PSB Speakers M4U 4 --- Hybrid BA/Dynamic IEM
Mar 21, 2017 at 1:04 AM Post #301 of 330
OK, so l have spent almost 2 months with these earphones and l think I'm ready to share my experience if anyone is on the fence as they are a pretty inexpensive, nowadays especially if you're in the U.S buying from Canadian dealers. With the conversion rate being as it is, it's a great deal.

Set up: Straight of iPhone 6, iPad Air2 and Dell laptop. No AMP or DAC required.

Build quality:
Simply awesome, small, solid, no cracks and clicks or sharp edges, cable is very nice, connectors are snug don't rotate randomly. Cable with mic is a bit tricky for first few days and won't stay still around the years, but after a good few days will settle down eventually. Mic is and inline control are great, clear and responsive - no issues there whatsoever. Shirt clip is nice too, tips: comply are included and silicon are not good, too thin and for my medium size ear-canals even the L size wasn't big enough, strange.

Sound quality:
Those have a unique shape and come in sharp black or beautiful white they if you like white earphones, they are quite small but you need to fiddle around a bit to get the right fit. Not a big deal but something to keep in mind since they are small but comfortable IF you find the right fit. The sound is pretty flat and neutral with a bit of a bass hump for the RoomFeel. First 2 weeks it was uninspiring, nothing special really. I was using the stock tips and l thought l was getting a good seal, but in fact, l wasn't. With regular tips l usually use M size tips, with the PSB even the L size won't provide a good seal, they are flimsy and thin and just don't get the job done. With Comply the seal is very good but the IEM can stick out quite a bit and they sound congested. l had a set of old Meelectronics at home and they improved things dramatically.
l often like my IEMs a bit warm, the M4U 4 don't really provide that. They are rather flat and dry, not in a bad way, just the nature of the beast. Bass is solid, not boomy and rather punchy but in a loud speaker type of fashion (RoomFeel?) They are fairly detailed and soundstage is really good.

Isolation is really good and lucky l didn't notice any microphonics which like all of us l despise.

They work really well with most genres, ADM, jazz, rock etc... You name it, they sound true and accurate, if you are used to warm sound and V shape signature they may sound on the boring side to you. Details are nice and crisp but non-fatigue, highs are never harsh or shrill, if you like strong and rumbly type bass you may want to look elsewhere. While bass has some nice texture it has a rather unique type of bass that l have never heard before.


Things to consider:
Like any IEM's these may not be work for some. They need to be inserted rather deep and are VERY tip-dependen, I can't stress this enough. The shell sits in a way that if your ears are small it may not work well for you and may become painful. If you over insert them they sound muffled, if the seal isn't good they sound thin and weak.

Sound signature is actually really close to the NAD Viso HP50 full size headphones. You get a little more bass though and a bit more sparkle in the high frequency if used with good silicon tips.

Bottom line:
I must admit, at first l was underwhelmed with the sound and overall fit. It took me a while to figure out the fit and find the right tips but once l did things obviously had improved dramatically.
They have a very interesting. Also, Paul Barton and Co. hand tune all their M4U 4 against the reference. This is really remarkable and in fact the first set of earphones that l hear and can really feel that they are well balanced.
While l bought and sold many IEMs the M4U 4 are keepers.

Highly recommended if you like balanced uncolored sound with a very unique bass.

Some great info from Paul Barton, Chief engineer of PSB Speakers about the M4U 4 and M4U 2 and the RoomFeel technology:

 
Last edited:
Mar 21, 2017 at 1:51 PM Post #303 of 330
Awesome! Yeah, l should have mentioned that the tips didn't work for my ears but they are not bad per se. They don't give any discomfort or itch like many tips l have tried. 
 
The sound signature can be seen as dry and textured for some and hiss-free but l actually think it works perfectly with the overall PSB/ NAD sound signature. Overall great value and a great set of earphones. 
2 yr warranty is always a plus in my books too since l use my earphones 8-10 hrs a day for work and pleasure. 
 
Apr 6, 2017 at 6:56 PM Post #304 of 330
For those who own and consider the sound signature of either the Focal Sphear or RBH EP3 favorable, how do they compare with the M4U 4's?  Thank you.
 
Aug 5, 2018 at 1:27 PM Post #307 of 330
Sorry to resurrect the dead however I am very interested in these. Curious as to why they didn’t make a bigger splash based on what I have been reading, for the most part it has been consistently great reviews. Perhaps too many new FOTM?
 
Aug 6, 2018 at 12:24 AM Post #308 of 330
The M4U4 IEMs are a nice sounding pair. I think you should audition them and compare them to other similar price point IEM's.

The PSB IEM's are not offensive in the high frequency range. I find them to be very easy listening and never fatiguing.

The world of IEM's is so big now that there is alot of different "flavours" to appeal to many people.
 
Aug 10, 2018 at 7:16 PM Post #309 of 330
At the price point of 149 they are an absolute steal. I am still allowing my brain and ears to burn in however so far I agree with most of the praise that these have received.

They are technically and sonically up there with the best that I have owned (we all know how sonic memory is) ymmv.

I am not too sure about the sound stage and positioning yet, hence the necessity for additional brain and ear burn in.

Without a doubt the best sonic purchase I have ever made especially considering the 149 purchase price.

I am going to email psb and see if they will advise as to which connector they used as I would like to upgrade the cable.
 
Aug 10, 2018 at 7:34 PM Post #310 of 330
I have these but I so rarely use IEM’s - except at the gym and then not even always there, and I wouldn’t want to sweat all over my M4U 4’s - that they just don’t get a lot of head time. :confused:

I put them on just now to refresh my memory, and they’re my best IEM’s for sure - I don’t spend a lot of money on IEM’s, granted, but they did cost me about $150 used, which is the most I’ve ever spent on an IEM.

I as listen them right, to me the first thing I notice is just how clean and balanced they sound to my ears, separation is pretty good, soundstage is definitely the best of my IEM’s, and everything sounds “good” but I’m listening to the same song I listened to last night on my NAD Viso HP50 and I still prefer the HP50 to these.
 

Users who are viewing this thread

Back
Top