High Resolution Document - Rockford Fosgate

About a 20 minute drive from my lab, over on Rockford Drivein Tempe, Arizona, is the world headquarters of RockfordFosgate. These folks live, breathe and sleep car audio. Ifyou have ever read any of Rockford Fosgate’s marketingmaterials, they talk a lot about passion for the car audiolifestyle, and it’s true. Their engineers have systems intheir daily drivers, and through daily use by these fanatics,new products are conceived, prototyped, developed, andas often as not, become production products that youand I can buy for our own rides. Just such a product isthe Power series of amplifiers, and in this review we’regoing to take a look at the biggest dog on the block, theT1000-4ad.FEATURESText and Measurements by Garry Springgay; published by PAS MagazineThe Rockford Fosgate T1000-4ad is a four channel ClassD full range amplifier that was developed by Rockford’sin-house enthusiasts to be their concept of the bestperformingfull-range Class D amplifier possible. Thepatent pending “ad” topology uses something Rockfordcalls “Dynamic Frequency Switching” to provide thebest possible performance. Additional feedback is usedafter the output inductors to further reduce unwantedswitching noise, and provide a clean musical outputsignal. The amp is rated at 250 watts x 4 into 4 or 2ohms, or 500 watts x 2 when bridged into 4 or 2 ohms.In addition, the T1000-4ad employs some old schoolcircuitry too, the famed Punch EQ circuit is on boardfor all four channels, and brings the same sort ofacoustic corrections to your car in 2011 that madethem famous in 1985. For those who like to tweak asthey drive, a remote mounted Punch EQ module isavailable separately. Front and rear high and low passcrossovers are adjustable from 50 to 500Hz, and theslopes are -24dB per octave.This is the biggest four channel model in the Power seriesline, but it’s still quite manageable from a size perspectiveat 14.9” x 8.1” x 2.4”. All of the connections and controlsare conveniently located on the long front side ofthe amp, to simplifyinstallation and setup. It’s a heftypiece too, weighing in at just over12 pounds.Inside the T1000-4ad, you’ll findtypical Rockford Fosgate build qualityand high performance components.The amplifier uses 0% tolerance surfacemount parts throughout, and clever constructiondetails like vertically-placed daughter boards not onlyadd circuit real estate space to the relatively compactamplifier, they also provide critical shielding to thesensitive audio input section. High current TO-220MOSFET devices are used in both the power supplyand the output stage. The inside of the amplifier isjammed with high tech, precision components, and avery intelligent layout, but I was somewhat appalledat the slipshod way great gobs of silicone was usedto help secure the heavier components. The use ofsilicone adhesive is a great idea, but I’d think it couldbe applied in a much neater fashion. On the other hand,there is no negative effect other than the cosmeticappearance of the inside of the amp, and since mostpeople will never look inside one of these amplifiers, itmay not matter.listeningIn my reference system I wired the T1000-4ad so it drovemy components with the front channels and a pair of4 ohm 12” woofers was bridged to the rear channels.After setting the crossovers and gain controls, I satdown to see if the Rockford engineering team still hadtheir chops. Almost immediately I realized there wasno question, the T1000-4ad sounded great on the firsttrack. For this session I began with some classic rockfrom Aerosmith, Deep Purple and Rush, and when Irealized the amplifier had way more power than myspeakers (or ears) would safely handle, I changedthings up to some classical tracks and concentratedon the “feel” of the music. The T1000-4ad is avery transparent sounding amp, adding almost nocharacter of its own to the music. Quiet details likea singer’s breathing, or the sense of motion on thesoundstagewere reproduced withsurprising realism. Musical timbre, orhow well the amp allows you to hear the differencebetween a Taylor and a Takamine was also surprisinglygood. Bass was incredibly tight, articulate, and seemedeffortless even at high volume. But let’s face it – thisamp is really about power, and lots of it. I ran the amp ashard as I dared and it never showed any sign of strain.My woofers would have tapped out before this ampever got close.MEASUREMENTSOn the test bench, the amplifier easily exceeded allthe specifications published in the owner’s manual,the amp actually made 286 watts per channel into 4ohms. I noticed that when the amplifier is switchedinto low pass mode, there is about 3.5dB of additionalgain added, but as long as you set your gains aftermaking the crossover adjustments, it shouldn’t bean issue. That one minor glitch aside, the actualaudio performance of the T1000-4ad was brilliant.It did get quite warm during testing, so if you aregoing to run one of these brutes hard, make sure it’sinstalled in a way to optimize the cooling. The ampis very efficient however, so at least the majority ofthe power consumed isn’t simply wasted as heat.ConclusionIf you need a powerful four channel amplifier andnothing you’ve seen seems like it’s quite enough,you need to check out a T1000-4ad. Designedby enthusiasts for enthusiasts, and built likethe proverbial brick outhouse, once again theRockford Fosgate team has developed anamplifier capable of satisfying even the mostdemanding user. The company tagline used tobe: “For those who think too much is just right.”Yes indeed.TECHNICAL DATAThe following power measurementswere obtained using industry standardmethods. (1kHZ @ 1.0% THD+N - Batteryvoltages shown +/- 0.2V)MEASURED PERFORMANCE SPECIFICATIONSActual Measured Power@ 1.0% THD+N @ 12.6V BatteryManufacturers Rated Power250 x 4 @ 4 Ω250 x 4 @ 2 Ω250 x 4 @ 1 Ω500 x 2 @ 4 Ω500 x 2 @ 2 ΩActual Measured Power@ 1.0% THD+N @ 14.4V Battery232 x 4 @ 4 Ω 286 x 4 @ 4 Ω308 x 4 @ 2 Ω 328 x 4 @ 2 Ω316 x 4 @ 1 Ω 343 x 4 @ 1 Ω624 x 2 @ 4 Ω 642 x 2 @ 4 Ω635 x 2 @ 2 Ω 657 x 2 @ 2 Ω33 VOLUME 4.0ROCKFORDFOSGATE.COM 34