Audio Systems: loss of power, duty alternator, alpine head unit

Question
i have two 10inch alpine type s subs at 2 ohms powered by an alpine pdx 1.600 class d mono amp and four 6x8 alpine type s speakers powered by my alpine head unit in my 04 ford supercrew and i had all this installed professionally and for the first couple of days it was very loud and my subs where hitting very deep and hard and after about four or five days it just is about 25 percent of what it was and my amp is supposed to tell me if i have a short or if something is wrong but it says everything is working good and no fuses are blown and i want to find the problem and i was wondering if i would need more battery for this system or a capacitor cause my lights do dim but i really have no idea

Answer
There are many things that can effect your perception of the bass level.  Most often, after you get used to the sound and you keep cranking it up your brain plays tricks on you and the sound pressure has not changed but your hearing levels have shifted!  So, in this case there is nothing wrong with the system but your hearing reference.  (Believe me, it is a real phenomenon that all audio experts are very familiar with).

If the lights are dimming you certainly are drawing lots of current from the vehicle electrical system.  The best thing you can do is put in a heavy duty alternator which can keep the charge on the battery up solid.  Adding a capacitor is a great help for short bass notes; it will help hold up the voltage for a very short period of time and give an improvement in the bass performance some, but it does not overcome a weak alternator and battery system.

Also, if you have a voltmeter you can check the voltage level at the amplifier when it is driving heavy bass to see if it stays up to the standard 13.5v when the engine is at about 1500 rpm or enough to get full charging current out of the alternator.  Then, also check the voltage right at the battery terminals under the same conditions; this will tell you how much voltage drop you are getting on the power wire that goes to the amp. If the drop is significant you may want to increase the size of the wire by dropping down a couple of gauges to keep voltage a little stiffer.

Let me know if this helps.  Send my  more questions after you have checked these items out.


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