Small "Voice of the Theater" Driver Chart
High Frequency Compression Drivers


Model
Tenure
Impedance
AES Power rating
Recommended replacement diaphragms
Comments

802B
1946-1954 16 ohms 15 watts 26420 8, 30W
26421 16, 30W
(909 diaphragms)
First permanent magnet, small format high quality high frequency driver. Gray crackle paint. 
        802C
1954-1957 16 Ohms 15 Watts Same as above Similar to above, green paint.

      802D
1957-1972 16 Ohms 15 Watts Same as above* Similar to above, most plentiful 802, longest tenure.
Most green, later ones black.
    802G Series
1977-1980 8, 16 Ohms 10 Watts Same as above Has new radial phasing plug, improved magnet structure. Originally equipped with very light diaphragm. Improved overall performance, last Alnico magnet.
      804A
1961-1964 16 Ohms 15 Watts Same as above Small magnet version of 802C, 2 db less sensitive. Used extensively in Hi Fi and other loudspeakers. Green in color.

       806A 
1964-1972 16 Ohms 15 Watts Same as above* New designation of 804A driver, green color.
     806-8A
1972-1975 8 Ohms 15 Watts Same as above * 8 Ohm version of 806A, all black in color.
807-8A
 
1969-1974 8 Ohms 30 Watts Same as above ** Used in first 8 ohm A7. Composite diaphragm (Symbiotic). Same magnet as 806, has somewhat less H F transient response than 806. Used extensively in musician's P A loud speakers. 
  808A Series
1969-1977 8, 16 Ohms 30 Watts Same as above** Symbiotic diaphragm model with 802D magnet structure. Electrically durable, but also has less transient response than 802. later 808s followed magnet development of 802.

902A Series

1980-1983 8, 16 Ohms 10 Watts Same as above Entirely new driver with ferrite magnet. Has the same radial phase plug as 802G.
Replaced both 802 and 806 drivers. Is thinner driver than older units. Originally built with very light and fragile diaphragm. Sounds fabulous.
      902T
1980-1982 8 Ohms 15 Watts Same as above** Same as 902-8A, but has diaphragm loading cap installed inside the rear cover to stop diaphragm over excursion on 500 Hz crossovers. Doesn't sound as good as 902A.
      902B  1981-------- 8, 16 Ohms 15 Watts Same as above** Has same rear loading cap as 902T and has a magnet centering ring which seals off the magnetic structure. Reverts to older style diaphragm. Doesn't sound as good as 902A, handles more power.

909A Series
1988------ 8, 16 Ohms 30 Watts Same as above** Newest Altec small format H F driver . Has same magnet structure and good sound quality as 902 and handles twice the power.
Costs the same, when rediaphragming
older 800 and 900 drivers, use it's diaphragm.
 Note:  The diaphragm loading cap as explained in 902T driver, prevents over excursion of
            the diaphragm at lower H F horn limits. While it prevents diaphragm failure, it also
            slightly reduces the naturalness of H F sound quality. Loading caps have come and
            went thoughout the years. Certain variants of drivers have been produced both with
            and without them
            * Denotes models build with and without caps.
            ** Denotes models that always had loading caps.

Low Frequency Drivers


     Model Tenure Impedance AES Power rating Recommended replacement diaphragm Comments
       803A
1947-1958 16 Ohms 35 Watts
R515, 16 Ohms, 75 Watts
Smaller magnet version of original 515. Lacks low bass 
of later versions. Green in color.

803B
1958-1964 16 ohms 35 Watts R515 16, 75W
R515  8, 75 W
Improved bass response with new cone hinge. Excellent all-round woofer. Green in color.
        416A 1964-1969 16 Ohms 35 Watts R416 8,  75 W
R416 16, 75W
Production refinement of 803B woofer. Multi-purpose loudspeaker. Can be used in both bass horns and vented boxes. Green in color.
      416-8A 1969-1976 8 Ohms 75 Watts Same as above 8 Ohm version of 416A. Later versions on 16" frame. Black in color.
     416B Series 1976-1981
1988-1990
8, 16 Ohms 75 Watts Same as above All units built on 16" frame. Has improved Alnico magnet structure. Best of all 803-416 woofers . Brought back in late 1980s for a short period. Black in color.
  416C Series 1980-1984 8, 16 Ohms 75 Watts Same as above Ferrite magnet version of 416 woofer. Does not work as well as 416B series. Does work as well as 416A series. Black in  color

    515-8G
1984------- 8 Ohms 75 Watts R515-8G, 8 Ohms, 75 W Newest model of venerable 515 series of woofers. Replaces 416 series in A7s. More efficient, cleaner mid-range than all previous models. Great woofer.