MANUFACTURER'S SPECIFICATIONS:
System Type: Two way, totally enclosed.
System components: 8-in. bass, 2 1/2-in. cone tweeter.
Crossover frequency: 1800 Hz.
Frequency response: 45 to 20 kHz.
Recommended amplifier power: 10 watts (min.).
Nominal Impedance: 8 ohms.
Dimensions: 11 3/4 x 20 1/4 x 10 inches deep.
Price: $94.50.
The name Bozak has always been associated with big sound, large domestic systems or high power speakers for public address. However, they do make bookshelf systems and a few months ago announced the Sonora which is a small system costing less than $100. It employs an 8-in. bass unit with a 2 1/2-in. cone tweeter--both having metal cones. The HF unit is mounted behind the baffle board which is chamfered to form a kind of horn. Crossover is about 2 kHz and no level control is provided. The system is a tube-vented reflex and the resonance measured 89 Hz. Cabinet finish is walnut and the grille is detachable.
Measurements
Figure 1 shows the response measured with one-third octave pink noise. A was taken on-axis, B at 60 degrees off-axis, and C is an average of five positions. Tone-burst responses at 100, 500, and 5000 Hz are shown in Fig. 2. The impedance characteristics are given in Fig. 3 and it will be seen that the lowest point is around 7 ohms. Low frequency THD and some SPL figures are shown in Fig. 4. Power outputs were 5 and 10 watts.
Fig. 1--Response measured with one-third octave pink noise. A was taken on
axis, B at 60 degrees off-axis and C is an average of 5 positions.
Fig. 2--Tone-burst response. A is 100 Hz; B, 500 Hz; and C, 5000 Hz.
Fig. 3--Impedance characteristics.
Fig. 4--Low frequency THD and some SPL figures.
The Sonora could handle 24 watts continuous power at 40 Hz without distress and 45 watts at 100 Hz. White noise tests showed a slight "boxy" coloration.
Listening Tests
Efficiency of the Sonora is somewhat above average and a genuine 10 to 15 watts per channel will be adequate to produce a room-filling sound. The receiver actually used for most of the tests was a Pioneer 424, which is an inexpensive model costing less than $200. This receiver has the advantage of a speaker switch, thus enabling quick comparisons to be made.
The first impression of the Sonora was a smooth sound, but a big sound typical of a much larger system. The extreme bass was missing, of course, and the high frequency response seemed just a little attenuated. On the other hand, it was free from spurious presence peaks and consequently quite easy to listen to. If you are looking for a good system in the $100 class, put the Bozak on your list.
-T.A.
(Audio magazine, Jul. 1973)
Also see:
Bozak speakers (ad, Feb. 1973)
= = = =