Ottawa tourism will tell you the Canadian Tulip Festival is held in the capital city every spring since the mid-1940’s because Canada offered safe haven for members of Holland’s Royal family during World War II.

PSB M4U 4 Headphones and my Trip to Ottawa

In appreciation, Netherland’s Princess Juliana gifted 100,000 bulbs to be planted on the capitol grounds along the Ottawa River. To this day, the city celebrates spring by lining the canal and parks with tulips bringing visitors even the Canadian Border Services Agency can’t keep away. Alas the flowers and the city were beautiful, I recent visited Ottawa and the NRC (National Research Council), housing the anechoic chamber still used by PSB speakers, located several hours away in Pickering, Ontario.

PSB M4U 4 Headphones and my Trip to Ottawa

Paul Barton, founder of PSB speakers is still their chief designer and makes the 255 mile drive from Pickering to Ottawa whenever he wants to test his new designs. In fact he has been doing it for almost 40 years as he modestly boasted on our tour. Impressively you can sense from Paul that this is home. Although the reputation of the NRC is legendary, I got the feeling that to Paul it’s an important enough place but more significantly, it’s where he comes to work and expand the passion he still has for speaker design. The place is full of scientists, over 1,000 PHD’s I’m told and yet apropos for what I see in Paul – he presents a hypotheses and sets out to prove it.

Secrets Sponsor


Trip to Ottawa

The NRC was established during a time of war in the early part of the century around 1916 with the intent to help support business and encourage prosperity for Canada by supporting research and development. The campus is sprawling and vast with many buildings all numbered beginning with “M”, I believe because they line Montreal Road. The buildings vary in size and shape greatly and at the end of one of the roads is a smaller non-assuming structure numbered M – 37.

PSB M4U 4 Headphones and my Trip to Ottawa - Campus

Occupied by the audio test lab and anechoic chamber, Paul makes himself right at home, he beams with pride and delight here and it’s infectious – you really want to partake. After a brief tour of both the chamber and the audio testing gear, Paul explains how his theory of headphones and how it applies to the testing lab.

PSB M4U 4 Headphones and my Trip to Ottawa - Testing Labs

RoomFeel ™ Technology

“Headphones should sound like a pair of flat-measuring, full-range speakers properly set up in a good room”, or as Paul might also say, your head. The anechoic chamber represents to Paul, the sound in your head, the best way to experience the sound of a headphone beyond the use of HATS or head and torso simulator produced by KEMAR. First developed for hearing aid technology it proved helpful in developing acoustic research for headphones. Paul felt the anechoic chamber could also best simulate the testing needed for headphones. The concept behind Roomfeel™ – what you hear in your head is akin to a properly set up listening room.

Secrets Sponsor

PSB M4U 4 Headphones and my Trip to Ottawa - Dummy

Paul talks about the psychology of listening to music in a space, that our brains map the space. Very much like your eyes adjust to brightness, or lack of light, so too does your sense of space, or sound within the space. This concept or psychoacoustics is how he approaches the technology behind the design of his headphones. Paul also talks about the perception of sound beyond typical limits of human hearing, well into 40,000 kHz, but that’s another discussion.

Paul Barton, founder of PSB speakers

PSB’s M4U 4 in-ear headphones were the center of the discussion. The M4U 4 is referred to as hi-definition and is a bit unusual in the larger housing beyond the ear buds that includes a hybrid design with an armature and driver combination. With Paul’s concern for the cohesiveness he created filters and therefore a crossover network. Each pair of M4U 4 is “hand-tuned” and Paul graciously handed out pairs of them with each frequency individually plotted. I don’t have the means to bench-test the headphones but I’d be interested in seeing Paul’s test compared to mine.

PSB M4U 4 Headphones - Components

PSB M4U 4 Headphones - Design


In Paul’s research, he presented four room (EQ) curves and played them back in the anechoic chamber – a bit unusual as typical other than the speaker and microphones for testing, the chamber is empty. Sitting in a chair about 10 feet back of a pair of full-ranged PSB Imagine T3 loudspeakers and the SubSeries 450 sub, I auditioned using music sourced from a laptop that I was able to control. Having had a pair of T3 at home for months now, I was enjoying the experience in this format, within the anechoic chamber. Partnered with Peter Hoagland who handles PSB’s marketing strategy and PR. We were quite consistent in our observations and a preference to the room EQ’s presented. I believe we were listeners 9 and 10 on the chart. My impartial preference was #1, go figure.

Paul used Dirac Room EQ software to tune the EQ’s. Paul’s experiment was successful in several ways despite understanding that this was hardly scientific – simply not enough time. The results Paul sent showed in the voting that the perfectly flat response was least liked. I can testify to the dullness of that EQ, lacking dimension and dynamics as well as spatiality.

The 4 different EQ choices were:

  1. RoomFeel
  2. Perfectly Flat response
  3. Low frequency Boost of RoomFeel only
  4. 50% low frequency boost and 50% high frequency cut of RoomFeel

PSB M4U 4 Headphones - Dirac Room EQ

Good-Bye to Ottawa

I leave Ottawa with a better understanding of Paul Barton, his creativity and his science as well as his passion for his work, his country and this city. I wish to thank him for his time and insight and to Lenbrook for their hospitality.

PSB M4U 4 Headphones and my Trip to Ottawa