SubSam

Lol don't worry I'm fully aware of prntscrn, but I'm sitting in my car with my laptop on the inverter in my center console and my 3G hotspot isn't working so I have to upload the pics off my phone. I made my fiance go grocery shopping while I sit here and CAD a sub box she's the best in that regard

So if you took off the top of the box this is what you should see after your 45's are in So this particular design is 7.38 cubic NET @31.3 Hz after port displacement BEFORE sub and bracing displacement so once you brace it and throw the woofer in the volume drops to 7-6.91 cubic (depending how you choose to brace it) and the tuning crawls up just below 32 Hz. Hope this helps, if you want bracing tips I will gladly help you there as well

That's how I would do it Did I mention the baffle is 1.5"?

I fully recommend 45's in all the corners, at a bare minimum these two corners, both being 5" long. You can go longer if you want, but no more than 5" in the port or you mis-tune it

A view outside

First a rough outline of the box innards... bear with me this will take a couple posts

^^ he is 100% correct I should have said that actually lol sometimes I assume ppl know... anyways I promised to fix your design dilemma, so here goes

Table shaker lmfao... you sayin I could keep my home-made pizza from sticking to the table? I'm in! I notice you said coils "as we use them" does that imply that you will be using a similar flatwind or something different (such as a 4" coil or ceramic) for the SG? I know the woofer is being designed strictly for SPL application, which means I will probably never get to use one, but I'm just itchin to know more... feel free to respond with something like "its classified" if you don't want to ruin the surprise

I can't tell you what an N218 sounds like, I don't think many could outside the Fi guys, but i caan yell you what winisd says That's corresponding tuning @ 7 cubic for 28-32 Hz, its kind of your choice what you want the box to sound like... I was just fooling around over breakfast, I can make an enclosure design for you when I get out of work later today. My biggest question is how big is your trunk OPENING? Are you willing to build the box inside ur trunk if its too big to get in and out based on the opening size?

Hah wow... that'd be a bit peaky eh? If its based off the N2 I'm assuming one neo unit will be @ 90 degrees from the other's orientation? That's still gonna be some serious flux!

@ stang - I used to moderate the rockford forums for the better part of a decade, dishing out free CAD renderings of enclosure designs to anyone that asked nicely I bought my first pair of Q 15's a few months ago, and I've been real interested in Fi ever since. count me in for plenty of first and second-hand business, as I can't find a better value anywhere

Shit, I ran mine on 12v at .4ohm and I'm doing the same with my db Drive's now. Yea I exaggerated a bit, mostly for the point that he would only be spending more money for electrical support. I try to encourage ppl to try and work within their reasonable limits, but its ultimately not my choice to make I know

Maaan I got all excited thinking the N1's were officially up on the site... I didn't even notice how it didn't include 18's on the BtL main page. Now I'm even more interested. Any chance the N1 twelves will have over 90 dB sensitivity? Hard to do with mass limitations I know, and mostly irrelevant towards most applications, but I'm just curious as heck.

Biggest you can afford! Voltage drop is the enemy; for the sake of the longevity of your amplifier and speakers the more charging power/reserve power you have the better.

might be fun to rebuild my saz-3k some day. Come on up to Rensselaer Polytechnic Institute in Albany during a school year and ill be happy to walk you through it... just sign up for some simple class, they love eager students in the machine shop

I agree with stang as well... the most useful part of most mass-produced amps are the heatsinks. Rip out the guts and you have a nice platform to start mounting some real fets (the kind you can only buy in ridiculous bulk for about 15 grand), an industrial power supply, mock up a basic signal processor and balance current demands and voila you got an amp! It's amazing how much better a well-built amplifier performs with proper components. I prefer smaller analog-style amps but some of my students graduate up to some pretty beefy digital circuitry. had one kid from England who took his Lanzar/ legacy p.o.s. stripped it and designed his own got around 2300 watt output, after a small headache cramming in so many fets. he was so happy he gave it to me as a gift when he graduated and moved back to England. now its in my fiance's jeep liberty mounted under the backseat; been pounding away for about 5 years now without really getting warm even (@4 ohms). I'm lucky to have lots of circuit components at my disposal tho

I apologize for trying to keep the internet free of misinformation... for the record I've hand-built more amplifiers than sundown has sold to date. If you don't wanna take advice from the Fi moderators you shouldn't be on this forum.

well i have the big 3 upgrade with all 0 ga and when i get the new amp ill be replacing my 4 ga that i have running to my amp in the trunk with all 0 ga The big 3 helps the flow of power from A to B, it doesn't however add power. So you still have a stock electrical. Due to your drivers dcr, you can either wire it to 0.5 or 2ohms. 0.5 is a bad choice unless you know what your doing, and you clearly do not or you wouldn't be asking. I'm assuming this is your daily vehicle, playing music, etc. So your gonna want to wire it to 2ohms. As several have stated, look for an amp that makes 1000-1500watts at 2ohms. If you do get the kicker zx1500, your going to need an inline ssf (check out fmods). alright yeah ill consider getting that kicker its a pretty reasonable price but are there any other good brands of amps thatll fit my situation like Rockford or hifonics? Buy an MB Quart dsc2000.1 and run it at 2 ohms for a cheap ($300) clean grand worth of watts. I've installed over a dozen of these amps, they work just fine with great THD and a 1000 watts+ verified. I'm sure I got one laying around I've clamped them before and gotten over 1000 even at the 50 Hz range, ill go clamp one tomorrow at work and post the pic if you want proof. Or buy two reasonable (500-1000 watt) amps and strap em for that power/impedance combo

Buy four 16V batts and two aftermarket alts with a MLA or other VCM capable of boosting alt performance up to 15.8V minimum and then you have a shot. Sundown used to warranty their amps down as they assumed ppl knew what they were doing until they realized ppl were running them at 12V on stock everything. You gotta know what ur doing, and don't stretch it if you can't afford to constantly buy new amps and woofers. Just find a happy medium, and be happy you can save some moolah

It is called not knowing any better, and simply being a lemming and doing exactly what the manufacturer that really makes them says. It's simply not understanding how an amplifier works..in conjunction with a speaker. When you start to drop an amp below 1ohm more heat is being built up because the power supply and output portion of things of the amplifier simply cannot handle the demand that the output stage is wanting to get. When you do not have a subsonic filter...or one that is set improperly...you then start to make this thing that you've just microwaved move... You are slamming the gates open/closed on the output transistors at 90+% duty cycle, which is absolutely asinine and they freak out. Take a can of coke, pop the top open and bend it back and forth a few millimeters...within it's mechanical limitations that tab will never break. Now if you start to bend it past its mechanical limitations is when you start to get into trouble. This is where the subsonic filter comes in and making sure that you are not playing full power below port tuning frequency of a sub. If you already have something that's hot from running it hard on one of the Korean amps and you start yanking the soft parts past their mechanical limitations more and more heat builds up... You get to the point where so much heat builds up that the spiders start smoldering...they won't catch on fire until you've clipped the signal to death, vaporized all of the flame retardant spray that the spiders are soaked in and then it smokes. (square wave form, dc voltage out of the amp because the power supply cannot handle what you are doing to it) It's not the sub, there is absolutely nothing wrong with running those leads like they are. What's going on is an issue of the big cheap Korean amplifiers in and of themselves...and total ill-regard to what a microwave and conductive material does. Hope this helps you understand...if you run a Crown A6000Gti you'll never have a problem...because it's an A/B amp....the other stuff that is cheap...don't run it below 1ohm or you are going to have nothing but problems because in order to get that big power cheaply and cut out on the parts that are going into the amplifier the switching frequency of the power supply must be ramped way up...in turn microwaving woofer parts. Yes, that is true, I think, that little which amp can work on on .5 ohm, daily. I think if you have a daily sub in daily(big) box, you have a very big box impedance rise, which mean that if you want more efficiency from amp ( without clipping, buy sub with dual 1 ohm wire and wire down to .5 ohm, because in real life you got 2ohm impedance or more, thats the point of this quote. I don't know for woofer box without impedance rise. HAHAHAHAHA THAT IS THE MOST A$$ BACKWARDS THING I HAVE EVER HEARD!!! IF YOU PLOT THE IMPEDANCE IT'S OHMS VS FREQUENCY THE IMPEDANCE WILL RISE AT LIKE 60 Hz AND PLUMMET DOWN ELSEWHERE. New rule: if you don't have a degree in acoustics, don't speculate about things you have no chance of comprehending. Running an amp @ one ohm, even if its rated at one ohm, increases the TOTAL HARMONIC DISTORTION significantly, draws more current through the transistors which increases heat dissipation at a parabolic rate, and has MINIMAL RESULTING BENEFIT probably a SINGLE DECIBEL if ur lucky, 3 if you do it PERFECTLY. There's no reason to run an amp at half its lowest rated impedance, unless you want those transistors to all POP like pimples. I've seen it, they blow up. Ruin your THD and make your speakers non-linear. Nothing you said makes sense at all. Period.

Back to the woofer size, you can't always make an 18 fit. I agree with whomever said you should go for a 15, saves you a lot of headache especially if you have limited box building experience. That being said, you can be as creative as you want with angled baffles and such, just don't over extend yourself and end up regretting you ever started. I can relate, as my trunk is huge but oddly shaped (Chrysler lhs) allowing only 14" of clearance where I want the sub to sit. Didn't stop me from getting a 15 in there

i just want to get at the t/s parameters... I can't wait to update my fiance's jeep with some Fi goodness

The majority of car audio applications can be sufficiently powered by stock electrical power. If you want loud, natural bass replication, you should only need 100ish (probably less, but for the sake of conversation)watts and a superbly coupled driver/enclosure. If you truly believe you need an extra few dB then you will have to keep increasing the power or adding more drivers, both scenarios requiring you to lose space or electrical efficiency. But that's your prerogative, not a flaw in speaker design. Keep in mind we live in 190+ dB atmospheric pressure, and all speakers have to overcome that pressure to make sound. Totally different underwater for example (anybody tackled pool acoustics?).

well I will take the initiative and ask a simple question... do ya'll ever get sick of building woofers and such? I love car audio; I've had a system in my car since before I could drive it. But now that I am an installation professional I sometimes find it harder to come home after a frustrating day of installation and especially customer service (try explaining to a guy that speaks only Spanish the difference between rms and peak power) and work on my own car. Back when I was a chemist I used to speed home and whip up a batch of resin before I even set foot inside my house. Now I have to consciously avoid taking shortcuts where I can to try and speed up the process. Now that I have a neo BtL on the way I can feel some more excitement in rebuilding but how often does something that different/new and interesting come along in the car audio world. Obviously the end result is still the ultimate incentive, but I imagine it must be taxing for someone even higher on the professional ladder...

Could maybe be a simpler problem... sounds dumb but how well is the driver secured to the baffle? If its not bolted in I've heard some funny frequency-specific sounds come from stripped thread screw holes and small gaps around the surround. Tee nuts + teflon tape never fails in that manner. I'm just trying to think outside the box... no pun intended