Wire Gauge
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New member Username: PrincealiScrewston TX Post Number: 1 Registered: Jun-04 | Is the Legacy LA2070 2400wt amp any good? High, Mid, Low Quality? Also, what gauge wire would I need to run from the battery thru the power distribution block to power that b#tch. And how big a fuse would I need for the power dis block. I already have a 4 gauge wire with a 100 watt fuse wired in my car. Its hooked up to a 1000watt amp do I need to rewire that? My goal is to jam my brand new 12" Sony Xplodes (1200wt apiece). thnks http://www.legacycaraudio.com/itempage.asp?model=LA2070 |
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Bronze Member Username: CainerCamberley, Surrey England Post Number: 100 Registered: May-04 | that legacy amp only pushes out 600w rms.. low quality. |
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New member Username: CarloDublin, Dublin Ireland Post Number: 4 Registered: Jun-04 | Legacy is low quality amp, if you only have one amp powering your system then you do not require a power distribution block. A distribution block is only use if you are using two or more amps. A 4 guage wire is fine for the one amp, the fuse rating should equal the sum of the fuses used within your system for example if u have two amps using two 30 amp fuses your power distribution block should equal a 60 amp fuse. What Cable Gauge do I Need? 1)calculate first the total power of each amp (multiply the number of channels by the number of RMS watts per channel). 2)If you have multiple amps, add up the total power figures to arrive at a grand total. 3)Next, double your grand total power figure. 4)Then, divide by 13.8. 5)The resulting figure is your system's approximate current draw.(in amperes) Use this chart to determine what guage cable you use:  |
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Anonymous | i dont exactly know what your talking about but what would i need for a jbl 1200.1 and a brahma 15? |
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New member Username: PrincealiScrewston TX Post Number: 2 Registered: Jun-04 | cainer, the legacy pushes 600w rms per channel? my sonys each handle 350watts rms at 4ohm. that should be enough to pop a few ears right? sorry carlo i didnt mean to say the power dis block, i meant to say the fuseholder near the battery. |
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Silver Member Username: CainerCamberley, Surrey England Post Number: 101 Registered: May-04 | no, you have to bridge it to 1 ch and with a 2ohm load to the amp you will get 640w RMS, if you wired your 4ohm subs in parellel you will get a 2ohm load to the amp so each sub gets 320w RMS, thats the most you will get but dont forget that to get that you will be using low quality equipment and pushing it to the MAX.... it aint gonna last long before it blows |
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New member Username: CarloDublin, Dublin Ireland Post Number: 6 Registered: Jun-04 | Your jbl 1200.1 = 1200watts * 1 channel total power RMS= 1200 Watts double the figure=2400Watts Divide by 13.8=173.91 approx draw in amperes Class D Amplifiers are between 70-80% efficent Class A/B Amplifiers are between 60-70% efficent Your Amp is a Class D Using these Variables and General Assumptions 70% efficiency 13.8 Battery Voltage 15 ft Wire Lenght(FEET) 4g Wire Guage 1264 Total Maximum Amplifier Power (RMS) If you use a 2 g Wire guage with the equivalent Variables you get 2007 Total Maximum Amplifier Power (RMS) Wire Gauge Recommended Maximum Fuse Size 2 awg 200 amps 4 awg 125 amps These are the recommended maximum fuse ratings for the corresponding wire size. Using a smaller fuse than what's recommended here will be perfectly safe. |
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Silver Member Username: SoccerPost Number: 163 Registered: Apr-04 | Please explain something to me. Almost everybody in the site measure the amp's quality by its power, and almost everybody prefer calss D amps due to efficiency! Now, I reckon it's the best type of amp for subs, but I think as far as components concerned, the AB design is best, although not as efficient. Why? D amps use the non-linear region of transistors, thus distorting the signal, or at least disproportioning. As the AB design uses only the linear region of the power transistors (that is, if the bias current is accurate), it will always have more quality than class D amps... Am I wrong assuming this? |
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New member Username: PrincealiScrewston TX Post Number: 3 Registered: Jun-04 | thanks for the help cainer, really. But one last question. could you reccomend an amp for my 2 Sony XS-L121P5. http://www.crutchfield.com/S-5JU1LxNPd2G/cgi-bin/ProdView.asp?s=0&c=10&g=67700&I =158L121P5&o=p&a=0&cc=01&avf=N&search= im looking for mid qual nothing way too expensive like $250-300 tops. |
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New member Username: CarloDublin, Dublin Ireland Post Number: 7 Registered: Jun-04 | Basically the class D amp uses the transistors like switches to control the power distribution.Class D amps boast higher efficiency, produce less heat, and draw less current than traditional Class AB designs. Class D amplifiers produce higher distortion than AB designs due to the high-speed switching on and off of the transistors, but this distortion occurs at high frequencies that are typically removed by a low-pass filter. Class A/B Design still run current through the transistors even if their is no audio signal. A class AB amplifier runs with low distortion and high reliability. However the Class T amp combines both the class D and class AB amp designs in effect you get the conventional Class AB designs, combined with the high power efficiency and low heat production of a Class D design. |
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Silver Member Username: SoccerPost Number: 168 Registered: Apr-04 | So, if we're speaking strictly sound quality, class AB would still be the best ('cause class A would need huge heatsinks?)? |
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Silver Member Username: Jonathan_fGA USA Post Number: 419 Registered: May-04 | That JBL 1200.1 won't pull that much current, it usually won't pull more than 115-120 amps at best. Glasswolf posted this a while back, read about it here: https://www.ecoustics.com/electronics/forum/car-audio/27570.html Very informative. Yes, a Class AB amp will sound cleaner. A class D amp's switching speed of the transistors is what generates higher distortion, a well designed amp retains linearity (never perfect, but close) regardless of frequency. The reason people use them is they're cheaper for the power, run cooler, are smaller, and it's harder to pick up distortion at low frequencies, so many people don't notice the difference. |
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Silver Member Username: SoccerPost Number: 186 Registered: Apr-04 | Thanks |
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