Elantra Limited w/ Nav Subwoofer and Amplifier Install and Setup (step-by-step guide)

Flatland2D · Dec 27, 2011

I’ve wanted to add a subwoofer to my Elantra since I bought it. The “premium” sound system is sadly lacking, but I guess most factory stereos are that way. It doesn’t sound that bad up to around volume level 15, but it sounds like it falls apart at higher levels. My goal was to come up with the cleanest installation that I could by maintaining the factory look and minimize the number of permanent, irreversible changes to the car. I’m a very hands-on and visual learner, so I’ve tried to include lots of pictures. I think it makes the process pretty straight forward.

This installation was stretched out over several weekends and I wrote a little bit of this at a time so it just kept adding up. The length of this is indicative of the amount of time I have obsessed over each detail of the installation. Many things included will be obvious to anyone who has done this before, but I also wanted to document some of the techniques I used that I thought worked well and share for others to use and improve upon. Regardless of the level of detail I’ve tried to include, I wouldn’t recommend doing this yourself if you are not at least adept at working with your hands and know a thing or two about electricity and wiring. But if you have the skills and willingness to do it, you will be happy with your results because no “professional” installer will do as thorough of a job as you will do on your own car.

I don’t want to go into too much detail regarding amplifier and subwoofer selection, as that is another topic in itself, but consider if you want something small to mount under the driver’s seat, or if you’re willing to sacrifice some trunk space, something a little bigger and louder. I went with the Rockford Fosgate 150-2 amplifier and R1L-1X12 sealed subwoofer. Both of these are rated at 150 W. Crutchfield sells these at a discounted price if you buy them together in a bass package. What I like about this one, other than that it got good reviews, was that its sloped backside was designed to fit up against the seat backs to make efficient use of the space.

The main things you’ll need to buy in addition to the amp and subwoofer is an installation kit and a line output converter (LOC). The installation kit should have all the wires, connectors, fuse, tie-wraps, and other odds and ends. The kit that I ordered is below. It is advertised as 8 gauge, but it is definitely not 8 AWG, which is a standardized wire size. Leaving off that designation allows them to sell a smaller wire than you’d expect, but for my purposes with a load of 150 W, even the misrepresented 8 gauge will suffice. The speaker wire is especially small and it could be used for connecting the LOC to the external amplifier since they will not be carrying any current, but I used normal 16 AWG gauge here because I had it. I would be hesitant in using it between the amp and subwoofer because it is so small.

Neither the Elantra’s head unit nor external amplifier have RCA outputs to go to the new amplifier, so the LOC is required to convert the speaker level signals down to line level. I originally ordered the PAC SNI-35 LOC because it was cheap, but later changed my mind because I started worrying about the bass roll-off. Most factory car stereos attenuate the bass frequencies as volume increases because it stresses the inferior speakers too much trying to reproduce those frequencies. But when you add in a subwoofer that is built for playing low frequencies, you’re not left with much signal in the bass range.

I instead bought the Audio Control LC2i which is an active LOC (requires power) that is designed to restore the bass that was reduced by the factory system. It’s a bit more expensive than the cheaper, passive LOCs but all the reviews I’ve read of people who upgraded to an LC2i after having a passive LOC said it made a big difference. I figured it would be worthwhile to do it right the first time instead of upgrade it later.

The LC2i has a feature that will trigger its own remote 12 V output (the signal that tells your amplifier to turn on) whenever it detects a signal on the speaker wires. However, I’ve read that this feature is not compatible on all factory systems, so rather than take a chance and have to redo it later, I decided to bypass the LC2i’s remote trigger and wire it up directly as you normally would. There is a jumper on the LC2i that enables and disables this feature.

You could avoid the LOC issue if you buy an amplifier that accepts speaker level inputs, but then you don’t get the bass restoration. There are other products that perform a similar function, but either way you have to add another component into the system.

Just to throw it out there, it might be possible to bypass the factory external amplifier. It looks like the external amplifier gets its audio signal over copper SPDIF, but car amplifiers with SPDIF inputs are hard to come by and extremely expensive. Also, the external amp is on the car’s CAN bus (for digital communications) which makes me wonder if the amp is doing some additional processing. If that was the case, you’d also need to replace the head unit, but that replacement would have RCA outputs and you could use a normal amp. The external amp also has a signal wire labeled NAV, which makes me wonder if maybe when this signal is asserted, it lowers the volume of the music so the nav voice can be heard better. So I guess what I’m saying is, if you want to get rid of the factory amp, you’ll probably be replacing the head unit as well. These are just my guesses though.

Anyway, on to the installation.

Running the power and ground wires

The first big step is running the power wire from the battery to the trunk. I literally spent hours thinking about the cleanest way to do this, sitting upside down in the driver’s seat with my head on the floor and feet by the roof, getting out to look at the other side of the firewall under the hood, and back inside again. My approach wasn’t original, but it was in-line with my desire to hide the modifications by keeping the factory look.

I borrowed the hole that the hood release cable is using for the power wire. The hole is lined with a rubber grommet that has a boot on the side that faces the engine bay. The actual hole in the metal is large enough for a second cable, so I used a clothes hanger to feed the power cable through the grommet. The clothes hanger ended up puncturing the boot, but otherwise went through without any snags. One thing I like about using this hole is that the battery is very close to the hole so it keeps the wire shorter, and the battery itself also hides the wire. Pull enough of the wire through to have several feet in the engine bay. Your power wire should be plenty long, so leave yourself some extra wire in case you need it when you come back to do the fuse.

Note that this was taken with the camera down in the engine bay. The hood release cable can only be seen at just the right angle when viewing from the outside.

I used the clothes hanger for the next few steps that involve fishing the wire under pieces of trim. I routed the power cable behind all the factory wiring before taking it down the cowl side trim. I’d recommend going behind the factory wires as much as practical because it will make the wiring look more like it’s supposed to be there and not slapped on as a modification.

I removed front door scruff trim by pulling straight up on it and the wire came out the bottom of the side cowl trim. I left the center pillar trim on and fed the wire through.

Before you can take off the rear door scruff trim, you need to remove these two screws and remove a bolt at the back of the rear seat. It is easy to access the bolt by folding the seat down and looking for it from behind. With the bolt out, you can pull up on the seat and the metal loop will pop out from the front of the seat, allowing you access to the two screws. It takes a pretty good yank to pop it out.

From there it’s pretty easy to feed through the rear wheel house trim and come out at the cut-out near the seat belt bolt. Then it’s a straight shot up to the trunk.

Success! Tape off the exposed end of the wire so it won’t short to ground by accident. Before doing that, you might want to set your multimeter to measure resistance and touch one lead to the exposed copper of the power wire and one to ground. This will let you know if you accidentally nicked the insulation on the wire while pulling it through.

I connected the ground wire to a seat bracket bolt. It’s stainless steel and a pretty good conductor.

I then wrapped the power and ground wire in split loom tubing and electrical tape. The ground wire makes a 180 bend near the connector and slips inside the tubing. Once I had two wires in the tubing, I spiral wrapped the wires so that the cross sectional shape would be round which helps the tubing better keep its shape. Sticky tie downs were used to keep the tubing positioned correctly. They aren’t quite factory looking (maybe if they were black) but they serve a good purpose. They’re available at Radio Shack.

Next I connected the other end of the wire in the engine bay to the fuse and battery. There is a convenient place to mount the fuse on the bracket at the bottom of the battery. I used a 6 mm bolt (12 mm long) to mount the fuse to the bracket.

I played around with some different options for connecting the source side of the fuse to the battery. I ended up removing the 6 mm flange nut from the stud and replaced it with two normal 6 mm nuts with the crimp connector for the power wire between them (note: I crimped AND soldered every crimp connector in this installation). The flange nut is taller and it doesn’t line up the crimp connector as well. If it gets too tall the cover won’t close. Flange nuts are designed to not back out, and I think double nutting it serves about the same purpose so exchanging these shouldn’t create any problems. The flange nut was reused on the 6 mm bolt holding the fuse to the bracket. Once you have your wires cut to length and crimped, you can leave off the connection to the battery until you’re ready to hook up the amp.

The finished work disguises itself pretty well as looking like factory wiring after being enclosed in split loom tubing and wrapped in electrical tape. The fuse is a giveaway but it’s critical that it gets connected as close to the battery as possible so there’s really no hiding it.

Tapping the speaker and remote 12 V wires

The next big step is tapping into the speaker wires for the LOC and grabbing a switched 12 V signal from the external amplifier.

The external amplifier is located behind this piece of molded carpeting. I started by removing the floor carpeting from the trunk.

I then removed the rear trim piece by gently prying off the three fasteners and pulling straight up on the trim. I really developed a dislike of these fasteners while doing this installation. Every third one seemed to be stuck and took a lot of effort to remove. They are plastic so be careful not to break or mar them too bad trying to get them off. I saw that Lowes stocks these under the name “variable depth fasteners” but they are black so the colors won’t match. The dealership could probably get you some if you needed them.

I also removed the trim behind the passenger side rear seat. There are some more fasteners and a screw holding it on at the bottom. I left the fastener on the far right in and swung the trim out of the way. You need to remove the fastener holding the carpeting on to get it out of the way. There is another fastener holding the carpeting on further down, but it is very difficult to pop off. I left it on and swung the carpeting over inside the trunk. This step is optional, but if you don’t remove the fastener shown above, you’ll have less room to work around the external amplifier.

Remove the two screws at the bottom of this molded piece and pop out the fasteners and finally you should have access to the external amplifier.

Pull off the connectors and remove the tape wrapped around these wires. You need to tap off the blue wire with a brown stripe for the switched 12 V source that will go to the LOC. Keep in mind that the connector drawings are looking at the female connector on the amplifier or the back (wire side) of the male end of the connector; however you want to look at it. As long as you know that the side of the connector that goes into the external amplifier is a mirror image of the drawing.

There are many ways to do taps and I prefer soldering them. I VERY CAREFULLY cut the insulation of the wire where I wanted to make the tap without cutting any of the copper. Take it slow and do a little at a time. I can’t stress that enough. Once it’s split, I pulled the insulation back in opposite directions to show more of the copper wire.

I stripped about half an inch of the blue 12 V signal wire and wrapped it around the exposed copper of the blue/brown wire. Then I carefully soldered the connection. I’d recommend bracing the blue wire with tape so that the two wires being soldered are parallel to each other. This is because the solder tends to wick back up into the wire, and if the wire was perpendicular when you soldered it, it won’t easily bend down and you’ll stress the joint.

I then wrapped the connection in electrical tape. I kept going past the actual solder joint to brace the two wires together and protect the joint from stressing when the cable bends or pulls.

I wrapped the group of wires back up in electrical tape and moved on to the other connector.

There are four taps to be made on this connector. I used the same process that I described above, but you can use whatever technique you’re familiar with. Fan out the wires and you should see the six twisted pairs. I went with tapping off the front speakers, but I don’t know if it makes any difference if you use the rear. Again, note that the connector drawing is looking at the back side of the connector (the side the wires come out of). I took my speaker wire and connected to +/- of the left channel with one wire and +/- of the right channel with the other wire. Don’t forget to label each individual wire as you solder it. Polarity matters.

Here’s what mine looked like when it was all done. Then I bundled the wires up in electrical tape and plugged the connectors back in. I wrapped the two speaker wires and 12 V signal wire in 3/8” split loom tubing and wrapped the tubing in electrical tape for the entire length. This is the step (tapping the wires) that I’d consider the most irreversible of what I’ve done, but at least it can be hidden in electrical tape and tucked away behind the molded carpeting so no one would notice.

Before and after shot. Looks like a factory job.

Finally ready for the amplifier and subwoofer to be installed.

[continued below]

Flatland2D · Dec 27, 2011

Mounting the amplifier and connecting the wires

I mounted the amplifier on the subwoofer enclosure. I’ve read much on the internet saying this is okay and that it’s not okay. It was a convenient place for me to mount it, so without concrete evidence that it was a bad idea, I went ahead and mounted it there. I did use some nylon nuts as spacers between the amplifier and enclosure just in case.

I got another length of split loom tubing to carry the 12 V and ground to the LC2i with the returning remote 12 V output back to the amplifier.

AudioControl recommends a 1 A fuse on the 12 V powering the LC2i, and I’d like to echo that for one important reason. The smaller gauge wire that will be powering the LC2i is, up until the 1 A fuse, still connected to the battery through an 80 A (or whatever it is) fuse. It’s possible that if the smaller gauge wire were to short to ground, it wouldn’t short circuit enough current to blow the main fuse, allowing that wire to burn up, melt, cause a fire, etc. Put the fuse as close as possible to the source end of the wire. Mine pops out of the wire loom and tucks back in as shown with the red arrow. Also note how well the back slope of the enclosure matches the seat back.

Tuning the amplifier and subwoofer

I first wanted to see if the factory head unit clipped, and if so, at what volume. I started by centering all the tone controls for treble, middle, and bass on the head unit. I was a little disappointed to see that it started clipping at around volume level 30 at 500 Hz and below and level 27 at 4 kHz and above. I chose the lower of the two values to avoid clipping at all frequencies. I would have hoped that since the head unit and amplifier were designed for each other that it wouldn’t clip all the way up to level 35, but doing the math on the output voltage just before clipping starts at 2 kHz ([7.49 ^ 2] / 2 Ohms) gives 28 W output which is close to the amplifier’s rated 25 W per channel. The gain on the signal coming out of the head unit is set a little too high, but there’s no changing that.

This is what the signal looks like with clipping and how it goes away as the volume goes down (indicated in red text). You can see at 2 kHz, the clipping is gone around 28. There is still distortion at 29 although it’s not very noticeable.

I then ran a test just for fun of the signal output at 100 Hz to 20 Hz in 10 Hz steps (volume at 27). The signal looks clean down to 50 Hz although it’s starting to drop in amplitude, but starts looking kind of triangular at 40 Hz. The corners turn even sharper at 30 Hz, and at 20 Hz it’s pretty much wasted. I had the meter on auto scaling to better show the waveforms, but keep in mind the vertical axis at 20 Hz is one tenth of the scaling at 100 Hz. Compare the volts to see how small the signal really gets.

I would expect that most Elantra navigation head units and external amplifiers begin distorting at around the same volume, but if you want to try this for yourself without an oscilloscope you can play pure sinusoidal test tones while turning up the volume. At one point you’ll start to hear a ringing in the tone and it won’t sound pure anymore. That’s distortion kicking in as the harmonics are showing up in the output. Using the spectrum analyzer app on my phone displayed these harmonics showing up at a couple of volume levels below clipping was noticeable on the oscilloscope.

This screenshot shows the difference between one click of the volume knob. The third and fifth harmonics are already showing up on the left, but the signal saturates with harmonics on the right, just one level higher. This change in tone is noticeable by ear.

When you play a pure sinusoidal test tone, it should have little to no harmonic components to it. A square wave on the other hand is really just a sinusoidal signal with an infinite number of harmonics added in. As you turn up the volume on your pure test tone and the signal begins to clip, it starts to transform from a sine wave into a square wave as you turn the dial. The more it starts to change, the more harmonics are being added into the signal.

Lastly, you could also set your gains using a multimeter, but this can be less accurate. Use the formula sqrt(rated RMS wattage per channel * speaker impedance). For the Elantra Limited with navigation, that would be sqrt(25 W * 2 Ohms) = 7.07 V. Connect your meter to the speaker wires and turn up the volume on the head unit until you see 7.07 VAC when playing a 0 dB test tone. Try it with different frequencies. The same technique can be used when setting the gain on your amplifier.

I then set the LC2i and turned the AccuBASS knob until I got a flatter bass response. I played around with different settings on the LC2i and it does boost the bass levels a great deal, but it doesn’t fix the attenuation problem. 40 Hz is as low as the stock amplifier will go and the only way around that is something like the AudioControl Epicenter which would be nice to try someday, but it’s significantly more expensive than the LC2i.

Next I set the gain of the amplifier with the oscilloscope. The amp could stay clean up to a little over 26 V, which equates to 174 W, exactly what the amplifier tested at in the factory. I nudged the gain back down to keep it at or below 24.5 V, which would make 150 W on the subwoofer.

I use PowerAMP (for Android) as my MP3 player. I’ve tried pretty much all the MP3 player apps and I think that one is the best. One of the nice features it has is a 10 band equalizer. I played a high quality pink noise track with the equalizer reset to zero. Then I adjusted the equalizer to get the frequency response as flat as possible. Doing this tunes the audio to the stereo equipment and acoustics of the cabin to account for resonant frequencies and other issues. Usually the resulting equalizer setting doesn’t quite sound right with too much treble, so some fiddling is in order, but this serves as a baseline to start with. From there I listened to songs I’m very familiar with and made small adjustments until all the levels sounded balanced. Prepare to spend some time doing this. It just takes a lot of tweaking and trying different things until it sounds the way you want it to sound. Even though setting the equalizer with pink noise gives the flattest frequency response, much of this comes down to preference.

One thing to note is that since I set the gains with a flat equalizer, I’m assuming that I’m never going to boost frequencies in the bass range or else I’ll get clipping. The sliders can only be adjusted down.

Going back to PowerAMP, you can have a default equalizer setting for Bluetooth, wired headphones, and phone speaker and it will automatically switch between each one depending on the situation. You can further have defaults for playlist, artist, and even track. You could manually set the EQ for each song if you really wanted. Just another feature I thought was neat.

This is the equalizer setting that I ended up with.

Finished!

That wraps up my installation. I hope everyone finds this useful. I tried to make this fairly inclusive from start to finish. It just kept growing and growing the more I sat down and wrote about it.

As for the end result, I’m pretty happy with how everything turned out. My objectives changed a couple of times as I was researching what to buy. At first I just wanted to fill in the lows, then I started wanting to go bigger. The 150 W setup I have I’d say does a pretty good job filling in the lows, but it’s by no means a heavy hitter. Part of the bass response is dampened because the subwoofer is in the trunk and has to travel through the seats. Leaving one seat folded down helps some, but I would rather not make a habit of doing that. Of the music I listen to (mostly alternative/indie rock) I’ve noticed the kick drum has a pretty good thump to it and the bass guitar stands out more. The walking bass line in Red Hot Chili Pepper’s “Snow” and the repetitive bass line in Sublime’s “Santeria” are good examples of that. I think a lot of this comes down to how the songs were mixed in the studio. Playing hip-hop songs that have an accentuated bass line makes the sub hit harder. If I were to make a recommendation here, I’d suggest maybe looking in the 300 W range for a subwoofer in the trunk if you plan on upgrading the door speakers, too, and want hard hitting bass. I think 150 W is sufficient, but it’s always nice to have some headroom for when you want to really crank it up. There is a break in period for speakers so I’m hoping mine tightens up a little over the next couple of days.

Rattles aren’t much an issue with my setup except when listening to a bass heavy song. If you go with a higher wattage, you’ll probably have to address that more.

Future upgrades

Next up, hopefully in the next month or so, I plan on replacing the door speakers. I’ll probably go with the Infinity Reference 6030CS that silvergls used in his guide. I’d also like to cover the car with Dynamat or similar material around the same time. I’ll see how that goes. Further down the road I’d like to buy a hardware equalizer instead of using the one on my phone. That way all the audio would be equalized correctly (FM, XM, Pandora) and not just what’s being played on PowerAMP. But, advanced audio processing equipment can get pretty expensive.

I may look into possibly upgrading my amplifier and subwoofer at some point. I’m worried that after upgrading the door speakers with Infinity References, which I’ve heard are louder than the stock ones, that my subwoofer won’t be able to keep up. I’ll have to wait and see how it sounds after upgrading the door speakers.

Resources:

Service manuals: www.hmaservice.com

Crutchfield cable gauge chart: Cable Gauge Chart

Boss 8 gauge amp installation kit: Amazon.com: Boss KIT-2 Complete 8 Gauge Amplifier Installation Kit: Car Electronics

These threads are worth reading for additional info about subwoofer installations:

Silvergls’s compact powered subwoofer: http://www.hyundai-forums.com/231-md-2011-elantra/128277-compact-powered-subwoofer.html

Mailboxmw’s sound system modification: http://www.hyundai-forums.com/231-m...s.com/231-md-2011-elantra/125460-elantra-limited-sound-system-modification.html

Android apps I used:

PowerAMP: https://market.android.com/details?id=com.maxmpz.audioplayer

Speedy Spectrum Analyzer: https://market.android.com/details?id=com.electronchaos.SpeedySpectrumAnalyzer

Test Tone Generator: https://market.android.com/details?id=de.guentherkrauss.audio.audiotesttonegenerator

***Disclaimer: This is provided for information only. I am not responsible for anything you mess up.***

Charliesaccount · Dec 1, 2021

Flatland2D said:
Mounting the amplifier and connecting the wires

I mounted the amplifier on the subwoofer enclosure. I’ve read much on the internet saying this is okay and that it’s not okay. It was a convenient place for me to mount it, so without concrete evidence that it was a bad idea, I went ahead and mounted it there. I did use some nylon nuts as spacers between the amplifier and enclosure just in case.

I got another length of split loom tubing to carry the 12 V and ground to the LC2i with the returning remote 12 V output back to the amplifier.

AudioControl recommends a 1 A fuse on the 12 V powering the LC2i, and I’d like to echo that for one important reason. The smaller gauge wire that will be powering the LC2i is, up until the 1 A fuse, still connected to the battery through an 80 A (or whatever it is) fuse. It’s possible that if the smaller gauge wire were to short to ground, it wouldn’t short circuit enough current to blow the main fuse, allowing that wire to burn up, melt, cause a fire, etc. Put the fuse as close as possible to the source end of the wire. Mine pops out of the wire loom and tucks back in as shown with the red arrow. Also note how well the back slope of the enclosure matches the seat back.

Tuning the amplifier and subwoofer

I first wanted to see if the factory head unit clipped, and if so, at what volume. I started by centering all the tone controls for treble, middle, and bass on the head unit. I was a little disappointed to see that it started clipping at around volume level 30 at 500 Hz and below and level 27 at 4 kHz and above. I chose the lower of the two values to avoid clipping at all frequencies. I would have hoped that since the head unit and amplifier were designed for each other that it wouldn’t clip all the way up to level 35, but doing the math on the output voltage just before clipping starts at 2 kHz ([7.49 ^ 2] / 2 Ohms) gives 28 W output which is close to the amplifier’s rated 25 W per channel. The gain on the signal coming out of the head unit is set a little too high, but there’s no changing that.

This is what the signal looks like with clipping and how it goes away as the volume goes down (indicated in red text). You can see at 2 kHz, the clipping is gone around 28. There is still distortion at 29 although it’s not very noticeable.

I then ran a test just for fun of the signal output at 100 Hz to 20 Hz in 10 Hz steps (volume at 27). The signal looks clean down to 50 Hz although it’s starting to drop in amplitude, but starts looking kind of triangular at 40 Hz. The corners turn even sharper at 30 Hz, and at 20 Hz it’s pretty much wasted. I had the meter on auto scaling to better show the waveforms, but keep in mind the vertical axis at 20 Hz is one tenth of the scaling at 100 Hz. Compare the volts to see how small the signal really gets.

I would expect that most Elantra navigation head units and external amplifiers begin distorting at around the same volume, but if you want to try this for yourself without an oscilloscope you can play pure sinusoidal test tones while turning up the volume. At one point you’ll start to hear a ringing in the tone and it won’t sound pure anymore. That’s distortion kicking in as the harmonics are showing up in the output. Using the spectrum analyzer app on my phone displayed these harmonics showing up at a couple of volume levels below clipping was noticeable on the oscilloscope.

This screenshot shows the difference between one click of the volume knob. The third and fifth harmonics are already showing up on the left, but the signal saturates with harmonics on the right, just one level higher. This change in tone is noticeable by ear.

When you play a pure sinusoidal test tone, it should have little to no harmonic components to it. A square wave on the other hand is really just a sinusoidal signal with an infinite number of harmonics added in. As you turn up the volume on your pure test tone and the signal begins to clip, it starts to transform from a sine wave into a square wave as you turn the dial. The more it starts to change, the more harmonics are being added into the signal.

Lastly, you could also set your gains using a multimeter, but this can be less accurate. Use the formula sqrt(rated RMS wattage per channel * speaker impedance). For the Elantra Limited with navigation, that would be sqrt(25 W * 2 Ohms) = 7.07 V. Connect your meter to the speaker wires and turn up the volume on the head unit until you see 7.07 VAC when playing a 0 dB test tone. Try it with different frequencies. The same technique can be used when setting the gain on your amplifier.

I then set the LC2i and turned the AccuBASS knob until I got a flatter bass response. I played around with different settings on the LC2i and it does boost the bass levels a great deal, but it doesn’t fix the attenuation problem. 40 Hz is as low as the stock amplifier will go and the only way around that is something like the AudioControl Epicenter which would be nice to try someday, but it’s significantly more expensive than the LC2i.

Next I set the gain of the amplifier with the oscilloscope. The amp could stay clean up to a little over 26 V, which equates to 174 W, exactly what the amplifier tested at in the factory. I nudged the gain back down to keep it at or below 24.5 V, which would make 150 W on the subwoofer.

I use PowerAMP (for Android) as my MP3 player. I’ve tried pretty much all the MP3 player apps and I think that one is the best. One of the nice features it has is a 10 band equalizer. I played a high quality pink noise track with the equalizer reset to zero. Then I adjusted the equalizer to get the frequency response as flat as possible. Doing this tunes the audio to the stereo equipment and acoustics of the cabin to account for resonant frequencies and other issues. Usually the resulting equalizer setting doesn’t quite sound right with too much treble, so some fiddling is in order, but this serves as a baseline to start with. From there I listened to songs I’m very familiar with and made small adjustments until all the levels sounded balanced. Prepare to spend some time doing this. It just takes a lot of tweaking and trying different things until it sounds the way you want it to sound. Even though setting the equalizer with pink noise gives the flattest frequency response, much of this comes down to preference.

One thing to note is that since I set the gains with a flat equalizer, I’m assuming that I’m never going to boost frequencies in the bass range or else I’ll get clipping. The sliders can only be adjusted down.

Going back to PowerAMP, you can have a default equalizer setting for Bluetooth, wired headphones, and phone speaker and it will automatically switch between each one depending on the situation. You can further have defaults for playlist, artist, and even track. You could manually set the EQ for each song if you really wanted. Just another feature I thought was neat.

This is the equalizer setting that I ended up with.

Finished!

That wraps up my installation. I hope everyone finds this useful. I tried to make this fairly inclusive from start to finish. It just kept growing and growing the more I sat down and wrote about it.

As for the end result, I’m pretty happy with how everything turned out. My objectives changed a couple of times as I was researching what to buy. At first I just wanted to fill in the lows, then I started wanting to go bigger. The 150 W setup I have I’d say does a pretty good job filling in the lows, but it’s by no means a heavy hitter. Part of the bass response is dampened because the subwoofer is in the trunk and has to travel through the seats. Leaving one seat folded down helps some, but I would rather not make a habit of doing that. Of the music I listen to (mostly alternative/indie rock) I’ve noticed the kick drum has a pretty good thump to it and the bass guitar stands out more. The walking bass line in Red Hot Chili Pepper’s “Snow” and the repetitive bass line in Sublime’s “Santeria” are good examples of that. I think a lot of this comes down to how the songs were mixed in the studio. Playing hip-hop songs that have an accentuated bass line makes the sub hit harder. If I were to make a recommendation here, I’d suggest maybe looking in the 300 W range for a subwoofer in the trunk if you plan on upgrading the door speakers, too, and want hard hitting bass. I think 150 W is sufficient, but it’s always nice to have some headroom for when you want to really crank it up. There is a break in period for speakers so I’m hoping mine tightens up a little over the next couple of days.

Rattles aren’t much an issue with my setup except when listening to a bass heavy song. If you go with a higher wattage, you’ll probably have to address that more.

Future upgrades

Next up, hopefully in the next month or so, I plan on replacing the door speakers. I’ll probably go with the Infinity Reference 6030CS that silvergls used in his guide. I’d also like to cover the car with Dynamat or similar material around the same time. I’ll see how that goes. Further down the road I’d like to buy a hardware equalizer instead of using the one on my phone. That way all the audio would be equalized correctly (FM, XM, Pandora) and not just what’s being played on PowerAMP. But, advanced audio processing equipment can get pretty expensive.

I may look into possibly upgrading my amplifier and subwoofer at some point. I’m worried that after upgrading the door speakers with Infinity References, which I’ve heard are louder than the stock ones, that my subwoofer won’t be able to keep up. I’ll have to wait and see how it sounds after upgrading the door speakers.

Resources:

Service manuals: www.hmaservice.com

Crutchfield cable gauge chart: Cable Gauge Chart

Boss 8 gauge amp installation kit: Amazon.com: Boss KIT-2 Complete 8 Gauge Amplifier Installation Kit: Car Electronics

These threads are worth reading for additional info about subwoofer installations:

Silvergls’s compact powered subwoofer: Compact Powered Subwoofer

Mailboxmw’s sound system modification: Elantra Limited Sound System Modification

Android apps I used:

PowerAMP: Poweramp Music Player (Trial) - Apps on Google Play

Speedy Spectrum Analyzer: https://market.android.com/details?id=com.electronchaos.SpeedySpectrumAnalyzer

Test Tone Generator: https://market.android.com/details?id=de.guentherkrauss.audio.audiotesttonegenerator

Disclaimer: This is provided for information only. I am not responsible for anything you mess up.

Hey my man I literally just registered just so I could respond to you. Your guide to installing a subwoofer and aftermarket amplifier in a Hyundai Elantra is absolutely immaculate. I have been researching and reading up on installations for the past 20 years and this by far my good sir is the best description, most detailed orientated guide that I have once again by far had the enjoyment of coming into contact with. I just wanted to reach out and thank you personally, believe it or not there are people out here that are trying to find all of the information you have collected and shared all in one perfectly presented orientation. Props to you Sir much appreciated and overwhelmingly accurate 👍

Louiceman · Dec 27, 2011

Nice write up good job that what I'm looking for.
Thanks

someguy · Dec 27, 2011

Another great car audio install thread. I might have to revise the sticky section and dedicate a thread to audio.

silvergls · Dec 27, 2011

Great write up!

someguy said:
Another great car audio install thread. I might have to revise the sticky section and dedicate a thread to audio.

Yeah, could it also be possible to create sub categories such as for audio, lighting, exterior, etc?

bigdogbitu · Dec 27, 2011

Great Job!

I am quite impressed with the time and effort you put into this project and write up.

Flatland2D · Dec 27, 2011

Thanks everyone. My initial frustration was not being able to find a picture of the stock external amplifier or where it was located other than somewhat vague text descriptions. I tried to make everything very clear here. I also thought it was worthwhile to show the actual setup involved because I think a lot of people skip getting it setup correctly. Setting the gains and equalizer at the right values will help the system last longer because it won't burn up and it'll sound better. I was guilty of listening at volume levels over 27 before I did these tests which is why I thought it sounded like crap. It was clipping badly.

Everything here would still apply to the GLS or Limited without navigation except for the wires you tap into for the LOC and you'd need to recheck the volume level where clipping starts. Other than that it's all the same.

I've been driving for about 5 hours in the last 24 hours and am very pleased with how it turned out. My new favorite song to listen to is "Paradise" off Coldplay's new album with it's dubstep inspired baseline that still retains a rock rhythm so it's not like the constant thump-thump-thump of rap/hip-hop. I'm happy even with the rear seat up and the trunk sealed off. 150 W is an appropriate amount of bass for this system. I'd only go larger if you really fancy the car shaking bass.

dliptak · Dec 28, 2011

Great job! Nice tutorial. I will be ordering the epicenter and should be starting my install in a week or two. I will send you guys updates.

Flatland2D · Dec 28, 2011

dliptak said:
Great job! Nice tutorial. I will be ordering the epicenter and should be starting my install in a week or two. I will send you guys updates.

I'm very interested to hear how the Epicenter works out. I'd like to move up to that in the future.

legendary151 said:
Excellent write up! I've been searching for a thread like this. I love the set-up in the trunk< doesn't take up too much room it looks like. With out the Dynamat how much rattling does the car produce? I am trying to decide between the set up that Silvergls has or yours. What do you think?

I believe silvergls has said that he couldn't sacrifice any trunk space so that is what made him go with a compact unit under the seat. There is an advantage to that by having the subwoofer in the cabin and not blocked off by the seats. I really wish Hyundai included the trunk access door when the armrest is folded down. But the bass is definitely still there, just a tad less punch. So far I've decided it's not enough for me to care (folding the rear seat down). With bass frequencies being non-directional, it still fills the inside and doesn't sound like it's only coming from the trunk. There is a practical limit to what size subwoofer you can fit under your seat, and 150 W is about it. In the trunk you can go as big as you want. The enclosure I have sacrifices a pretty minimal amount of space in my opinion. It does block off a little over half of the trunk access if you need to put long items in the trunk where you need the seats folded down.

So far I'm not really experiencing much rattling. I'd say none with normal rock music and a minor amount at times with hip-hop. I don't have much rap/hip-hop music to listen to so I'm limited in my experience right now. The rattling is not loud enough when it does happen to be a nuisance to me. This may change over time, but it started thinking today while I was driving if I really needed to put any Dynamat down because it wasn't a problem. It'd still be nice to block out road noise, though.

legendary151 · Dec 28, 2011

Excellent write up! I've been searching for a thread like this. I love the set-up in the trunk< doesn't take up too much room it looks like. With out the Dynamat how much rattling does the car produce? I am trying to decide between the set up that Silvergls has or yours. What do you think?

dliptak · Dec 28, 2011

I will let you know how it goes. I first put in the SO b8pt under seat subwoofer. It made a decent difference just not loud enough first one died in a month just didn't get the complete sound like I wanted. So in an effort to get great sound in the next couple of weeks I will be installing:

New Speakers SO P67c(front) & P67(rear)
Cache COE8 8 Channel LOC
SO M4075 Amp (4channel)
Audio Control Epicenter
2x Pioneer TS-W254R Subs
Custom Built Enclosure for trunk
SO M1500 Amp for subs

Keep you updated.

Flatland2D · Dec 29, 2011

Compared to the stock system, that is going to get LOUD!

eekaz · Jan 11, 2012

Very nice write up. I am tweaking an install that I did in my wife's car. I am going to incorporate some of your suggestions as I can't seem to get the amps to ever turn off as long as the car is running. Low level hiss is driving me crazy. I opted to remove the Styrofoam spare tire insert and place a shallow mount kicker 12" and two JL amps in the spare tire well. I also swapped out the stock speakers for a set of infinitys. Very clean and no lost trunk space.

Flatland2D · Jan 11, 2012

eekaz said:
I can't seem to get the amps to ever turn off as long as the car is running.

Are you wanting the amps to turn off when the radio is off or something?

charlesj123 · Jan 13, 2012

Terrific write-up dude!

I wish more members like you.

congrats

Charles

RedDogDarren · Jan 15, 2012

I'm not trying to hijack your thread at all just to add to it. Apologies if it seems that way and I will throw this into a new thread if you like.

I posted the following on another forum as well and it may give some of you a new option for your perspective systems:

2012 Elantra.
I HATED the stock sound.
Speakers replaced with Hertz front and rear. Power supplied by a JL Audio XD700/5 amp and processing handled by the Audison Bit Ten off the factory headunit. The Boston Acoustics G108-44 8" subwoofer sits in a box I made and downfires directly behind the center console. The gear is on a platform I made to sit exactly under the passenger seat so it cannot come out without unbolting the seat. Subwoofer volume knob under the parking brake lever. Absolutely nothing in the trunk except my spare tire and it sounds INCREDIBLE.

Remember that this is still an 8" sub and I usually leave it set to just fill in the lower part of the music. I don't need it to shatter windows or burst my eardrums. This little sub can be left at a lower setting due to being in the cab with you but it can really grind when fed power. It's no 12 in a ported box but it is surprisingly good and it runs at 2ohms like I wanted. I made this enclosure REALLY solid. 64 drywall srews, wood glue covering every join, non-silicone adhesive/sealant lines every inside angle, it's made of mostly angles so it places most forces against itself, and a good dose of polyester fiber-fill all contribute to minimise annoying resonance even though this speaker seems to model better in a ported box. The space savings this little gem provides is worth it's weight in gold.

soit78 · Aug 7, 2012

Amp Harness in trunk.

Hi,

Thanks for this write up... Going to tackle sub and amp next. I want to use the trunk and was wondering if any one knows if that harness is behind there if you don't have the the factory amp as my GLS only has the standard non-GPS stereo. Probably not but, would make life easier.

Flatland2D · Aug 7, 2012

I believe the harness is behind the head unit on the non-external amp models.

Xion · Aug 22, 2012

The carpet in my trunk is different then yours ??? very different.

Flatland2D · Aug 22, 2012

What's different? Pics?

pendo · Sep 1, 2012

2013 Here....wire colors are different on the 12 pin amp plug :-/

Where did you find that pin layout diagram?

Flatland2D · Sep 1, 2012

Connector diagrams are from hmaservice.com. Create a free account, use the Detail Search, and search all documents for AVN.

pendo · Sep 1, 2012

Thanks, I found the link a little bit ago (my apologies for missing it initially) and it shows the same layout as the diagram you posted.

What's got me a little confused is that these colors don't match what I have in the door. I wouldn't have even checked this as I paid a shop to install a basslink a couple weeks ago (didn't have time and it was worth the $80 to be done, or so I thought). But I just put intone infinity 6030's and changed the sub and things weren't sounding right as I panned around to check phase. Well after investigating I see that the shop just tied the left and right high level inputs together to run to the amp! Talk about lazy...

Anyway, they did it at the drivers door sill instead of the much easier and better method of coming from the amp.

In any case, this is pretty straight forward so I'm just going to go from the diagram. Thanks for your help and thanks A LOT for your detailed op.

pendo · Sep 3, 2012

It seems like one could use either the lc2i or an epicenter plus. Any advantages to using both?

Flatland2D · Sep 3, 2012

The LC2i unfortunately doesn't have the right bass restoration to fix the Elantra's problem. The LC2i amplifies the lower frequencies if they have been attenuated, but there needs to be something there to work with. If you look at the waveforms I posted, the low end is completely filtered out, so although I do notice a difference turning up the bass restoration on the LC2i, it just can't do enough at the really low end (20 to 30 Hz).

From what I've read about the Epicenter, it can restore bass completely removed by looking at the harmonics, but the resulting output is more boomy and less accurate. Good for rap/hip hop, not good for anything else. Liberty guy says that his BitTen completely restores the bass and I'd imagine does a much better job.

elantraVT · Sep 22, 2012

This lack of low end output from the elantra may actually benefit me.Although it has not been confirmned in the GT.

I just ordered the LC2i, and a Polk Audio PA D1000.1 mono amp this week to power the 4 8" subs i installed last week. Being that i am doing an infinite baffle set up and using a subsonic filter...i don't want output below say 25-28 hz in order to protect my drivers.

I will be re-reading the first page here several times as i plan the wire install this weekend, and then when in comes to tuning...and i may have a few questions

Thanks for such an informative thread!!

torrey · Sep 9, 2012

summed signal

Do you happen to know if the signal coming out of the amplifier is summed or not. I'm planning on putting a JL Audio cleansweep OEM interface.

libertyguy20 · Sep 9, 2012

Yes the bit10 restores the bass and it is my favorite piece of car audio equipment I've ever owned. Works well too at keeping everything looking stock.

The JL cleansweep ($300) will properly restore the bass, but in the end you are left with no EQ ability as the JL curve is the curve you are stuck with. The audio control LCQ-1 ($300) does the same thing but at least has some Eq features you can use after the bass has been restored. For $100 more the bit 10 does everything. I'm done preaching...it just blew me away with its tuning and flexibility and really helped me tune my.overall sound to my car.

torrey · Sep 13, 2012

stock amp

the stock amp, do you know if the signal is summed coming out of the stock amp?

elantraVT · Sep 23, 2012

slight change of plans...holding off on the 2ci and going with a rockford Punch 500.1BD. So if anyone wants to buy a slightly used Audio Control 2ci pm me.

I only changed my mind on the AC loc, because i changed my mind on the amp at the last minute.

OkieRich · Sep 23, 2012

Wow! Absolutely WOW! Although I never intend to do this mod, I still enjoy seeing the work done by others. And your install is not only well written and thought out, but easy to understand. In a word: "Impressive!" Two thumbs-up!

Flatland2D · Sep 25, 2012

Thanks! The thread was posted a while ago and there have been upgrades since then. For continuity's sake and for future readers, here's where this upgrade went after I started wanting more. I'm loving it now!

http://www.hyundai-forums.com/231-m...1-md-2011-elantra/141763-upgrading-premium-125-watt-sound-system-800-watts.html

http://www.hyundai-forums.com/231-m...1-md-2011-elantra/142378-applying-sound-deadening-elantra-doors-trunk-pics.html

Elantra Limited w/ Nav Subwoofer and Amplifier Install and Setup (step-by-step guide)

Top Contributors this Month

Recommended Communities