Making of M1

By Man-Sun Huh
20 Jan 1998

Test Results

Anechoic response of system Fig. 6. Anechoic response. Sensitivity is around 84dB/2.83V and -6dB point in bass is about 47Hz. It is very satisfactory result for small speaker. It's bass roll-off is about -8dB/Oct. With room enforcement in bass, this speaker can reach down to 40Hz.

Impedance of system Fig. 7. Impedance. Minimum impedance is 7 Ohm and it's a very kind load for amp. No wrinkle in graph shows good restriction of cabinet vibration.

Anechoic response of each unit Fig. 8. Anechoic response of each unit. Anechoic response when tweeter polarity is reversed Fig. 9. Anechoic response with tweeter polarity reversed. Well designed crossover must show steep dip at crossover point and M1 also shows steep dip.

Sound
For my experience, It need more than 2 weeks of burn-in. And It's bass improves dramatically during burn-in. It's sound is well balanced. It make me feel comfortable and I can't hear any booming sound in bass. Finishing my project, I sold my $2,000 speaker system.

Part List

Units
Tweeter Scan-speak D2905/9300: 2 ea.
Woofer Scan-speak 18W/8545: 2 ea.

Capacitor
Cresendo 5.0 uF: 2 ea.
Zen (10+2uF): 2 ea.

Resistors
Ohmite 10.0 Ohm 10Watt: 2 ea.
Ohmite 5.0 Ohm 10Watt: 2ea.

Coils
North Creek Air-core 2mH 14AWG: 2 ea.
North Creek Air-core 1.2mH 14AWG: 2 ea.
North Creek Air-core 0.7mH 18AWG: 2 ea.

Miscellaneous
Dupon Dacron: 24 oz. (12 oz. per box)
Back cup: 2 ea.

Specification
System: Closed box 2-Units 2-Way system
Drivers: 28mm soft dome tweeter (Scan-speak D2905-9300)
7" Paper cone with carbon fiber (Scan-speak 18W/8545)
Crossover Frequency: 1800 Hz
Sensitivity: 84 dB (1m/2.83V)
Impedance: 8 Ohm (Minimum 7 Ohm)
System Resonance: 47 Hz
Frequency range: 47 Hz - 20 KHz
System Damping: 0.53
Size: 470 x 230 x 350 mm (H x W x D)
Weight: approximately 16Kg/each

Man-Sun Huh

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