April 2003

World Premiere!
$400 Two "Pi" Tower Loudspeaker Kits
Review By A. Colin Flood

  Single-ended Triode (SET) tube amplifiers are among the nicest toys of the tweaking audiophile low-power, big speaker elite - with red Ferrari pocket rockets running a close second. SET amplifiers use a single triode tube in the output stage for both the positive and the negative portions of the musical waveform. They have very little power compared to the gargantuan amplifiers available today. Most are below 10 watts. Yet, for many tweaking audiophiles, there is no going back to push-pull tube or solid-state amps after hearing what a newly-tubed and warmed-up SET can do with the right loudspeakers. 

Unfortunately, the choice of super-sensitive loudspeakers is drastically limited if you choose the SET route. It is a little like applying for Harvard, when you can afford only state college. Audio nirvana is out of reach. Fortunately for tweaking audiophiles with a skill for the saw, there is now Wayne Parham and his big Two π ("pie") Towers loudspeakers. π Speakers is the creation of Wayne Parham. He is Electrical Engineer. His main business is Parham Data Products, which does contract engineering and programming. His customers include Wal-Mart Stores, Whirlpool Corporation and MCI World.com. 

The loudspeakers are a hobby for Wayne that turned into an avocation a long time ago. But his career in computers was much more lucrative, so he focused all of his attention to his engineering consulting firm through the eighties and nineties. When the Internet started becoming popular, he placed his speaker plans online, and interest grew and grew. "Now days," he says, "it appears that my career path may turn again towards loudspeakers, because the web site gets more than 40,000 hits per month, the Pi Speakers forum is very popular and sales are growing at a surprising rate."

Wayne says that his "personal favorites are the seven π cornerhorns, and there have been times when they were the most popular. But for the last year, the "darlings" have been the Studio two Pi's and the Theater fours." The Two p Towers are tall, low-cost, bass reflex two-way loudspeaker system in a big square hollow box with plain and simple looking drivers. They are available in kit or assembled form. My assembled review models came shipped together in one large box, strapped to a troublesome palette.

Only $54.31 For The Kit

The π loudspeakers are available in a wide range of prices. There are 29 models in the line. The unassembled drivers for the Two π Towers start at only $54.31 for a kit, plus shipping. Basically, the kits come with everything but the cabinet. They include the loudspeaker drivers, the connector panel, hook up wires, "a black "pie" logo decal and a printed copy of the plans. For larger speakers that incorporate a compression tweeter and crossover network, kits also include the crossover, tweeter compensation cable assembly and Zobel woofer damper. All cable assemblies are completed and ready to install. Every kit containing a compression driver also includes the horn flare and the bolts to mount the driver to the horn.

The kit is a "plug-and-play" deal, with all cable assemblies soldered and ready-to-go. "We're just providing a collection of parts at a good price," he says. "That's really the case, we've done the homework to ensure it's a good design, and we've bought the parts in quantity so the price is right." His company assembles everything that needs to be soldered, so that the kit installation is "plug-and-play" from an electrical standpoint. But essentially, it's just a collection of parts with a copy of the plans. Wayne says that is what really is best for kits though. If he cut the provided wood panels, that would bring the shipping cost back up. So the best option for kits seems to be to have the buyer purchase wood locally. Specifically, the Two π Towers driver kit cost is $54.31, and shipping is about $20 for two kits, anywhere in the lower 48 states and Canada. Kits are the most popular method of delivery.

The Best Cabinetmaker And The Finest Wood

Although I have shipped three by two feet 100-pound loudspeakers half way across the US for as little as $57 each, the extra height of the assembled Two π Towers puts them out of reach of common UPS shipments. Shipping them by freight company instead, could add as much as $300 to $500 per pair of speakers in the continental United States. Wayne does sell far more kits than assembled loudspeakers, about 20 to 50 kits for every assembled one sold. The reason, he says, is the high cost of shipping. "For the cost of shipping, a person can get the best cabinetmaker in their area and use the finest wood."

Delivery time is guaranteed to be eight weeks. Wayne says even though the speakers are hand-made to order, they are often done in three to five weeks. Still, he quotes eight weeks because missed schedules are a "pet-peeve" of his. "We don't miss schedules and we don't make commitments that we can't keep." Trial period is within 30 days of delivery; if the loudspeakers are returned in the container shipped and in the same condition as they arrived.

Assembled Two π Towers are $399.95 each: finished in oak, maple, birch, ash or black Formica. The most popular finish is oak. Shipping charges and special woods add to the price. You can see the components used in each model of loudspeaker at his web site. The Two p Towers are part of their Studio Series. The choice for the Studio Series drivers was primarily low cost, high efficiency and flat response curve. The series is very high sensitivity at 97dB SPL and therefore easily driven by flea-powered tube amplifiers. The "Pi" Thermionic Series is slightly higher efficiency and hence its name.

Thinking Inside The Box

The assembled Two π Towers have minimal internal bracing. The minimum that Wayne suggests is 1" x 2" braces tying the panels together every 18". This practice is to pre-load each panel, he says, and stiffen it as much as it is to simply hold them free from vibration. There is no internal fold in the tall cabinet. " The cabinet," Wayne says, "is actually just a "box" with a port, forming a Helmholtz resonator. (Helmholtz was a German physicist who formulated the conservation of energy law, 1847.) 

"Anything inside the box is just used to brace it," Wayne says. "The only exception is the presence of acoustic insulation on one of each opposing panels, and it is used to attenuate frequencies above the Helmholtz frequency." It is a hollow and simple bass-reflex cabinet, which uses a Helmholtz resonator as its bass loading and damping mechanism. The tall review models came with a sumptuously tawny brown coat with dark rivers of grain that any Tiger would be proud of. Deliciously golden French Walnut. If you like gorgeous wood finishes on loudspeakers, this was one of the best. A 90 or more for the Enjoy the Music.com™ quality of wood category. The review pair of Studio Series Two π Towers cost $200 extra, without shipping, for model. So this particular speaker set is $599.95 each, or $1199.90 for the pair. 

Except for the plain black Eminence Alpha 10-inch paper and Motorola KSN 1038 piezoelectric drivers, the only notable feature is a simple, wide hole at lower rear of the cabinets. Other wise the loudspeakers are stark. There was no grille cloth to cover the fronts. The Two π Towers look raw without it. The unrefined exposure of the two black drivers is a stark contrast to the golden savannas of its sun-baked flanks. 

The mid-range woofer cone provides wide range, high sensitivity, good speed, modest transparency and good detail. A paper cone tends to be less stiff than other materials such as B&W's yellow Kevlar or Klipsch's copper-colored metal. Paper though, does not have the shimmer or ringing resonance often found in Kevlar and metal. Many cone speakers claim to need a long break-in period. Generally, I do not find my initial first impressions changing substantially after using a speaker or amp in various configurations over a period of time. The speakers seem to need less break-in time than the listeners need time to describe what they are hearing. The Two π Towers were no exception. Extended listening did not seem to change their nature or tone.

The port is large enough for the family cat, but only if it is fed adult formula food. The large rear port tunes the 5 cubic foot cabinet down to 30Hz. "If it were smaller, Wayne says, then the tuned frequency of the cabinet would be lower." In many loudspeakers, he does use a ducted port. But a smaller or longer port would tune the Two p Towers boxes too low. So the lack of a duct on the Two p Towers model is required by its size and tuning frequency. The Two p Towers include medium size gold-plated banana plug connector with thumbscrews to allow connection of loudspeaker wire. Crossover frequency is in the tricky middle of the critical music range (3.5kHz) but the transition seemed smooth enough. 

The Two π Towers drivers themselves perform the crossover. "In a sense," Wayne says, "this is like a "full range" or single driver speaker in that there is nothing throttling the drivers. There is, however, a coil on the mid-woofer that serves to attenuate the upper range where it enters breakup mode. But while it may be a technical concern, I think it might be interesting to note that the drivers roll-off at 24dB/octave, which is fourth order. So the coil is much too small to act as a crossover, and is instead just "taking the edge" off the upper octave of the mid-woofer. Some call this 'voicing' the speaker."

"The Studio Series is extremely versatile. They'll work on any amp that is working properly. The only thing I've seen that can be a problem is when a heavily "modded" amplifier is used. Sometimes a guy will "tweak" his amplifier so it sounds good with his speakers, and then it's not frequency true anymore. It's like he's hard-wired a tone modification inside the amplifier. So that's not going to work on another speaker, but I'd consider that to actually be a defective amplifier."

"This particular loudspeaker," Wayne says, "works well on both transistor and tube amps, largely because of its high sensitivity and low impedance at resonance, giving it a smooth overall impedance curve." If you have high-efficiency speakers like the Two π Towers reviewed here and a delicate-sounding flea-powered tube monoblocks like the Bottlehead 2A3 Paramours; then you have could have a wonderful combination.

Dynamic Range Near High-powered Sand Amplifiers

The Two π Towers did sound good with my SS amplifier, better with the flea-powered Bottlehead 2A3 Paramours. Wayne agrees. "If a person wants to have a nice tube stereo, I'd suggest the SET designs, or some of the moderate powered push-pulls. The Paramour is an excellent choice for the SET enthusiast, and so are the Consonance amps. There has been a lot of excitement about the two Pi's on the Decware Zen, and Decware guys love 'em. If you run push-pull, you can get dynamic range up near the levels of the high-powered sand amps. But if you run SET's, then you get that simplicity that so many people like." In fact, Wayne owns Bottlehead 2A3 Paramours, and has used their Paraglows on his Theater four Pi's as well. "That's a nice combination," he says.

This isn't true of all of his speakers though. The Professional Series, he says "must" have 20 watts or more. "If you connect a SET to them, you'll have no bass at all." Sound-wise, The Two π Towers greatest strengths were their easy-to-drive nature and deep, "clean n' lean" bottom. They did sound like a majority of conventional loudspeakers in its price category, with the notable exception of its deep bass reach. Although the largest loudspeakers of any that I have seriously auditioned in my home (with the same equipment for Enjoy the Music.com™) were the Two π Towers, they are quite large as my classic Klipsch corner horns (see my Bio for the context of my reviews). They did, however, exhibit much of the same accurate acoustic bass response. This is not the "over-the-top" muscle car boom of techno music. Instead, this is real bass. The kind that you hear from live, un-amplified upright string bass instruments. 

A pair of Two π Towers with the right integrated tube amp could make a very charming system. One with some definite qualities that many tweaking audiophiles will appreciate: a fairly even mid-range, a seamless integration of low, mid and high range, easy load, very reasonable cost. Yet, the low power of the Paramours is still not enough to drive the last Nth degree of musical resolution from the efficient Two π Towers at the loudest volumes. To effectively scale the peaks, more power, or more drivers, is required. The Two p Towers are not any less of a party loudspeaker though, than most other $400 off-the-shelf loudspeakers - the exception being the "ready-to-rock" $279 Audio Axioms M3Ti.

So far, I have auditioned loudspeaker systems for Enjoy the Music.com™ from $279 to $4,090 in price. There is nothing like enjoying the music with a variety of different style loudspeakers, a choice of two amplifiers and your own musical favorites! So far, each loudspeaker in the price scale is different than the one before it. Each one has its strengths; each one has its values. Each loudspeaker can also alter the music so much that it seems like another recording.

Better Dressed

The Two π Towers acquit themselves well. As good as most off-the shelf loudspeakers in this price range, but with much better low bass extensions and of course, though starkly raw, they are better dressed than any pseudo wood you will find in any Best Buy showroom. The Two π Towers are not however, a spectacular loudspeaker in many audiophile or showroom terms. They lack rumbling or punchy bass. They don't have the sparkling high end which many tweaking audiophiles love. Their tonal balance is not so unique to win instant converts. Their soundstage is not extra-ordinarily huge and imaging isn't extraordinarily precise. The immediately obvious difference between the Two p Towers and the other loudspeakers I fawned over here is their rock-bottom low price, large size and low bass. 

When I think of bass, the low booms from the German leaning transmission line Newtronics Skates, or the mid-bass punch of the Canadian line driver array Axiom Audio M80Tis excel over the clunky Two p Towers. Of course, the Skates cost about ten times the price of the Two π Towers, while the M80Tis are only five times more! When I think of delectable treble, the metal ringing of cymbals on the dual M80it tweeters comes first to mind. The Two π Towers have modest treble, more of a tizz or frizz than a sizzle or sparkle. Grading all loudspeakers reviewed here on the same curve is a little unfair, like suddenly sending an average fourth grader to Harvard. Wayne Parham's $399 entry model yields a competent, but unwieldy, loudspeaker with modest musical qualities properly suited to low powered, sensitive amplifiers. If you have the cabinets already, his driver kits could be astounding bargains. 

His scores then, reflect a low priced offering up against some fairly expensive and sophisticated competition and that should be kept in mind when reviewing my scores compared to other reviewers. You won't get easy grades in Mr. Flood's class. Most scores are about average for loudspeakers reviewed here by me and in this price range. Tonality is not exceptional compared to the charming little Axiom Audio M3Tis for only $279. Not surprising for such a large box, bass extension is. Despite the stark appearance of plain black drivers in a big square boxes, I loved the golden French Walnut finish and give the Two π Towers an above average score in that category. 

Money is the difference here. If you have a low powered amplifier and some skill with the saw, then you should check out Wayne's offerings. His modest sounding loudspeakers could provide you with far-above average values. Unless you are ready for Harvard, the fourth grades for many tweaking audiophiles are still a lot of fun.

Specifications

Mid-range Woofer: Eminence Alpha 10-inch paper cone

Tweeter: Motorola KSN 1038 piezoelectric 3-inch ceramic

Frequency Response: 30Hz to 20kHz

Power: 100 Watts RMS

Sensitivity: 97dB/W/m

Peak: 117dB

Dimensions: 46 x 16 x 13 (HxWxD in inches)

Assembled: $399.95

Premium finishes: Cherry, Elm, Mahogany, Rosewood, Teak, Walnut or Zebrawood

Driver Kit: $54.31

Company Information

Wayne Parham 
p Speakers 
P. O. Box 702006 
Tulsa, OK 74170

Voice: (918) 663-2131
Website: www.pispeakers.com