haemphyst's new system

OK, all... This weekend is the weekend it's all happening. I'm sick and tired of having no tunes in that damn car! Ticket total for this system? I added it all up, (equipment, wires, wood, all of it...) without labor, and I guessed roughly $7 to $8K!Anyway, I won't be able to mount the amplifiers in a stack, like I wanted to, so, I'll be mounting them on the back of the sub enclosure. (Don't worry about vibration, I don't BELIEVE in vibrating enclosures... translation: VERY heavy bracing)If I'm lucky, I might even be able to re-design the enclosure (since I have about an additional cubic foot with which to play) to possibly take care of some of the peak I had before. DYohn, I'm leaning toward the stuffed TL design, again; I'll end up with an FS of 24, (and an f3 around 18Hz) with my existing available dimensions! Can you say CRAZY STYLE!?!Pictures WILL follow, I bought a camera JUST for this project, but for now, here's a drawing of the sub...It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Ok that is an interesting design that I haven't seen before. So, the subs are mounted face to face in an enclosure that is one big transmission line? Got me curious. Is this similar to a tuned isobarik bandpass? Will you have access to the subs once everything is built? Just curious. Years ago I had an isobaric dual reflex bandpass enclosure that I thought did really well, so, just kinda wondering what the comparison is.

Looking back at it, I can see the confusion... The front (top) line is the front lip of the bottom of the box. It isn't a wall. The terminus (the space next to the front woofer magnet) is in the front wall. It's a single turn, true tapered TL, that's all :) "nothing more to see here!" LOL Bandpass, NO!!!!! Eeech! But, yes, it is indeed isobarik loaded. Linearity is our friend! As far as access to the subs, the back panel will be installed on cleats, with hurricane nuts, and stainless button cap hardware, in case the need should ever arise. The woofers will be held in place by the same hurricane nuts and stainless button cap hardware, but the hurricane nuts will be buried inside (between) the two ¾" mdf pieces.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Nice TL Dave.  I like the concept of ISO mounting which will change the geometry requirements... does it help make required line length shorter?  You are the man with these designs - me, I'd build ISO bass reflex!Support the12volt.com

No, the line length will remain the same, as a TL isn't based on Helmholtz's formulae, like a vented enclosure is. TL's are all resonance, and ignore the Vas of the driver. In many respects, TL's are the easiest enclosures of all to build, (or rather DESIGN) as all you have to know is the Sd and the Fs of the driver. My best overall results have always followed the following basics: Your inlet to the line should be at least 50% Sd, (it can be larger) with the terminus ALWAYS 25% of the driver Sd, and your line length should be a ¼ wavelength of the driver's Fs. Done and done! The major benefit (and WHAT a benefit, it is) to the iso loading is the linearity improvement, especially at Fs, but across the entire passband. We all know the detriments to iso loading, but the reduced efficiency will be well worth it, I think! All I know is the 2 Infnity 12's in stuffed lines that I had in my 86 Civic produced the FINEST bass I have ever heard in my car. When I realized that the large(ish) deep tuned vented box wasn't going to allow me to install everything the way I really wanted, I plugged the TL numbers in, and lo, and behold, they worked! I have some pretty high hopes for this one as well! :::::Editor's Note::::: Sitting here thinking about this, I also realized that the additional mechanical stiffness can indeed inprove the overall control of the air in the line, potentially further improving transient response. This will be my first ever iso loaded TL, so it might require more tweaking. Wait, I just came up with ANOTHER enclosure in my mind, where I could possibly use both 10's! Notes to follow! Look for 'em, kids!It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Notes and diagram for second TL enclosure! While not a TRUE transmission line, it can certainly qualify as a quasi-transmission line.Quasi-transmission line notes. None of these are benefits, or detriments, just notes!Reduced efficiency, due to much heavier stuffingImproved damping, due to much heavier stuffingImproved output due to additional driver coneSimpler construction – no additional steps requiredCan leave rubber trim rings in place on wooferShallower enclosure, allowing for additional trunk spaceTaller enclosure, requiring additional steps in construction phaseTuning (i.e. stuffing) could be more difficultCould conceivably tune each half for a different frequencyTerminus would be larger at 46 square inches (=Sd)It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Ouch, my brain hurts.

I'm going with the first design... It's actually almost finished, sitting in the back yard, waiting for the Gorilla Glue® (LOL) to cure, so I can use the clamps elsewhere in the thing... I'd put screws into the thing, so I could do this SO much faster, but I left my Makita at work on Friday... I guess I COULD go get it, I do have to change the backup tapes...It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Pics pics pics....hope your documenting this build!

Input from the build team! This has to be one of the most painstaking enclosures I have ever built... Everyplace I turn, I have to make a change... Luckily, I'm a fairly resourceful young man! LOL Turns out that the cleat idea for holding the back panel on, while brilliant, (if I do say so myself) will work, but I have to cut a gap in the cleat to allow the woofer to even get INTO the box, after the septum is installed! That's gonna be the fun part - I need to remove enough cleat to allow the woofer through, without drastically compromising the strength of the entire assembly! Three days, three sheets of MDF later, (three different thicknesses - ¼, ½, and (mostly) ¾ inch) gallons of sweat (it's been pushing 100 degrees here in Bakersfield), and surprisingly, less cussing than I think I have ever spouted in ANY build... Box form is finished, cleats are all installed, rear panel is laminated, baffle/septum lamination is curing as I type, front panel is ready for installation... All I have to do is cut a hole in the baffle, and screw everything into place! Almost done! One more piece of half inch MDF to cut to length, and this job is OVER, save for the finishing... I'm in love with the idea of a grey fleckstone for the front, with Honda carpet to blend into the trunk... Not totally settled on the finishing touches, yet! Pictures are being taken every step of the way, and when I am finished with it all, I'll post them!It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."