QuestionQUESTION: I have a 1987 Caprice classic and I want to run 8 12" SPL GLWs on a earthquake sound PH 10000 D1 5000watts Mono 1 channel class D amplifier. Will I need two of the amps? Or would it the better to run 4 15" kicker cvrs?
ANSWER: Pretty potent system you are working on!
The 12" SPL GLW has two voice coils, each having a 2 ohm impedance according to the manufacturer. You would need to wire them so that the final impedance on the amp would be 1 ohm in order to get the maximum power transfer into the speakers. If you hooked 4 of 2 ohm speakers in parallel that would provide a 0.5 ohm load; the other group of 4 could then be wired in series with the first group providing a 1 ohm load to the amp. That would distribute about 600 watts to each speaker. Therefore, you would not be driving the speakers to their full power consumption level. Further these speakers are only 84 db sensitive - which is pretty low.
Based on the above I would suggest you add a second amp although that will only double the power level which is another 3 db level up.
But the more important consideration is the draw on your cars current capacity. Most alternators are rated at around 60 amps. That translates into 720 watts which is woefully inadequate to supply the necessary current. The amp, if 5000 watts would require more like 400 amps!
Therefore, you should look at double or trippling the battery and replacing the alternator with a high output one. Most high output alternators are rated at 220 amps.
Using the same process as above you can determine the power/current requirements of the kickers or any other combination.
Hope this helps. Happy pumping.
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QUESTION: First off Thank you. The answer you gave helped me a lot. So, what I've done is changed up and It looks like the OrionHcca 124 12"×3 wwith the Earthquake PH 10000 + They are offering the amp Kit with this package deal. Will I need 3batteries? And one more question What would be your best suggestion on all these different Ideas,because I want pictures off the wall when I come around?
AnswerThe OrionHcca 124 12" units have dual 4 ohm voice coils and a power rating of 4,000 watts. They are great units I am sure.
However, the power consumption is still BIG. With a rating of 4KW each you'd be looking at 12KW for the 3 units total. Using ohms law, the current required to support 12KW is 1000 amps. (P = I*V or I = P/V = 12,000/12v = 1000 amps.)
It is highly unlikely that you would actually drive them that hard; with music, even in heavy bass passages the likely hood is you would peak up around 1/2 of that or 6kw and 500 amps peak. Actual realtime power is likely to be much less. So, in my opinion you still need to beef up the power deliver system in the old Chevy (which, by the way, is a grand old vehicle!)
My suggestion is you go ahead with the install and after you get it working see what happens after you crank it up a little. First try a big power cap or 2F if you can and see if that helps. But, eventually, most likely, you'll have to add a battery and the heavy duty alternator.
In show cars that you may have seen they sneak in a 120v power line and hook up a big converter to the system so as not to burn out the cars electrics).
Good Luck. Sounds like you are going to create your own earthquake in the neighborhood.
PS: You said nothing about the enclosures you will mount the drivers in. The acoustic loading on these woofers is super important. There is an enclosure spec for these units that you can download from the net.
