I currenlty have an Infinity kappa 10" dvq sub wired parralell to my Alpine MRVF357 Amp. the amp seems to overheat quite fast. am i wiring my sub adequately or what. here is the spec sheet from alpine. please let me know the
MRV-F357
Per channel into 4 ohms (CH-1 – CH-4) ..... 50W, 0.08% THD
Per channel into 2 ohms (CH-1 – CH-4) ...... 60W, 0.3% THD
Bridged into 4 ohms (CH-1 – CH-4) .......... 120W, 0.3% THD
4 ohms (CH-5) ......................................... 150W, 0.3% THD
MRV-F357
Per channel into 4 ohms (CH-1 – CH-4) ........................ 90W
Bridged into 4 ohms (CH-1 – CH-4) ............................ 240W
4 ohms (CH-5) ........................................................... 300W
best way to wire and if i need to put it into series or not? thanks
That is a DVC 4 ohm sub. Rewire to series and use it that way. The amp has no tolerance for either 2 ohm bridged or 2 ohm on the mono channel. The output will be 75 watts on the 5th channel. A different sub (different coil configuration) would be in order for best subwoofer use with this amp (DVC 2 ohm or SVC 4 ohm).
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Thanks for the help. I'll wire it in series. should i be getting more power than in series. Or do i get more in paralell but its not safe for the amp?? and when you say 75 watts is that what i'm getting now nominal, or what i'll get in series??? thanks
You'll get most watts through channel 5 as long as your deck has a sub preout and you select "5" for your amp input setting. At 12 volts, the amp's 5th channel is rated at 100 watts into 4 ohms; with 14.4 volts, it's 150 watts into 4 ohms.
With your load at 8 ohms the power output decreases by a factor of times two. So the amp will output from 50 to 75 watts into the series-wired 8 ohm load. (The output I told you in the previous post was based on the numbers you listed, which were first at 14.4 volts and second as "max". We'll throw out that "max" number...).
You need as much as you can get from this amp so you can see how using a sub capable of 4 ohms will get you the most this amp can deliver. You've been pushing a 2 ohm load onto it and it's been heating up quickly. This will kill an amp. What you're getting now as far as power output is a non-issue because the amp will not tolerate such a low impedance load for very long.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Thanks man, I appreciate the help. The last thing I want to do is blow my amp! I would rather replace the Sub than My amp! It was a little more expensive. I'm an employee of electronics store so I get accomadations prices on Harman Kardon and Infinity as well, that makes it nice!