hazestorm23 Posted January 17, 2014 Report Posted January 17, 2014 I was minding my own business on eBay lol scrolling through some amps and ran across a earthquake class j amp that is rated 3000 at 2 ohms now what does this class j have in special?
Nightshade Posted January 17, 2014 Report Posted January 17, 2014 Read here to see what class j is http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5604342&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5604342 From what the article says class j is pretty efficient at low impedance. However a class d will be more efficient. The benefit of class j may be thd, other than that it appears to be inferior to class d for subwoofer purposes. Also the article suggest that the class j amp described is used for microwave frequencies which are in the above 2 gigahertz range. That is way too high for audio so I'm not sure how this is optimized for use as an audio amplifier. 2013 VW Jetta GLI 2.0 Turbo 1 Sundown Audio SCV2000 1 Sundown Audio X15 V2 1 XS Power D3100 Audio Control LC6i Stock Deck 146.4 sealed on the dash at 37hz 2001 Focus ZX3: RETIRED Team Sundown Audio, Team XS Power, 2 time NSPL Car 3601-Up Champion, 2 time NSPL Car Hardcore ChampionHighest NSPL Scores to date:154.3db on the dash sealed at 46hz, 156.2db in the kick at 46hz155.2db unofficial on dash at 43hz
hazestorm23 Posted January 17, 2014 Author Report Posted January 17, 2014 THD: >0.04% <<<<<<<this Signal-to-Noise Ratio: >95dB Max Power: 5000 Watts RMS Power 2-Ohm: 3000 RMS Power 4-Ohm: 1500
Krakin Posted January 17, 2014 Report Posted January 17, 2014 I wouldn't worry about THD. Krakin's Home Dipole Project http://www.stevemeadedesigns.com/board/topic/186153-krakins-dipole-project-new-reciever-in-rockford-science/#entry2772370 Krakin, are you some sort of mad scientist? I would have replied earlier, but I was measuring the output of my amp with a yardstick . . . What you hear is not the air pressure variation in itself but what has drawn your attention in the two streams of superimposed air pressure variations at your eardrums An acoustic event has dimensions of Time, Tone, Loudness and Space Everyone learns to render the 3-dimensional localization of sound based on the individual shape of their ears, thus no formula can achieve a definite effect for every listener.
hazestorm23 Posted January 17, 2014 Author Report Posted January 17, 2014 Yea it carries a hefty price tag for being what it is. I had just never heard of a class j sub amp before
RooTxBeeR Posted January 17, 2014 Report Posted January 17, 2014 Yeah that's some low tdh right thhur. Any damping factor on the info? On 11/20/2012 at 8:54 PM, AMI CUSTOMS said: Turned mine up today at a light, guy next to me his steering wheel started moving and he looked over at me like I was a magician lol. On 5/9/2012 at 8:45 PM, skittlesRgood said: fuck the plating. look at what the main metal used is. you could buy unicorn blood plated terminals but if its just covering up dog shit, whats the point On 4/10/2013 at 12:26 PM, mrd6 said: I'll admit, half way through sanding that fiberglass in the rain and cold while I was all itchy I was definitely starting to question why i was doing this haha Soon To Be '04 Ford Escape US Alternator 280A Hairpin D4800 Under the Hood (6) XP3000's in Rear 1/0 SHCA & XS Power 4 runs to back TORK2 kit from Tony @ CE Auto Supply Pioneer DEH-80PRS DD AW6.5 (2) per door *Tweeter Unkown* DD SS4a & C3d (2) SCV4000 @ .5Ohm (2) 15" Sundown Zv5
hazestorm23 Posted January 17, 2014 Author Report Posted January 17, 2014 I wouldn't worry about THD. yea I know but I'm just intrigued by what its supposed to do bit I had never heard of anything like it do you think it even does rated power?
hazestorm23 Posted January 17, 2014 Author Report Posted January 17, 2014 Yeah that's some low tdh right thhur. Any damping factor on the info? straight from the website. Turns out they made the same amp in class j and class d .Damping Factor: >800 Earthquakes Class-J amplifiers deliver far beyond your expectations with blazing performance, intelligent design, and unique features that are second to none. These killer amplifiers operate in the range of 95% efficiency. Heat sink designs, larger input and output terminals, and precise fine-tuning have put the reigning champions in an untouchable category. The heat sink evenly distributes heat from the amplifier so the amp stays extraordinarily efficient and cool. Class J PowerHouse amps even have power connections 4-gauge and larger. All of these design features and improvements will dramatically increase presentation, output capabilities, sound quality, and your status in the winners circle. Sold and priced per piece. Specifications Model nr.: PH-5000W-D1 EAN: 3-000668-975983 Class: "J" Channels: 1 (Mono) THD: >0.01% Signal to Noise Ratio: >95dB below rated power Max Power: 5000W RMS Power 2-Ohm: 3000W RMS Power 4-Ohm: 1500W
Nightshade Posted January 17, 2014 Report Posted January 17, 2014 Okay now that you mentioned it is an earthquake amp we can stop wondering. They used to make a quality product but are way behind the times. They do not do close to rated power and boasting a crazy 95% efficiency they are flat out lying. Class j is not that efficient under perfect conditions. It will run hotter than class d and heat decreases efficiency. 2013 VW Jetta GLI 2.0 Turbo 1 Sundown Audio SCV2000 1 Sundown Audio X15 V2 1 XS Power D3100 Audio Control LC6i Stock Deck 146.4 sealed on the dash at 37hz 2001 Focus ZX3: RETIRED Team Sundown Audio, Team XS Power, 2 time NSPL Car 3601-Up Champion, 2 time NSPL Car Hardcore ChampionHighest NSPL Scores to date:154.3db on the dash sealed at 46hz, 156.2db in the kick at 46hz155.2db unofficial on dash at 43hz
RooTxBeeR Posted January 17, 2014 Report Posted January 17, 2014 Wow, that's probably why. That is a high ass damping factor. And damping factor is most important at low frequencies so it's mostly needed in sub and midbass. Most amps I see dont even get higher than 400. On 11/20/2012 at 8:54 PM, AMI CUSTOMS said: Turned mine up today at a light, guy next to me his steering wheel started moving and he looked over at me like I was a magician lol. On 5/9/2012 at 8:45 PM, skittlesRgood said: fuck the plating. look at what the main metal used is. you could buy unicorn blood plated terminals but if its just covering up dog shit, whats the point On 4/10/2013 at 12:26 PM, mrd6 said: I'll admit, half way through sanding that fiberglass in the rain and cold while I was all itchy I was definitely starting to question why i was doing this haha Soon To Be '04 Ford Escape US Alternator 280A Hairpin D4800 Under the Hood (6) XP3000's in Rear 1/0 SHCA & XS Power 4 runs to back TORK2 kit from Tony @ CE Auto Supply Pioneer DEH-80PRS DD AW6.5 (2) per door *Tweeter Unkown* DD SS4a & C3d (2) SCV4000 @ .5Ohm (2) 15" Sundown Zv5
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