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New member Username: Charli3Post Number: 1 Registered: Oct-10 | My Sub stops working once the gain on the amp hits a certain point which is a little over half but kicks back in when you turn down the gain. Also the Green light is on the whole time the red protection light doesnt come on. |
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Platinum Member Username: PlymouthCanada Post Number: 15109 Registered: Jan-08 | Welcome to eCoustics charlie List your amp then brand and model, wire dimension! It can be a lack of voltage! is this problem new? |
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Platinum Member Username: GlasswolfPost Number: 13920 Registered: Dec-03 | As mentioned, it can be a lack of current to the amplifier from your car's charging system, or it could be that you're overdriving the input stage of the amp and causing it to clip severely. The gain should be set to match the head unit's line voltage, and not used as a volume knob to get more bass. If the gain is properly set, and you don't have enough output, then you need to buy a bigger amplifier. |
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New member Username: Charli3Post Number: 2 Registered: Oct-10 | The sub is a dc audio lvl 4xl. The amp is a memphis 16 st1500d. The head unit is jvc kw xr610. All the wiring is from a rockford 4 or 8gauge kit I forget its about as thick as a sharpie marker |
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New member Username: Charli3Post Number: 3 Registered: Oct-10 | The amp is a memphis 16 st1500d. The sub is dc lvl 4xl. Head unit is jvc kw xr610. All the wiring is from a rockford kit I don't remember gauge but its bout as tthick as a sharpie marker |
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Platinum Member Username: PlymouthCanada Post Number: 15111 Registered: Jan-08 | Charlie Is this problem new or you had always this problem? |
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New member Username: Charli3Post Number: 4 Registered: Oct-10 | I just bought the amp from a guy on craigslist and he let me hear it full power on two mtx8500's. So the problem is new to me, I was confused that when I hooked it up it didn't work when I just heard it pounding then I played with the dials and it kicked it when I turned the gain down |
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Platinum Member Username: GlasswolfPost Number: 13925 Registered: Dec-03 | my reply answers your issue. |
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New member Username: Charli3Post Number: 5 Registered: Oct-10 | How do I match the head units voltage? New rca cables? Or a different deck? |
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Platinum Member Username: PlymouthCanada Post Number: 15114 Registered: Jan-08 | Is this problem continue when the motor run? The voltage can be too low then the amplifier can turn in protect mode or like Glasswolf said you enter in clipping protect because the gain is set too higher. |
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Platinum Member Username: GlasswolfPost Number: 13929 Registered: Dec-03 | you find out what the line voltage is on your current head unit. It's probably 2 or 4 volt pre-out. Then you look at the input sensitivity (gain) knob on the amp and find the corresponding voltage mark, and set the dial to that point. Here are directions on a method if you don't have markings on the amp's dial. http://www.glasswolf.net/papers/dmmgain.html |
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New member Username: Charli3Post Number: 6 Registered: Oct-10 | Ok so if I just leave the gain in the middle it should be safe from clipping? My amp doesn't have markings but in the middle is plenty loud I was just curious to see what it would sound like on full power. |
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Platinum Member Username: GlasswolfPost Number: 13933 Registered: Dec-03 | you mean full clipping. The gain knob isn't a power level adjustment. It's an impedance circuit that matches the input line voltage to the input stage of the amplifier to avoid over-driving the amplifier and clipping the output waveform. Anyway, yes just leave the gain set between a quarter and one-half up from "maximum sensitivity" (in other words, 1/4 to 1/2 turn clockwise.) |
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Gold Member Username: SkdooleyRoanoke, VA Usa Post Number: 1252 Registered: Oct-09 | What kind of car is this in? You may not have enough amperage from your alt to properly support the power you're pulling off it with that amp. Setting the gain as recommended will help a lot, as will upgrading the big 3. If power is still an issue, then you'll know if you need a larger alt or not. To set your gain you'll need to invest into a digital multi meter and download a 50 Hz sine wave. Be sure the 50 Hz is in WAV format when you play it. You'll then want to measure the impedance of your sub and set your gain according to that. |
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Platinum Member Username: GlasswolfPost Number: 13937 Registered: Dec-03 | the DMM is cheap. you can get one (that reads "true RMS" or AC voltages) at Harbor Freight or similar for $10 or less. With that DMM you can not only set the gain on the amplifier(s) properly, but you can test voltage in the car while the system is in use (and alternator is above 1200-1500RPM) to see if voltage is dipping below 12VDC. If the voltage does drop below 12VDC, especially for prolonged periods, or frequency, then yeah, time for a bigger alternator upgrade. |
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Bronze Member Username: JaymoungMichigan Post Number: 65 Registered: Dec-09 | i had dual 12s 4got the model and had a cheap 2 channel sony amp and i have them bridged and they slammed but when u turnt it up it would cut off and i basically found out that the problem was the amp wasnt stable at 2 ohms in bridge mode or i might have wired it 2 1 ohm idr but i kno that was the problem could b your problem also sorry if someone said this i kinda didnt rear the respones |