PSB Alpha P5 loudspeaker

It is said that while any competent engineer can design a superb loudspeaker if allowed an unlimited bill of materials, the true test is being able to produce a great-sounding, budget-priced speaker out of parts that cost a mere handful of dollars. With PSB's Alpha series of bookshelf speakers, Canadian engineer Paul Barton has illustrated this truism many times over the years.

The first PSB Alpha was reviewed for Stereophile by Jack English in July 1992. A modest-looking two-way priced at just $199/pair, it combined a reflex-loaded 6.5" woofer using a plastic-doped paper cone with a 0.5" plastic-dome tweeter. Jack concluded that it was "simply one of the best buys in audio, providing a musically satisfying sound; . . . a sensational audio bargain." The Alpha went on to become one of the most popular audiophile speakers ever, with over 50,000 pairs sold by the end of the last century.

Paul Barton revised the Alpha in 1998, replacing its plastic-dome tweeter with a more refined unit, upgrading the crossover and terminals, and magnetically shielding both drive-units for use in home-theater systems. The revised speaker was called the Alpha A/V and cost $249/pair; I enthusiastically reviewed it in April 2000. The next iteration was the Alpha B, which the late Bob Reina reviewed in May 2002. The B retained the magnetic shielding and featured a 5.25" woofer with an injection-molded polypropylene cone. The ferrofluid-cooled, 0.75" aluminum-dome tweeter was recessed within a short flare and protected by a plastic "phase plate," and the enclosure now featured molded plastic front and rear baffles. "Considering again the quality of construction and sound of these remarkable little boxes and checking the price yet again," BJR wrote, "I'm still shaking my head [at the fact that] this speaker doesn't cost $250 apiece but $250 per pair."

An increase in price to $279/pair accompanied the next revision, the Alpha B1, which I reviewed in May 2007. The B1 retained the B's molded plastic front and rear baffles, but had a slightly greater enclosure volume. The woofer was still a 5.25" polypropylene-cone unit, and the aluminum dome tweeter was retained. I concluded my review of the B1 by saying "Even if not in the market for a cheap mini, audiophiles should buy them for their Bose-owning friends and family, to give those unfortunates more than a taste of what a true high-end loudspeaker is capable of."

And now we have the fifth generation of the Alpha, the P5, which is priced at $349/pair, $150 more than that original Alpha in 1992. However, an inflation calculator revealed that 199 1992 US dollars is equivalent to 363.24 2019 dollars: In real terms, a pair of P5s is $14 and change cheaper than their distant ancestor.

Design
The Alpha P5 is still a small two-way design, marrying a 0.75" aluminum-dome tweeter surrounded by a shallow waveguide to a 5.25" polypropylene-cone woofer with a rubber surround. However, the tweeter dome is now anodized black and the black woofer cone has a textured, woven-looking finish that's said to minimize cone breakup. And in a radical departure from convention, the tweeter is now mounted at the bottom of the front baffle rather than the top. In conjunction with the drive units' acoustic polarities and the topology of the crossover—this set at 2.5kHz, compared with 3kHz for the B1—this unusual arrangement tilts up the main response lobe toward the listener's ears.

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While the Alpha B1's enclosure used molded front and rear baffles and its MDF "sleeve" featured a slight front-to-back convex "bow" to its top, bottom, and side panels, the Alpha P5's enclosure is all-MDF, its panels all resolutely straight. The front baffle is 1" thick; the other panels are all formed from 0.5" MDF and are finished in Black Ash or Walnut wood-grain vinyl. The flared reflex-loading port, 2" in diameter and 7" deep, is mounted toward the base of the rear panel, above a single pair of recessed five-way binding posts. A black metal-mesh grille is fastened to the baffle with magnets concealed beneath the baffle's vinyl wrap.

Setup
I placed the PSB Alpha P5s on 24"-high, single-pillar stands in the positions where other small stand-mounted speakers have worked well in my room: each woofer about 3' from the book-and-LP–lined sidewalls and 6' from the wall behind the speakers. The stands placed the woofers 32.5" from the floor, a few inches below the height of my ears. The PSBs were toed in to the listening position, and I left the vestigial grilles in place.

The next question to be addressed was which ancillary components should I use for my auditioning, given that Alpha P5 owners are not going to match the speakers with cost-no-object products? As someone who studied the scientific method as part of his bachelor's degree course more years ago than I care to admit, I strongly adhere to the principle that a reviewer must not change more than one component in his system at a time. Otherwise, he will have no idea which change in sound quality is due to which new component.

Accordingly, I started my auditioning of the PSB Alpha P5s with my reference front-end—a Roon Nucleus+ server feeding networked data to a PS Audio DirectStream D/A processor—and Lamm M1.2 Reference monoblocks, hooked up with AudioQuest Wild Blue balanced interconnects and AudioQuest K2 speaker cables.

After a couple of weeks of auditioning the PSBs in this system, and well aware of the discrepancy between the price of the loudspeakers—$349/pair—and that of the rest of the system—the amplifiers and AudioQuest cables alone cost $46,540 at retail—I retrieved our review sample of the NAD C 328 integrated amplifier ($549) that Ken Micallef reviewed in October 2018. For consistency, I kept the digital front end the same, but the PS Audio DAC was hooked up to the amplifier with inexpensive Canare single-ended interconnects that I purchased from Markertek. The loudspeaker cables were now AudioQuest's affordable CV-6.

Listening Round 1
As always with my loudspeaker reviews, I started my auditioning of the Alpha P5s with the test tracks I created for the magazine's Editor's Choice CD (Stereophile STPH016-2). The half-step–spaced low-frequency tonebursts spoke cleanly down to 50Hz, with no emphasis of any of the tones. When I listened to the enclosure walls with a stethoscope while these tonebursts played, there was some "cabinet talk" audible between 256Hz and 512Hz. The Alpha P5s reproduced the 1/3-octave warble tones on Editor's Choice with full weight down to the 63Hz band, with then a gradual reduction in level. The 32Hz tone was just audible, with some help from the lowest-frequency mode in my room, but the 25Hz and 20Hz warbles were missing in action. Commendably, however, there was no "chuffing" from the port with these lowest-frequency tones unless I turned up the volume to an unrealistically high level.

COMPANY INFO
PSB Speakers International
633 Granite Court
Pickering, Ontario L1W 3K1
Canada
(905) 831-6555
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COMMENTS
Bogolu Haranath's picture

Other speakers in this price range include, JBL Stage A130 ($250/pair), Wharfedale D320 ($250/pair) and ELAC Debut 2.0 B5 ($250/pair) :-) ...........

Bogolu Haranath's picture

The new Marantz PM7000N streaming integrated-amp ($999) could be a good match for these speakers :-) ..........

Ortofan's picture

... in a network capable device for a $349 pair of speakers, would be the $300 Yamaha R-N303.

https://usa.yamaha.com/products/audio_visual/hifi_components/r-n303/index.html

https://hometheaterhifi.com/reviews/receiver-processor/yamaha-r-n303-network-stereo-receiver-review/

https://www.avhub.com.au/product-reviews/sound-image/yamaha-r-n303-r-networked-stereo-receiver-review-517632

Bogolu Haranath's picture

Agreed ...... Seems like the HEOS (Denon) has more different products available, which the Marantz can connect wireless-ly :-) .........

Bogolu Haranath's picture

Denon DRA-800H ($499) with HEOS capability (and, with all the other bells and whistles) could also be another choice :-) ...........

Bogolu Haranath's picture

Another possibility is Denon HEOS digital integrated amp ($499) :-) ..........

svg223's picture

This...

Ichiban's picture

Hi John,

I have a couple pairs of speakers (Angstrom loudspeakers) where the tweeter is below the woofer. I have mine on 30" Sanus stands to bring the tweeter closer to ear level. I'm curious to know why you chose 24" stands for your tests? Aren't we supposed to follow the prescribed method of placing the tweeter at/near ear level when listening?

Thanks, Vish.

John Atkinson's picture
Ichiban wrote:
I'm curious to know why you chose 24" stands for your tests? Aren't we supposed to follow the prescribed method of placing the tweeter at/near ear level when listening?

The intended listening axis for the P5 is with the ears level with the woofer. As I wrote in the review, "In conjunction with the drive units' acoustic polarities and the topology of the crossover . . . this unusual arrangement tilts up the main response lobe toward the listener's ears."

John Atkinson
Technical Editor, Stereophile

Bogolu Haranath's picture

May be Stereophile could review the new Lexicon SL-1 active, wireless speakers with 'steerable sound' technology ($40,000/pair) ........ KR mentions about them in one of his show reports ....... They are about the same price as Wilson Sasha DAW and less expensive than Wilson Alexia2 ......... Both the Wilsons require external power amps :-) ..........

Bogolu Haranath's picture

Five of the Lexicon SL-1s for surround sound ($100k) would cost less than a pair of Wilson Alexx speakers :-) .........

Bogolu Haranath's picture

You can always position them (PSB P5) upside down, if you don't like the way they sound :-) ........

dial's picture

Nice to have at last an affordable peace of gear tested.

Bogolu Haranath's picture

The least expensive speaker Stereophile ever reviewed was Dayton Audio B652 .... $30.88/pair :-) ........

JBLMVBC's picture

"...and the black woofer cone has a textured, woven-looking finish that's said to minimize cone breakup"

Really? My first reaction looking at the picture was to believe they used a carbon woven cone, usually for quite expensive drivers.
See for instance http://www.davis-acoustics.com/serie-carbone/
So in fact, this is an old polypropylene cone made to look like an expensive carbon fiber one. The gist of "minimizing cone breakup" is disingenuous at best and smacks a made up excuse to cover their deception IMO.

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