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Bronze Member Username: Jay_boyRochester, NY Usa Post Number: 34 Registered: Feb-10 | Many of you are familiar with my ignorance. I have jl HD 750/1 running 2 8w7s sealed. I want to continue to use my stock HU. I plan next week to put in a MTX RE Q so that the bass will not diminish when the vol. in increased. (unless I get adverse feedback) How do I increase the volts?????? I "believe" that the volts are low (amp is sometimes hot) Inc. in volts would be better for the amp and also increase the RMS output. (from what I've read) Also, where does the amplifier get the volts? Is it from the HU, battery, alternator or combination thereof? Should I get another battery for run them in series? Upgrading the alternator is going to be expensive and I don't think it is necessary but I don't know what to do so please advise.} |
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Gold Member Username: IlluminatorUSA Post Number: 5069 Registered: Apr-05 | First, there are two kinds of volts here: the actual voltage used to power the amplifier and the voltage driving the audio signal to the amplifier. To increase the audio signal voltage, you need an aftermarket head unit with pre-outs that have a high voltage (~3-4v). This won't make a significant difference in any case. To increase the voltage powering the amplifier (~13.8v)...you really can't ;) Unless you get a new alternator or decrease the load on your current electrical system. |
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New member Username: Joe1234Post Number: 5 Registered: May-09 | Buy a capacitor for the amp and a better battery and maybe thicker power lines to the amp, what you want is to prevent voltage dropping transiently due to the amp impedance lowering as bass is played. Amps are designed to work with the 13.8 if you want more power better get a 1000/1. |
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Gold Member Username: IlluminatorUSA Post Number: 5141 Registered: Apr-05 | ^ Noooooooooooo. A capacitor won't help, neither will a 'better battery' which is pretty ambiguous. Thicker power wires aren't going to help voltage, either. You get thicker wire for more amperage. For more info on charging systems: http://spinsharp.wordpress.com/category/car-audio/electrical-capacitorsbatteriesalternators-etc/ Amp impedance lowering as bass is played? That just isn't true. Where did you hear this? Why would he get a bigger amplifier if his system is already struggling to keep up with the amp he has currently? |
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New member Username: Joe1234Post Number: 6 Registered: May-09 | Sure, none of my suggestions will provide the amp with higher voltage but since "all" amplifiers have a regulation stage, the actual voltage to the amplification stage will stay the same! maybe it will run hotter.. Amps draw more current as bass is played since bass drivers require more power than say tweeters.. this is not to say that nominal output impedance is changed.. Finally to keep up with a processed signal (with stronger low frequency content) he will surely need more power.. and a lower internal resistance battery and maybe a capacitor which helps to supply current transiently to the amp(s). To JasonP, a sligthly higher voltage from the alternator is good to charge your battery faster but that will not translate into a change of spec in RMS power of your amp. |
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Platinum Member Username: GlasswolfPost Number: 13557 Registered: Dec-03 | "I plan next week to put in a MTX RE Q so that the bass will not diminish when the vol. in increased. (unless I get adverse feedback) " OK That's not how the MTX Re Q works. The ReQ is MTX's answer to the AudioControl EpiCenter. It's just a "bass restoration" processor that adds bass to things like radio broadcasts that lack bass from the broadcast itself. It's basically just a glorified bass boost circuit, which your JL Amp already has. The Re Q has nothing to do with your stereo's volume knob. It simply puts bass into signals with little to no bass already. This idea came about in the early 1990s when AudioControl came out with the Epicenter to correct for the lack of bass in radio stations versus a CD player or tape deck, before radio stations caught on to the fact that people were putting big stereo systems in cars and wanted the bass curve increased. Prior to this, any low bass on the radio would just distort and blow speakers in factory radios that often consisted of nothing more than a single 4x10" speaker in the center of the dash. "How do I increase the volts?????? " Line voltage from your head unit can be increased by using a "line out converter" (LOC) such as the AudioControl LC7, which takes a factory radio speaker level output and converts to RCA line level outputs, while also acting as a line driver to give a solid voltage signal to the amplifiers. "I "believe" that the volts are low (amp is sometimes hot) [Increasing] in volts would be better for the amp and also increase the RMS output. (from what I've read) " OK, this is going to take a bit of explaining. the benefit of having a higher line voltage (2V or 4V instead of say, 500mV) is that you get a lower noise floor (better signal to noise ratio) and a better signal resolution, much the same way you get a better end result from enlarging a JPG image if the original JPG was higher resolution, than if you tried to blow up a tiny thumbnail JPG from which you'd get a big, really blocky looking pile of crap in the enlarged image. The line voltage does not make the amplifier any louder. When your gains on the amp are set properly, the input stage of the amplifier's impedance should match the line voltage supplied by the head unit or line driver. If the line voltage is too low, you get a weak input signal and more noise. If the line voltage is too high, you end up with an over-driven input on the amp, and your signal get sclipped, which will drive the amplifier into clipping and possibly cause damage to your subs and amp. TL;DR: overdriving the amp doesn't make it produce any more power. the end. "Also, where does the amplifier get the volts? Is it from the HU, battery, alternator or combination thereof?" well, the input stage of the amplifier gets the line voltage (source signal) from the head unit. This signal is then amplified by increasing the amplitude of the source signal with transformers and capacitors in the power supply, and output through the finals (FETs typically) to the speakers. The amplifier gets the power to amplify the source signal from the car battery if the car's engine is turned off, or from the alternator when the car engine is running. The alternator supplies 13.8 to 14.4VDC (volts of direct current) and as much amperage (the variable factor here) as needed up to the maximum amperage the alternator can produce. volts is fixed @ (for now we'll say) 12 volts the resistance (impedance of your speakers) is relatively fixed (for simplicity sake) at say, 2 ohms. Now due to Ohm's Law, we only have one other variable, which is current, or amperage. This is what supplies the *oomf* for the amplifier to produce the power to make all that sound by converting a low voltage, high current input into a high voltage output. (at high volumes, amplifiers can often put out an AC voltage to the speaker wires in the 100-150 volt range.. like touching a wall outlet.) "Should I get another battery for run them in series? Upgrading the alternator is going to be expensive and I don't think it is necessary but I don't know what to do so please advise" batteries are run in *parallel* unless you want the voltage to be added. two 12V batteries in series would give you a 24 volt output, which would fry everything in your car. Capacitors won't do anything for power requirements so don't bother. the alternator is really your only answer other than just turning the volume down if the lights are dimming and voltages are dropping while playing the stereo system. If you don't have any issues with voltages in the car now though, then no need to upgrade anything yet. The way to tell is with a digital multimeter (DMM) to test to see if voltages drop below 12VDC in the car while the system is playing. Read the links here under miscellaneous and electrical. They may help you understand all of this better: http://www.glasswolf.net/papers/index.html I wrote these to help folks like you. God I hate these long replies. I lose all of my new message pointers by the time I finish one response. lol |
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Platinum Member Username: GlasswolfPost Number: 13558 Registered: Dec-03 | "Buy a capacitor for the amp and a better battery and maybe thicker power lines to the amp, " http://www.glasswolf.net/papers/capacitors.html http://www.glasswolf.net/papers/nocaplesson.html http://www.glasswolf.net/papers/charging.html |