Hegeman Model 2

For sale is a pair of extraordinarily rare Hegeman Labs Model 2 speakers – Stewart Hegeman’s final masterpiece. Very few of these were made. These bear serial numbers 33 and 34.

Description

The speakers stand 14 x 12 x 34 inches high, weigh about 42 pounds each, and feature 10-inch hand-spun aluminum woofers of Hegeman’s own design. These powerful woofers, featuring AlNiCo magnets, are back-loaded with Hegeman’s unique cabinet: a sealed labyrinthine box of 6 staggered quarter-wave stubs designed to completely and evenly damp the driver’s resonance, allowing your amplifier complete control over the movement of the woofer.

Loading the woofer from above is a semi-spherical diffuser that disperses the woofer’s output, giving it an equal power response across its range.

The woofer naturally and smoothly rolls off at 3.5kHz, no crossover (anyone who has seen the jagged and horrifying roll-off of a typical 10” aluminum woofer knows what an extraordinary engineering accomplishment that is). From there, the tweeter – mounted atop the semi-spherical diffuser – comes into play.

The tweeters Hegeman chose are the renowned-in-their-time Audax/Polydax TW8B Super-Tweeters. Their powerful motors and shallow, dimpled spun-aluminum cones produce a smooth, extended response that was unmatched at the time. They are crossed-in using a single capacitor.

Mounted above the tweeter, attached to the cage, is another semi-hemispherical diffuser which disperses the tweeter’s output to create an even power response across its range.

The resulting speaker has a full, even, perfectly controlled and time-coherent response from 20Hz to above 20kHz with nearly perfect dispersion.

Here is a link to some literature on this line of speakers.

You can also read more about their design philosophy from Don Morrison at www.morrisonaudio.com. Hegeman passed his designs on to Morrison in 1977; Morrison has continued to develop them under his own name ever since.

Sound

These speakers are extraordinary. They have an open natural sound that is hard to describe. A quick search for people’s impressions of the Hegeman Model 1 – the Model 2's small brother – will yield many glowing descriptions of what you can expect. They sound live.

Notably, bass from these speakers measures flat to 20Hz in my small listening room. And it is the cleanest bass I have ever heard. Do not expect lush, wet, or “warm” bass. The bass from these speakers is best described as tight. Bass tones start and stop on a dime. No boom. No resonance. You’ll hear exactly what is on your recording, and you may be so unused to hearing it, that you won’t recognize it at first.

That said, these speakers show no mercy. Bad recordings will sound horrible. Bad equipment will sound horrible.

Though they are omnidirectional, I find the Model 2’s sound their absolute best when I sit with my ears on-level with the top of their cages. I recommend a large room. These love space. The closer to the walls you place the speakers, the better the bass, but you pay with imaging quality, which benefits from being away from the walls. You, the listener, should sit at least 10 feet away for best effect.

Condition and Restoration

These speakers arrived a bit worn-out and have been expertly restored. They are functionally like-new.

Cabinets

The veneer – a vinyl “teak” – has few apparent flaws. It was cleaned. Please see the photos and note: the seams are visible on the back. As anyone who has owned a pair of Hegeman-made speakers knows, he was an exceptional audio engineer but a merely alright craftsman. This is a factory defect.

All black painted areas of the speaker were stripped, sanded, filled, and re-painted. The result is not a perfect Bugatti-like finish, but quite beautiful and significantly better than the factory finish.

The Woofers

Like all the upward facing woofers in Hegeman’s speakers, these suffered from suspension sag caused by the inevitable effects of gravity and time. The woofers were carefully disassembled and restored.

The cone assemblies were found to be in excellent condition with a few superficial scratches and small imperfections. They were cleaned and set-aside for re-installation. The rubber surrounds were in excellent condition and were left attached to their cones.

The original spiders were found to be deformed, leaving the woofers’ coils out-of-center and mostly out of their magnetic gaps. They were replaced with new parts matching the originals’ specifications.

Suitable replacement spiders were found after months of research through old parts catalogs and careful measurement of the originals. Lest you worry Hegeman used some fancy unobtainable part, fear not. The spiders he used in these woofers were off-the-shelf parts used by the Utah speaker company.

Several possible modern replacements of the same size, weight, and compliance were found and tested. The pair that yielded the proper parameters when installed in the drivers were selected. The proper parameters were reverse engineered based on 1.) the design of the quarter wave tubes, 2.) the known parameters of the original spiders, 3.) measurements of the woofers taken with the original spiders still installed and consideration of how age would have affected the original spiders’ parameters.

The newly restored woofers operate as-new.

The Tweeters

The Audax TW8B tweeters that came installed in the speakers were not functional. The adhesive Audax used to assemble the magnet structures is known to fail over time. The original tweeters suffered that fate, resulting in the magnet structure coming out of alignment and clamping the voice coils in their gaps. They were replaced.

Several new-old-stock pairs of TW8B tweeters were acquired. By testing them, a matched working pair was found. Before installing them, their glue joints were reinforced with a substantial amount of epoxy. These tweeters operate perfectly to specification, and will never come out of alignment.

The Crossover and Everything Else

The crossover consists of a single 5.6 uF capacitor and an attenuator.

The capacitors were replaced with Solen SilverSound MKP Silver Metalized Polypropylene Capacitors – they are, in my opinion, the best crossover capacitors on the market. Their dissipation factor is unmatched, their ESR is vanishingly low, and nothing sounds better than silver.

The original attenuators, which are substantial mil-spec units, were disassembled, cleaned, and lubricated with products from Deoxit.

All wire was replaced with DH Labs’ OFH-14 Stranded Silver-Plated Continuous Crystal Copper Hook-up Wire.

The tweeters originally connected to two steel screws which were screwed into t-nuts mounted on the baffle. The backs of the t-nuts had wires soldered to them, which connected to the crossover. I chose to remove the screws from the t-nuts and route the tweeters’ wires through them directly to the crossover. Those connections were terrible, and the more direct the connection of the tweeters, the better the sound.

The original speaker terminals on the back panel (two steel screws in t-nuts) were replaced with high-quality gold-plated binding posts.

Shipping, Payment and all the Rest

I am new to Audiohon, but not to audio. Check me out on eBay (same username: Knarfor). I have been selling audio gear for years with 100% feedback. I will pack these to survive war, and will fully insure them. I guarantee they will arrive safe and working.

Any questions, please ask.