Introduction

• The first 301 speaker was introduced in 1975. According to a review of the Series V by Peter J. Sammon, the first 301 had a single 8-inch woofer and a tweeter on the side with a rotating vane to control high frequency direction. The speaker also had a rear port to give it better bass response.
  
  

Series II

• The 301 was given a facelift as the 301 Series II in 1983. The Series II remained in production until 1991. The Series II added a second tweeter to create the Free Space Tweeter array. The two 3-inch tweeters were stacked one on top of the other at the side of the speaker cabinet, and were angled in different directions, one forward and one backwards. The speaker had an 8-ohm impedance and was rated for amplifiers between 10 and 75 watts per channel. The speakers measured 10.5 inches high, 17 inches wide, and 9.5 inches deep. Their shipped weight was 38 lbs. per pair. They were available in a walnut grained vinyl veneer.
  
  

Series III

• The 301 was upgraded to Series III in 1991. The Series III kept the dual 3-inch tweeter design, but changed the bass port on the back from a ducted port design to a slotted port design. The Series III had an 8-ohm impedance and was designed to work with amplifiers between 10 and 150 watts per channel, a substantial increase over the Series II. The Series III had the same dimensions and shipped weight of the Series II. It was also available in black, white and walnut cabinets.
  
  

Series IV

• The 301 Series IV was introduced in 1996. The cabinet had rounded corners, instead of the sharp angles of the first three series. The two tweeters were separated more in the enclosure, and instead of having two 3-inch tweeters, the Series IV has one 3-inch and one 2-inch tweeter. The Series IV had a tuned port enclosure for better bass. The speakers were rated for 8-ohm impedance. Each speaker measured 10.25 inches high, 16.375 inches wide and 9.5 inches deep, and weighed 11.6 lbs. In addition to the normal black cabinet, the Series IV was offered in a rosewood as well.
  
  

Series V

• The Series V 301 was introduced in 2002. The Series V has a flared slot port design on the back of the speaker to get better low frequency response. The Series V went to a pair of 2-inch tweeters, instead of a single 3-inch and single 2-inch. The Series V is available in black or cherry, and measures 9.75 high, 14.25 inches wide, and 9.75 inches deep. Each speaker weighs 12.5 lbs. The Series V is available in light cherry and black.