Obsidian 18 D2 V2 in 2001 E38 BMW 740i

[-X-RaTeD-]

First of all, thanks to this forum for the plethora of information that is just freely available here. I've learned so much here, been basically remastering my whole music library. I'm surprised at how many songs that I've purchased left the studio clipped to hell. I've asked a lot of question and gotten a lot of ideas from here, and some day hopefully I will be in the position to turn around and give something back to the community.

I bought 1 Obsidian 18 back when the pre order was open, and finally about 2 weeks ago built a sealed box for it, against recommendations. My first time building a box, so I am sure that I made some mistakes, but live and learn. I bought a sheet of 3/4 birch ply from Lowes (I know not all the ply's are birch, just the faces and maybe 5 layers in between) , stained all the sides except the top in black, undecided about whether to leave the top natural or dye it black, or paint it frost silver to match and contrast with the amp. Anyways,

New sub next to my old Alpine Type R 12"

Amp ordered from Germany.

Bro smoothing off the edges... MDF would have been much easier to make clean cuts with.

Letting the stain soak in.

Used Titebond between each mating surface, and an extra bead in all the edges since it's going to be a sealed box. 2 1/2 wood screws with holes pre-drilled.

Didn't have a router, but a guy was selling a jig saw for $10 on CL so I picked it up. First time using one, hole wasn't perfect but was cut a little too small for that reason, to give room for when I mess it up, lol.

Centering the amp.

Used some of the extra scrap cuts to space the amp and allow some air between the amp and box.

Amp mounted

Used some 2" zinc plated bolts and wing nuts for terminals for each coil.

Used a 1 1/4 spade bit to make 2 countersunk holes

1 1/4 dowel rods used on each side of the woofer for reinforcement since I didn't use a 1" baffle. Screwed and glued in place. Counter sunk the top spots for the dowels also, and the baffle slid right on, screwed an glued.

[-X-RaTeD-]

Again, its my first box. One of the cuts was off like 4 mm at one corner, and I didn't want to effect the structural integrity of the box by screwing it all the way down, so I used some of the wood dust, dyed, and wood glue to make a past to fill it in.

Tee nuts on the backside of the baffle.

Sub mounted

In the trunk

Perfect measurements, enough room for excursion

Temporary wiring until I get some 0 AWG and 12 AWG cable.

Bimmers have the battery right at the back right side, so very short power cable run. Again, temporary, I'll clean it up when I get the 0 AWG.

Pushed all the way back, I can still fit my bass guitar amp in there so, win win for me.

Can't get the spare out though without taking the box out. That's fine, I'll just keep allen keys in the trunk just in case I need to unhook everything.

I will be voiding my Obsidian warranty and shooting for 1000 watts clean. While driving normally, alt charges at 13.9 volts. I'm not getting any voltage drop while the engine RPM's are above ~1.2k, but below that the voltage does drop to around 13.2V full tilt. The amp is an EmPhaser EA1800D, rated for 2200 watts at 1 Ohm, some have wired them to 0.5Ohms over in Europe without problems, although it's labeled as being 1 Ohm stable. I have it wired at 4 Ohms now until I get better cables.

Test results, in German but you can make it out. Real solid amp and does damn near rated.

Nennleistung gemessen nach DIN 45500 bis 1% Klirrfaktor bei 13,5V
Emphaser EA 1800D

1 × 847 Watt Kanal 1 an 4 Ohm
Stromaufnahme 75,2A
Wirkungsgrad 83,4%

1 × 1458 Watt Kanal 1 an 2 Ohm bei 13,4V Versorgungsspannung
Stromaufnahme 137A
Wirkungsgrad 79,4%

1 × 1880 Watt Kanal 1 an 1,33 Ohm bei 13,4V Versorgungsspannung
Stromaufnahme 184A
Wirkungsgrad 76,2%

1 × 2172 Watt Kanal 1 an 1 Ohm bei 13,3V Versorgungsspannung
Stromaufnahme 231A
Wirkungsgrad 70,7%

2172 Watt Gesamtleistung

Now I made some videos last night but video does not do it any justice at all. If someone has a recommendation for a camera that can record bass for under like $200, please let me know. I got a lot of shit for considering a sealed 18" but, when I pulled up to FIve Guys today, I could see their glass vibrating to the tune of the Decaf version of I Cook. Needless to say, I am more than happy with my sealed 18".

Car: 2001 BMW 740i

Amp: Emphaser EA1800D @ 4Ohms for now

Sub: Obsidian 18v2 D2

Alt: Stock 140A liquid cooled

4 gauge power cables, soon to be 0 AWG

Box dimensions: 32x20x15 ~4.0 cu.ft after sub displacement

I learned a lot, already have some ideas that I will put into practice whenever I build my next box. Let me know what you think!, or any suggestions.

[Casket]

Looks great , man. Nice job. Were going to need some videos of that bad boy when you get done

Edit: Nin'jad LOL

[stroupe79]

looks pretty good, since you have to remove the box to get to the spare are you going to build a ported box in the future to maximize the trunk space?

you can run it in 4.5cubes ported minus sub/port displacements...and by the looks of it you have enough room to add that volume with relative ease!

[I am Poncho]

looks good, if you ever want more out of it but still want it sealed, bump up the volume a bit 5cuft maybe, will deff hit the lows better, or if you decide to port youre going to lose that trunk space. lol 5-6 cubes minimum ported after all displacement.

[-X-RaTeD-]

Thanks guys.

I haven't really considered porting it for two reasons, don't wanna sacrifice my whole trunk for a low tuned ported 18 box, and after finding this response chart, although I'm not sure how accurate it is or what the real world difference would be, I'm not sure how worthwhile it would be.

Also, I'm a noob at this whole thing, but I was reading somewhere that an EBP of 70+ is ideally suited for a ported enclosure and below that it would be better sealed. The Obsidian's free air resonance is 27Hz, and Qes is 0.75, so it's EBP is 36.

I like the idea of maybe 5cu.ft sealed box, but I have my battery and some fuses in that right side bay that I wouldn't really want to block.

Only thing is that there is a sound of the sub gasket letting some air escape, which is over emphasized in the video, but still. I was able to walk to the other side of the shopping center parking lot (about 800 feet according to google maps) and still hear the bass. My phone doesn't pick up anything standing right next to the car, sucks. Hopefully I can get a proper video, because my phone takes downright disgraceful bass videos, lol.

[Brandon15zzz]

It's a nice looking build good work.

[-X-RaTeD-]

Was able to borrow a better phone today to make a quick video. Hopefully this weekend I'll have time to get a few in the daytime. I slowed down My Chick Bad - Ludacris, and clean bass boosted everything <70Hz.