# sub barely moving - HELLLLP!



## mkiv94 (Aug 13, 2013)

hi guys, heres the story. My 200 watt rms walmart pioneer sub, and 380 watts rms amp used to bump hard in my old bmw. Installed the same setup in my new car and its barely hitting at all. I need the bass boost on the amp, and the headunit on for the bass to be at an acceptable level, Ive turned them off though because i dont want the amp clipping. The stock 5x7 subwoofer is hitting harder. I cannot figure out what the problem is, i bought a sundown sd 2 10 2 ohm, the output is still negligible. The only difference between this setup and my old one is that I'm now using rca cables instead of a line out converter. PLEASE HELP, this is really really getting annoying now. 

Thanks guys, awaiting your response


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## qwertydude (Dec 22, 2008)

First turn all bass boosts off and set your head unit EQ to flat. Get a 0 db test tone on a CD, then turn the volume up to 3/4 and measure the AC voltage with the test tone playing. You can calculate the wattage from there. If the wattage doesn't add up high enough, say at least 200 even with the gain turned all the way up then you're not getting enough line output voltage. Try unplugging one RCA to see if it's a short, also look to see if your amp has an input sensitivity switch, if so try flipping it and see if it improves.

If these don't help then we need more details, head unit type, any LOC's used, amp model.


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## mkiv94 (Aug 13, 2013)

I tried switching the left and right channel of rcas, made no difference. I played some music with only left and only right, and only half the bass comes through, so i assume the rca cable is fine. I dont have a multimeter but if necessary i will get one, Is there a tutorial on how to measure the ac voltage, im a car audio newbie . I dont see any input sensitivity switch on the amp. The amp is a pioneer 5400t, and the headunit is a pioneer avh-p4100dvd


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## mkiv94 (Aug 13, 2013)

Ok so I bought the RCA to 3.5mm cable and connected it to my iPhone, seems like I'm getting about twice the output of bass with the iPhone 3/4 of the way up, than I do from my headunit. However I doubt its the headunits fault as its only 2-3 years old, and the subwoofer output has never been used. So is the bass louder if u connect from iPhone to amp, or does this mean the rca to the headunit is faulty? The head unit is a pioneer avh p4100dvd.

Thanks guys!


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## TheBetterMethod (Sep 19, 2012)

First be sure the sub is wired to the amp properly. Wire the sub to 4 ohms by wiring the coils in series. Is the enclosure the proper size?

You now need to adjust your amps gain setting. You'll need some sine waves, get a 40hz sine recorded at -5db. 

Set the EQ flat, 
Turn off bass boost on the HU
Turn off bass boost on the amp
Turn the subsonic filter down all the way
Turn the amp Gain setting all the way down

Does your headunit volume go to 62?

If so, play the 40hz @ -5db sine wave at volume 57 on the HU. Adjust the amp gain up until you hear distortion then back it down. You should be good to go at that setting.


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## miniSQ (Aug 4, 2009)

there was another thread exactly like this last month...and after about 6 pages the guy realized he had a setting wrong or something. Try going back and finding that thread. There were pages and pages of responses.


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## quality_sound (Dec 25, 2005)

Yep, check and make sure you don't have a high-pass filter turned on somewhere.


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## mkiv94 (Aug 13, 2013)

i honestly cannot find anything wrong with the wiring, ive been searching for about a month. This is how i wired my sub http://m.seimg.net/product/img/subwoofer_wiring/1_sub_DVC_2_ohm_2ch_bridged.jpg. Yes the high pass filter is on, on the headunit however it doesnt affect the subwoofer channel. Also the subwoofer channel on the head unit is on level 6 to ensure the rcas are getting enough voltage. And my amp doesnt have a high pass filter. doubt its the gain either, at half way up i expect the subwoofer to at least move a little bit. Cant be the enclosure, because the same one in my old car would hit a lot harder. So im at a loss, i cant figure out at all what it is, trying the rca to 3.5mm adapter i think i narrowed it down to either the head unit(2 years old) or the rca cable. The amp is a pioneer 5400t

!!!!!!!!!!!!


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## miniSQ (Aug 4, 2009)

mkiv94 said:


> hi guys, heres the story. My 200 watt rms walmart pioneer sub, and 380 watts rms amp used to bump hard in my old bmw. Installed the same setup in my new car and its barely hitting at all. I need the bass boost on the amp, and the headunit on for the bass to be at an acceptable level, Ive turned them off though because i dont want the amp clipping. The stock 5x7 subwoofer is hitting harder. I cannot figure out what the problem is, i bought a sundown sd 2 10 2 ohm, the output is still negligible. The only difference between this setup and my old one is that I'm now using rca cables instead of a line out converter. PLEASE HELP, this is really really getting annoying now.
> 
> Thanks guys, awaiting your response


i missed this the first time thru about the RCA vs Speaker level. 

Speaker level connections will send a much hotter signal to the amp. So if your gain is set to the same place with the RCA's as it was with the LOC...then lower output would be expected.


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## chad (Jun 30, 2005)

mkiv94 said:


> Ok so I bought the RCA to 3.5mm cable and connected it to my iPhone, seems like I'm getting about twice the output of bass with the iPhone 3/4 of the way up, than I do from my headunit. However I doubt its the headunits fault as its only 2-3 years old, and the subwoofer output has never been used. So is the bass louder if u connect from iPhone to amp, or does this mean the rca to the headunit is faulty? The head unit is a pioneer avh p4100dvd.
> 
> Thanks guys!


Is that the only amp? if not do the other speakers have any odd noises/alternator whine?

Does the sub have pops/whine?


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