hispls Posted September 20, 2016 Report Share Posted September 20, 2016 So let's preface this by saying that I was really happy with the sound of the C-pillar wall but it had a couple big problems. First of which is that it was designed for a different amp and the new amps never really mounted in a way I liked which caused some trouble. Next the subs were definitely too crowded in the space I wound up with and I wasn't happy with the low port area, and finally barring switching amps I was pretty much stuck at 153.1 being about the best it was going to do. I also have found over the last couple years that I almost never have back seat passengers so having back seat functionality was pretty pointless. Luckily I didn't build this last wall too permanent with the thought that eventually I might want to tear down and go bigger. Also I had to blow off about a week's worth of work to get done what I got done. I'm heading into my busy season for sales so time will be very limited through December when I'll be heading to Florida and won't have any tools. So apart from a few hours here and there any "finishing" may well not happen until next year after maple syrup harvest. Goals are to get the subs into a box volume they like with more port area and get a bit louder. I also need to consider cargo space for general life stuff and annual road trip to Florida. I live on a dirt road and there's chicken and turkey shit all over, I make maple syrup and sugar so I'm usually sticky and pick up a lot of soot, sawdust, and am just typically dirty from farm life. I do a lot of driving and it's improbable that I will ever have a clean car. I'm not playing the low impedance game to get big numbers, I want to be able to play for hours on end without worry of breaking things and I don't want to have to re-wire everything to compete or play music. 8X Zed Minotaur Zed Leviathan Zed Ra 4x Shocker USA neo sig 15" SEAS lotus tweeters Anarchy 6.5 midbass Exodus 6.5 midrange Kenwood KIV-bt901 Excessive Amperage alternator Various parts store batteries and a mish mash of wire and terminals and such that I've gathered over the years. Link to comment Share on other sites More sharing options...
hispls Posted September 20, 2016 Author Report Share Posted September 20, 2016 We used mostly scraps too build out from the sides, the only purpose of those is to build out to a point where I can build a square box sealing off the front and having a few points to mount the first layers of the sides. The way the front seat sets in here I need to be well behind the B-pillar to be comfortable driving so sealing off to the B-pillar is pretty much dead. I opted to seal off tight to the C pillar and just use a trim piece for a flush look up front. Link to comment Share on other sites More sharing options...
hispls Posted September 20, 2016 Author Report Share Posted September 20, 2016 All in I wound up with about 26 cube net and just by the look of things I didn't leave much volume on the table by not trying to build an oddball shape to fill out the sides and drop down a couple inches over where the back seats were. Link to comment Share on other sites More sharing options...
hispls Posted September 20, 2016 Author Report Share Posted September 20, 2016 Link to comment Share on other sites More sharing options...
hispls Posted September 20, 2016 Author Report Share Posted September 20, 2016 I'm really thrilled with the way this back of the box worked out. Amps are just temporary mounted here for testing but the back of the box pulls out easily so that I can get inside to work and use it for cargo area on long road trips. Link to comment Share on other sites More sharing options...
hispls Posted September 20, 2016 Author Report Share Posted September 20, 2016 Tuning was way too low with 9" of port depth. I knocked out most of the port wall and it tunes a bit higher but I'd still like to get it higher still. In retrospect I wish I had V'd the baffle to open up even more port area but I kept telling myself as I went that I wouldn't have as much volume as I thought I would once all was said and done. As you can see with the low power graph points it plays relatively smooth but I'd like to see that whole bar graph shifted up about 10 cycles..... might be next year before I can try to shorten that port more. Not so much that I'm unhappy with the sound but these subs want to play higher to get any really decent numbers. Also a caveat here, low power testing indicates I'll gain around 2.0dB from taking the seats out, I may have time for full power testing later this week. There's a lot of other things that need doing so I'm confident I can post up some 57's with the amount of time I have left this year. Inverter is super handy, that glue drip scraped right off. New home for Minotaur and new amp rack to make the cargo space more practical. Sadly I ran out of carpet and I'm sort of trying to find a place with some local so that I don't have to buy a whole 5 yards for the yard and a half I need to finish. Link to comment Share on other sites More sharing options...
hispls Posted September 20, 2016 Author Report Share Posted September 20, 2016 I had an amp out for a tune up when I took this pic. I had hurt a few of them when I had them mounted in the old setup (from vibration) and I suspect one or two more will fail at some point from that past problem. Luckily with small amps they're pretty cheap to ship, cheap to repair, and I still have plenty of power to get me by while they're out. Headliner is a disaster, whatever is under the thin fabric just keeps disintegrating so I glue and it fails within a week every time. I have about 5 or 6 cans of spray foam between whatever that is and the steel of the roof so removing the whole thing may be nearly impossible at this point. Another thing I'll try to deal with next year when I have time. I have put in a little work filling screw holes, sanding, and painting. I've got 5 yards of carbon fiber and some epoxy here that I intend to use inside once I'm sure I don't need to add anything else. Since I already have the epoxy, dollar for dollar, strength vs. strength, the carbon fiber vs. fiberglass weave works out almost the same cost-wise and should look pretty cool. I'm also fighting some flex in the baffle which is a first for me. I've added a couple 2X4 braces which don't seem to fully fix the issue so I've commissioned a local welder to build something up out of steel that hopefully will shore up the front. Wound up with 2 layers on the sides, 3 on top and bottom (plus some pieces), 4 on the back, and 5 on the front. I may add more layers just for the sake of shrinking the box to try to raise tuning, but I know I won't have time for that this year. As it sits I can play down to 26hz (the lowest test tone I have) which for me is a total waste. I almost never listen to anything with material below 38hz so everything below that represents only lower numbers on the meter and less output where I actually will use it. These subs definitely do not need or want to be tuned low, ideally I'd tune around 38-42...perhaps I can figure out a way to get there without sacrificing too much box volume. They do seem to really like the volume of this box though. Link to comment Share on other sites More sharing options...
hispls Posted October 4, 2016 Author Report Share Posted October 4, 2016 This escalated quickly. Basically I hit a wall with the wall here I feel that tuning is too low. I can't shorten the port any more and can't shrink the box any without losing functionality of the removable window in the back of it... which I definitely need for cargo space a few times a year. Had a friend came by this weekend to build a sub for him and we decided that I could cut the side out and open up the port some. Right off the start I raised my peak from 43 to 45 (the sound on music is dramatically different though) and was sitting at 156.1. Pikcked up .3dB with some tape (if you can't duck it, fuck it) and that also seems as good a way as any to keep the headliner from falling down for now. Seems as though another tenth is hit or miss by running the vent on defrost but I can't get that consistently. So I figured nowhere to go but up once I built the sides back out to mate with the door and sanded down the bondo where I mated in the new port side. A couple hours of piecing together the side and sanding later my peak is down to 44hz and I lost down to 156.0. Picked up a couple tenths adding some bracing which I'd been meaning to install but pretty much stalled at 156.2 and 44hz peak. It peaks at 48 with the driver's door open but doesn't gain much on the meter. I'm getting low on ideas here but tried a little something today that gets me up to 1656.5 but lowers my tuning still more down to 42hz. I suspect it could gain a little more if I made it solid, permanent, and finished, but lower really isn't the direction I want to take my tuning here. Sadly I'm really limited on options without losing functionality and I simply don't have time this year to rebuild the baffle (though I don't think there's any more port area to be had either way). Perhaps next year? Also I might be coming into some money soon so I may well just double the power and battery and see what happens. As it sits it's hard to get the subs hot so I know impedance is quite high so getting a big amp and having some lower impedance options could be substantial. Link to comment Share on other sites More sharing options...
kryptonite Posted October 5, 2016 Report Share Posted October 5, 2016 Build looks awesome! Love the use of multiple smaller amps! One thing I would suggest is don't use the side post terminals on your batteries. They are just 1/4" extensions off the top post itself. I'm sure you could gain by using the top posts directly. Better to spend a couple bucks on new top post adapters and gain a few tenths if you're after numbers. Other then that awesome build!! DC SOUND LAB NUT HUGGERCurrently Own 4 - 18" lvl 6s (m3) w/full Carbon Fiber option 2 - DC 5k lvl 4 motor lvl 2 motor On 8/2/2013 at 8:13 PM, n8ball2013 said: this is much worse. Its old n8 without the time or patience to hold fucking hands. I'm supposed to be doing school work but yet here i am making sure jr fuck fuck isn't trying to poke the other kids with a stick. Link to comment Share on other sites More sharing options...
hispls Posted October 6, 2016 Author Report Share Posted October 6, 2016 Build looks awesome! Love the use of multiple smaller amps! One thing I would suggest is don't use the side post terminals on your batteries. They are just 1/4" extensions off the top post itself. I'm sure you could gain by using the top posts directly. Better to spend a couple bucks on new top post adapters and gain a few tenths if you're after numbers. Other then that awesome build!! The Zed amps use a regulated power supply, chasing 10ths in battery voltage doesn't = tenths on the meter. Bear in mind that while I'd like to gain some this really isn't the optimum setup for SPL. Amps make power at 2 ohm and subs are D2 with one amp per coil. I'm not trying to play the low impedance game with these so "more power" pretty much isn't going to happen until I get into some different amp(s) and more battery. Going forward I've got my eye on something big for next year and I'll probably get a big boy LiFePo battery with some beast terminals built in. Actually I thought I did order the top post terminals when I ordered them but dealt with it when I realized I screwed the pooch there. AND it's over 200$ worth of Toolmaker battery blocks sitting there so it would break my heart to just throw them away at this point. Anyway, I tried a little something and found some gains. Let's see if I can lose a few tenths after I bondo and sand tomorrow. Link to comment Share on other sites More sharing options...
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