The Model 14 was a one of a kind consumer  loudspeaker from Altec Lansing. It incorporated their new Mantaray horn technology, along with a mid and high frequency equalization network. While the 14 appears to be just a smaller version of the older and larger Model 19, it’s substantially different in many ways.  Altec also made a professional version, the 9842-8A/F, which had a more utilitarian cabinet design.

The Model 14 uses the Altec Lansing RCA34633 low frequency transducer to reproduce the range between 35 Hz and 1.5 kHz. It is sometimes mistakenly thought to have been manufactured by RCA due to its part number. Mid and High frequencies between 1.5 kHz and 20 kHz are reproduced by the Altec Lansing  902-8B compression driver mounted to the newly designed Mantaray horn. The 902-8B utilizes Altec’s famous Tangerine phase plug for extended high frequency response. The Model 14 also incorporates a variable two band equalizer in its crossover circuit to correct mid and high frequency tonal balance based on listening preferences.

The Mantaray is a Constant Directivity (CD) design horn that keeps the dispersion angle constant for all frequencies, and reduces the beaming inherent in many loudspeakers.

The crossover also introduced a sophisticated speaker protection circuit known as Automatic Power Control. Altec claimed this circuit added “absolutely zero distortion” and that it in no way limited frequency response. It’s purpose was limit input power to 75 watts continuous RMS while allowing for dynamic peaks up to 200 watts. In the event of an overload it would automatically reduce power to the drivers by introducing a large resistor into the circuit via a relay. The listener was notified by a flashing red light on the crossover control panel. The system could also be tested by raising the input above 7 watts RMS and depressing the  Overload Test button.

During its production run Altec issued four known revisions to the crossover circuit. Unfortunately, no one seems to know the order in which they were issued. All of the crossovers use a .25 mH inductor while two of them have an additional .667 mH inductor. The resistor leading from the board to the mid frequency equalizer control varies in value from 6 to 7.3 to 8 ohms, depending on the revision.

Richard Christianson designed a new crossover for the Model 14 in the mid 2000s. He also took measurements of the RCA34633 low frequency transducer using the Woofer Tester II.

RCA34633 TS Parameters

Fs=22.4 Hz
Qes=.1569
Qms=6.8436
Qts=.1534
Zmax=261.65 ohms
Le=2.1394 mH
VAS=380 L (13.42 ft^3)
BL=15.8724 N/A
Sens=96.2 dB@1W/1M
Eff=2.63 %

Christianson Model 14 Crossover

The cabinet of the Model 14 is constructed out of a dual density particle board manufactured for Altec Lansing. The process causes the smallest wood particles to move to upper and lower surfaces, resulting in two dense layers separated by conventional particle board material. The exterior is finished in oiled walnut veneer.

The cabinet is divided into four parts: horn enclosure, frame, woofer enclosure, and base. The frame is screwed to the bottom of the horn enclosure and two bolts on either side are passed through these into the woofer enclosure to make the complete cabinet. The base, which is essentially another frame, is screwed to the bottom of the woofer enclosure, and has four plastic furniture feet affixed to it. The cabinet is lined with R-6.7 fiberglass insulation.

The speaker terminals are located on the bottom of the cabinet and utilize spring loaded push pins that allow for a 16 AWG wire.

Altec Lansing Model 14 Specifications

Nominal Impedance: 8 ohms
Crossover Frequency: 1500 Hz
Enclosure Type: Vented
Sensitivity: 95dB (1W/1M 500 Hz – 3 kHz)
Frequency Response: 35 Hz – 20 kHz
Dynamic Range: 44 dB minimum crest factor above 70 dB SPL at 1 meter
Dispersion: 90° at -6 dB Horizontal, 40° at -6 dB Vertical (1 meter, 800 Hz – 8 kHz)
Continuous Power: 75 watts RMS
Recommended Power: 10 – 350 watts RMS
Continuous Acoustic Output: 114 dB at 1 meter
Dimensions: 30″H x 21″W x 16.5″D (with grill)
Weight: 77 lbs (34.9 Kg)

Click here to view the original Altec Lansing Model 14 sales brochure.