Problem With New Subs - Please Help!

[cpbass6259]

Hey Car Audio Community! I'm excited to be here. I'm having a problem setting up my new subwoofers and I'd appreciate any advice. The problem is, I'm getting (what I believe to be) distortion at low volume. If I turn my amp up more than halfway, the speakers begin to rattle and sound horrible (especially on hard-hitting kicks). At this point, I'm guessing they're underpowered... but this doesn't make sense to me because I thought I matched the components pretty well- here's my set up...

I recently bought two Pioneer TS-W303R 12in subs mounted in a sealed enclosure. The specs on the back of both speakers say that they have 4ohm impedance and can handle 1200watts max, 250watts "nominal power" (RMS?).

I'm trying to get these speakers running inside my house so I bought an amp and computer power supply (AC to DC converter). The amp is a Rockford Fosgate R500X1D 1-Channel Amplifier that is rated for 300watts RMS @ 4ohms and 500watts RMS @ 2ohms. The power supply is a EVGA SuperNOVA 750B1 which can handle up to 750watts.

I wired the subs in parallel so the total impedance should be 2ohms... which means the amp should be pushing 500watts, 250 to each speaker. This should be pretty spot on for the speakers so I'm not sure why they sound so weak. Any help would be greatly appreciated!

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[garychoffmann 10+ year member]

I believe that's a 20 amp power supply. At maximum it can feed the amp enough 12v constant average of 140-180 watts.

 

[bldunn]

I thought that if you got distortion then the gain was too high? What did you have the volume set on with your head unit or sound source when you set the gain?

 

[Papermaker85 5,000+ posts]

You sure you wired the drivers in phase? Disconnect one driver and test it out..

 

[Wick3D]

Your problem is with the power supply, that PSU you got has 4 x 12v 20 amp rails. You really wanted a high amp single rail PSU. Unless you want to return it, the only other solution is to bridge the rails.. even 2 of them might work. NOW I take no responsibility if you fry something. Each rail has its own voltage regulator and will work independently... UNLESS those 4 rails are all on the same single circuit then branch out.. You can put a multi-meter set to OHM's with the psu off, probe 2 different 12v rails and see if there is continuity.. if it does then you know its a single rail split, no continuity means its truly 4 individual rails. For 500 watts you need around 50 amps..2 rails bridged will get you close, you will just need to set your gains to match 400 watts instead.. else you need to bridge 3.. might as well all 4.. Best solution is return that PSU and get one that has more than 50amp single 12v rail.

 

[Wick3D]

 

[Wick3D]

Reasonably priced single rail psu's:

Rosewill Hive750 Rosewill HIVE Series HIVE-750 750W Continuous @40°C, 80 PLUS BRONZE Certified, Modular Design, Single +12V Rail, ATX12V v2.31/EPS12V v2.92, SLI Ready, CrossFire Ready, Active-PFC Power Supply-Newegg.com

Roswill Arc-750 Rosewill ARC-750 ARC Series 750W 80 PLUS Bronze Certified Single +12V Rail Intel 4th Gen CPU SLI and CrossFire Ready Power Supply-Newegg.com

EVGA 110-B2-0750 EVGA 110-B2-0750-VR 80 PLUS Bronze 750W Semi-Modular NVIDIA SLI Ready and Crossfire Support Continuous Power Supply - Newegg.com

Corsair CX750 CORSAIR CX series CX750 750W 80 PLUS BRONZE Haswell Ready ATX12V & EPS12V Power Supply-Newegg.com

Obviously there are 1000's of choices.. just linking you a couple.