ncc74656

what is the proper formula then for the determination of port area. im not sure what 70% BL means.

yes port area

my old BL box had 2 24" long 8" round ports and my builder said they work better and he preferred them over a slot port. im leaning towards a slot port as they seem to take up less space and are easier to build. now knowing about minimum port area it seems that my old box did not have the recommended amount of port? im basing this off of this website: http://www.carstereo.com/help/Articles.cfm?id=31 it seems to take Xmax and compute the port area, should i consider this to be accurate?

from what i just found on-line i need 167 cubic inches of port... at that size i am having a very hard time tuning anything below 40hz... does that port area sound correct? i would like to make this box some what rectangular so i can turn it and face it up, back, or forward to play around with acoustics.

But no matter what, this isn't going to happen. It just isn't. It's the equivalent of saying "I want a car as fast as a Ferrari that I can also use as a moving van that triples as a vehicle to tow my motor home with." i understand there are trade off but why then can i have a home stereo that is also ported that can hit the lows and the highs equally well? perhaps im not explaining what i am after well enough or perhaps home audio and car audio are different? i would think tho that a ported enclosure is the same whether its a 15" 750W home sub on my computer or a 3000W 18" Fi sub in my truck no?

does it matter how large the box is? i originally wanted 8, then i was told stay around 7. how do i know whats best for me, if the sub requires less power in a larger box then does that mean it also makes less noise? should i stay around 7 or go up to 8?

im going to let my phone charge a bit and then ill give you a call. i was told for port area that i just need a large enough one to prevent port noise but aside from that it only matters in the realm of tuning.

going over some numbers, if i do .75 the box will be much smaller. it was suggested that i would want to stay around 7 cubic feet, my old box was 5.5 cubic feet and tuned at 44hz. this is the box that i had built for me. i was thinking for my new box to tune around 35 or 36hz and make 8 cubic feet. my thought behind this was that a larger box would aid in the low notes and a higher tune would help keep the higher frequencies. i have had some input however that tells me i am incorrect about this assumption and i should tune at around 32-33hz and a larger box would only reduce the amount of power the sub can hold. wich direction should i go? does anyone happen to have skype or some kind of voip? id love to have an actual conversation about what exactly im trying to do here and where im going wrong. thanks.

ok, so i will run a single 3/4" MDF on the box. what should i do for bracing? connect the front/back side/side top/bottom? or just a couple of those? i did order a dual 1 to explain my 3rd paragraph: i own a vidsonix 15" sub that ive had for 10 years. its hooked to my computer and i love the clean, rolling, phasing bass it can produce. songs from poker face to kaskade eyes, to disturbed and godsmack sound good. the sub i had (Fi BL 18) totally blew away anything i had ever heard in the higher frequency ranges of bass, such as what kaskade puts into most of his songs. the lows however were another story, lady gagas song just dance had no bass in it. the low bass was kind of felt but you could not hear it, my 15" had more power than my BL. Love game by lady gaga however sounded bloody amazing as it was all high frequency bass. i want to be able to have amazing bumping like on disturbed, god smack, just dance; while at the same time not loose that crazy high end power that i had. I have owned Kicker L7's and those were able to pound the low end bass but were just like the BL but reversed where they were hollow on the higher songs such as kaskade eyes and love game. I feel like i traded low end for high end and as most of my songs are high end i was ok with that but then the BL just ended up not being loud enough even on the high end. i started it off on a ZX1500.1 and then put a 2500.1 behind it and it got quite a bit louder but still not enough. this is why i sold it and ordered a SP4, with my 10" and 8" door speakers and tweets and super tweets the sub just got drowned out. what im looking for is a box that will give me every last bit out of the SP4 that is possible, i want to be able to hit every conceivable frequency that this sub is built for and i want to do it while being so loud you need to time your next breath with the bass... I prefer to build this box myself but i am looking for quite a bit of help on design.

thank you, the last BL that i bought i paid a guy (who came very highly recommended i might add) a lot of money to build a box and i feel like i did not get what i wanted out of the sub. this time round i really want to get a firm grasp on all the concepts of box building and do it myself so i know what im getting. to his defense he did say he had never built a box for an 18 before and after delivering mine he said he never would again.

i just ordered my SP4 18 today, i thought i had a box idea but i was told it was not very good so i need some help. back seat of a dodge ram 2500, i have 30HX36WX31D max space, smaller is better but thats what i have to work with. i intend to mount it on a new tool box im installing in place of the rear seat. if i use 2 .75" MDF sheets to make 1.5" panels and build the entire box of that do i need to double up on baffle? do i need bracing? i currently have a ZX2500.1 to power it (do you think i should upgrade?). i am not sure exactly where to tune it so i planned on starting with a high tune and an extra thick bottom and then extending the port and pulling parts of hte extra bottom panel out to keep the cubic footage the same while tuning. sweeping from 32-34hz is what i was going to try. what are your thoughts? here is a picture and tores of what i think i should have for optimal. i listen to lots of techno, rock, trance, kinda all over the board and i want to be able to kill the lows while still destroying hte highs. i seriously do not want any dead spots. im upgrading from a BL 18 that was just not loud enough. what should i change? thanks. http://imgur.com/a/rl7BU#1

i cant find a pre-build for a SP4. i finished my final design cut outs last night and i think its all good. i do have one final question however. my port bends and at the bottom of my port are 2 vertical braces. does this effect the port? if so what needs to be changed? here is a picture:

well i think i have tuned it all right but i just want someone who knows more than me to verify it so im positive before i start gluing stuff... maybe ill just extend the length by .5" to take the box up to 7.89 cubed and then the port area will be at like 15.8" squared.

its 4ga, its silver wire and came with my kicker amp. i do not know what purity it is but i know that silver has a hair lower resistance than copper does. on a side note... your damn banner ///M5!! i cant even figure out what im going to type, totally derails my train of thought >.< if i upgrade my sub i wont be using that wire anyway because ill be going up to 0ga through out the amp setup and i suppose maybe 4 into the sub. idk how large the terminals are on a SP4. the main concern i have is if my box that i intend to build is setup right. in some of the fi videos they talk about a certain port area that is optimal and i cant find that info on the SP4's. i have mine setup with a 16.29 squared port area right now. my thought was that adding some poly fill will make the sub think its in a slightly larger box and off set that port area, or does it not work that way?

i posted a box build question in another forum. if anyone happens to know anything about boxes id appreciate any kind of validation on whether or not im an idiot. thanks.

sooo, does this box have the proper port area and build? is the sub placement in the middle alright or should it be lower down on the face?

I own a BL and am buying an SP4. will this box design work perfectly for the SP4 and well enough for the BL? did i screw up on anything? at the bottom of my port i have bracing crossing it, will this be an issue? should the port be fully open down to the bottom of the box? i could not find any great info on port area for the SP4 so im sitting a bit over the 16 multiplier right now. i was thinking of adding a bit of that fluff to the box to make the sub feel it was in an enclosure closer to 8 cubic; is this a good idea? im going for SQ at high volume, or at least as much SQ as the SP4 can give me. what should i change, all opinions welcome. thank you. http://imgur.com/a/JJ7XV#0 ^ box design and maths most people seem to ask about electric so ill throw it out there. i run a factory alternator with factory battery banks. all 00ga connections between my 2 2600ca semi batteries, 4ga grounds to body and 0 ga to frame and block. the factory alternator puts out 230A @ 2100RPM. currently i have no issue with the ZX1500.1 but dont now what to expect with a [email protected] ohm, guess ill find out.

ok so the amp sees each sub coil as maybe .8-1ohm per coil. i use silver wire so the resistance is a bit lower there. suppose that explains why my kicker has not blown up running at 1.4ohm. because its really running more like 1.7-2.2 ohm depending on various things. i should ohm it all out one day and find out exactly what the amp is seeing... i was thinking of using a BC3500 because i believe the SP4 fully loaded could handle the power. however from what im reading now the SP4 would be closer to .5 ohm anyway and thus would deliver 3200W+ to the sub. i think that sounds like a very good pairing, no? another question in regards to the baffles of the box (and maybe ill make a new thread about box construction), if i have 2 sheets of MDF on the face and 2 holes cut, one for sub basket mounting and the other for the diameter of the sub so its recessed past the outside baffle. does that still count as a double baffle? or should both holes be even so the sub screws through both sheets? finally does anyone have a good link for info on how to o-scope gains/bass boost levels on the deck/amps.

I own a 18" BL fully loaded on a kicker ZX1500.1. this has done me well as a DD setup for a year but now i want more. I am looking for more low end and more volume with out sacrificing much of my high end. my box is currently tuned at 44hz @ 5.4 cubic feet and i was planing to build a new box tuned to 35hz @ 7.99 cubic feet. i have the option to swap my 1500.1 with a 2500.1 plus a couple hundred and stick that behind the BL. would i blow it with this setup assuming im not an idiot with gains and the bass blow knob? my second thought was to sell my sub and box to buy a SP4 and stick that on a BC3500.1D crachendo amp. i read that this amp can run .5 stable where as my kicker prefers to sit 1.5-2ohm. my understanding of things is if i change my parallel/series wiring on my current dual 1ohm sub that it will run at .35ohm as each coil is .7. would i blow something up running a SP4 with a BC amp at such an ohm rating? I am currently satisfied with the frequency response of my BL with the exception of low end, which i acknowledge is a box design issue rather than a sub spec issue. i am unsure what route to choose. will the SP4 match the BL in sq? will the kicker be to much or to little for the BL, will the BC melt at .35ohm, am i not understanding anything correctly? The box i was planing to build is .75mdf with a coat of resin and rounded edges. i assume other than changing some bracing for mount depth that a BL and SP4 could run in the same box? this is what i was planing on building: http://imgur.com/a/coFsq