Measurements taken at 12.5 volts with all channels driven into 4-ohm loads at 1,000 Hz unless otherwise noted. Bold type indicates superior performance.
High-pass channels:
Max. Power @ 1 % THD (dBW/Watts/Specified) 16.2/42/60 16.6/46/50 17.2/52/50
At 14.4 volts 17.8/60/60 18.0/63/50 17.2/53/50
At 2-ohms and 12.5 volts 17.6/58/80 18.3/68/65 18.6/72/75
Low-pass channels: Max. Power @ 1 % THD 16.7/47/60 16.6/46/50 17.2/52/50
At 14.4 volts 18.1/65/60 18.0/63/50 17.2/53/50
At 2-ohms and 12.5 volts 18.5/71/80 18.3/68/65 18.6/72/75
At 1-ohm and 12.5 volts 21.4/138/110 19.3/86/85 20.8/121/NS
Max. power into three bridged 4-ohm loads 20.8/120/160 21.3/135/110 21.6/144/150
Max. power into one 2-ohm bridged load on low-pass channels with 2-ohm loads on remaining 4 channels 24.4/275/160 22.4/172/170 23.8/242/NS
Overall frequency response (dB down at 20/20,000 Hz) -0.1/-0.6 -0.6/-1.1 -4.5/-0.2¹
Low-pass filter: Measured -3 dB freq. (Hz) 42 to 400 90 or 140 30 to 150
Specified 50 to 500 80 or 120 40 to 200
High-pass filter: Measured -3 dB freq. (Hz) 90 to 6,800 200 or 5,000 60 to 6,600
Specified 55 to 4,200 120 or 5,000 45 to 5,000
Midrange low-pass filter: Measured -3 dB freq. (Hz) 180 to 2,800 90 40 to 1,800
Specified 55 to 4,200 80 45 to 2,300
Stereo separation (dB) 54 dB 76 dB 78 dB
Signal-to-noise-ratio @ max./min. gain (dB) 88/102 100/100 88/110
THD+N @ rated power 0.03% 0.1% 0.3%
@ 10W 0.05% 0.025% 0.02%
Input voltage range for rated output power (volts) 0.12 to 7.9 0.30 to 2.5 0.11 to 8.0
Input impedance (ohms) 9,200 22,000 22,500
Damping factor @ 50 Hz >100 80 30
Gain control tracking for each channel pair (dB) 0.7 0.5 0.4
Idle current (amperes) 0.8 0.7 1.0
Filter cutoff slopes: High/Low/Sub (dB per octave) 12/12/18 12/12/12 12/12/12 - 24²
Turn-on noise None None Soft Click
Turn-off noise Very soft click None Soft thump
Turn-on delay (seconds) 1.0 3.5 7.0
Fuses 40A in-line 2x30A plug-in 40A in-line
Power and Speaker connections Stacked term. Stacked term. Stacked term.
Size: Length (each + is an extra inch required for wiring) 17 + + 17 + + 16 ¾ +
Width 9 9 8 d
Height 2 d 2 ½ 2 c
¹ The USA6300 has an infrasonic filter that rolls of channels 5 and 6 by 3 dB at 25 Hz.
² The USA6300 subwoofer low-pass filter is 12 dB per octave in stereo mode and 24 dB per octave in mono mode.
Manufacturer Planet Audio Select Corp./ Qupix USAcoustics
Model P706 QA-8900 USA6300
Parameter Max. Points
Sound quality 60 58 58 56
4-ohm power 50 47.5 48 50
2-ohm power 20 19 19.5 20
1-ohm power 20 20 18 19.5
Measurements 20 18 17.5 17
Separate inputs for all six channels 5 0 5 0
Filter characteristics/ performance 30 25 18 27
Total 210 187.5 184 189.5
Rank 2 3 1
|