Finished my install!
 

(More pics coming)
Well it's been a long week. I wanted to document and film the install, but my GoPro supplier fell through and I was only able to take so many pictures. Anywho, I started last Friday (21 Apr) around 3 in the afternoon. I started by sanding and prepping my sub box. It is a custom box made specifically for a JL 10W7 and 2 amps to fit in a C6 Corvette. I decided to wrap it in carbon fiber vinyl. Wrapping complex shapes in vinyl sucks to say the least. It came out meh...I'm going to change it back to charcoal carpet. The next day, I got busy. I cleaned out the garage so I could park the car in it almost sideways. Complete access was needed with both doors and hatch open for long periods of time. I also wanted to measure before and after sound deadening with a dB meter to see how much of a difference deadening made. So I took a bunch of measurements. Car running, off, cutouts open, closed, windows up, down, etc. After the measuring period, I then completely gutted the interior. Seats, console, waterfall, carpet, trim, hatch trim and carpet, and all speakers (minus the center chime speaker) came out. Now the fun began.

Since I'm an analytical person, I researched the best possible sound deadening materials. I ended up ordering a ton of sound deadening from various places...all because they were the best. I used a combination of CLD tiles, KnuKoncepts Kolossus mat, HMF, butyl rope, speaker baffles, and industrial strength Velcro to complete the process. I used about 45 of the tiles (never did remove the headliner like I wanted) and 5 sheets of the Kolossus. I knocked or tapped on almost every inch of the car doing everything possible to remove "tinny or hollow" sounding metal or plastic. Turns out the hatch area is very poor at keeping sound out...even with all the added material. I couldn't get it to quiet down as much as I wanted. Yes, the sound deadening material made a dramatic difference, but it still wasn't as much as I had hoped. I spent easily 15 hours on sound deadening...rolling, tapping, applying material, rolling, tapping more, in attempts to neutralize vibrations, rattles, and noises. I was as meticulous as possible. After the butyl based material was applied, I got to the Hydrophobic Melamine Foam (HMF). This stuff is great! Its very light weight, won't absorb water, and provides a "barrier" between panels and the interior. It's MUCH better than the factory denim type insulation. I lined the hatch, driver and passenger floor pans, waterfall, and tunnel with it. A word of caution, even though it's only 3/4" thick and very compressible, it did make parts of the carpet "bulge" a bit more than normal. Also, even after cutting out holes for the seat hardware, the seats were about 25% more difficult to install. The rail covers on the front of the seat rails were a PITA to get back on. Just push REALLY REALLY hard and cuss a few times and they'll go back on...or just cut a larger hole in the foam. After the deadening was all said and done, I'm happy (as I can be) with the outcome. This took me about 12-13 hours in total to do, not including the tear down. In the timeline however, after the butyl based material was applied, I got to the wiring part of the install.

Wiring. This IMO is the most CRUCIAL part of any install. You can have awesome gear (amps, speakers, subs, etc.) and completely ruin it with crappy wiring. I was appalled at the quality (or lack of) the wiring from previous installs done by "professional installers" in some of my vehicles. Trust me when I say, a car audio shop DOES NOT CARE about going the extra mile or spending a few extra minutes making sure their wire job is good. They just want it done as fast as possible and to get your car out of their shop. Trust me on this. I didn't want that for my Z. So, I spent the extra money on things like wire ferrules, tech flex, and heat shrink to do the wiring right! I'm just sorry that I don't have more pics. This is also where the real work began. I put the box in the car and started to work out a "wire plan." I decided the power will run along the factory ground wire path through the right rear fender well area. I ran a 100A fuse about 8 inches from battery post then about a 2 foot section of 4G wire to a fused distribution block. I ran a 40A on the 4 channel and a 50A on the mono (per JLs instructions). I kept the 4G wire throughout because I don't like the idea of stepping down to an 8G. I wanted max power delivery and max ground. So my ground wires are also 4G, grounded to the factory location behind the passenger seat. I also run the ground to a distribution block tucked behind the right rear speaker in the cubby. I secured both distribution blocks with heavy duty Velcro. They don't budge. Now that power/ground are run, it was time for RCAs. I pulled the HU and connected my 3 RCAs. I chose 16' RCAs because I didn't want too short of a cable. I also "braided" the 3 RCAs together in a standard weave. This helps reduce interference and supposedly makes for a cleaner sound. 16' was right on the money after braiding. I had just enough length to tuck everything into a conforming position as to not interfere with panels/carpet going back on. Now since the RCAs were done time to move onto the speaker wire. This sucked. I decided to run 12 gauge because that was the smallest wire I could run at the lengths I needed that wouldn't cause signal degradation. The crappy part is the need to drill a hole in the cover that closes off the door "accordion conduit." Once I popped the covers, I had to contort my body into positions I didn't know I could flex into to get the drill in a position effective enough to drill the holes. I had bought a 50' roll since I was wiring every speaker and crossover with the 12G stuff and I didn’t want to run out. After the running of all the wires, I had about 2 feet unused. 48' of wire later....LOL! :woohoo: Just enough. Popped the caps back in place and ran the wires to the amp location. I ran the wire along the factory seat wiring and up the waterfall into the hatch area. Then I joined them with the RCA bundle. The rear speakers were super easy because the sub box sits right between them. No crossovers or anything. In "quality wiring" fashion, I used heat shrink on ALL ends and KnuKoncept "Y"s on all amp to speaker connections. These just keep the wire from splitting further down than you intend...in addition to making it look clean, but they can be finicky to put on. Just be patient. I also used gold wire ends on all connections. Now that all my wires were run, I did the first test fit. Box in, amps in, wires mock installed. All the lengths checked out. Happy with that, I stopped for the day.

Day 3, onto the speakers. I installed the Nakidparts door adapters. These made the install of the speakers very easy. Great product! I lined them with butyl rope and installed them in the doors and then taped down the speaker baffles temporarily. After test fitting the speakers (which all fit perfectly), I had to decide where to mount the crossovers. I ended up putting them in the base of the door on the flat spot between the inner/outer door. I cleaned the area with alcohol and used heavy duty Velcro again. (NOTE: Use a “Dynamat” roller to stick down Velcro, it is VERY effective) Once the crossover location was determined, I ran made the tweeter/woofer wires and finish mounted the woofers. I also drilled a hole in the door adapter to run the tweeter wire out of since they’re mounted to the door panel. Now that all the component wires are setup, I vacuumed up the area and finish mounted all of it and reinstalled the door panels. The rear speakers were super easy. Out with the old, in with the new. I just had to be VERY gentle with the negative posts since they’re so tiny and fragile. So all speakers were wired and ready to go, it was time to check my work. I plugged up the amps, installed all the wiring (minus the sub…hadn’t installed that yet) and fired it up. They all worked! :woohoo: Now it was time to start “final assembly” of everything.

Day 4, I kept wondering of a good way to “mount” my sub box. After all, who needs 80 pounds of audio gear flopping/sliding around every time you move? I had some ideas to weld “L-brackets” to the floor pan and use bolts. I thought about drilling through the waterfall (risky because of gas tank). In the end I copied another forum member method of gluing a sheet of ¾” MDF to the hatch floor and drilling into that. Makes the most sense since you’re not putting holes in the car. So I grabbed a piece of MDF from Lowes and had it cut to the desired size. Then I cleared the deadener off that particular spot and applied the glue (a combination of Loctite adhesive, and DAP multi-surface adhesive around the edges) on the raised portions of the hatch ridges. In the valleys, I ran Kolossus strips. I let that sit overnight and in the mean time I drilled the pilot holes in the base of my sub box. Now is also when I started to cut and fit the HMF mentioned earlier. I used a combination of carpet tape and gorilla tape to tack down the HMF. I didn’t want any of this stuff to be permanent in case I wanted to install a roll cage or do some other work that required its removal. At this point, the car is now as “deadened” as it was going to get and I started to reinstall the interior panels and carpet. The driver/passenger carpet “buckets” were vacuumed and reinstalled. Then the waterfall carpet. And finally the hatch carpet. I did remove a section of the factory insulation under where the sub box sits. That facilitated running the wires under it and ensuring I didn’t need a 5” screw to hold the box down. With the hatch carpet laid down, I took some measurements to figure out where to make my cuts. Cut my slits and pulled the wires through. Of note, I made sure to orient and route my wires so that each one was lying flat and not tangled around other wires. This made the carpet sit as flat as possible. I also laid each of the 4G power and ground wires in a “valley” of the hatch floor. That made them invisible from the top. The ¾” MDF also created a nice “channel” for the RCAs and other wires to rest in. At this point, I finished reinstalling the interior, except for the waterfall and center console. I left this off until last in case I needed to re-adjust any of the cables from the HU. Poured a drink and called it a night.

Day 5 rolls around and it’s time to get this finished. I grabbed the sub box, and put her in. Grabbed all the wires and ran them to the correct places. Installed the amps and secured them. Connected the power/ground/remote wires and RCAs. Now I needed to set my gains. I grabbed the volt meter and did the math. I needed 18.9 volts for the front speakers, and 15.4 volts for the rears. I set them with the HU at 50% playing pink noise. Hooked the speaker wires back up and bolted the sub box down. I dropped in the sub and bolted her down. Hooked up the sub wiring and DONE!!! Finally after a week of working day and night it was finally here. I fired it up and cranked it up. MISTAKE!! I forgot to adjust my crossovers first. I was hearing too much bass from the small speakers and it could’ve been dangerous. I managed to dodge a bullet and turned the volume down. I set the front crossover to HPF on and playing everything to 65Hz with a sharp 12db roll-off. I then set the rear to 100Hz with a gradual 12db roll off. No sense in anything below 100Hz going to a 5 ¼” speaker. Everything was still REALLY loud. So I turned my gains down on the speakers and volume up on the HU. This was the balance needed. I got the mids/highs sounding clear and clean and turned it up as loud as I could handle. Still clear, clean, and no distortion. Then I got the sub going. Turned the gain up to where it was needed. Now that she’s tuned…I can safely say that it sounds GREAT! The combination of speakers and parts really complement each other. Every song I played sounded razor sharp and you could hear the “detail” in the music. It’s pretty much everything I wanted. On a bummer note, I will have to pull the sub box out and cover it in carpet. I didn’t know this, but vinyl has a “plastic” consistency that you can hear as a vibration from the sub box. Live and learn I suppose. The only remaining items to do is make my amp covers. I have a sheet of clear lexan that I need to trim and drill, and then I also want to line the amp trays with some felt, fleece, or maybe some pleather. Overall I’m VERY happy with my work and I’m glad to know that my system was not hastily installed and that it was done right! :woohoo: (NOTE: I will add the list of parts I used, db measurements before and after, and pics after I get home from work, stay tuned!)

Measurements Before/After:
(Engine off)
Windows up - 39 db / 38.5 db
Windows down - 39.8 db / 39 db

(Engine running)
Windows up (M2W closed) - 57 db / 53.5 db
Windows down (M2W closed) - 59 db / 58 db
Windows up (M2W open) - 70 db / 65.3 db
Windows down (M2W open) - 73 db / 71 db
Stereo playing W/U - 94 db (as loud as I could get it without distortion) / 102 db (metal song, not bass heavy and at normal volume)
Stereo playing W/D - 91 db / 97 db

Equipment List: (Disclaimer: I already had 4 gauge wire from previous installs that was in great condition, so that wasn't an expense listed here)
Pioneer 8200NEX - $650
Subwoofer enclosure - $675
JL 300/4 Slash series Amp - $770 (a few years ago)
JL 500/1 Slash - $689 (Also a few years ago)
Subwoofer JL 10W7AE - $450 (got it on sale a while back)
Morel Maximo 6.5" Components - $150 (on sale from Crutchfield)
Focal Integration 5.25" Coaxials - $100 (on sale from Crutchfield)
Sound deadening - $400
Capacitor - $30
Wires/Wire accessories - $181
Hardware/Miscellaneous - $327
Total Cost - $4,422

Some more pics...sorry for the crappy quality. Taken on an old cell phone. Still making the amp covers...got some Lexan to cover them.

What are the measurements on your sub box? I have a wind restrictor in the hatch area that sits right by the struts. Been looking for a custom box Thx

I'll measure it tomorrow for ya

Thanks for the detailed write-up. Very helpful

Some more from the teardown

Those are all the pics I have for now. I only wish I would've got some pics with the HMF in place so you all could've seen how I ran it.

Box is 40.5"W and 41.5"W with the end caps on. It's 16" deep and 7.5" tall in the front by 11.5" tall in the back.:cheers:

Interesting phenomenon. So the position of my sub is causing a decent amount of wave cancellation. Since it's pointed right at the hatch glass, when the windows are up, the sub is NOTICEABLY quieter. Now given, it's still is plenty loud. But I just find it funny that when I roll down the windows, the SPL dynamic changes completely and the sub is quite a bit louder and hitting "cleaner." So much so, that I have to reduce the sub output level substantially via the HU to "clean the music up" so it's not so bass heavy.

This is an issue I can't see happening with a stealth box and smaller subs. Food for thought. Overall though, the system sounds damn good and the sound deadening is absolutely worth doing. After some more minor amp tweaking, this will give me years of enjoyment. Solid investment.

I still found a fair amount of cancellation with both a single 10" corner stealth box and dual boxes, one in each corner. The C6 cabin is prone to cancellation (at least making a null at the driver's head/body), so I'm not surprised. I don't think scrapping your current layout in favor of a conventional corner box would make you any happier.

I ASSume your enclosure is sealed? What internal volume? You may try experimenting with making it ported if you can find a way to fit a 3" or larger vent to it. Aiming the vent a different direction (along with the phase shift) may help your cancellation. I run a single 15" vented that points up at the glass and found it much better with regard to cancellation than the corner loaded solutions before.

Yep, she's a sealed box. Internal volume is just over 2 cu ft...per JL recommendations. I'm not sure I'd feel okay with punching a hole in that box though. That was almost a $700 kick to the nutz. I think the BEST port location would be right behind the waterfall though. That would ensure venting into the soundstage...but also right into the passengers ears. Knock the fillings out of your head for sure. I'll think about it...

Looks great, awesome attention to detail. Feels good to get wiring right. I don't want to dilute your efforts, but I once spent a crazy amount of effort and time sound deadening a Z28 I had. I came away with the impression that it's not worth it ultimately. I'll just buy as quite as a car I want and be careful not to induce noise generators (headers). I like that location of sub, I was considering doing the same. Is that box mostly MDF?

Yeah...all MDF...

(EDIT: And fiberglass/body fill) where the sub itself is mounted

Nice system. I bet that 10w7 is insane for sure. I noticed you went fairly cheap on the rest of the speaks. They sound in line with the rest of your gear?

I did go pretty cheap. I found some great deals on Crutchfield and spending $250 was far better IMO than trying to amplify the stock crap. As far as performance goes, I'm still listening to them in the "break in" phase so I'm not demanding too much from them just yet. I will say that when amp'd and crossover'd properly, they do sound quite nice. The Morel's have plenty left in them and the Focals contribute well to a "full" sound stage. The compliment each other very well. I honestly believe I will not need to upgrade these until they either die, or I decide to go higher end. The amp/crossover settings are truly what make the Morels shine. The tweeters sound very clean and not too "bright" like my K2Ps. I must admit, I still like the system in my truck a bit better at the moment, but I think that's because I've had several months worth of "tweaking" to make it sound like it should, where as I've only had days with the Z. I think she'll get there eventually.

UPDATE: So after a month now...As amazing as the Focal's are, they are WAY TOO BRIGHT compared to the Morel's. They absolutely drowned out the front sound stage, and even the Morel tweets can't overpower them. So, I'm at an impasse. I want the fronts to project the main sound and the rear speakers to support them. What's happening now is that the rears are projecting the sound and the front's are supporting. It sounds weird and is frustrating when trying to produce clean music. Rap music sounds great because of the limited range of frequencies involved (bass/vocals) compared to a complex music like metal. So..my options are, convert to a great 3-way component up front and keep the focal's in the rear position. Or, ditch the rear co-axial speakers and go with a woofer ONLY to make them sound less "bright."

In all honesty, I think I'm going to do the 3-way components and ditch the Morel's. They just don't impress me...and they can't compare to a 5.25" Focal.

FWIW, I auditioned Focal Flax, Morel Hybrid, Dynaudio, Audiofrog, and Hybrid Audio. I placed them in ascending order of my preference. I could not afford Hybrids, so I went with Audiofrog. I agree the Focal tweeters are too bright, the Morel are too muted.

For a three way I recommend Dynaudio's 8, 3, tweeter or Audiofrogs GB10, 40, 60 combo.
For rears, I recommend a DSP, (I prefer Helix), L-R for left rear, and R-L for right rear, only from 300hz-3khz 6db slopes, 20ms delay.

I was leaning towards the Focal ES 165 KX3 3-ways...they're a bit pricey, but it's a K2P with an additional 3.5" woofer and crossover. I've had K2Ps for over 10 years now and struggle to find another speaker that can compare. Obviously subjective to listener...but so few of us are "audiophiles" that it's hard to drop coin on an unheard set of speakers.

Dynaudio is very promising and I like their video's and production standards. But I've never heard a set before...and when we're talking in the thousands for a set...I would need to really be blown away. Test drives are mandatory IMO. Hopefully, someday I'll run into another vette guy that cares as much about audio quality as I do.

EDIT: And yes, I'm starting to believe that a DSP is necessary. I took all the time delay measurements and input them into my head unit. It sounded better...but literally ONLY on the song I was playing. Every other song sounded like garbage. It was frustrating. I'm starting to be reminded of being a bad-ass mechanic and piecing together a bad-ass motor, only to have a weak tune/tuner finishing the combo.