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Roughly 1.5-2 inches. I have the box sitting on 2 pieces of oak scrap that I used for bed slats. Sound is "vented" in 360 degrees but "focused" front/rear due to the oak slats on either side of the box. It basically forms a "channel" for the waves to travel. This wasn't an intentional or desired affect. It was really the only way I could secure the box temporarily as to not flop around the car like a pizza box. As mentioned...terrible pic.
Food for thought. A multiple sub system is not as sensitive to sub placement/positioning as a single sub system is. The reason being you have more "volume" coming from more surface area (meaning more cone area) over a single sub. The output from multiple subs will reflect off panels and occasionally cancel out when colliding with the same frequency emitted from the other sub. But the fact that there is so much more output and reflections coming from multiple sources and angles means that there is less sensitivity to wave cancellation and placement versus a single sub. So this was a lesson I learned the hard way. The reason it sounds louder/better in a down firing placement IMO is because the sound only goes fore or aft horizontally (or close to horizontal). So it reaches my ear ***** without have a chance to be affected by a reflection or cancelling against itself coming off the curved rear glass.
Of course...I could be completely wrong. I've learned so much along this journey, that I realized that I still know very little. LOL!
Update! So there was nothing wrong with the OEM guy...but just not enough OOMPH for what I'm doing. So in a whopping 6 minutes, he was gone to make way for.... This BAD MAMMA JAMMA! Singer custom 290A As you can see, voltage is NOT an issue now. This pic was taken with my sub thumping, headlights on, and AC going full blast with the seat heaters on. I didn't like the power wire's orientation, so i fixed it. This is the final installed position.
The whole process took me a little over 2 hours. I did have to "re-clock" this one before installing it. But the good news is the factory pigtail worked just fine making this a true plug-n-play bolt-on upgrade. Very happy! I'm so excited for this weekend!
Yep, purdy battery alright, but for $322 I think I'll just stick with my boring black ones, but of course I'm not running a stereo system like yours. One question, aren't the pos and neg terminals on the wrong side ? It wouldn't work in my car because they're reversed, but of course my battery's under the hood, if you have a trunk mount battery they might be right, but I've never seen a trunk mount so I don't know
Yeah, I double checked that. In a ZO6, this is the one you would need. In a non-Z (or anything with a front mount battery), you would get the D4700R which stands for reversed.
Yeah, I double checked that. In a ZO6, this is the one you would need. In a non-Z (or anything with a front mount battery), you would get the D4700R which stands for reversed.
Ronin, great job so far! On a side note, I can't help but notice the irony in your thread title though. "Finished my install!" dated April 2018.
Tell me about it man. It's been very much a series of phases. I thinks it's safe to say that I'm entering almost a final phase...or at lease I freaking hope so.
Tell me about it man. It's been very much a series of phases. I thinks it's safe to say that I'm entering almost a final phase...or at lease I freaking hope so.
I used to have a big name AGM battery in my TT C6. I ended up going back to a traditional battery after years of constant jumping it after being parked for more than a week or two. It didn't matter which magical charger I kept on it (Battery tender, Optima), it STILL died if you didn't drive the car often enough. To me, the 20# weight savings was just not worth the hassle and my car is much further along the power-weight ridiculousness curve than yours.
After re-tuning with the new single 13TW5 I can say that the down firing theory has been proven correct. At least it has for me in this particular scenario. No longer does my system suffer from a lack of bass when I get it out on the road. Additionally, the reduction in box size really "uncorked" the rear speakers. They were MUCH more prominent to the point of giving me a headache (until tuning of course). Our initial settings for the sub were a 12 db slope from about 160 hz. This sounds pretty good on most recordings but I did have to turn it (the sub output) down on a few songs that were recorded bass heavy.
A word about output. A single 13TW5 is a GREAT sub choice for a C6. It's powerful. It's musical. It uses a relatively small footprint (based on typical sub boxes available just behind the seats in Corvette's). And it has quite a range to it. Honestly, placement of this sub should be as close to the listening position as possible because with good time alignment, you can actually have bass imaging come from the front of the sound stage. CAREFUL tuning is required for this however. I think the 160 lpf we have set on the sub is just a bit too high for my liking, but we did that to get more midbass response from the system as a whole. While I truly LOVE the Focal KX2 drivers, I think switching to a larger 8" driver (or maybe a shallow 10") in the door would be just the ticket to bring that true mid-bass back "up-front" and let the sub handle the 20-100 Hz range. I think the 8-10" driver is ideal for playing that 80-200 Hz mid-bass signal. Yes my current drivers can play 80-200 (and higher) with ease, but that is not where they truly shine. I think the 6.5" size really shines just outside of that 200 Hz range. In this particular case, I believe size does in fact matter. The reason I think that is: clarity and detail while at listening volume. At lower volumes (like when parked and tuning) the system sounds balanced, beautiful, and plenty loud. But when you start competing with road, engine, wind, and vibration noises, things get MUCH more complex. I think that when increasing listening volume (such as when driving) that clarity and precision begin to fade quickly, mainly due to the competing noises mentioned before. I truly believe that increasing cone area and power output is just as important in the mid-bass drivers as it has been proven to be true with the sub(s), particularly in the C6. It only makes sense. When driving, the competing frequencies are in the 100, 400, and 1-2K Hz range. Notice that 100 and 400 Hz are separated by quite a bit in the spectrum. But one peculiar thing about sound and tuning a curve, when you make a change in say the 150 Hz range with a wide "Q", every frequency from 80 to almost 500 Hz is affected. This is true IMO when driving down the road. The broad frequencies encountered in road/driving noise acts like a "wide Q" which wreaks havoc on your "curve." So more cone area and more power can be used to raise the "noise floor" into what you actually hear. Essentially, use MORE POWA to kill the evil road noise.
Also, another side note about rear speakers in the C6. I know now why some say keep them and others don't. It's all about what music they listen to. I will argue against ANYONE that says they "pull" the sound stage to the rear. If it does, your TUNE sucks...NOT the speakers or their position. Where rear speakers have paid dividends is from any recorded music that is lacking in the 200-2000 Hz range (at least in my setup). There are some tracks/albums where that range is producing less output (for whatever reason) versus another tracks/albums. This is where you want the versatility of the rear speakers. For instance, when i listen to Shaed, "Trampoline," I don't need the rear speakers at all as this is truly a beautifully recorded track and it sounds absolutely perfect. Kudos to their sound engineer. But when I switch it up to say Poison, "Nothing But a Good Time" on a remastered album, that 200-2K just doesn't hit as hard. So I turn on the rear speakers to get that nice "full" sound. So my suggestion to the C6 community is to find a way to control your rear speakers (either on or off). A lot of HU's give you that option, as well as the end user getting creative. VXi allows you to have multiple pre-sets adjustable by switch. It's fascinating to hear what well tuned/timed rear drivers can do to boost a poorly recorded track, or be shut off when the track doesn't need their help.
Meeting with the enclosure builder next week some time to get the 2nd 13TW5 and 1000/1 permanently installed. I'm also shopping around for 8-10 inch drivers.
There was a thread over at DIYmobileaudio discussing midbass cancellation that triggered a light bulb over my head on the C6. The geometry of a C6 lends itself to cancellation between the front midbass speakers at the driver's head position. No matter how much more cone area or power you put to them, it will still cancel. Adding 10dB to each speaker may only get you 1dB at your head. This was with my previous though process of "let the midbass drivers do what they can, cross them over as low as possible to let them make strong midbass up front." I was using a 12dB @ 70Hz high pass with a similar low pass on my sub. For reference, I have Morel 6" Titanium mids driven by 150WRMS from a JL slash amp, plenty of capability. This worked AWESOME in my previous M3 and Mustang, but not in the C6 for getting clean, "punchy" bass. I previously had Dayton 8" mids in my C6 doors too. The Morels are better all around, even with less cone area.
Changing my crossover settings to a completely new strategy help a TON. I went with 12dB @ 120Hz high pass (which should give me LESS output from those fantastic mids, right?), and let the subs (a pair of 10W3's in a rear firing bulkhead enclosure, running off a JL HD750) play much high frequencies than I previous let them see. In other cars, this got "muddy or boomy" and had the subs wasting energy on playing frequencies that were handled just fine by the mids. In the Corvette, it's the opposite. Since the door location for the mids yields cancellation, letting the subs take over in the 70-150Hz range made a huge improvement. For me, image localization usually starts above about 120Hz where I can tell where the source is. Yes, the subs are behind you (I don't have any other rear speakers, and love a solid front stage), but it doesn't draw the image off the dash even with them playing these higher frequencies. The midbass presence is much better because I'm not trying to fight the physics of cancellation.
TL : DR Use a slightly higher mid-sub crossover frequency (120Hz vs 100 or less) in the C6 to avoid cancellation and get stronger midbass.
That may be worth trying Turbo. I think I'll give it a dance and try it out. Currently, as mentioned, my sub is running as high as 160. This range helps that "bass guitar and kick drum" range out a lot. But I think I would like the subs at a 100-120 range with a 12 db roll-off. I want the woofers to play down in that 100-120 Hz range. That's why I was looking at a 10" driver. The MW182's crush it all the way down at 70 Hz. So they're in their butter zone from 90-1000 Hz. Then I could run the subs in a more sub-like frequency range.
And yes, I too have been thinking about cancellation. The center hump being as beastly as it is...I wonder if beaming could be causing some of it. Normally, beaming isn't a factor in the low frequency range. But the driver position in the C6 has it pointing right at the hump. If you pointed them more at the drivers nugget, I have to hypothesize that cancellation in that freq range would be reduced. Pointing a driver is far easier than buying new drivers. Maybe some else worth trying...
Last edited by Pb82 Ronin; May 8, 2020 at 10:03 AM.
(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! 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! 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! (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
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.