This hasn’t gone unnoticed by other manufacturers. As well as existing headphone companies tailoring their output to appeal to a wider audience, companies who have not previously entered the category have released products to get in on the action. PSB is a Canadian loudspeaker company with some forty years of experience in box loudspeakers and a very loyal following. Until now, they have not produced a pair of headphones but buoyed on by the growth in the market has now unveiled the M4U2. This noise cancelling model is a completely clean sheet design and as such not only is this review an opportunity to see how good the M4U2 is, it is also a chance to see if starting afresh with no baggage about what has gone before allows for certain advantages.
The M4U2 makes use of a pair of 40mm dynamic drivers for output. This is relatively large for a portable design and suggests that the packaging for the enclosure is efficient. The driver itself is right behind the fabric enclosure but the padding is effective at keeping this away from the ears - more of which later. PSB doesn’t specify exactly what the drivers are but given their expertise in this field with conventional speakers, they should be up to the task.
The M4U2 has three operating modes selected by a switch on the right hand enclosure. The first is entirely conventional. With the switch set to “Off”, the M4U2 is a normal pair of enclosed headphones. They are entirely dependent on voltage from the headphone socket to function and to their design for noise isolation. The second position activates the on board amplification in M4U2. Resistance drops from 32 Ohms (still hardly a tough load for a pair of headphones) to 10 kOhms. This makes the PSB enormously sensitive. If your headphone device cannot produce enough output to produce ear frying levels in this mode, it is unusually feeble.
The third mode is what PSB calls Active Noise Control. This keeps the amplification active and then adds active noise cancellation to the signal hoping to remove the everyday annoyances of the outside world. The method for achieving this is a pair of microphones that are actually concealed in the earphone enclosure itself. The intention is to have to provide the minimum amount of active cancellation as possible. The thinking behind this is relatively straightforward. The less noise that needs to be aggressively cancelled out, the more natural the sound will remain.
To achieve this, the right hand enclosure has space for two AAA batteries that provide the power for the active and noise cancelling modes. PSB quote a battery life of 50 hours and nothing I’ve seen in use makes me doubt this figure. Putting the M4U2 in passive mode doesn’t drain the batteries and means you can save them for when you need them. Another nice touch is that the enclosures are still of an equal weight when the batteries are in which makes for a more comfortable product to wear.
The attention to detail that means that the M4U2 to be equally weighted also shows through in a great many other areas as well. The M4U2 seems to be a useful demonstration that developing a pair of headphones with no pre-existing ideas about what is required in a design can help produce a product people might consider useful. As such the design teems with impressive little details.
The simplest of these but in many ways the most consistently useful is the fitting of two sockets where the detachable cord can connect to the headphones. How does this help you might ask? Well, if you are connecting to a laptop where the headphone socket is at one side or perhaps you have a coat where the inside pocket is on a particular side. With the PSB you can ensure that the cable doesn’t have to go “across” you to a particular side (unless you want it to). This is a very simple design feature but one that is rarely seen on other designs.
Another welcome feature (if one that does appear on other designs) is that PSB supplies two cords with the M4U2. One is a simple 3.5mm to 3.5mm cable intended for use with laptops and non Apple type phones and tablets. This still contains an inline microphone for Skype and phone calls but does without the volume commands. A separate cord is supplied with an inline remote for an iDevice allowing you to decide what you need based on what you are connecting it too.
The headphones themselves have more than a little of the Beats models to their design (“Dre-esque?”) but there are some clever details that are welcome. The headband is a fixed hoop with the earpads swivelling on mounts on either side of the pad. The movement of the pads is considerable and coupled with the deep padding makes for a comfortable fit. The review pair was black but white is also available. A high quality carrying case is also supplied that is also large enough to hold the headphones, the cord and some spare batteries if you needed them.
As such, while £300 is a significant sum of money for a pair of headphones that are a “first attempt,” the overall impression as you unbox the (beautifully thought out) packaging is that these are impressive value for money. The combination of build, featured components and overall design is hard to criticise at the price. Normally, I like to find something I’d like to have added or changed to the overall packaging of a pair of phones but (annoyingly) these have got it pretty much spot on. The build is good, the ancillaries are good and the design is sound. If I were nitpicking, I’d prefer that the iDevice cord had a straight plug connection at the external device end rather than the 90 degree one they are fitted with but in terms of the overall design is pretty much it.
For portable use my iPhone 4 was the most commonly used device, using a variety of MP3 and AAC files. I also used an iBasso D4 portable FLAC player to run some high res file tests. These being noise cancelling headphones, I used them in some typically noisy environments such at the Tube and during various singing and piano lessons conducted by my wife - this isn’t a reflection on the calibre of the people involved in the lesson but simply a useful test!
Before I activated the ANC function, I spent some time listening to the PSB as a conventional passive headphone. The results were largely extremely positive. The M4U2 is a commendably neutral performer and doesn’t over-emphasise any part of the frequency spectrum. There is the very slightest lean towards the warm side of the tonal balance but this helps keep slightly crude recordings listenable when you push them at the cost of a very slight sense of air and space on some well recorded pieces.
The sensitivity is impressive too. Even before you switch the PSB over to the active mode, you are unlikely to have difficulty driving them to impressive levels. They do benefit from a good quality output stage though. The Furutech ADL headphone amp and the iBasso portable player both showed improvements in quality over the headphone sockets of the Thinkpad and the iPhone. Using the latter produced perfectly good results but there is little question that there are further improvements to be had.
Perhaps the final surprise for a noise cancelling design is that in passive mode with none of the designed noise reduction features engaged, the level of isolation is still extremely good. The M4U2 neither lets a great deal of ambient noise in and neither does it leak much back out again. This sounds a little strange but it is best to see the PSB is effective as an isolating headphone full stop and that the active modes give additional isolation at the point you need them.
Switching to active mode generally needs to be accompanied by reduction in the volume level of whatever you are listening to. What is already a very sensitive headphone becomes an incredibly sensitive one when the active setting is engaged. This does have the effect of amplifying background noise slightly but not unmanageably so. Otherwise much the same tonal balance is maintained with the PSB staying basically flat. There was the slightest thickening of low end notes with some pieces but this was not consistent nor especially distracting. Children of the Sun on Dead can Dance’s Anastis retains the sense of the enormous performing space and sophisticated layering to the performance.
Pushing on to full active noise control, the results stayed positive. Firstly, I didn’t throw up or feel like I was likely to. The placement of the microphones in the enclosures themselves does lead to a genuine reduction in the amount of cancelling the PSB has to perform as only noises that penetrate the already impressive amount of natural isolation have to be dealt with. This also means that the amount of external noise the PSB can handle is impressive. The Tube proved no challenge and even the most potent of my wife’s pupils - a fully fledged opera coloratura capable of breaking wine glasses as a party piece - was barely audible.
The result is that while there are still lower levels of background noise than in passive mode, the overall performance stays much the same as it does in passive mode. There is a very slight hardening of the tonality especially with the upper mid and treble but unless you are listening to extremely poor internet radio or other low quality recording, it stays entirely listenable. Another area where the noise cancelling really comes into its own is making and receiving calls - even the faintest of callers can be effectively isolated from the outside world and call quality was generally good.
Comfort is impressive too. The fitting of a deep pad with a relatively soft sidewall means that the PSB doesn’t exert a great deal of pressure on the head when wearing them. The padding at the top of the headband isn’t especially deep but it is enough to keep the PSB mounted comfortably. The all up weight of 362g is fairly high but not unmanageably so and thanks to the even distribution is still comfortable. The grip they exert on the head is enough to keep them solidly in place while walking about but they probably aren’t totally suitable for gym work.
As was the case with the packaging and supplied equipment, there isn’t much to criticise the PSB for. Comparing the PSB to a conventional non-noise cancelling headphone from the Grado range generally reveals the Grado to sound slightly more open and natural with a better sense of rhythm and timing. The moment that the listening environment becomes louder, the PSB has all of the advantages though as the open back design of the Grado starts to leak noise both in and out. It is rather harder to beat the PSB once you are on the move than it is in a quiet listening room type environment.
- Excellent performance in passive and active mode
- Impressive supplied extras
- Comfortable and well built design
- Slight loss of transparency compared to the best passive designs
- Right angled connection on “iDevice” cord can snag
PSB M4U2 Active Noise Cancelling Headphones Review
The PSB M4U2 is an exceptionally accomplished all rounder. By the very nature of the basic design this is an extremely capable headphone that provides excellent noise isolation in and out with a good comfortable fit. Switch to the active mode and they are capable of handling pretty much any real world environment without breaking sweat. They are sensitive enough to be used with most portable devices even in passive mode and they also respond well to improvements in the recording and source. The useful collection of ancillaries and sturdy carrying case are also welcome features.
All the time, perhaps the single most impressive part of this whole package is that this is a clean sheet design from a company with no prior history of making headphones. PSB has clearly looked at what they wanted to achieve, how others were going about it and set out to improve on the competition wherever they could. The result is one utterly convincing and seriously impressive headphone.
Ease of Use
Design and usability
Value For Money
Our Review Ethos
To comment on what you've read here, click the Discussion tab and post a reply.