New box pics

[CdnCory]

Here are some pics of my box. Each has 3.95 cu.ft. of airspace, and dont bother asking me what they are tuned to. I had went into a local car audio store and wanted to know what port sizes I should make, so he called the guy in NY who designed the subs and he said the port should be 23 x 8 x 1"deep, but this was before I had the box built and the guy only took rough measurements. So I made the ports as big as would fit for now, and I will be making new tops for the boxes as soon as I hear back what the ports should be for my actual box. As of now, I resined whe inside of the bottom and will just screw on the top. I still have to add 1" polyfill all the way around too.

Here I am still trying to find out how things are going to fit. I didnt measure anything, and lucked out that my three amps actually fit on the rack!
I dont really want to have my distribution block showing cuz its not the nicest looking piece of equipment in the world, so I might flush-mount my EQ underneath the component amp, then have a cutout underneath the amp so that when I have to change fuses all I have to do is remove the one amp.

Next step is to install the two yellow tops, isolator, drill all the holes for wires in the amp rack.

Once I get the finished box with the correct port, I'll probably get it painted to match the exterior and then carpet the amp rack (since I have a feeling it will be taken on and off a few times).

 

[BeauJ]

Impressive. What kind of subs/wattage are you putting in?

 

[CdnCory]

Im dropping in 4 12" GTi's, powered by two 1200W amps. They will run @ 3 ohms and get around 600 wrms. I know they're really underpowered but if I were to buy amps with sufficient power I would never be able to fit them anywhere. Next season, I will prolly downgrade to two subs, sell the boxes I have then pick up a A3000GTI, and build a box perfect to spec.

 

[mcG]

hope you don't need any trunk space lol, but it looks like it's gonna be pretty loud

 

[CdnCory]

hope you don't need any trunk space lol, but it looks like it's gonna be pretty loud

What do you mean? I have 9 cu.ft. of trunk space, I can still stick things in massive holes that I call ports

 

[Nasty350LT1]

Dam, that is one awesome box. I like it. What does that weigh ? I bet your X sits pretty low in the back, no need for "Lowering Springs.

 

[XLoudFN97X]

Thats a pretty damn big box dude- Id be careful pushin' any serious wattage to those nice 12"s until you educate yourself on port dimensions. An incorrect (and I mean WAY off) port size can have dangerous and damaging effects to the system. I'm no expert at it, but I recommend checkin out a software program for Windows called WinISD downloadable at the developers website, www.Linearteam.org It sounds like youve got a good understanding of ohms, wattage restrictions, and power management so you should catch on to the education easily. Looks good!

~stu

How do you have those amps wired to 3 ohms? You could maybe get more wattage by wiring them down to a 2 ohm load. Are the subs DVC? What ohm load?

 

[CdnCory]

Ya, I am aware I can damage the subs, but I am pretty confident that I will be alright since the ports are so damn big, and only 1" deep. Also, there isnt much wattage goin to the subs either so they should be able to handle it. I did download winISD and messed around with it, it said to put ports 4x4x2" deep, I think something was wrong there so I just went close to the 23x8x1" that I was told from the rough measurements.

The subs are dual 3 ohm voice coils, so I cant get two of them down to 2 ohms.

 

[XLoudFN97X]

yea those dual 3 ohms are tricky, not very compatible with capable amplifiers, but still good subs. And the way I remember the whole porting deal is the larger the port, the deeper you need it to be to tune to the same frequency (i.e. my 4" port is 7.5" deep, an 8" port or an additional 4" port would require twice the length to keep the tune). I need to do some refreshing as I haven't built a box in about 3 years. It just seems like with that big a "hole" in your box, there'd be no backpressure to keep the voice coils in line. Cant remember... too many smoke-outs. O Well.

~stu

 

[CdnCory]

I swear I have the worst luck ever with stereos. First of all, if it wasnt for
my luck, this all would have been installed last summer, all of it has been
sitting at home for the last year.

I spent all today hooking stuff up, after blowing a fuse, it all fired up,
sounded great, last step was to screw on my amprack... and it doesnt fit. I have pics showing the piece of MDF in place and everything in my first post.

I am pretty sure the MDF grew overnight... worst part is that I made all my
RCA's myself, so I drilled the holes in the amprack to fit the cable, not the
ends, so the amprack is goin in the garbage with all my RCAs in it.... maybe all my amps and subs will follow too.....

 

[tweakedlogic]

You need to work on those ports. You will have awfull low end performance. I know car stereo and encluser design, and those are not ports, those are massive holes in your box for the rear wave to cancel the front wave. You may as well take the sides off too. You need to go back to the software and redisgn the ports. Take into account that all four subs share the same space. which means you need to multiply you Vas by a factor of 4. Having four 4" ports is probably the way to go, that will keep port noise at bay. You can't just best guess this stuff and expect it to work well (or in this case at all). It won't take much to afix a pice of MDF to your holes and install ports to it. I'm not flaming, but you will be very disapointed if you keep it this way.
I have found that the best place for speakers or ports is in the rear of the cargo area, in, or pointing up to the corners. this yeilds the best cabin gain so you don't need as much power to play a certain loudness. But 600 watts each sub is plenty to get you around 140 dBs, if that is true rated power. Remember that with a 3 Ohm load being less than the standard 4Ohm load, the amp will crank out abit more amprage. Which means you will get abit more power to the VC.
One more thing, is your box braced in the middle? If not do it. All you need is PVC or 2x2s and fiberglass resin, but add some mat to make it stonger. Sides too.
Good luck and don't forget to fix your ports. Think, have you ever seen ports like that in even a generic prefab box? No.

 

[CdnCory]

like i said before, I had some rough measurements taken, they werent THAT far off, and the person who designed the subs suggested a 23x8x1" deep port so I just went as close to that as I could, and it did sound good when I was playing music though I didnt play anythin with good lows yet. As long as it sounds good playing music, its all good.

All generic prefab boxes sound like crap IMO. This box already sounds way, way better than the prefab I wad my 10" rockfords in, HUGE difference. And the JBL are mono blocks, there will not be huge gains in output going from 4 ohms - 2 ohms - 1.5 ohms (in my case, they are dual 6 ohm coils, though they were dual 3's but was wrong)