PSB M4U 8 Over-Ear Wireless Noise Canceling Headphones Measurements

Measurements Wired Passive
Click on graphs image to download .pdf for closer inspection.

Measurements Wired Active

Click on graphs image to download .pdf for closer inspection.

Measurements Wired Active Noise Canceling On

Click on graphs image to download .pdf for closer inspection.

Above I am only showing the wired responses. Measurements were taken in wireless modes but are much the same as the wired response. Measurements sheets are available here for Wireless Active and Wireless Noise Canceling modes.

Looking at the raw responses of the PSB M4U 8 in all modes you can see there is very little effect on response with movement on the head. But I do need to say I had to work fairly hard to ensure a seal at each measurement. I think this was more due to the materials and size of the measurement head than the headphones. I found no problem getting a good fit and seal on my head in listening.

You can see in the raw response in passive mode that the bass emphasis doesn't return to baseling until about 500Hz. This bass boost bleeding into the mids was quite audible. In both active and NC modes the bass boost is limited to around 150Hz by the RoomFeel EQ in DSP.

Bass quality as seen in the 30Hz square wave waveform top and low THD+noise seems quite good. In Active and NC modes the 30Hz square wave is more tilted due to the drop off below 20Hz, but has fairly good shape (little sway back). THD+noise rises in the active modes due to the added noise of the electronics, but the curve remains flat in the low frequencies apart from a minor increase in bass distortion at 100dB in NC mode.

Raw frequency response in passive mode above 600Hz has very good shape, and were it not for the bass boost bleeding into the midrange overshadowing the perceived character of these cans this would easily be the best sounding mode of operation due to it's excellent response above 600Hz.

In Wired Active mode, raw response starts rising at about 600Hz towards the peak at 3.3kHz. The shape of this curve is good, but the overall amount of emphasis is about 5dB too high, which can be seen in the bump between 1kHz and 4kHz on the compensated response plot. It can also be seen as excessive ringing on the leading edge of the 300Hz square wave. Some clean ringing at 3kHz at the leading edge can be virtually inaudible (as with the Sennheiser HD 650) but the M4U 8 is a bit excessive. Point is, while this is not ideal, it's also not as bad as it looks in listening.

Response drops off rapidly above 4kHz and is probably a few dB low between 4kHz and 8kHz. Fortunately, this is an area where you're better off having too little rather than too much energy as these frequencies can be quite annoying if over-done.

Raw response in Noise Canceling mode is largely the same as active mode but for a significant feature between 1kHz and 2kHz. This change was clearly audible when switching modes as an increased high frequency hootiness...sounding something like a person who has a little whistle with their "S" sounds.

Distortion is fairly low in passive mode, and increases in distortion in active and NC mode will largely be due to increases in noise of the active electronics circuits.

Passive isolation in passive and active modes is fairly good for a headphone of this type. Increases in low frequency isolation is pretty dramatic, but some loss of isolation in mid and high frequencies also occurs. Still this is a good result, though not quite as good as the Bose QC35.

Needing only 13mVrms, 20mVrms, and 43mVrms to achieve 90dBspl at the ear in NC, Active, and Passive modes respectively, this headphone will play quite loud out of a portable device.

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

frp bypass apk download

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?