*sigh*
That sigh? A sigh of relief - relieved to have this project done, and the satisfaction of knowing all turned out better than I could ever have thought (especially as I consider myself a car audio novice). I'd never make it as a car audio professional, as I'm way too slow & clumsy (see finger hack job in previous post). LOL...
The original question was what would happen if the sealed chamber of the DB was increased? In short, I won't know that answer until I build another DB to spec. and compare. I plan on doing this eventually (for the home), but it will be a while. The question was asked originally because I knew I wanted to use the MTX 8410-44’s, and was concerned about the sub’s displacement, and I wanted to make sure that I could get them to hit as low as I possibly could without changing the plans too much. Other considerations were making sure they’d still fit into my design, etc. In the end, as mentioned previously, the sealed chamber was lengthened by one inch.
The boxes weren’t too hard to build, but I did take my sweet time with them. Lots of sanding, and making sure everything was accurate. The amprack on the other hand did prove to be a bit of a challenge. Making everything clean with hidden inputs, holes, assembly, etc., was a pain in the arse. It was also tricky to make sure that the amprack was securely mounted to the vehicle – however I was able to resolve that issue with some ingenuity and a few special order bolts… If you read my previous posts I wanted to finish the rack in vinyl, however, after a few test runs I quickly discovered that the vinyl wasn’t as forgiving when it came to blemishes in the wood, etc. Padding helped that issue, but ended up looking too bulky for me. In the end, I went with good ol’ old-skool sub box carpet for the finish. I dunno, it looks good enough I suppose.
Power is provided by Stinger all the way around. 0/1 gauge supply to a distributor that splits into 4 – 4 gauge power wires (between the DB’s). The old-skool PPI’s have standard 8 gauge inputs, so to accommodate this I bought eight 4 gauge to 8 gauge reducer adapters. They look sweet in addition to being functional.
After wiring everything I was more than happy to power her up. Gently turned up the volume 1/4 of the way and heard sweet sweet sound. (everything flat, no processing). I was pleased with what I was hearing. However, a little intimidated to turn it up until xover and tuned, etc. Played with the setting’s a while, and came up with settings that I felt really pushed the DB’s. (I was anxious to hear them both in concert pushed to the limits!). Here’s the settings:
# Crossover #
[Frequency(Hz)/Slope(dB/oct)/Level(dB)]
Front:160.0/24/-1
Center:160/24/-1
Rear:160.0/24/-1
SW:63.0/24/-1
# Parametric-EQ #
[Frequency(Hz)/Level(dB)/Width(Q)]
Band1:40.0/+6/3
Band2:125.0/-3/3
Band3:1.0k/+4/3
Band4:2.5k/+5/3
Band5:8.0k/+6/3
I’ve got the ability to set six parametric configurations, as well as six xover configurations – so I’ll be playing with those more in the future to accommodate various musical genres. But for now, the above is what I went with to initially hear the system pushed. With the gains set properly I finally cranked her up! LOL, OMG, WTF?!!! PURE INSANITY!!!! There was nothing but crystal clear sound as loud as I could take her (or stand it). The sound was full, rich, deep, crisp, pleasing tones from across the spectrum. Bass tones literally blurred my vision and took my breath as the DB’s executed them effortlessly. A friend who came over later to watch the Nuggets game with me sat in the VehiCROSS as I cranked it up. With the same blurred vision I was experiencing he looks and tries to yell over to me, “I can feel the bass crushing my nuts!”. My labors are validated. LOL… I wanted the ability to enjoy DEEP clean bass as well as overall SQ on demand. I’m pretty sure mission accomplished!
Setup:
Optima Yellow Top
Stinger 0/1 & 4 gauge power/ground
10 gauge speaker wire throughout
Stinger HPM 0/1 gauge to 4 – 4 gauge dist.
Alpine CDA-9835
Boston Acoustic Pro 6.5 (Front)
Boston Acoustic Pro 5.5 (Rear)
Alpine SBS-05DC DIN center channel
2 – MTX 8410-44
2 – PPI A600 @ 3ohms
PPI A1200 @ 4ohms
PPI A100 @ 4ohms
Here are the final pics of the build. Thanks for reading. Enjoy!

-biju.