Verum Audio - Exciting high performance DIY planar

@ReAlien - yes please, pm me your propositions about the pads. Also, i've finally made new pads made from perforated lambskin leather. Oval hole, angled and less thick. Will send them to @cskippy next week for evaluation.

 

Verum 1 plays just fine out of all my headphone amplifiers (Stratus, Kenzie, Fulla 2), therefore probably better not to overblow the impedance missmatch or power rating thing. But then we all tend to listen at different acoustic pressure levels, me rather at lower levels to mitigate fatigue and permanent hearing damage.

If possible, I would suggest @Garuspik to use different female connectors in future Verum Audio products. I am able to reproduce a sub-second signal cutout when male (cable) connector gets miss-aligned with the female connector even when fully inserted. This applies to both channels. Such miss-alignment rarely happens in practical scenarios and therefore I do not consider it as an actual issue. Just a feedback for the future.

My review of the headphone is posted in this thread if interested in yet another point of view.

 

After 2 days with the Verum, here are my impressions:

First impression stuff (ergonomics, build quality,etc):

Packaging was literally a box with lots of bubble wrap, although mine arrived fine it would've been nice to have a foam mold or something a bit more reassuring, though I understand that can get expensive.

Comes with a flexible 3.5mm cable, not very long (6ft at most?), with 3.5 to 6.5 adapter. Good.

Design: Utilitarian is the way I'd describe it. The design is huge, with the whole suspension system going on. Earcups pivot vertically but not horizontally, to rotate them horizontally you angle the steel bands at the top. The adjustment system is not the quickest, you have to unscrew the L/R screw, pull it out and then adjust, but I don't see why you'd need to adjust it too quickly since the suspension and huge cushions for pads basically makes for a "one size fits all" for most. Headphone jacks are properly positioned and easy to plug and unplug.

Ergonomics: Freaking great. I remember the biggest problem with the (mostly high-end and expensive) headphones that I felt at the SBAF NYC meet last year was that the planars focused all of their weight on your ears and the top of your head was left not feeling much, which was not good at all for security and comfort, since any slight movement of your head back and forth would loosen the headband from your head and blamo. On the other end, the Focals definitely left a hotspot on the top of the head for me, which didn't help the slight headache I had at the time. All in all, it's a bulky rig but with the huge benefit of distributing weight almost perfectly. I don't notice the weight until I go back to using HD650s.

Finish/Cosmetics: There are some sharp points on the steel band, which is not great. The carbon finish looks good enough from a distance, which is all I need it to be. The metal grill is definitely not polished, but who cares really? It's not an LCD2C in looks, but just about as tanky, possibly more, while being more ergonomic which is all that matters to me really.

(To be continued below)

 

Impressions (continued):

First comes the bad news.

My pair is not really defective, I don't think, but...

I think one of my earcups are from a pre-production version.

First thing I noticed when I checked out the whole thing: One earcup was being pushed in by the other, though slightly.




With more pressure, however:




So I took them out and checked them more thoroughly. Here are a few noticeable differences:

1. The right one is slightly darker and shinier :


2. The right one is more angular, while the left one is more rounded at the edges:





3. The mounting sleeves where you put the metal ring in are different. The left one has a shiny ring on the sleeve while the right one is pretty much matte. Also, the left one fits much tighter while the right one leaves a noticeable gap where the metal ring sticks out (seen in pic) :



4. Finally, my kitchen scale shows that the right one weighs 20 grams without the metal ring while the left one weights 24 grams, a 20% difference:



Note that I'm not exactly sure which earpad belongs to which earcup since I had swapped them around a few times to fix the audible channel imbalance that they caused. For now, I'll just assume the right one is the production one, since that seems obviously more well made to me. Moving forward, I'll be calling them "round" and "production" pads.

This is not the only difference I've noticed. The two diaphragms are also different as well. When putting on the headphones, both pads squeeze into the side of your head, therefore pressurizing the inside, enough to flex the diaphragm a little bit. While the left side only makes a slight metallic ping noise, you can hear the right entire right diagram flex around even when you're only gently squeezing the earcup against your cheek. Here are the recordings of the flexing noise (note that these are done on the other side of the earcup, so they won't be as loud as when right against your ear, plus crappy mic noise):

Left side: https://instaud.io/3l4u
Right side: https://instaud.io/3l4x

This leads me to believe that they were tensioned differently, with the left one being more tensioned and therefore flexing lex. So, combining information from this thread that @Garuspik increased the tension for production and what I can guess is the production pad, I'll be basing the sound impressions off of that, with some inclusions of how it differs from the less tensioned diagphram combined with round pads. Well, actually, I think I'll wait for a response from @Garuspik in order to determine what is production and redo my impressions from there.

 

@Ash1412 sometimes foam inside can be of different density. If it’s a problem for you - pm me and I’ll send a replacement. Rings are the same one side of the ring is polished and another one is brushed. Check it.

Wow guys, 4 grams difference in ear pads... you’re really go into details. But you gave me an idea- I’ll be matching pads by weight. If I’m not matching channels - I should be matching at least something!

 

Its not just that for me. The round one creates a literal vacuum seal while the other one definitely lets out air, probably through the leak in the sleeve. Right now I'm getting noticeable channel imbalance in the higher frequencies with these two pads, where the test tone moves around instead of staying in the center, and yes, the way it moves reverses when I swap the pads. This is significant enough to be a problem IMO.

Also the ring, yes the metal rings are the same on both. Those are fine. The "shiny" I was talking about is the sleeve of one of the pads, the round one, as shown in the picture.

EDIT: Another go at nailing down the difference. Tried playing test tones through each side, one by one, and using a phone mic plus an app to measure the loudness difference. It's approx 10db, with the left side (with higher tension diaphragm and "production" pad) being the louder one. Even without measuring, I can hear left as being obviously louder. I was putting the channel imbalance down to the Liquid Platinum's pot since it was around 6-7 o'clock also with left side louder, but this was done through a Macbook's 3.5mm with digital attenuation involved. I really should've gone to this test from the start. Swapping pads still shows the left side as being louder overall, though the pads do affect treble peaks enough to mess up center imaging in my tests. I'm now almost completely certain one of these cups are defective/from a wrong batch/a mixed-up prototype.

 

Then send me back whole unit and I’ll send you a replacement. Also i’m absolutely sure there is no imbalance in cups. It is either working or not working. 0 and 1. Binary system. It can be 1db imbalance and that's all.
But as if you stated in public that one cup plays 10 times louder (10 dB is 10 times) then I also in public tell you - send them back and get a new pair.

 

I experienced channel imbalance at first as well. Vocals were always slightly left of center. This has evened out overtime, moving closer to center. I'd imagine the differing DC resistance on the drivers, 1 is 15 ohm and the other is 17 ohm, may effect this. I don't have a way to test impedance. There is a device available from Parts Express but it's $100 and I really don't have much use for it. I don't build speakers.
It is important to note the amp you are using when describing sound, higher imbalance as noted above may have the amp as a contributor.
The Verum is over the limit for the THX789 and I could easily picture 1 channel being louder as that channel is struggling or starts struggling.
By the way, the THX789 manual states you may not be covered by warranty when using headphones lower then 12 ohms impedance!!!!

 

All production units are about 8 ohms with cable.

This situation (from todays post of @Magnetostatic_Tubephile ) :


Is typical. I can imagine situations when there is no current on membrane due to bad contact. But i can't imagine situation with 10db difference. However as a responsible manufacturer I'll do my best to leave customers satisfied. Any problems? Write me and we'll solve the problems if anything happens. But first please try running several amps (or even smartphone\ PC sound card).

Yes, that's very important. When I started this project I didn't realized the whole variety of headamps on the market and had a naive thinking that if Verum 1 runs ok from old Iphone it will be the same with any amp in the world. It was a huge mistake.

 

To give me a wider range of amps to use , I am purchasing the adapters from alibaba that you linked to earlier in the thread. I'll add some pads too the cart too. Price is nice over there.

 

- despite community here asked you to reconsider the impedance, "I told you so" moment
Probably as a partial damage mitigation, for future buyers, you could include balanced cable option and advise to use it when possible.

 

Yep, you was absolutely right. As a solution I can recommend an impedance jack

 

I have a balanced cable on the way but I am not sure it is still a solution with the THX789 amp. It will still be 8 ohms impedance and operating out of warranty specs. Output impedance doubles thru balanced in the amps that list that spec that I have seen. I won't use it with the THX789 but probably will with the Loxjie, specs unknown and it is a $99 amp after all. There is an XLR impedance adapter on Aliexpress. I may consider that. The balanced cable should work with the MCTH because it's XLR is single ended.

 

I am confused about one point though.

@Ash1412 was referring to a mismatched pair of pads, which can make a difference in sound.

IIRC @Vtory had a similar issue with the Auteur loaner, which had a different style pad installed on each ear, which resulted in a channel imbalance similar to what Ash is referring to.

Could that not be an issue, or am I missing something?
(I definitely could be missing something)

 

Yep, he definitely has 2 different ear pads. Mine are the same though there may be minor variations. I swapped pads l/r and no difference I think the DC resistance of the drivers would reflect in impedance as well. Mine differ by 2 ohms dc.

His 10 db difference did not come as a surprise to me. I have had similar experiences and I believe it is amp related, volume will decrease in 1 channel while playing even.
I do know that with the MCTH, I am not having this issue. Imaging is a smidgen left of center whatever amp I use, so this is the driver. Any large difference in volume I am attributing to the amplifier.
I would not use the THX789 with this phone as the manual tells you not to. The MCTH manual does not discuss it.

See this webpage for diy instruction if you want to make your own impedance attenuator or to buy one made at garage1217 (pricier) https://diyaudioheaven.wordpress.com/headphones/headphone-attenuation-adapter/

 

Sorry, this just can't be so. Also all Verum 1 have impedance of ~8 ohm (you said that yours have 15&17 ohm) with cable.

 

When measured with a multimeter the DC resistances are 15 and 17 ohm. The impedance is more complicated and is an AC measurement. The difference in the 2 drivers may be a lot less when impedance is measure. This is not something I can work out in my head easily and mu googlefu ain't helping.

 

Again, that just can't be. I never made such high ohm transducers in my life and yes, I'm talking about DC resistance.
Anyway, I'm happy that you have a working Verum 1 and as far as I understand it met your expectations (and it is 8 ohm!)

p.s. I Love this meme:

 

Been listening to Verum with THX extensively today, about 6 hours of continuous play. No problems with anything whatsoever. Channel balance OK. Using custom balanced cable.

Today we had a board games party at my home and I asked my guests — who are no audiophiles at all — to compare Verum to HE560. All of them said they preferred Verum. Some admitted that the HE560's level of detail was superior but still preferred the kind of sound Verum creates.

I can definitely agree with them. HE560's sound has high resolution, clarity with THX is astonishing. Bass control's superb. Yet when I switch to Verum I feel as if music had moved towards me. Mids are much more energetic and engaging. Bass is very natural and thick. Verum's highs are much less fatiguing than HE560's brightness, yet in some tracks, highs become a bit irritating. Most of the time no problems there, however. Sound fluidity & dynamics, that feel of the authentic experience, are much better with Verum. In the ideal world, I would like to have Verum's sound with 560's level of resolution. Maybe Verum 2 will have a thinner membrane and will become such ideal headphones for me?))) Until then, I'll listen to both headphones on a rotation basis, I guess.

Really looking forward to receiving my own pair, these ones were given to me for a few days test by an audiophile buddy, will have to give them back soon. I don't want to!)

 

What should the DC resistance of the driver be then? What reading would you expect to see?