Reviews and Awards
Home Theater Review
"Branded sound systems are often gimmicks that allow automakers to charge more for equipment from renowned names in audio. Unfortunately, most of them are fairly disappointing. Take the $6300 Bang & Olufsen upgrade Audi offers, for example.
"But the Acura RLX premium sound system by Krell Industries lives up to the expectations of this enthusiast, making it one of the best factory sound systems I've tested. Acura doesn't charge much for the package, either; it's an extra $2500 if you were already leaning toward the technology bundle."
Sound and Vision
"A great-sounding, reasonably priced analog two-channel integrated amp from a high-end brand that many people thought they would never be able to afford - and it's got an iPod interface, too"
The Absolute Sound
"At 43 pounds, it outputs 150Wpc and doubles that rating into 4 ohms thus likely making the S-300i the most powerful amp in this price range."
Downloads
Specifications
S-550i
Inputs
1 pr. balanced via XLR connectors
3 pr. single-ended via RCA connectors
1 dedicated iPod input via 30-pin connector
Outputs
1 pr. preamp outputs via RCA connectors
1 pr. speaker outputs via gold-plated binding posts
Control Inputs
1 RS-232 input via 9-pin D-subminiature connector
1 remote IR detector input via 3-conductor 3.5 mm connector
1 12 VDC trigger input via 2-conductor 3.5 mm connector
Control Output
1 programmable 12 VDC trigger output (30 mA maximum current) via 2-conductor 3.5 mm connector
Input Impedance
Balanced: 95 kΩ
Single-ended: 47.5 kΩ
Frequency Response
20 Hz to 20 kHz +0, -0.08 dB
<2 Hz to 140 kHz +0, -3 dB
Signal to Noise Ratio
>89 dB, wide band, unweighted, at maximum gain, referred to full power output
>96 dB, "A"-weighted
Gain
32.0 dB
Input Sensitivity
Single-ended or balanced: 1.18 V RMS
Total Harmonic Distortion
<0.025% at 1 kHz, at 275 W, 8 O load
<0.20% at 20 kHz, at 275 W, 8 O load
Output Power
275 W RMS per channel at 8 O
550 W RMS per channel at 4 O
Output Voltage
133 V peak to peak
47 V RMS
Output Current
20 A peak
Slew Rate
80 V/μs
Output Impedance
<0.073 Ω at 20 Hz
<0.08 Ω, 20 Hz to 20 kHz
Damping Factor
>110 at 20 Hz, referred to 8 O
>75, 20 Hz to 20 kHz, referred to 8 O
Power Consumption
Standby: 1 W
High-current standby: 40 W
Idle: 90 W
Maximum: 1800 W
Heat Output
Standby: 3.4 BTU/hr
High-current standby: 140 BTU/hr
Idle: 310 BTU/hr
Maximum: 2400 BTU/hr
Specifications for Preamp only:
Gain
6.3 dB (single-ended)
Volume Control
Current-mode, 12-bit, discrete R-2R ladder
Input Overload
Balanced: 12 V RMS
Single-ended: 6 V RMS
Output Overload
8 V RMS (single-ended)
Frequency Response
20 Hz to 20 kHz +0, -0.05 dB
<2 Hz to 1.0 MHz +0, -3 dB
Total Harmonic Distortion
<0.009%, 20 Hz to 20 kHz, at 2 V RMS
Signal to Noise Ratio
>87 dB, wide band, unweighted, at maximum gain, referred to 2 V RMS
>94 dB, "A"-weighted
Dimensions
17.26 in W x 5.84 in H x 17.70 in D
438 mm W x 148 mm H x 450 mm D
Weight
Unit only: 64 lb [29.0 kg]
As shipped: 76 lb [34.4 kg]
S-300i
Inputs
1 pr. balanced via XLR connectors
3 pr. single-ended via RCA connectors
1 dedicated iPod input via 30-pin connector
Outputs
1 pr. preamp outputs via RCA connectors
1 pr. speaker outputs via gold-plated binding posts
Control Inputs
1 RS-232 input via 9-pin D-subminiature connector
1 remote IR detector input via 3-conductor 3.5 mm connector
1 12 VDC trigger input via 2-conductor 3.5 mm connector
Control Output
1 programmable 12 VDC trigger output (30 mA maximum current) via 2-conductor 3.5 mm connector
Input Impedance
Balanced: 95 kΩ
Single-ended: 47.5 kΩ
Frequency Response
20 Hz to 20 kHz +0, -0.14 dB
<2 Hz to 140 kHz +0, -3 dB
Signal to Noise Ratio
>84 dB, wide band, unweighted, at maximum gain, referred to full power output
>93 dB, "A"-weighted
Gain
32.5 dB
Input Sensitivity
Single-ended or balanced: 800 mV RMS
Total Harmonic Distortion
<0.035% at 1 kHz, at 150 W, 8 O load
<0.26% at 20 kHz, at 150 W, 8 O load
Output Power
150 W RMS per channel at 8 O
300 W RMS per channel at 4 O
Output Voltage
99 V peak to peak
35 V RMS
Output Current
15 A peak
Slew Rate
50 V/μs
Output Impedance
<0.080Ω at 20 Hz
<0.11Ω, 20 Hz to 20 kHz
Damping Factor
>100 at 20 Hz, referred to 8 O
>75, 20 Hz to 20 kHz, referred to 8 O
Power Consumption
Standby: 40 W
Idle: 60 W
Maximum: 1000 W
Heat Output
Standby: 140 BTU/hr
Idle: 210 BTU/hr
Maximum: 1600 BTU/hr
Specifications for Preamp only:
Gain
6.3 dB (single-ended)
Volume Control
Current-mode, 12-bit, discrete R-2R ladder
Input Overload
Balanced: 12 V RMS
Single-ended: 6 V RMS
Output Overload
8 V RMS (single-ended)
Frequency Response
20 Hz to 20 kHz +0, -0.05 dB
<2 Hz to 1.0 MHz +0, -3 dB
Total Harmonic Distortion
<0.009%, 20 Hz to 20 kHz, at 2 V RMS
Signal to Noise Ratio
>85 dB, wide band, unweighted, at maximum gain, referred to 2 V RMS
>94 dB, "A"-weighted
Dimensions
17.26 in W x 4.09 in H x 17.70 in D
438 mm W x 104 mm H x 450 mm D
Weight
Unit only: 42 lb [19.0 kg]
As shipped: 51 lb [23.1 kg]
