So........ many years ago when i was in high school, i worked for a place called Pro Electronics on South Saunders street, just outside of downtown Raleigh. At the time, car stereo was very popular, and i had a blast, pushing my abilities in a semi professional environment. I learned so much about 12v electronics while i was there. After i had been there a year or 2, we bought some software called Bassbox 5.0. This was a huge step in the right direction because previously the only way to design enclosures was to do the math long hand, and hope that you got what you wanted for frequency response, and hope that you didn't make any math mistakes. After playing with the software for quite a while, i learned that if i chose a 7th order bandpass enclosure that i had 4 separate variables to play with , and that if i adjusted them incrementally that i could create large efficiency peaks thru a limited bandwidth, as well as greatly extend the low end efficiency of the speakers. On several of the designs i had between 6 and 9 db increases in efficiency thru a range of 25-80hz. (as a point of reference a 3db gain is essentially doubling your output) The really cool thing is that a car will naturally emphasize the 90-140hz range and it would always "color" the sound. So a work around became building boxes that emphasized the frequency response below that point to get a more flat response, as well as the really deep bass that most every speaker loses as the frequency lowers. At this point I realized I am able to take into consideration the acoustics of a car as well as recover the low end most systems lose by efficiency losses below 45hz.
so..... i built this really trick little speaker box with 2 tiny little 6.5" Orion XTR subwoofers. I didnt think it would be super loud but i was hoping to prove a point, and show off a little. The box was tuned so low that it would literally play perfectly flat all the way to the point where the speakers frequency response became the limiting factor. This box sat in the display room at Pro electronics for years, for many reasons. First it was really cool, and it was fun to show off how deep and loud a pair of 6.5" subs can play, rattling the walls (we didnt really want to sell it) 2nd, This box was kind of expensive because i spent so much time playing with it and building it, and the speakers were kinda pricey way back then too.
fast forward to 2008..... i ran into one of the crack heads i used to work with at Pro Electronics, because i was using him to polish compressor covers for me on the high end turbochargers. He was extremely unreliable and ended up screwing me over on a couple turbos, and cheating me out of some money. Just prior to us having a "falling out" he pointed out to me that he had been able to "acquire" the speaker box that i built so many years ago, when we worked together. Apparently it had been bought and sold a few times and he came across it many years later. I bought it from him OF COURSE. To me it was so awesome to get something from way back in the day..... that i spent so much heart and soul creating. I had so much fun designing and building this thing, and i was REALLY excited to get it back.
when i got it home and installed it into my typhoon i immediately noticed that it was fucked. the frequency response was so far off it sounded terrible. I rode around with it like that for about a year and then the stock typhoon engine blew up. The typhoon sat in the vacant land that i later built my dream house on, while i worked on building a nice new engine for it. i was almost done and literally bolting the heads on the finished shortblock when a tree fell on the typhoon. I was so disappointed...... many years later i sold the typhoon still squished with a half complete engine. I just never could justify the time and money it would take to fix it correctly.... but the speaker box was sitting in my shop "hiding" in the corner.
so fast forward to now.... my whole world has changed over the last few years...... i'm divorced, dont have a lot of money because of how much i have to pay every month to my x/kids, i sold turbotime to a friend of mine to get away from all the "crazy"...... and I'm dating a younger asian girl that i really like a lot, who also loves car stereo. Next thing i know, i find myself digging thru the old TT garage looking for this "magic" box that's been thru hell and back. I take the cover off of it, and what the fuck do you know? The guy i used to work with has changed out the speakers for something totally different, then signed the inside with his name and cell number, taking credit for my work...... or maybe he was just taking credit for screwing it up? who knows..... that guy was always such a crack head. anyway......
So the first thing i do is a little research online. I contact Orion and of course they are no help at all..... in fact they are probably as usless as AT&T's customer service. Next i try ebay to buy some 6.5" XTR's with no luck. So i find some other brands online and eventually settle on something that has published specs online. I totally redesign the box over about 6 hours of playing off and on when i have the time, (the software has changed so much i had to do a bunch of reading to come up to speed on it) and as luck has it, i was able to re-tune the original enclosure with only some minor woodworking and new port tuning frequencies. the outside dimensions are "almost" the exact same. So i ordered new 6.5" speakers, and started undoing everything retard did to my box.
.....and now starts my car stereo adventure on my 05 forester