• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

PSB M4U 1 Review (headphone)

milosz

Addicted to Fun and Learning
Forum Donor
Joined
Mar 27, 2019
Messages
584
Likes
1,643
Location
Chicago
EQ.gif
 

bigjacko

Addicted to Fun and Learning
Joined
Sep 18, 2019
Messages
721
Likes
359
housing design of the HD800 itself
Yeah, it's in the angle, distance openness, and also the larger driver. I don't think that throwing an HD650 driver in there would work as well though.

It's flat out touching your ear in the HD650 chassis. Move it out 3/4 of an inch, increase the volume on the ear side by several times, and get rid of almost all the damping and you'll probably be asking it to move too much air.
Is the housing the only reason makes the sound stage so big? If that is the only reason why don't other companies do the same? Even DIY people can try to 3D print and come up with more than half decent result. Not bashing you guys but I wonder why no one has done such things. I like big sound stage and want to know more about it.
 

maverickronin

Major Contributor
Forum Donor
Joined
Jul 19, 2018
Messages
2,527
Likes
3,308
Location
Midwest, USA
Is the housing the only reason makes the sound stage so big? If that is the only reason why don't other companies do the same? Even DIY people can try to 3D print and come up with more than half decent result. Not bashing you guys but I wonder why no one has done such things. I like big sound stage and want to know more about it.

I've pieced together a few rules of thumb from DIY experiments over the years.

The basic shape of the soundstage is often determined by FR and can usually be modified to a degree by EQ. IMO a DF EQ usually give the most natural soundstage with more forward projection. Reducing DF's 2.7kHz peak and/or shifting its frequency can adjust the depth and width to a degree.

Overall "openness" is another factor. This is kind of akin to cabinet resonances in speakers. An open design can just let the backwave and any other excess energy radiate away. Closed designs need to damp and absorb it.

IMO, the biggest factor in soundstage is the positioning of the driver with respect to the pinna. When the driver is is larger, farther away, or at an angle with respect to your pinna it adds more of your personal pinna transfer function to the final sound reaching your eardrum. This makes it sound just a bit more natural and will increase the size of the soundstage.

Putting these all together we can examine a couple designs.

The HD800 has a larger than average driver held at an angle and distance for the pinna in a very open design. This gives a greatly enhanced sense of space. The downside of holding the driver in that position is the less than ideal FR with a peak corresponding to the wavelength of the diameter of its cups.

In contrast the HD650 has a smaller driver pressed directly against the pinna. This makes for a much more controlled "room" for the driver but greatly reduces the sense of space.

Electrostatics are also known for their large soundstages.

Compared to dynamics they have much larger drivers. They are also very open. Their baffles are sealed (or ported) on the ear side, but the drivers themselves very acoustically transparent. Some planar magnetics can nearly match a 'stat in driver size but the drivers themselves are less acoustically transparent. This can be easily demonstrated by just holding your hand an inch or two out from the back of headphone and hearing how much the sound changes. No current production 'stats I'm away of though have angled drivers. There is the old Stax Sigma though.

Overall, this makes a very open sound with a great sense of space. The non-angled drivers drivers keep it from having much in the way of forward projection though.

As to why this kind of thing is copied more? I'm not entirely sure.

Part of it is probably difficulty in getting a good FR in a physical design like the HD800. The HD8XX is now their third try and the prototype still needs just as much EQ as the original.

Part of it is probably cost. The other path to this is large drivers and those are expensive if you want them to sound good.

'Stat drivers aren't inherently expensive, but the amps they require are, and that is a hard market to break into.

Large planar drivers are expensive too. Lots of strong magnets trying to to tear apart the stators, lower yields on larger diaphragms, probably more issues tensioning them, and then the issues in making them acoustically transparent.

If you make a dynamic driver too big it stops being a tweeter and turns into a midrange. There are plenty of 40 and 50mm headphone drivers which are already twice as large as average tweeters on speakers, but which are expected to got up to 20khz on their own none the less. That's probably why Sennheiser went to the trouble of making the HD800's 56mm driver a ring radiator.

...

Anyway, these are just some random thoughts before I've even finished my first cup tea this morning...
 
Last edited:

solderdude

Grand Contributor
Joined
Jul 21, 2018
Messages
15,891
Likes
35,912
Location
The Neitherlands
They most likely are the same drivers. The only difference being one is passive and the other one is active/NC
 

don'ttrustauthority

Addicted to Fun and Learning
Forum Donor
Joined
Feb 10, 2021
Messages
679
Likes
377
Is the housing the only reason makes the sound stage so big? If that is the only reason why don't other companies do the same? Even DIY people can try to 3D print and come up with more than half decent result. Not bashing you guys but I wonder why no one has done such things. I like big sound stage and want to know more about it.
No everyone wants soundstage. If the drivers suck just moving them away won't help. Even if they're good, some drivers are balanced up close, others not.

Finally, it's expensive to design properly so the plastic doesn't creek [sic].
 

Harmonie

Major Contributor
Forum Donor
Joined
May 30, 2020
Messages
1,927
Likes
2,084
Location
France
Thank you for this review.
These have been pushed strongly by AudioAdivisor with their weekly clearance list.
You are reviewing all the HP that I was wondering about.

Merci ;)
 

Coffee_fan

Member
Joined
Apr 26, 2020
Messages
52
Likes
62
Thanks Amir!! I have these cans and they are a good daily driver for my ears. They are not stressful, but because they are closed back they can get tiresome after some time -- Note, that's just my gripe with closed back cans --. Anyhow, I personally like more the MDR-7506 for overall tonality and I like these more than the Sennheiser 280s or some Open back AKG I have.
 

BogdanR

Member
Joined
Dec 28, 2019
Messages
82
Likes
86
Location
Richmond Hill, ON
@amirm I have a pair of M4U1 I bought in 2012 and they've seen a fair amount of use daily actually until 2018 when I got a pair of HE400i. They are still in use especially in last past year due to the pandemic and my wife and I sharing a working space. They have faired significantly better than the ones shown here. I love them. PSB designed them to try to reproduce the feel of pair of decent speakers, and I think they succeeded. All the measurements I've seen elsewhere and my experience with them varies quite a bit from your measurements. Perhaps my only complaint about these headphones is the fact that it is not easy to get the proper seal and then, indeed the bass response suffers and they have a tendency of sounding a little "nasal" for a lack of a better word. But play a bit with the adjustments, get a good seal and they will sound excellent, detailed and unusually open for a closed design but without any trace of sibilance and with good weight and extension on the bass region. I believe the state of the measured pair's pads negatively influenced the measurements and your overall impression. The NAD's you measured you actually liked... well these PSB's are pretty much the same thing. Same drivers same design by PSB's Paul Barton.
 

Robbo99999

Master Contributor
Forum Donor
Joined
Jan 23, 2020
Messages
6,878
Likes
6,674
Location
UK
@amirm I have a pair of M4U1 I bought in 2012 and they've seen a fair amount of use daily actually until 2018 when I got a pair of HE400i. They are still in use especially in last past year due to the pandemic and my wife and I sharing a working space. They have faired significantly better than the ones shown here. I love them. PSB designed them to try to reproduce the feel of pair of decent speakers, and I think they succeeded. All the measurements I've seen elsewhere and my experience with them varies quite a bit from your measurements. Perhaps my only complaint about these headphones is the fact that it is not easy to get the proper seal and then, indeed the bass response suffers and they have a tendency of sounding a little "nasal" for a lack of a better word. But play a bit with the adjustments, get a good seal and they will sound excellent, detailed and unusually open for a closed design but without any trace of sibilance and with good weight and extension on the bass region. I believe the state of the measured pair's pads negatively influenced the measurements and your overall impression. The NAD's you measured you actually liked... well these PSB's are pretty much the same thing. Same drivers same design by PSB's Paul Barton.
Your description sounds very similar to my experience with my NAD HP50, which you also draw comparison to......so there's probably something in that.
 

tarikuz

Member
Joined
Nov 18, 2019
Messages
34
Likes
30
@All, I still have this gear but not in use because the headband got cracked after a couple of years. I tried to find the spare spart but no way... A guy posted the DIY 3D model (https://www.thingiverse.com/thing:2196782) but to print it I need 40€ and it's a non sense. Do anybody know where to buy a spare headband ?
 

Thermionicon

New Member
Forum Donor
Joined
Apr 5, 2021
Messages
3
Likes
3
Location
just north of Austin Texas
Thanks for the review-- I just picked up a factory 'refurbished' pair on Ebay-- $99!! They appear totally brand new, they have all original packing, cables, and a spare set of ear cushions! I broke them in for 24 hrs driven by random Amazon music on my computer through a Focusrite Scarlett 2i2 cranked up...all I can say is wow what a nice balanced overall sound-- bass goes deep but not obnoxious, highs are soft like my Meze 99 Classics and mids are open and smooth. I'm sure there are phones with more upper mid/lower treble detail that aren't 'etched' but dang these are very comfortable and non-fatiguing like the Mezes just a little bit heavier. I have larger ears but the ear cups are quite roomy. And for $99? Very pleased.
 

WickedInsignia

Active Member
Joined
Mar 6, 2021
Messages
184
Likes
408
Location
Australia
I had (and loved) the PSB M4U 2 for ~4 years, but unfortunately it eventually broke in every way possible. The top pad disintegrated, the earpads disintegrated, the headband developed cracks, and eventually the left phone stopped working. It spent most of its life at home in its case! It also had a very audible hiss when the power was on, was generally uncomfortable over long periods of time and would pick up interference from wireless signals. The PSB M4U 1 is built almost identically so I expect many of the same issues will occur.

It really was just a bad and over-engineered design apart from sound, and I don't regret ever buying it considering how much joy the sound brought me. It was also my first brush with the Harman Target (or alike). Paul Barton's research was aimed at recreating the sound of good speakers in a listening room, much like the SRF targets that resulted in the 2013 Harman Target.

The M4U 8 looks promising but I can't pull myself to buy another PSB considering the plethora of design issues. I think they're a wonderful manufacturer, but they need a few more iterations before I could broadly recommend their headphones.
PSB has sound down, they just need to work on a comfortable and robust design!
 

Human Bass

Addicted to Fun and Learning
Joined
Nov 25, 2018
Messages
653
Likes
660
Quite impressive low distortion for a DD. Put many Focals to shame.
 
Top Bottom