Reign of the Mini-Monitors I: PSB Speakers Alpha P5

Summary and Conclusion

The $199–$599 price range that the new Alpha series joins is a crowded space. Besides scores of popular big box offerings and ubiquitous “smart” and active Bluetooth models, there are other respected audiophile brands with entry-level products to contend with. Each designer has their own principles and priorities, so it’s up to you to decide which ones align with your own.

My opinion, based on this experience with the Alpha P5, is that Paul has created something rather special in this new Alpha series line. If, like me, you value sound quality in a variety of listening environments over fancy features and furniture-grade veneers, the P5 will almost certainly amaze and delight you. They have my enthusiastic recommendation as main speakers in an entry-level primary system, for audio enthusiasts just getting started with the hobby who want something they can grow into, and for second systems throughout the house.

Sidebar – a Conversation with the Designer, Paul Barton

Mr. Barton was gracious enough to chat with me on the phone about the history of PSB and the Alpha for nearly two hours. Here are a couple of passages from that conversation.

DS: I recall reading about the launch of the original PSB Alpha back in 1991, and I’m curious to hear about how that product came to be and its development over the last 28 or so years.

Paul Barton: It’s kind of an interesting story. What drove the original concept of the Alpha was trying to make a speaker with performance as a priority; features were not as important as its performance. Those speakers were actually built in Canada at that time using good components, but, for example, the grill cloth could not be removed because it was literally wrapping the baffle. The philosophy was to create something that was bare bones when it came to features— just really basic.

It was a philosophy that I developed a few years earlier when we were making the speaker that was originally called the “Atom.” This was around ‘85, and we kept producing them until the Alpha in ‘91. For this design, the drivers were mounted from the inside, the back was removable, and the baffle was simply wrapped with grill cloth to keep cost low and performance as high as possible. The reason we changed things for the Alpha was due to the very different shape of the Atom. It was quite wide, maybe 14 inches wide by 26 inches tall by, maybe, 5 inches deep. It was not a shape that you see people using today. This was before PSB joined forces with Lenbrook in ‘91.

Lenbrook was NAD’s and PSB’s distribution company in Canada, and our partner company, Lincolnwood, was the distribution company run by Peter Tribeman for NAD in the US. Of course, being business partners in NAD distribution, we lobbied to have Lincolnwood also take over the distribution of PSB in the United States. That is what inspired us to do a new version of this concept, the Alpha— a simple design (similar to the Atom) that was cost effective.

We debuted Alpha at the Mirage Hotel in Las Vegas in the 1991 CES. We had one of those portable rooms that they do demos in, in the big hall. At that time, the big push was home theater, and the Mirage hotel ballroom was where all of the candidates for pushing the new HT platforms did their displays. We had a couple of rooms, and one was dedicated to showing this very cost effective Alpha. So, I was doing demos, and I was using Cosmic Hippo, the album from Béla Fleck, which has some tracks with really amazing low-frequency percussion and bass guitar. Making a speaker of that size produce something of that magnitude was pretty impressive.

So, I was having a lot of fun demoing, just demoing the Alpha, and people were kind-of going “WOW, I can’t believe what this little speaker can do.” From time to time, I’d take a break and go out into the hallway at the Mirage to have a cigarette. There were a couple of chairs just outside the door. I’m sitting there, just minding my own business, when a guy took the seat beside me. When I looked over, I saw his badge and noticed that it said, “Stereophile.” So, I started talking to him. We had never met before, but I had already received some positive reviews in Stereophile at that time— just getting started with distribution in the US. His name was Jack English, a freelance writer for Stereophile who actually worked full-time on Wall Street. Writing for the audio magazine was just his hobby.

I introduced myself and PSB and gave him a little bit of a story. At the end of that conversation, he said, “let me come down and have a listen.” So, I brought him into our room and played that Béla Fleck album; he was blown away. Not long after that, Stereophile requested that we submit the Alpha to him for review. John Atkinson did the measurements (they were in Santa Fe at that time). Prior to the review’s publication, Jack English did a show report of what he had experienced at CES, and I think he coined the phrase, “The Amazing Alpha.” Everything took off from there. So that’s how the whole Alpha philosophy and pedigree you referred to back in 1991 got its start.

We did the Alpha B1 in 1999, and it was in continuous production for almost twenty years. The last production of the B1 was about four months ago. It seemed to have a life of its own over that period of time because, as PSB was making a forceful distribution effort through our relationship with Lincolnwood in the United States, each year we’d tackle another distribution area around the world. Every time we went to a new region, the Alpha was brand new for them. It just kept rolling forward!

Back when we started building the original Alpha, we were importing a lot of parts to build the speakers in Canada. Some parts came from China while the drivers came from India. It really was an international product. At some point, as we evolved in terms of manufacture, getting parts from China and building up relationships with vendors there, one of the factories we worked with was also a box maker. They had woodshops and plastic injection molding plus an automated paint system. They were primed and ready to take on a turnkey product. In 1999, the B1 was the first product that we built in China from the ground up.

We continued to build the Alpha B1 and it grew unchanged over the years simply because our distribution was growing. We were selling these products into other countries by the container load! Of course, everyone benefits when you consolidate and do this sort of thing at scale, so it was able to be maintained at a very constant price over those years. If you look at the price of the Alpha P5 today and adjust for inflation, it’s actually less expensive than the original Alphas! That gives you the historical background of the Alpha.

DS: What lead you to retire such a successful design and start this new series?

Paul Barton: First of all, people like new things— just for the sake of it being different. The landscape in China has also changed a bit. I had been developing a relationship with a vendor there who is really philosophically better aligned with what our intentions were. I took that as an opportunity to completely clean the table and start right from scratch to develop a product with the same philosophy. Hence the P3, P5, C10, and T20.

Before this project, we did an Alpha Intro series “home theater in a box” (bookshelves, towers, and a center channel) speaker compliment for a number of years. When I designed that, I was trying to be pragmatic, so I ended up using the same woofer platform for all three models, tuning appropriately for the different cabinet sizes. It’s not, engineering-wise, the best way to go if you want to make each speaker optimized. In contrast, I was able to optimize the woofers in the new P5 and T20. The woofers used are not the same driver platform. I mean, same cone, same surround, but voice coils are different, magnet structure is different. These are more ideally suited for the application. Now I was given the freedom to really optimize the woofer specifically for the new P5. The tweeter was also a ground-up design from scratch, including the waveguide for it. You’ll notice that it has a bit of a horn.

When you listen to a pair of loudspeakers in a room, the first sound you hear comes directly from the loudspeaker. The second sounds you hear are early reflections from things near the speaker where the sound bounces off. In a typical room with the speakers set up slightly closer together than you are away from them (a typical 2-channel configuration), think about where the second most aggressive sounds come from after the direct sound from the loudspeaker. If you do the math, you’ll notice the second sound comes from reflections off of the sidewalls, somewhere between 60 and 75 degrees off axis. Because those early reflections are so close in time to the original acoustic event directly from the loudspeaker, your brain actually integrates those two sounds as one acoustical event. But, the timbre of the two together is what you hear; tone or frequency response wise, you perceive a blend of those two.

If we look at the off-axis frequency response of the speakers at that 60 to 75 degrees, the woofer is starting to roll off but the tweeter, at its crossover frequency, has got much better dispersion than the woofer does at the same frequency. The response off-axis, if it’s not controlled, will be very un-flat. You’ll have a big suckout and then a rise at typically around 5 kHz. This can make a speaker that measures beautifully on-axis, put in a room, sound very harsh because there’s not a nice blend between the woofer’s output off-axis with the tweeter’s dispersion at the crossover frequency. Because they both contribute equally at the crossover point, but the tweeter has better dispersion off-axis, the tweeter is doing much better than the woofer. When I design any speaker, that’s something that I take into account.

Putting the tweeter into a waveguide like that little horn that’s on the P5 limits the tweeter’s dispersion. Although on-axis it remains flat, off-axis it’s not as good, so it better matches what the woofer is doing at the crossover frequency. That’s the purpose of a waveguide. It also gives you a little bit more sensitivity so that you can crossover the tweeter a little lower. That’s always a good thing because the lower you can crossover the tweeter, the less the phenomenon I just mentioned occurs. Even though this is a simple design, it’s applying techniques I’ve developed over the years trying to mitigate this issue where early reflections taint the perceived response in real rooms.

We discovered this issue many years ago with all of the blind-screen testing that we did in Ottawa under the direction of Floyd Toole. Prior to this discovery, we used to wonder why one speaker would sound harsher than another when both measure flat on-axis. At the NRC (National Research Council), we do something that’s called “sound power.” We measure at 15-degree increments the energy in a complete sphere around the speaker. We’ll then evaluate the frontal hemisphere to see what it’s doing relative to the whole sphere. There are certain interpretations that can be done to predict how this speaker will behave in a typical room. We got to the point with blind-screen listening tests that you could look at the measurements of a speaker and I could tell you that it’s going to score about an 8.5. For these tests, we usually listened to four speakers at a time. You could take one model and keep it in the test but put all kinds of others in each subsequent test…three other models that were not in the test before. The only one that continued to be in the test was this one model.  There were listeners so good that they would give that one model the same score, no matter what other speakers were in the room — bad, good, better, whatever. It eventually got to the point that data we were accumulating with blind-screen listening tests was actually becoming a measuring tool, but it had to go through the psyche of a human being to get the output. Comparing measurements with listener preferences gave us the guidelines on how to design a speaker that got high scores. This learning is what I’ve applied to my designs since the beginning.

Associated review equipment