Sub install not so loud

[baaaa1233333]

My first post on the forum so I'll try and make it as complete as possible. I have a 2002 330ci with the harman kardon system. I bought an Alpine MRP-M500 amp and an Apline SWR-1243D Type-R 12" DVC sub. I used a Stinger SGN11 line output converter, 4 gauge power and ground, and 8 gauge speaker wire from the amp to the sub (overkill but I orignally was using 18 and I thought that could have been the problem). The sub is wired up at 2 ohms. The problem I'm having is that the sub isn't loud, like at all. Even when the volumes up the factory system puts out a lot more power than the sub. I think theres a little whine coming from the sub but I'm not sure if it's still there or not. So the main problem I'm having is that it comes on but does not sound very loud. I had an older car with a cheap setup, 150w P1 and 150W amp and when that sub hit it actualllllllly hit.

If someone could help me out that would be great. I'm in Norfolk, VA if anyones local and I live at ODU.

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[Cruzer 10+ year member]

where are your gains set? have u tried cranking them? using the stock hu, voltage might be very low, so the amp gains might need to be set higher(unless the LOC increases it, never used one, wouldnt know). my aftermarket HU only has 2 volt rca outputs, my gain on my sub amp is almost maxed out and i still have to turn the volume up pretty high to get it to be where it should be as far as output.

another option to test it, would be splice into some speaker wires and buy cheap speaker to rca wires. see if anything changes to see if perhaps the LOC is having problems.

the amp should push the sub well, the sub should be loud for a single 12 off 500 watts.

 

[baaaa1233333]

I have the gain set at 0.5 and the bass EQ at 6 and then LP filter at like between 100-140 I think. The stinger sgn11 says it has 12W RCA outs. Not sure if thats what it's actually pushing though. I was thinking about trying another LOC, but I didnt want to buy one if I didn't have to.

 

[Cruzer 10+ year member]

all i can suggest is try pushing the gain, obviously pay attention to the subs and increase it slowly. hear distortion or bottoming out, go back down, but imo its gain not set right or the LOC is causing a problem.

which is why i also suggested splicing speaker wire as it might be cheaper than buying new LOC

 

[baaaa1233333]

What do you mean by splicing speaker wire? Sorry its probably a pretty common thing, but I'm lost haha. I had to tap into the rear speakers for the LOC for the RCA's. The sub like barely moves when its playing music even if I turn the gains up. I'm using a sealed box but it was within the size requirements of what alpine recommended. Should I have gotten ported?

If I go to advanced auto is there any way for me to use a multimeter or something to check the output coming out of the amp? I've never used one so I'd be lost but is there any way to check that the amp is pushing the right amount of sound?

 

[Cruzer 10+ year member]

cut into rear speaker wire(the outside cover over the actual speaker wire) buy two speaker to rca wires, wrap them to the speaker wire where u cut the outside casing, then plug them into the rca spots on ur amp.

here is the wire im talking about, not sure if u can buy cheaper one, or maybe it would be more cost effective to just try another LOC. i thought they were cheaper

24-Ft. 18-Gauge Speaker Cable with RCA Plug - RadioShack.com

even being sealed it should still be loud, not as loud as ported but u deff have something not working right

u can use a dmm to measure something but u would have to look it up i dont know how, and dmms are cheap and helpful for car audio and repairing things around the house

i dont know why no one else is chiming in, they know more than i

 

[baaaa1233333]

oh okay I didn't know those cables even existed. Everyone always just said LOC or if the amp takes High-level inputs use those. mine does but I already did the LOC and i lost the little cable for the high-level inputs. Maybe I'll just take it to a shop and have them redo everything or have them fix it haha. Wanted to do it myself buttt this seems to be a little over my head i think. maybe someone else will help out too.

 

[Cruzer 10+ year member]

its gotta be the LOC or the amp. one isnt doing its job right. LOC should be cheap enough to try a different before paying a shop big $ to try it.

but maybe someone else has a better idea of what u can do to test, or know exactly whats wrong for u to fix

 

[lilboom 10+ year member]

I have the gain set at 0.5 and the bass EQ at 6 and then LP filter at like between 100-140 I think. The stinger sgn11 says it has 12W RCA outs. Not sure if thats what it's actually pushing though. I was thinking about trying another LOC, but I didnt want to buy one if I didn't have to.

you don't think that the .05 gain setting is fishy

what head unit

and rca's are you running?

 

[baaaa1233333]

I already replaced the amp once. So it's prob the LOC. It doesnt really change much if I set the gain higher. Stock head unit. Some twisted pair RCA's from kicker.

 

[subzero 5,000+ posts]

the converter is not going to give you a large low level output. assuming you hooked up the converter correctly, it is naturally going to take more juice. Suggestion would be to fade to the back until everything seems equal. Check your amp gains. the will probly have to be increased as well.

The best bet would be to get a line driver.

HOWEVER... most BMW are not that easy to install a sub because the system has an amplifier under the seats that control and separate all the speakers.

I would yank out all that harmon shit out.

 

[baaaa1233333]

If I had the money I would yank it all out and go after market. Yeah the amp for my car is in the trunk. I "spliced" into the rear speaker wires on it. I didnt know there was a thing called a line driver. Other people who add subs onto their BMW's haven't said they need a line driver. I think theres just a problem with something specific to my setup/car.

 

[dcktp37 10+ year member]

Wait, you said you spliced at the amp? Before or after the stock amp? The wires going in to the amp from the stock HU should already be low level. (Someone correct me if I'm wrong.) So if you took low level and lowered it you wouldn't have much left hence the gain not helping much.

 

[Dj-torn 10+ year member]

I would check to see if you wired your LOC to the amp outputs, and not the amp inputs, this sounds to be your problem if you have messed with all the amp settings. If you don't know which the outputs are, run speaker wire from each channel of your LOC to the your rear or front L & R speakers, whichever is easier.

LOCs are great solution for this installation type, but they are not reliable, so swap it out before going to the shop.

If you are sure you are connected to your amp output, (make sure its the output for the mids not the tweeters) and you have swapped out your LOC. I would suggest you look into a sound processor which has a sub output, these are more reliable and more than likely what a shop will try to sell you on.

 

[akheathen Premium Member]

well, since nobody picked up on the "alternator whine" i'll point it out. first things first, check power and ground voltage at the amp, then from the power wire to bare metal. sounds like you may have a ground problem. do the tests, both with the amp on and off, and with the rcas connected, and dis-connected. if the amp shuts off, you definately have a bad ground. running it like that can damage the amp, loc, and rca's. likely, especially if the whine did go away, you have damaged the loc, if this is the case. did you hook up the loc ground as per instructions?