BigDaddy13440

Can ANYBODY run some projected numbers, see what kind of output and response each would have? (4) 15's vs (9) 10's vs (16) 8's? For curiosity's sake, say the enclosure is 42 x 34 x 27 - now there is PLENTY of space to put (20) 8's on the baffle. Approximately .65 cubes each..... numbers for (20) 8's?

What specs do you have for the box? Internal dimensions? I know you said you had 40x36x20 initially, what size do you have now? W/ or w/o the double baffle? I'd have to agree with you, you really don't have the accommodations to do anything other than subs up. Two 15's forward or back would be fine, but I wouldn't recommend two firing forward AND two back - you'd end up with some funky cancellations.

Even if he just goes with 15's, with that much power..... he'll need at least 250-300 watts going to each of a pair of 8's, even 10's for midbass, from probably 60-150hz..... and then probably at least 100 watts to each of his separates (or stock coaxes ). Who you kiddin? It's all going in a '85 Chevette 2-door!

Find some bucket seats that match the color of the interior, can be from pretty much any make or model, and fab up some brackets to put buckets in. I had an S-10 Blazer, I put some Grand Am bucket seats in, modified the brackets to fit. They sat about 2-3" lower than the stock seats, and went back further too. Whatever sub you get, building an enclosure to spec is key. A $50 sub can sound very good in a well-built enclosure, while a $500 sub can sound like ass in an enclosure off-spec.

Awesome attitude. Awesome. The point to type properly would be to act as educated as you pretend to be and not look like a hood rat when reading your posts. Oh, and making them easier to read. What Adrian is trying to say (A, pardon my correction of your correction, the kid needs help....): If you are as educated as you claim to be, why not make an effort to use that knowledge to put forth a thought in a manner that anyone can clearly understand? It's just pure laziness not to give your best effort, and if you should need to give all your attention to some matter, you'll have already had enough practice in communicating clearly: it won't seem nearly as hard when you HAVE to do it. In other words - don't be a lazy Biatch. Clear, concise, to the point - if you want answers, give someone that might have that answer for you the courtesy of you making an effort. Understand?

I'm using a Kenwood KGC-6042A 1/2 Din EQ in my system. It has 9 fixed frequencies, and 2 parametric channels, each with a 12dB boost/cut. It accepts one set of RCA inputs, and has front, rear and subwoofer outputs, with fader capabilities between the front and rear. The subwoofer outputs can be defeated with the push of a button, with a slider for subwoofer level and crossover frequency. Kenwood EQ at Crutchfield

Anyone else? For SQ, I'd probably do the 10's myself, as each sub would receive less power, and would in turn be less likely to fatigue and come close to a thermal meltdown. If I wanted the maximum low-end response, probably the 15's? But for sheer SPL, would it be best to find the resonant frequency of the vehicle, and probably go with the 10's?Again, back to the whole "efficiency vs power" debate? At 40" x 32" for the baffle, it would almost be possible to do (20) 8" subs, but I don't think I've ever seen an 8" with an OD of under 8.25"..... but (16) of them would surely fit on the baffle. So...... (16) 8" subs as another option? Approximately 0.8 cu ft each ported?

Does he have bucket seats in the Ranger? If so, build a custom center console between them, stretching from under the dash, contouring down to a height the same as the armrests. The top of it would most likely be about 7-9" wide, but you could flare out the bottom pretty easily. A buddy of mine competed about 12 years ago with a '93 Ranger Splash, went to the Worlds for SQ. But, he still hit something like 145dB with ONE 12" sub firing down at the floor, pushed by a 1000watt amp. Think he had just under 3 cu ft for the net enclosure volume. I'm thinking a DCON 12 would suit your/his needs quite nicely, and the existing amp (480watts @ 2ohms) would be perfect.

Do the speakers have a baffle preventing the pressure from the sub from affecting them? Or are the back of the speakers exposed to the pressure? If they aren't sealed, they should be. I know XTC makes foam baffles that drop in the hole before you put your speakers in, they alone will help - a lot. It would also clean up the response from your rear fill speakers. If you can't find the XTC baffles, fab up an enclosure around them.... and make sure they are securely bolted in place. Use bolts with Nylock nuts (they won't ever back out), and use a gasket sealer to cushion the speaker from the deck vibrating. And make sure there is sufficient room for the pressure from the SSD to get into the cab. If it's firing up at the back deck, the deck had better be perforated to let the air move. Unless you like the buzzing of metal vibrating, in which case disregard anything you've ever learned....

Or, 6 coils in parallel, then the (3) groups of 6 in series.... either way gets you to 1 ohm. But back to the original question...? Suppose two 3500's strapped @ 1 ohm, or 7000 watts (give or take a few).... 1750 watts per each 15" woofer, or roughly 778 watts per each 10". I'd assume the lower power to each 10" sub would make them more efficient?? Doesn't efficiency exponentially lower as you add more power??? Would you go for the maximum low-end extension of the 15's (assuming the frequency response differs from a 10 to a 15)? Or would you go for max SPL, assuming the (9) 10's would be more efficient than the (4) 15's? Which would be better for a daily driver, SQ-wise? Would the 10's have better transient response, and blend better with the rest of the system? What if you already have an excellent 8" (or 2) or 10" midbass driver? You've got the box, what to put in it!?! What's the chance anyone has (9) 10" subs and (4) 15" of the same make and model? Any of the -CON's, DP's, lvl4's, etc???? Simple matter to change a baffle......... :bigclap:

OOPS - inadvertently posted while I was replying..... see the next post.....

(4) 15's, either single 4 ohm coils, or dual 1 ohm coils Parallel or series/parallel config to equal one ohm. (9) 10" subs - dual 2 ohm models, 18 coils total Wire coils in series groups of three, gives you a 6 ohm load. Then wire the 6 groups in parallel, gives you a 1 ohm load. The only reason I'm assuming driver Xmax of 20mm is to give adequate port area for the subs to breathe, using Port Calculator. Still a shade smaller than what is recommended......

You could do 10HZ in the 10cu ft box if you wanted to, but your port would be ridiculously large. Use Port Calculator to get you started in the right direction. 1)Figure what size enclosure you want (Cubic feet x 1728 = cubic inches) 2)Determine your tuning frequency 3)Figure how much space the port will take up (Cu in) 4)Add in the displacement of the speakers (Cu in) 5)Add the sum of 3) and 4) to your enclosure size (Cu in) 6)Divide by 1328.25 (interior dimensions of 38.5" x 34.5") = your interior height of your box. So....using an Xmax of 19mm.... 1)10 cubes = 17280 cu in desired space 2/3)35hz requires a slot-loaded port displacement of 4942 cu in (38.5" wide port x 6" high x 19" long, 231 sq in of cross-sectional area, slightly smaller than the 277 sq in recommended) 4)If you say .25 cubes displacement, then X4 = 1728 cu in. 5)Total interior space required = 23950 6)Interior height of box = 18.03" Note: does not add in the space required for crossbracing, or for 45'ing the corners! Without crossbracing, the enclosure would be 20.25" in height, assuming a 1.5" double baffle, made from 2 layers of 3/4" MDF

With those dimensions, and a double baffle, you get a gross enclosure volume of 13.64 cubes. I don't know the displacement of each of the HX's, but let's just assume .16cu ft ea - you've got 13 cu ft internal volume. Now, depending on the port size, and the internal bracing, I'm willing to bet you're going to be down to around 12.25 cubes or so. AND - gotta agree with firing the subs up. Even if you were to raise the box up 5", that's a LOT of space to give up to be able to carry material. Some kind of cover is a must. BUT.... Will the HX's work fine in 3 cubes each? Can you go smaller? Are you looking for Max SPL, or just good SQ? If you're looking for sheer volume, I believe a smaller box, tuned to a higher frequency, will get louder than a larger box (but I may be mistaken). If you can drop to 2.5 cubes each, you're down to 10 cu ft after all displacements, and probably somewhere in the 11.5-11.6 cu ft gross range. With the box still being 40 x 36, it would only need to be approximately 17.25" in height - Then, you COULD raise the box and fire them down - lift it just 4" off the floor, should be plenty of room for the subs to breathe.

You can also gain some space by lifting the rear seat a couple of inches, and building an L-shaped box partially underneath the seat. Might pick up a couple cubes of airspace by doing that.

Weld some steel rod or angle iron across the ribs, give that panel something to brace against. Then, 'glass the living crap out of it, minimum 8-10-12 layers, probably more. You want a panel that isn't flat, with some horizontal and vertical bracing (hence the rod/ribs) - something at least 3/8" thick, preferably 1/2" or more. Put some type of damping material on the inside, and build the front of the enclosure out of 3/4" MDF or birch. Don't think you need anything thicker, as you are only using 8's. Just make sure you do some internal bracing, the front baffle should be fine. I fiberglassed the inside of my enclosures for my two 15's, built into the quarter panels of my Tahoe. Used 4-5 layers and silicone to seal the seams, don't notice any panel flex at all. Granted, I'm only pushing 250 watts to a 15" sub with only 6mm of excursion, but still..... I did an enclosure inside a VW Rabbit quite a few years back... laid 1/2" of foam against all the interior panels (and glass), then fiberglassed EVERYTHING, made the enclosure over 1/2" thick, and 'glassed in cross-bracing. Did a 1" baffle on the front, put (4) 15's in it, had approximately 14-15 cu ft. So yes, you CAN use the back wall and sides for the enclosure :bigclap:

Regardless of how "loud" it is..... kids' ears are as sensitive as their bones, which break much more easily than those of an adult. Just the amount of air that system moves could potentially damage hearing, no matter what frequency. If that box plays down to 15hz, and you can feel the pressure yourself, what do you think that pressure is doing to little eardrums? BTW, I'd do something like that if I had the available space. Not knocking your install by any means, love what you have done - just be EXTREMELY careful with the kid in the car.

Dude, play that chit when you and the wife are in the car. If your kid is in there, keep it down. WAAAAAYYYYY down, as in OFF. My kids are 5 and 7, and I don't even play my 10's at anywhere near even half volume with them in it, much less the 15's full bore.

Better to have a bit more cross-sectional area for your port than not enough.... I'd reasonably say that 70-80% of what they recommend is probably adequate. So, for your 15" SI D2... that'd be 56-64 sq in of port. If 45 sq in worked for you, kudos to ya.

I built a box for a Beretta as two separate enclosures, and glued-n-screwed them together inside the car. A typical drop-in box would only accommodate about 3.6 cubes, I was able to get almost double that, or about 6.7 cu ft. I removed the seat back, had the 15" subs firing forward, and reached through the openings securing the two halves together. Installed the subs, replaced the seat back after hollowing out about half of the foam. Looks like you don't have all that much height to work with, you'll probably have to fire the subs back. Build whatever size enclosure will fit in the forward section, maximize the space. Instead of having a baffle facing you as you stare into the trunk, make it a flange, maybe 2" in width all the way around, it'll leave you with 1 1/4" inside the box to screw from one flange to the other. Build the outer portion of the enclosure so that it will drop down through the trunk - basically, the same size as the one you currently have (if that's the absolute biggest you can do that will still fit). Have the subs fire rearward, and reach through the cutouts to secure the two box "halves" together with screws - obviously, a nice healthy bead of silicone between the two flanges will help it be airtight. If you've got 40"w x 16"d x 12"h in the forward area (just a "for instance"), you'd pick up about 3.64 cubes - you could also reduce the size of the outer enclosure to give you similar internal volume as to what you have now, and leave yourself a LOT of floorspace to mount the amps and batteries. Now, the only other question would be..... do you have room to mount the batteries and/amps in the corners of the trunk?

Is there any way you can do an enclosure that will use the space up on that shelf? Maybe make it sort of an "L" shape? That would gain you more space between the subs (firing back) and front of the trunk, you could move the batteries there.

Ain't it great learning that you don't have to limit yourself to such a small enclosure? Anyways, 1.5 cubes (3.0 total) ported would work fantastic for a pair of tens, as opposed to choking off most of the twelves with that size enclosure. I'm thinking a couple of DCON 10's would be pure buttah! If you want some SSA stuff, you'll have to find a shop that carries them, and order from them (not directly from SSA) - maybe if you grease somebody's palm with something green, they'll play the middleman for you iin your insurance purchases. AND... if you wanted to face the subs forward, you'd could pick up the space allowed for the subs to fire downward... maybe get you another .3 cubes each? Then, you could conceivably be looking at over 4 cubes..... now you could do 12's!

Truer words have yet to be spoken.

Try this: Port Calculator You'll need to know the XMax of those SX's, and your intended tuning frequency. From there, it's simple math.

Have a bunch of steel bolts down stairs, so I think I'll just go with those. Not trying to cheap out, but if we have them why not use em Ring terminal at the end of your leads from the sub, and the same from the terminals on your amp. Hex bolt with washer, secure the speaker leads from inside the box (duh!). On the outside, another washer, and then a nut to keep the bolt tight - I'd even go so far as to use some Loctite to make sure the nuts don't loosen from the vibration. Then, secure the amplifier leads (ring terminals, again) with another washer and nut - I'd use a Nylock locking nut to prevent it from loosening, but still be readily able to be removed should you need to.