Polish

That is pretty freakin wicked for a single 12. I misread the title and thought it was 4 12's at first and was still impressed, then realized it was just one making all that racket.

Well I am a big giant fail. I was dinking around in WinIsd today (software I designed my box with for those unfamiliar with the name) and noticed a tragic error. I enter the Vas as L instead of Ft^3. It is still tuned to 33hz but the response plot changed drastically when I corrected the error. I thought I was getting a pretty decent gain at tuning frequency but it turns out, I don't get one at all. The peak is actually in the mid 50's, although it's not a huge peak. Needless to say, I want to build a new box now. I am thinking a 4th order is in order but we shall see. I may change woofers or just add 4 more as cheap as they are in order to get the amp down to 1 ohm. Having 8 10's certainly sounds like a fun time to me.

Yea I am pretty impressed with them considering the price. I am not sure what I'll do next for the sub stage, thanks for the suggestion though. I need new batteries among other things first though.

Looking great so far, I always liked VW's.

New Vid for your viewing pleasure...

I went ahead and pulled the back seats since I never use them anyway. I need more MDF to make a proper amp rack so it's just on basic amp board for now. I didn't bother making the wires pretty since I'll be getting MDF within the next week or two. This is what it's looking like for now. MB Quart ONX1.1600D plus a Scosche Distribution block which I am merely using to monitor the amps voltage for now. It only has 100 amp fuses in it at the moment so I bypassed it for the time being. I did run some small wire direct from the amp power terminals though so I can watch voltage. The subs now centered in the back. I can't tell if it made any difference yet really since I made a lot of other changes at the same time. What is left after the rear view mirror falls off. I have remounted it for now but I may need to modify the way it mounts if it keeps falling off. So that is the update for now.

Well, I am a dumbass. I don't know what I was doing wrong the other day to get 7.9 ohms per coil but it wasn't right. I metered my box again and got the same .8 ohms but when I touch the probes together, I still get .3 ohms. So there is a little resistance in them. I loved how much power the amp was making at .5 but I didn't want to leave it like that due to it not being stable that low. So I pulled all 4 subs once again and checked each coil directly at the tinsel leads which got me about 4 ohms per coil, so the subs are correct. I wired each sub in series as I had it before and got about 8 ohms per sub, then paralleled them all and ended up at 2 ohms final load. So the amp won't make as much power but I'd rather play it safe. I'll eventually be upgrading anyway and will buy subs that give me a 1 ohm final load. Just finishing up the 2 gauge install today as well as some more sound deadening. More pics to come later.

Thanks for the info, your post prompted me to do more research and I learned basically that a multimeter is not going to give an accurate reading of the speakers actual impedance like you said. I guess I assumed resistance and impedance were the same thing and assumed wrong. Thanks for posting this. Thanks Alton. I wasn't quite sure on the block thing, I see a lot of people saying to ground right to the alternator but mine doesn't have a grounding point that I can see. So I figured this would suffice since the alternator is bolted on right next to this spot.

Update time, I got a bit of work done today. See pics for progress. New amp next to old amp. MB quart ONX1.1600D on the left MB Quart FX1.400 on the right. OEM ground spot next to battery. Sanded to bare metal. 4 gauge engine block to battery ground. You can see the OEM wiring which grounds the engine block. I left it and added this 4 gauge to an empty bolt hole on the head. This is as close as I can get to grounding the alternator. I will be doing the positive feed from the alternator once I get some 0/1 and adding 0/1 grounds as well. New 4 gauge battery to chassis ground added in conjunction with the OEM ground. It will be 0/1 eventually but I only had the 4 gauge to use for now. 2 gauge wire to amp connected to battery. I mistakenly had it on the lug to the right before this, I didn't realize it had an 80 amp fuse there. As you can see it's connected right to the battery now. OEM battery (replacing with AGM soon) with new 2 gauge wire to amp and 2 new 4 gauge grounds. Dirty engine bay with new 2g wiring to amp and new fuse holder. Also the 2 new 4 gauge grounds.

Well I was finally able to turn it up on the way home and holy cow, for 4 cheap woofers it gets down. My entire rear view mirror assembly fell off after about 3 seconds at full tilt. It should be even better once I do the 2 gauge wire and Big 3 this weekend. Pics to come soon.

Got my budget 2 gauge kit today, going in this weekend. Will have some new pics soon.

It was driving me nuts so I checked it again and this time got .8 ohms final load. Which is about right for 8 x 7.8-7.9 ohm coils all paralleled together. So either my meter is flaking out, the battery is dying and thus giving false readings or I just wasn't getting a good connection the first time. Either way, if the speakers were actually dual 4 ohm as advertised I'd be at .5 ohms with 8 coils in parallel not .8. So I'll try a new battery in it tomorrow and see if it makes any difference.

Yea, you'd think something is off but I double checked it all. I want to verify my meter is correct before doing anything else though. I understand ohms law quite well, I understand what I am saying sounds impossible but that's what I got as strange as it sounds. I could have made a mistake though, certainly not impossible. Once I test my meter tomorrow with some resistors and am sure it's 100% I will pull the woofers and check again. That's the thing, I expected to get a 2 ohm load the way I originally had but - but I got 6? Then checked each coil and got about 7.8 - 7.9 ohms per coil. So either my meter is off or the speakers are WAY off spec.

The new amp is in and I was severely underwhelmed at first but after some checking I found the issue. So what was it you all may wonder? The subs were not the OHM rating they were advertised as. I bought these 4 Lanzar MAX10D advertised as Dual 4 ohm, so you'd think that they would be 4 ohms per coil. Then when wired in series each woofer would be 8ohms then when you parallel all 4 together you'd have a 2 ohm final load - Nope... Not even freaking close. I metered the wires coming out of the box just for kicks and got roughly 6 ohms. I was thinking maybe I had some loose wires in the box so I pulled all 4 woofers and metered each coil - every single one measured about 7.8 - 7.9 ohms. WTF? So I went ahead and paralleled each woofer (which should have given me 4 ohms per woofer and a 1 ohm final load) and metered again - I got about 3.5 ohms final load after this which still doesn't make any freaking sense to me. It should be 1 ohm but I think something is strange about these woofers. Either way this tells me my old amp wasn't pushing but probably 100-150 watts at the most considering the 6 ohm load it saw. It was pretty damn loud for each woofer only get 30-35 watts rms though. Either way, this is as low as I can get it for now with these woofers considering it's all paralleled at this point. I fell like a dumbass for never metering them from the get go but I guess live and learn - always meter your subs. So onto the results, I just tried it with the car off for now and it was a MASSIVE difference even with the weak ass 3.5 ohm load - which this amp probably only makes like 600ish watts at. It still pounded like never before. I'll be beating down the block on my highway commute tomorrow for sure. This however makes me want new woofers sooner than later. Mainly so I can actually show the amp a 1 ohm load and see true power, as this 3.5 ohm stuff is for the birds. I'll be bringing my meter to work tomorrow to verify it's reading correctly by metering some various resistors that I know the rating of for sure. It's a hell of a lot louder though and no fault of the amps, just the cheap Lanzar subs but what did I expect considering I got all 4 for $96. I think a trio of 18's are in the cards though for roughly 750" of cone area where as my 4 10's are only about 300". I may also do 4 15's - which is also about 700" of cone area. It depends what I can find and what fits the budget.

You could have been a bit more detailed... (totally kidding, nice job with the write up)

I got my new amp today, will have it installed tonight. Can't freaking wait to see what it can do.

I may come down and spectate for a day but I'll have to see what my schedule is like once the date is closer. I'd consider competing but I assume you have to be there both days for that and really I'd only want to do the audio portion anyway, my car isn't a show car by any stretch of the word.

I'm up by Fort Wayne, a little north of it.

Small update time. I've just placed an order for more goods. I've got 20 more sq/ft of FatMat on the way (This will make a total of 50sq/ft) to finish off the hatch. The best part is a new amp - MBQuart Onyx 1.1600. It's rated @ 1,100wrms @ 2ohms which is what I'll be running it at for now but it does 1,600 @ 1 ohm so I'll configure it for that when I upgrade woofers down the road. It should really wake the 4 10's up even at 2 ohms. I will update with pics once I get it. I also grabbed a 2 gauge amp kit to give the new amp plenty of juice.

Another short demo video. Sub flex (not much with this little power) at around 25hz along with a paper trick in the window.

How is a hatch classified as far as trunk class? If it's all behind the back seat and below the window it can be in trunk class but beyond that it is out I assume is how it works. Also, what is the usual entry fee for a show these days?

I am a state over in Indiana but will surely try to make it to one of these shows this year.

Thanks guys. Here is a short demo video.

Added some more deadener. Only had enough to do the passenger side wheel well/hatch area. Bare - aside from the one lone piece I stuck on before taking this shot. After a couple sq/ft... Finished off the last 10 sq/ft of fatmat I had. Need to order another 50sq/ft or so. Thats all for now, more updates soon.

I finally installed the speaker wire bolt connection setup I got when I built the box originally. I didn’t want to bother with a terminal cup because I intend to install 10-12g wire with ring terminals eventually. I just bolted the bare copper down for now. This low power setup wouldn’t benefit much from more anyway. I also cleaned up the amp wiring a little bit, plus it looks much better without the speaker wiring hanging out of the port. Inside the box. Cleaned up the wiring around the amp. I also utilized both connections on the amp, so two pairs of the thin speaker wire feeds the 4 instead of just one. Current shot. Thats all for now. More updates soon...