Expert: Cleggsan - 10/6/2009

Question
I'm looking in to getting a QCA4000D and 2 new 15 inch subs only, i'm stuck. heres what i'm looking at.
BRAND NEW - Hifonics OLM2415 - 15" Olympus Series Subwoofer (OLM-2415)
15" Olympus Series Subwoofer
Power Handling:
Peak: 4800 watts
RMS: 2400 watts
Fiber-Glass Infused FEA Structured Cone
1" Hi-Excursion Surround
Die-Cast Aluminum Chrome Speaker Frame
Front-Plate & Voice-Coil Cooling
Double-Laminated Integrated Spider Tinsel-Lead Design
Push & Insert Wire Terminals
3" Multi-layer high-temp dual 2 ohm voice coil
180oz. High-energy magnet
---------------------------------------------------------------
BRAND NEW - Hifonics OLM1615 - 15" Olympus Series Dual 2 ohms Subwoofer (OLM-1615)
15" Olympus Series Subwoofer
Power Handling:
Peak: 3200 watts
RMS: 1600 watts
Fiber-Glass Infused FEA Structured Cone
1" Hi-Excursion Surround
Die-Cast Aluminum Chrome Speaker Frame
Front-Plate & Voice-Coil Cooling
Double-Laminated Integrated Spider Tinsel-Lead Design
Push & Insert Wire Terminals
3" Multi-layer high-temp dual 2 ohm voice coil
160oz. High-energy magnet

Now what I want to know is whats the diffrence really is. Will my amp be able to handle the 2415 or should I look in to getting a 6000 watt amp. or should I just go with the 1615. Which ones will pound more. Will a 30F cap, 1200Amp battery be able to handle the 2415? Dunno what would it take to handle them, or just go with 1615. Thanks.


Answer
You are right to concern yourself about battery power capacity and the alternator of the vehicle.  The current being pulled off your car system under heavy music load can be enormous.  You really should look at that very carefully.

Next, you must look at the connection of the amp to the subs;  matching of the impedance loading is very important for maximum power transfer.

Then, after all said and done, the matter of how the subs are loaded acoustically and the volumetrics of the vehicle they are mounted in will have significant influence on the final performance.

It is not a question of which sub is the better but a question of how to optimize the one you have chosen.

You have sufficient power and plenty of cone excursion for building up some big low frequency pressure using either sub.

Low frequency resonances and sensitivity are two additional factors that you might want to investigate.  Enclosure loading will be important as well. There are many good discussions about these matters in my other replies to similar questions and elsewhere on the Internet.

That's it for now; got to run, but let me know if you have further discussion.

C