Interfire IF 4700C

Price & Contact: $297; 877-90-AUDIO; www.interfireaudio.com
All measurements @ 14 volts unless otherwise specified.
Frequency Response (4-ohm IHF Load, 20 Hz to 20 kHz (1 kHz Ref.): +1.4 dB, -.6 dB
L/R channel error (max deviation 20 Hz to 20 kHz): .07 dB
Phase Response (4-ohm IHF Load, 20 Hz to 20 kHz (1 kHz Ref.)): +41.3 degrees, -29.5 degrees
Signal-to-Noise Ratio (Below Rated Output, “A” weighted): -96.5 dB
Distortion at Rated Output @ 1 kHz: 0.1% THD+N @ 177 watts x 2
Output Power (resistive) minimum output 20 Hz to 20 kHz @ 1% THD+N, all channels driven into 4 ohms: 61 watts x4 @ 14 volts; 50 watts x 4 @ 12.8 volts; 33 watts x 4 @ 10.5 volts
Output Power (resistive) minimum output 20 Hz to 20 kHz @ 1% THD+N all channels driven into 2 ohms: 89 watts x4 @ 14 volts; 73 watts x 4 @ 12.8 volts; 48 watts x 4 @ 10.5 volts
Output Power (4-ohm IHF Reactive Load @ 1% THD+N @ 60 Hz): 200 watts x 2
Crosstalk (Referenced to Rated Output, 20 Hz to 20 kHz): -37 dB
Damping Factor @ 100 Hz: 57
Voltage for Rated Output: 223 mV to 3.3 volts
Idle Current Draw: 0.8 amps
Current Draw @ 1/3 Maximum Power: 30.4 amps @ 67 watts x 2
Efficiency @ 1/3 Maximum Power: 31%
Power-Up Noise: 26.7 dB SPL
Power-Down Noise: 19.2 dB SPL

		Interfire IF 4700C www.interfireaudio.com
		The IF 4700C offers significant power along with a compact design and a beautiful polished chrome finish.		Interfire IF 4700C Specs Price & Contact: $297; 877-90-AUDIO; www.interfireaudio.com All measurements @ 14 volts unless otherwise specified. Frequency Response (4-ohm IHF Load, 20 Hz to 20 kHz (1 kHz Ref.): +1.4 dB, -.6 dB L/R channel error (max deviation 20 Hz to 20 kHz): .07 dB Phase Response (4-ohm IHF Load, 20 Hz to 20 kHz (1 kHz Ref.)): +41.3 degrees, -29.5 degrees Signal-to-Noise Ratio (Below Rated Output, “A” weighted): -96.5 dB Distortion at Rated Output @ 1 kHz: 0.1% THD+N @ 177 watts x 2 Output Power (resistive) minimum output 20 Hz to 20 kHz @ 1% THD+N, all channels driven into 4 ohms: 61 watts x4 @ 14 volts; 50 watts x 4 @ 12.8 volts; 33 watts x 4 @ 10.5 volts Output Power (resistive) minimum output 20 Hz to 20 kHz @ 1% THD+N all channels driven into 2 ohms: 89 watts x4 @ 14 volts; 73 watts x 4 @ 12.8 volts; 48 watts x 4 @ 10.5 volts Output Power (4-ohm IHF Reactive Load @ 1% THD+N @ 60 Hz): 200 watts x 2 Crosstalk (Referenced to Rated Output, 20 Hz to 20 kHz): -37 dB Damping Factor @ 100 Hz: 57 Voltage for Rated Output: 223 mV to 3.3 volts Idle Current Draw: 0.8 amps Current Draw @ 1/3 Maximum Power: 30.4 amps @ 67 watts x 2 Efficiency @ 1/3 Maximum Power: 31% Power-Up Noise: 26.7 dB SPL Power-Down Noise: 19.2 dB SPL
		by Brian Smith

		The IF 4700C is a four-channel amplifier featuring selectable internal crossovers, bass boost, gold-plated connections, and a polished chrome heatsink. Power ratings are listed as 59 watts x 4 into 4 ohms or 177 watts x 2 into 4 ohms in a bridged configuration. Performance Performance from the IF 4700C was surprisingly good. Its packaging boasts that the amp was ‘Designed & Engineered in the U.S.A.,’ but no mention was made about the country of manufacture. This will usually raise an eyebrow or two around the lab. Even in the U.S., the world’s greatest design can be compromised in the manufacturing process. Combine this with a production facility half way around the world and things have the potential to get pretty hairy. It can be done, as evidenced by the endless array of inexpensive electronics that are available, but Interfire seems to be one of the few car audio companies that have figured it out. At 61 watts x 4, the 4700C isn’t a huge powerhouse, but it’s very well behaved. It seems relatively immune to noise, it doesn’t break into freaky oscillation when it’s clipped, and it went through our entire battery of tests without a hitch. The amp does lose a substantial amount of output as the power supply is decreased to 10.5 volts, but you’re not apt to notice this unless you spend a fair amount of time listening with the engine turned off. Overall, the IF 4700C is a capable performer with more chrome than a Harley-Davidson. What more could you ask for? Installation Installing the IF 4700C could present an unusual challenge compared to the average amp. Installation limitations are usually either physical (it won’t fit where I want it to) or electrical (requires a course in ‘Advanced Grounding Principals 105’ to achieve quiet operation), but the IF 4700C is small enough and well enough isolated to avoid both of these problems. The question here is not where it will fit but where to put it — hiding this much chrome in a trunk or under a seat seems positively un-American. Connections & Adjustments Connections to the IF 4700C consist of RCA inputs and 3/8-inch spade receptacles for all power and speaker connections. All adjustments control a pair of channels and include input sensitivity, stereo/mono switch, selectable 0/+6/+18 dB bass boost, crossover mode (high-pass/low-pass/full-range), and switches to select the cutoff frequency in each mode.