Pioneer HPM-100 - Alternate Versions

Alternate Versions

Display models were manufactured that have clear Plexiglas enclosures (versus the solid wood with fiberglass enclosures) in order to demonstrate the inside of the speaker to customers in retail stores. Though they look interesting, they have a thinner, lower quality sound output compared to the wooden enclosure.

Different versions of the HPM-100 were manufactured with different crossovers. The original “A” crossovers were rated at 50 watts with a peak power of 100 watts. However, later “B” and “C” models, manufactured from circa 1977 on, used a more accurate, less conservative power rating of 100 watts with a peak power of 200 watts. HPM-100s that were manufactured with the “B” and “C” crossovers also contained an accent ring around the port purely for aesthetics.

Variations of the HPM-100 were released as cheaper alternatives. The HPM-60 was a smaller speaker that scaled the woofer down from 12 inches to 10 inches. The HPM-40 has a 10 inch woofer and eliminated the mid-range driver. The HPM-40 also has a cheaper vinyl finish that mimicked veneer instead of true walnut veneer.

The HPM-150 (HPM-1500 in Europe) sat at the top of the HPM line with a $500 per speaker price tag. The crossover network, midrange and tweeter all possessed a higher power ratings, additionally the midrange and woofer baskets, as well as the tweeter frame featured a polished aluminum finish. The horn loaded high polymer omnidirectional super-tweeter was redesigned, mounted on top of the cabinet and has a wider angle of coverage. The woofer was also increased from 12 to 15.75 inches, allowing the speaker system's frequency range to reach 25Hz. The cabinet quality was the same as the HPM-100, but the HPM-150 possessed a thicker walnut veneer. The foam surrounds were made of cheaper material that rotted out over time, needing to be replaced, degrading the sound quality.

The HPM-900, along with the HPM-700, were released a few years later. The HPM-700 was comparable to the HPM-60: a smaller HPM-900 with a 10 inch woofer. The tweeter and mid-range drivers on the HPM-900 and HPM-700 contained individual metal grills to protect the cones. These two speakers featured another new supertweeter design - one that more closely matched the 180 degree projection of the HPM-100. The woofers were constructed with graphite modulus - a stiffer composite material, and had foam surrounds. Also like the HPM-40 the cabinet was covered with vinyl instead of veneer.

The HPM-1100 had a cabinet which improved on the HPM-100, being larger with built-in stands. The HPM-1100 also had 15 inch woofer; however, the cone was made of a polymer graphite material for increased rigidity at the expense of durability. The earlier series had carbon fiber cones. Like the HPM-150, the foam surrounds caused driver rot to become an issue, which resulted in inferior sound quality.

There were also other speakers released in the HPM series, including the HPM 30, 50, 70, 110, 200, 300, and 500. By 1981, Pioneer had discontinued the HPM series.