PSB M4U 8 Over-Ear Wireless Noise Canceling Headphones

It was a real treat being able to talk with Paul Barton about the PSB M4U 8 and NAD HP70 at RMAF last year. Paul has lead acoustic design for PSB, NAD, and Bluesound for a long, long time now; he's got a strong understanding of audio and when he designs a product it speaks of this knowledge. In listening to this headphone, I find myself listening to both the headphone and what Paul may be trying to tell us with them. It's been an interesting dialog.

PSB M4U 8 ($399)
The PSB M4U 8 is a fully featured around-ear, noise canceling, wireless headphone. Styling is a bit clunky to my eyes with large oval gimbals around the rear capsule housing as the main design feature.

Visible materials are mostly plastics but apear of good quality. The headband has a sturdy internal spring steel structural element; headband hinges apear to be of chromed metal. Adjustment sliders are detented and slide in and out of the headband end/yoke piece, which is matte black, somewhat flexible, and slightly rubbery to the touch. Fit is secure and stable once set.

Headband and earpad covers are a nice quality leatherette. Ear cushions are memory foam. Earpad openings are somewhat small at 35mm x 60mm, but earpads are undercut on the rear side to permit room for the pinna to fit more comfortably. Overall fit on my slightly larger than normal head is cozy; this headphone hugs my head. I loosened the fit a little by bending the headband outward carefully, but I do think headphones for travelers should be quite secure on the head. A good seal is important for noise canceling to be effective.

The M4U 8 is amply accessorized with: a 59" analog cable (which can be plugged into either earpiece) terminated with a straight 3.5mm plug on the headphone end and a 90 degree 3.5mm plug on the player end; a 59" USB cable for charging and digital playback from a computer to 24/96; a 1/4" to 3.5mm adapter; an airplane adapter; a hard clamshell travel case; and, surprisingly, an extra pair of earpads.

The PSB M4U 8 has numerous modes of operation. It can be used in both analog and digital wired modes with the supplied analog and USB cables. With the analog cable, the headphones can be run passively without need for battery power. Active mode turns on the internal electronics and the analog signal is converted to 24/96 audio internally. The digital signal then passes through a digital signal processor (DSP) to impose the "RoomFeel" tuning. Another click up on the mode switch and active noise canceling (ANC) is engaged to further reduce interference from outside noise. When the USB cable is used the headphones must be turned on; only Active and ANC modes are available with the USB cable. The M4U 8 will accept up to 24/48 digital signal bit rates/depth over USB. When used wirelessly power must be on and "RoomFeel" tuning is always active. Again flipping the switch up to ANC will engage noise canceling.

Batteries for the M4U 8 are two AAA rechargeable batteries mounted behind the aluminum cover plate on the left earpiece. PSB claims about 15 hours of wireless active noise canceling run time on a full four hour charge. Should your batteries run out while on the move, in addition to just running them passively off the wire, you can replace the rechargeables with store bought AAA alkaline batteries. If you forget they're in and try to recharge them, there is a sensing system in the headphone to know it's loaded with alkaline batteries and will not attempt to charge them.

In both active and noise canceling modes a momentary push on the volume toggle will lower the volume of the music played and turn on the external microphones so you can hear external sounds like the flight attendant asking you if you want peanuts or cookies with your coffee.

The heart of the M4U 8 is Qualcomm's latest whiz-bang CSR8675 Bluetooth Audio SoC (system on a chip). This chip has all sorts of cool stuff on it including: Bluetooth 5.0; USB 2.0; aptX, aptX Low Latency, aptX HD, MP3, AAC, and SBC codecs; and 24-bit fixed-point 120MHz Kalimba DSP. This chip does have digital noise canceling capabilities, but PSB opted for an analog feed-forward and feed-back noise canceling circuit. Paul claims it delivers much lower latency for a more effective noise canceling circuit. My measurements indicate to me this is this headphone does a very good job of noise canceling—not quite as good as the Bose QC35, but close.

There are a total of six microphones on the M4U 8: two within the ear cup for noise canceling feedback; two on the top outside of each ear capsule behind the headband yokes, which are used for noise canceling feed forward and as the listening mics to hear your environment in 'Transperancy Mode'; and two mics on the bottom of the right earpiece, which are used only as a beam forming array for your voice in telephone conversation.

All controls are mounted on the rear of the bezel of the right earpiece and act precisely as one would expect. Both NFC and standard pairing is initially quick and easy. Subsequent pairing is lightening fast and reliable. Controls are ergonomically easy to identify and operate with your right thumb tip.

In sum, I found the PSB M4U 8 a solid, fully featured noise canceling headphone. Styling is a bit old school but finishes are tidy and well executed. Build quality and materials are very good at this price. Controls and electronics work flawlessly and lickity-split. Accessorization is very good. If sound quality is good, this is a solid product offering...let's have a listen.

PSB Speakers
633 Granite Court
Pickering, Ontario L1W 3K1
(905) 831-6555

Suuup's picture

I'm stunned. This headphone measures like complete ass. In passive mode, it actually looks okay, but for some reason, the active mode turns the FR into a rollercoaster.

Compared to the competition, it looks like a clear loss.
Who in their right mind releases a product with a 15 db rise from 1.5khz to 3khz? This looks like the RAW measurements of a headphone before correction for pinnae etc. is applied. I actually had to double check first time I looked this up, that I hadn't pulled the raw measurements.

I think PSB just beat Ultrasone at the rollercoaster FR game...

Argyris's picture

Yeah, it does measure pretty badly, and in pretty much the same way a lot of active headphones do. I wonder if Tyll was onto something in an earlier article when he speculated that it might be some Bose patents that stop other companies from effectively smoothing out upper midrange/lower treble bumps in active mode, since virtually every non-Bose competitor's wireless headphones (especially in NC mode) exhibits some variation of this tuning flaw.

I'm about tired of closed headphones in general suffering from midrange wonkiness. When they were just passive designs with closed cups, it was understandable because this was never an ideal acoustic system. But now that we're shoving active electronics into these things, it's time to seriously invest in corrective DSP. There are a few AKG models that do this (I believe several were featured on IF), but I'd like to see the practice spread to more manufacturers and models, and further down the price scale.

crenca's picture the PSB M4U 8?

brause's picture

Exchangeable batteries...hurrah! In 5 years, the Bose competitor will be hazardous waste while this one will be still going. Pack that into the equation, potential buyer.

Impulse's picture

A Li-Ion pack would yield much longer battery life in the same space, it's a trade-off. For something like headphones which could/should last a long time I'd view it as a positive trade-off but still...

A removable Li-Ion pack would be best but then they'd probably need to add a charger to the package, it complicates support, etc. Loads of camera flashes still use AAs, probably for the same reasons even to virtually all cameras use Li-Ion packs now and some are even rechargeable in-camera via USB.

brause's picture

Li-ion pack would be good as long as it does not cost the world to replace it. Li-ion battery of my camera was $84 to replace (or a third-party for $7), 4 AA rechargeables at IKEA are $8.99 CAD.

I love my Bose QC-15 on one AAA at 35 hrs battery life. It is from 2010 and still goes strong.

Geoffrey's picture

This newer PSB would be a why bother closed over ear headphone for me as never watch TV. My love is listening to solo and small ensemble classical music as well as great American song book as played through Jazz. The closed back over ear headphone hunt is not an easy one as more often than not sound quality and comfort are mediocre, unlike open headphone realm with many good choices. Past five years have owned six different closed over ear monitoring headphones as they generally offer ear cups/pads which are not torture devices for people with larger than baby ears and generally offer closer less exaggerated parts of the sound spectrum. I use Bose QC25's with replaceable AAA battery. Not a serious music listening headphone by any means, but very good active isolation. Been frustrated by two things more than any others in headphone offerings. That is closed over ear passive headphones which are not really very good at isolation from outside sounds and my number one gripe - headphone designers who spec earpads which are frustratingly small. In most cases the introduction of new closed back over ear headphone brings anticipation and then usual letdown. The 1More Triple Driver closed over ear headphone another case in point, that is a headphone with many pluses crossed off the list by ear cups/pads to small for many would be buyers, and when a closed back over ear headphone comes along ticking all the boxes to the positive - it's invariably going to be nose bleed expensive as with upcoming Sennheiser HD820. Don't get me wrong, I love Sennheiser, and in them is my largest hope for more affordable closed back headphone at reasonable price with good isolation, comfort and sound quality. They can do it and I am waiting.

brause's picture

$499 CAD. Nein danke!

ScubaMan1970's picture

It’s a pity, eh. I wonder if the direct-sale model (instead of going to bricks-n-mortar stores) will bring the prices down for Canadian shoppers...

Three Toes of Fury's picture

Im a big fan of some new names hitting this website.

I have some experience with the PSB M4U 2 (Wired, over ear, active noise cancel). I picked them up after finding some glowing reviews of them from another put them 2nd to OPPO PM3 in a closed back battle royale competition. My take on them is that they are a bit big/bulky but comfortable and great sounding (i typically run them passive mode). Its nice to see a new offering from them and that Tyll liked enough to review and put on the wall o fame.

Peace n Living in Stereo


Mark Up's picture

It is interesting is that the headband on this model seems to have changed from a more ideal oval in earlier PSB to the NAD Viso "makes no sense" wide curve style. I tried this and the newer NAD wireless and both didn't extend far enough to fully reach my ears. Sound was okay but that's moot given that issue. That said, I'm surprised Tyll that you haven't tried the new Sony WH1000XM2. I tried those extensively side by side with Bose QC 35. While the Bose is a touch roomier the Sony are comfortable enough. NR is very close on both.

Sound-wise, the Bose are no longer my NR favorite. They come off as grainy and cheaper sounding after the Sony experience. The Sony is about as good as them in passive mode. Active with NR improves it, and fully wireless after you use the Sony Phone App to optimize them, is amazing. I think you'd find them maybe a touch warmer on top that you'd prefer, but the bass really is amazing to me, and the mids are solid, not recessed or clouded by bass. I would say other than the Bose small comfort advantage, these sound better.

CREED's picture

I'm in the market for new noise canceling headphones, I owned the QC35 for a year but it broke so I'll go either with his one or Sony, what do you think?

Geoffrey's picture

"Active with NR improves it, and fully wireless after you use the Sony Phone App to optimize them, is amazing"

IMO Bose QC over ear headphones are not for serious music enjoyment. They are principally for lessening the effects of background noise in increasingly noisy world. The gold standard in headphones for audiophiles is still totally wired operation. Wireless headphones have their place and no denying, no longer being anchored to a cable with ones head/earphone is wonderful. Wireless limits some of the higher resolution files many of us have in our digital libraries. Wireless has its own sacrifices with interference and range. Wireless will get better and I'll be pleased as punch when I can ditch the cable. In meantime will listen to music wired and use NC headphones for podcast listening and with no sound at all to lower my stress in noise saturated environments many of us endure in the day to day.

raysmith's picture

that an amazing headphone

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DavidK442's picture

Being a fellow Canadian, I always root for the home team, and PSB seldom disappoints. I have enjoyed the M4U-1's for years, and just this week picked up a pair of NAD Visio HP50's based on Tyll's glowing review from several years back. The NAD's less aggressive mid-range is a nice change from the PSB's. From this perspective, I have high expectations for Paul Barton engineered headphones. The luke-warm review of his new flagship M4U-8 is disappointing. The passive-wired frequency response compares quite favorably with the HP50, though I can see the slight mid-bass bulge noted. The other modes, well...better than the PSB M4U-4 in ear response at least. (A real disappointment that was.) I hate when my heroes become tarnished.

tvad's picture

Hello Tyll, and thank you for your thorough review. With each review of the Bose quietcomfort 35 II, Sony WH1000XM2, and now these PSB M4U 8 my purchase decision becomes more confused. I suppose it's a good problem to have, but I find it difficult to pull the trigger. I listened to the Bose and Sony cans at a local Best Buy. The music comparison was useless, but I found the Sony cans to fit a little low on my ears, and the Sony were a bit heavier than the Bose. So, from a comfort standpoint, I'd have to go with the Bose. I keep reading from others that the sound reproduction of the Sony phones are superior to the Bose (I am a longtime owner of Sony MDR-7506). However, I am fascinated by your preference for the Bose. Have you auditioned the latest Sony and Bose models?

ScubaMan1970's picture

I’m puzzled by this review. I had a terrible time with my M4U 2 cans ([indoor use only, yet...]cracking plastic head-band, hinges & removable cables shorted out). My experience with customer service was top notch. . After the 2nd replacement, I gave up & tossed them into a closet. After this article, I fished them out & will try them out on my Magni3 headphone amp. Perhaps my PSB product can redeem itself...
I moved on to Senheisser HD650 & Sony MDR7510 units (they can withstand my abusive noggin).

John0001's picture

Is this headphone's earpad a good replacement for the hp50's? My pinna hurts after using the hp50 for a short while. And will it badly affect the sound signature?