not the shadow of a wrinkle of the two membranes; they are real silver mirrors, perfectly stretched evenly.

Yes quite concerning. I still have essentially until the end of January to return my "loaner" unit as it was purchased through Amazon during black friday. But I really don't want to do that especially after the recent pad swap. Besides these DO have a 1 year warranty? Or is it 3? Wish it was 10...

 

[wmedrz]

My drivers look fine as well, smooth no wrinkles.

I don't think this has to be from some sort of rough handling of the driver housing. Yes the outside is sturdy, but what about pressure buildup in the headphone when putting it on? When I applied my new pads I could feel the pressure buildup increase dramatically. There is a very large surface area inside. I remember a similar issue with Audeze years back and how people were careful while putting them on their heads being told the crinkle and pressure was normal, which for the most part I think can be, but then Audeze had a bunch of driver failures... How about too high of a listening level? I think these can all contribute to wrinkled drivers but I'm no expert.

 

[eric65]

Yes quite concerning. I still have essentially until the end of January to return my "loaner" unit as it was purchased through Amazon during black friday. But I really don't want to do that especially after the recent pad swap. Besides these DO have a 1 year warranty? Or is it 3? Wish it was 10...

The warranty on my Moondrop VENUS is 2 years in France (via the distributor Audiophonics).

The condition of the drivers of my VENUS and that of my friend René K (in France) is impeccable and 100% operational: no visible wrinkles; I'm glad it's the same for your own copy of the VENUS.

My friend René K's hypothesis is that the VENUS on loan (whose membrane is wrinkled) may have been listened to too loudly, which would have deformed the membrane irreversibly, with the negative consequence of less good damping of the sound. driver (with an increase in distortion), and as a positive consequence, an increased bass level on the wrinkled (distended) diaphragm driver.

 

[eric65]

My thoughts exactly. And here I was hoping quality was going to be better than some others...

Don't worry, the build quality is still better than that of other brands, such as Hifiman.

Even if one of the two diaphragms on this Moondrop VENUS planar headphone tried on loan is wrinkled, either as a result of poor handling, with sudden overpressure of one of the drivers irreversibly distorting the diaphragm (which then becomes wrinkled at rest after the stretching), or as a result of listening at a far too high SPL level, which would have distended the diaphragm ; but I can't explain why this distension followed by wrinkling only affects one of the two drivers; in short, whatever really happened to this loan unit, the VENUS driver is more solid than the Hifiman Susvara driver: no hole or "spontaneous" tear (because the driver's protective grid is unaffected) on the Hifiman Susvara's nanometric membrane, occurring only a week after its acquisition; that's a bit harsh for a 6,000-euros/dollars headphone!

Source: https://www.head-fi.org/threads/hifiman-susvara.853031/page-926#post-16769542
and : https://www.head-fi.org/threads/hifiman-susvara.853031/page-928#post-16772804

 

[eric65]

Hi all.

Let's be wary of the absence of established statistics, and of generalizing a headphone's observed defect (e.g. for its driver: here, the wrinkled membrane of a VENUS planar helmet) to 1 or 2 isolated cases (out of how many headphones manufactured in total?), without even knowing the conditions under which the case or cases in question were established; especially, for the example shown in the photo (below), for a loan headphone that has seen several users who were more or less careful with the material used.

(Note: one of the two planar diaphragms on this loaner VENUS has been crumpled (wrinkled) as a result of overstress established on the wrinkled driver).

As far as the wrinkling mechanism of the VENUS membrane is concerned, as our friend René so aptly suggests, it's undoubtedly the result of an excessive stress applied to the wrinkled driver (a pressure force having stretched the membrane excessively, irreversibly, causing it to wrinkle once the membrane is at rest and the stress stopped).

What stress has irreversibly stretched the diaphragm beyond its elastic range?

Personally, I can think of two:
- Sudden external over-pressurization of one of the diaphragms when the VENUS headphones are placed on the ears (not gently): the driver's internal chamber (on the ear side) is airtight if the earpads seal is perfect, and over-pressurization can occur when the headphones are suddenly placed on the ears; this sudden over-pressurization has repercussions on the driver's diaphragm, potentially leading to irreversible stretching of the diaphragm.
- The other stress mechanism of the diaphragm is, of course, listening at far too loud SPL (and dangerous for hearing), with the diaphragm's planar stretching becoming excessive.

The fact that only one of the two drivers of the loaned VENUS headphone shows stretching/wrinkling of the planar membrane would support the first hypothesis.

The VENUS is a fragile planar headphone: do not drop it on the ground; do not suddenly put it on your head; do not listen to it at excessive SPL.

 

[eric65]

Potential buyers of the Moondrop VENUS should be aware of :

- The VENUS headphone weighs 560 g (without the wire), but its wearing comfort is very acceptable thanks to good weight distribution on the head via its self-adjusting suspension band; the clamping force (clamping) is perfect.

- For metropolitan dwellers, this headphone is not suitable for use in the metro, as it is an open-face headphone, and its total lack of discretion encourages snatch-and-grab theft.

- Due to the structural weakness of the VENUS suspension headband's anchoring point on the headphone frame (*), we strongly recommend preventively reinforcing the headband's fastening by doubling it (on the inside of the fastening face), either by a small piece of metal strap (René method, system guaranteed "ad eternum" https://www.homecinema-fr.com/forum/post181281916.html#p181281916,
or with a simple nylon strap (a small piece of 10 x 20 mm nylon webbing cut as reinforcement, for lining) (my system is guaranteed to last only a few decades of use: https://www.homecinema-fr.com/forum/post181282181.html#p181282181 ; DIY cost (for the nylon strap + Superglue: less than 10 Euros + cost of the 1.5 mm Allen wrench, I believe, to dismantle the two small screw used to secure the headband).

and last but not least, a few final words of advice for future happy VENUS owners (like René and me)

[WARNING MODE ON]

- don't lend your VENUS headphone to ASR (for testing), it WILL BE DESTROYED during the test; they're bullies!
https://www.homecinema-fr.com/forum/post181306838.html#p181306838

- the VENUS is a delicate and fragile headphone :
. Don't drop it on the floor (as with your smartphone).
. Don't step on it (as with your smartphone) .
. Don't feed it to your dog (**)
. Don't put it (don't put it on) roughly on your head, as you risk creating a sudden overpressure that could stress (stretching/wrinkling) the driver's (very thin) membrane.
. Don't listen to it at too high an SPL level (> 105 dB SPL); it's dangerous both for your ears and for the headphones.

[WARNING MODE OFF]

(*)

Spoiler

Spoiler

(**)

Spoiler

With these caveats in mind (especially for anyone with an unruly dog at home ), the VENUS is a damn fine headphone that will easily compete with headphones costing up to 5 or 10 times as much; it would be a shame to miss out on such a bargain.

 

[acclimatise]

I bought the official upgrade cable from Moondop, and I think the sound of this cable is stronger in low frequency and thicker than the original cable, but the resolution has not improved. Considering the price, it is acceptable