Memphis Car Audio 16-ST1000D
www.memphiscaraudio.com
Memphis' 16-ST1000D offers raw class D power in
an attractive, compact design.
Memphis Car Audio
16-ST1000D Specs

Price & Contact: $650; 910-525-5711; www.memphiscaraudio.com
All measurements @ 14 volts unless otherwise specified:
Frequency Response (4 Ohm IHF Load 80 Hz Ref. Crossover @ highest setting): +0 dB, -.9 dB (Crossover -3 dB @ 249 Hz)
L/R channel error max deviation 20 Hz to 20 kHz: N/A
Signal-to-Noise Ratio (Below Rated Output, "A" weighted): -79 dB
Distortion at Rated Output @ 60 Hz: .4% @ 300 watts into 4 Ohms; .5% @ 500 watts into 2 Ohms; 1.1% @ 1100 watts into 1 ohm
Output Power (Resistive) (2 ohms @ 60 Hz to 1% THD+N): 791 watts @ 14 volts; 643 watts @ 12.8 volts; 231 watts @ 10.5 volts; 425 watts @ ***
Output Power (Resistive) (1 ohm @ 60 Hz to 1% THD+N): 997 watts @ 14 volts; 886 watts @ 12.8 volts; 246 watts @ 10.5 volts; 688 watts @ ***
Output Power (Reactive) (2 ohm IHF Load @ 60 Hz to 1% THD+N): 846 watts
Crosstalk @rated output, 20 Hz to 20 kHz: N/A
Damping Factor @ 100 Hz: 25
Voltage for Rated Output: 182 mV to 4.5 volts
Idle Current Draw: 1.7 amps
Current Draw @ 1/3 Maximum Power: 33.2 amps @ 332 watts
Efficiency @ 1/3 Maximum Power: 71%
Power-Up Noise: 51.3 dB SPL
Power Down Noise: 51.1 dB SPL
*** Output Power @ onset of clipping.

by Brian Smith
The 16-ST1000D is a single-channel, class D subwoofer amp featuring line-level outputs, an 18 dB-per-octave lowpass crossover that's continuously variable from 250 Hz to 50 Hz, and a defeatable subsonic filter that's continuously variable from 20 Hz to 50 Hz. Power ratings for this amp are listed as 300 watts into 4 ohms, 600 watts into 2 ohms, and 1100 watts into 1 Ohm.

Performance

If Elvis's Caddy had a subwoofer, an amp from Memphis Car Audio would almost be expected. Nashville was never the King's first choice, and nobody could take an amp from Pigeon Forge seriously. Like most class D amps, the 16-ST1000D excels at delivering lots of power into low impedance loads. We measured 791 W into 2 ohms and 997 W into 1 ohm with a 14-volt supply. We were able to confirm the 1100-watt rating into 1 ohm, although it occurs at a slightly higher THD+N percentage of 1.1%. As you can see in the chart, with a 10.5-volt supply, distortion rises rapidly above about 250 watts, although the amp doesn't begin to hard clip until about 700 watts. However, this won't be a problem unless you spend a fair amount of time thumping at the car wash or in a competition lane. Efficiency is a large consideration when you're dealing with an amplifier in this power range, and the 16-ST1000D's 71% at 1/3 max power is in the thick of the class D efficiency race. Fit and finish on this piece is also quite good, all of the controls and connections feel beefy and positive and the overall package looks really slick.

Installation
The 16-ST1000D is quite small considering its prodigious output. It measures 16.5- x 6.5- x 2-inches, just about small enough to fit anywhere. The amp's heatsink is also well designed. It sports something that's becoming an increasing rarity in the car audio world these days, an absolute slew of fins. The laws of physics that include thermal-dynamics say surface area rules the day if you intend to dissipate heat, but fins are still disappearing at an incredible rate. Maybe they just don't look cool enough for the marketing folks. From an installation standpoint, about the only gripe we can offer is for the fuse access. It's through the bottom panel, necessitating the amps removal to replace a fuse. However, the amp does provide a 'Fuse Fault' light that indicates blown or missing fuses. In addition, the two 40-amp fuses supplied with this amp proved to be quite resilient, passing well over 100 amps of short bursts several times without popping.

Connections & Adjustments
Connections to the 16-ST1000D include RCA inputs and outputs, wired remote connector, and beefy captive-style terminal blocks for all power and speaker connections. The manual recommends 4-gauge or larger for power and ground connections, although 4-gauge seems to be about the maximum amount of copper that can be crammed into the terminal block. There was no recommendation for speaker wire size, but the connectors accept up to 8-gauge. Adjustments to the 16-ST1000D include input sensitivity (also controllable via the wired remote), lowpass crossover cutoff frequency adjustment, subsonic filter cutoff frequency adjustment, and subsonic filter disable.