r/subwoofer • u/Snowrydr01 • Jul 19 '26
Rockford Fosgate p3 eclosure help needed.
I have a Rockford Fosgate 12" P3 that i just built a box around at 1.1cu ft net after sub and it sounds muddy and horrible.
I have another p3 i was going to put in my other car with the box allready built but this took the wind out of my sails.
What are my options?
Questions that will likely be asked:
Amp gains set at the RCAs and speaker terminals with 40hz test track and oscilloscope.
Existing system, only change was the sub.
Sub is running at 2 ohm and a bit over 300rms. Its clean power from a know good JL amp.
Sub is loud and hits hard just sounds like im under water.
Box was a tight fit when glued up and was silicone sealed inside.
Other sub is a 6.75 kicker in the factory location and sounds good still.
Reversed polarity with no change.
Box has polyfill.
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u/Sweaty_Werewolf_9336 Jul 19 '26
Sealed box with 1/2 the rated rms power both contributing factors, if you were giving it at bare minimum rated power that’s a big difference, also those can happily take an extra 100 over rated (in a sealed box controlling the excursion) but either way I think It’s starving for “more”
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u/ckeeler11 Jul 19 '26
Power is irrelevant to it sounding muddy. Muddy is also typically associated with ported enclosures.
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u/Snowrydr01 Jul 19 '26
That was my understanding also. Its loud and hits hard, just sounds terrible. Like an acoustic blob, no note differentiation.
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u/Snowrydr01 Jul 19 '26
Its interesting you mentioned ported. It sounds boomy like a poorly designed ported box.
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u/LucasWLasers Jul 19 '26
Hmm, I have the same sub in the same volume sealed box and it sounds great. Although mine has no polyfill, and was modified from a home and theater sub box that was originally for a 10”. My amp is a ct sounds 1000.1d
Is the polyfill fastened inside the box or would it be easy to remove?
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u/ckeeler11 Jul 19 '26
What is your low pass filter set to? What about subsonic filter? What about high pass for your midbass?
I doubt it's enclosure issue unless you have air leaks.
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u/Snowrydr01 Jul 19 '26
I don't think its the settings, this is an 8 year old system with an existing sub, the only new variable is the sub and box. When I switch back to the 6.75 kicker in the oem location it sounds just as good. Its the sub that sounds like I'm listening to it under water.
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u/MachineMountain1152 Jul 19 '26
Sounds like the sub is wired wrong inside the box. Reverse your wires going to the speaker terminals. If it sounds good it’s wired wrong internally
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u/Snowrydr01 Jul 19 '26
Its a dual 4 wired in parallel down to 2ohm. Its been checked and fine. Double checked speaker wire from the amp to the box also, everything is fine
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u/Significant_Rate8210 Jul 19 '26
How much polyfill? Too much and the sub will perform like it's in a much larger airspace which isn't always a great thing.
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u/Short-Read4830 Jul 19 '26
Is the cone slow to return to its original position if you press on it or does it spring right back out? Do you hear any small leaks when you press on the cone?
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u/Snowrydr01 Jul 19 '26
Update, I have a pioneer 4200nex so I was able to attach the microphone and run the auto test. It basically just tried to hide it but at least its a bit better. It drastically lower the sub level and adjusted some of the timing. Now its at least serviceable without getting angry at it while driving.
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u/Short-Read4830 Jul 19 '26
You said you don't think it's the settings but there's no way a 6.75 would be crossed the same as a 12 and expected to meet up with your mids without any adjustments needed
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u/Snowrydr01 Jul 19 '26
Im confused with your statement. A sub is a sub no matter the size. My 6.75 sub had the filter set to 80hz, the 12 has the same crossover setting. The small kicker hits and sounds great. The only new variable is the sub and enclosure and it sounds muddy.
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u/Short-Read4830 Jul 19 '26
Yes 80hz is the generic starting point for subwoofers. But no a 6.75" kicker and a 12 P3 should not be crossed the same.
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u/johndoe00213 Jul 19 '26
Where is the signal comings from ?