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How to: Subwoofer installation

26876 Views 128 Replies 28 Participants Last post by  RednDead
Howdy. Sorry if I suck at writing tutorials. I know a subwoofer is something the majority of the owners of these cars are going to want, so I figured I’d share my knowledge a bit.
Background on me, I spent 4 years as a 12 volt electronics installer, and I’m pretty sure I still have an active MECP Advanced certification. The techniques I’m using in this guide are exactly what you’d get if you took your car to get a sub amp installed professionally.

There are some things I may or may not show in my install that I don’t advise doing because they’re not cost effective - you can get a professional sub amp install for about $120 labor, and anything that runs up the cost closer to that mark makes it less worth it to DIY.
1. Integrating with the factory amplifier by making your own T harness. This is cool, but also costs about $40 in parts just by itself. We will be using a military splice instead.
2. Wire dressing. Also very cool, but not cost effective if you’re doing a single install. The power kit I recommend has the engine compartment portion of the power wire pre-dressed, which is the only part that actually needs to be dressed.

With that said, here’s a list of stuff I used.

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So at this point,
-I've replaced the door speakers, running at full range of separate amp
-Added a set of component pods that sit in my back seats, running full range off separate amp
-Added some 6x9 boxes in the trunk, running 50-200hz on separate amp
-Added bass hub in tire well on separate amp
-Added 8 channels of amplification,

I took the signal for all of this "pre-amp" before the door speaker amp in the rear, which feeds into a separate eq before the amps so I can eliminate the static from 1,5-6khz. ground wire is the "latch" bolts.

The gawdawful sound is coming from the dash speakers, so I just bumped up the gain on everything else. All that and hours of tuning and it still sounds worse than the factory Alpine in my jeep. :( the bass hits harder though.
why wouldn't you replace the dash speakers then? or just remove them since you have presumably co-ax in the doors
why wouldn't you replace the dash speakers then? or just remove them since you have presumably co-ax in the doors
Yes, correct, coax in doors, and 2 way in pods. So, I'm not 100% sure but I believe that since those front speakers are split off of the signal that goes to the rear oem door AMP, that the telematics module is pumping sound through those dash speakers accordingtothe diagrams, so I would lose my ability to hear calls. I was 100% going to buy the OEM + speakers for door and dash but they couldn't (wouldn't) tell me if:
1. their door speakers could handle an aftermarket AMP of any size
2. If they would sell me just the dash speakers.

I have yet to see what folks have had success with in regards to the factory HU amplification and aftermarket speakers other than those that did the OEM +.

The factory speakers are 3ohm I believe and I am a little nervous that anything else will give the HU fits. I would also like to replace the rear kick panel speakers and have some 4ohm infinity to match the door and pod speakers. I would like to just put some infinity in the dash too, would make my tuning a lot easier.
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Reporting back! I disconnected the subwoofer’s power wire from the battery. The static is mostly gone and the volume can go up slightly more (with bass at -8 on the head unit EQ) to 28 before distortion and cutting out happens. Before I touched my sound system, there was absolutely no static or cutting in and out whatsoever, up to the point of 32.

So yeah, the butt splices I used definitely added some noticeable static. Im gonna try two things. First, Im gonna get rid of those connectors and try a direct, wire to wire splice with electrical tape to cover the ends. This should eliminate the static altogether. If it does not, I will take out the cut RCA cables and try the high side wiring.

Will report back when I have answers
Nvm lol still got some static. The new grounding point did get rid of I'd say about half of it but it sounds like the artists I listen to have lisps. Probably just gonna buy an amp because if it isn't the butt splices I used to connect the RCAs to the low side, idk what it is
That's a good way to describe the static, like they are holding on to their S's
Reporting back! I disconnected the subwoofer’s power wire from the battery. The static is mostly gone and the volume can go up slightly more (with bass at -8 on the head unit EQ) to 28 before distortion and cutting out happens. Before I touched my sound system, there was absolutely no static or cutting in and out whatsoever, up to the point of 32.

So yeah, the butt splices I used definitely added some noticeable static. Im gonna try two things. First, Im gonna get rid of those connectors and try a direct, wire to wire splice with electrical tape to cover the ends. This should eliminate the static altogether. If it does not, I will take out the cut RCA cables and try the high side wiring.

Will report back when I have answers
If just disconnecting the power wire solved your issue, it’s likely an issue with the sub’s integrated amp rather than a problem with your connections. I’m all in favor of removing the butt connectors in favor of a wire to wire splice (as long as that splice includes solder, don’t just tape them together) but i’m not confident this will help.
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if the new connections dont help i would try a ground loop isolator inline on the RCA's to see if that helps. also the RCA's that were included with that sub are probably trash too wouldnt hurt to try a better pair. ive only used the kind like below that are straight forward. ive seen some just now that have wire connections as well but no idea on their performance in comparison
Update: Got my sound system back to sounding stock. The highs and mids are back to perfect, no lisp or static in the songs, only I didn't have time last night to try tapping into the high level connections so my subwoofer sits idly in my trunk. I'm off work early today so I'll try splicing the high side today.

One question regarding wire gauge for the high side, do I need to use a certain gauge of wire to connect from my subwoofer amp's smaller 22-gauge wire high side wires to the existing high side wires going into the car's amp (which are probably something like 16 or 18 gauge)? I have some new 16 gauge audio cable and I'm not sure if the size difference in gauge will make a difference.
One question regarding wire gauge for the high side, do I need to use a certain gauge of wire to connect from my subwoofer amp's smaller 22-gauge wire high side wires to the existing high side wires going into the car's amp (which are probably something like 16 or 18 gauge)? I have some new 16 gauge audio cable and I'm not sure if the size difference in gauge will make a difference.
Going bigger won’t hurt.
3
Hello. I am back for my final update. I completely eliminated the static in my speakers, it’s not present at all even when my speakers are at 32 which is the absolute highest I’ll turn them up to (head unit EQ: bass 0 treble 4 and mid 4).

What it looked like when it had static: RCA cables with one end of each R and L connector cut off that were hooked up from the subwoofer’s low end connections to the cars’ amp low side cables, using CRIMP CONNECTORS. This is important because those were what was giving me so much static. Sub ground/negative was hooked up to the strut bolt.

What it looked like after I fixed it: I repaired the low end connections at the car’s amp, yes, with solder, electrical tape’d the exposed copper to fix the low end connections. Scrapped the RCA cable. Used 16 gauge audio cable, included with the Rockville 8 inch trunk subwoofer’s wiring kit, to connect the sub’s high side connections (R+/-, L+/-) to the car amp’s high end wiring. Spliced and insulated with electrical tape. Moved the sub’s negative/ground cable to a seat mounting bolt as the Audio God removedonut suggested.

There was technically nothing wrong with reusing the low end cables, but they were mangled enough from my fuckery that I left them alone and used the high end connections.



For anyone needing help,

Low level (RCA)
FL (+/-): Itgrn pin A3/yellow pin A9
FR (+/-): white pin A4/Itblu pin A10

High level:
FL (+/-): Itgrn pin A1/blue pin A5
FR (+/-): brown pin A2/purple pin A6




@removedonut Thank you so so much for your instruction. Truly doing the Lord’s work.
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