SkylarDunn Posted July 7, 2011 Report Share Posted July 7, 2011 Also, I want to ask, how much port area do I need for an 18? depends on the airspace you have, and the tuning the box wants. but for an example, in 3ft^3 that sub would need 135in^2 of port area with a tuning of 33hz. Getting bass into the cabin of a W124 mercedes is impossible. Current setup: Temp 1999 panasonic HU rockford 300.2 for fronts rockford 200.2 for rears rockford 400.1 for sub Leaning towards a 8" in an exponential horn DAMN YOU GERMANS AND YOUR 5" SPEAKERS! Link to comment Share on other sites More sharing options...
OldsBoomer Posted July 7, 2011 Report Share Posted July 7, 2011 Depends I have 2 12's in a 8.6+ cube box right now and its loud lol Suburban Coming Soon Link to comment Share on other sites More sharing options...
Shigshwa Posted July 7, 2011 Author Report Share Posted July 7, 2011 Depends I have 2 12's in a 8.6+ cube box right now and its loud lol But that's more cone area.. Link to comment Share on other sites More sharing options...
soundsystemaniac Posted July 7, 2011 Report Share Posted July 7, 2011 there isnt really such a thing as the correct airspace, just the correct port area and tuning, for the airspace you want.an 18" in a box designed for a traditional 15" would be louder (as far as the new btls go) due to the thiele small specs. the 18" would have much louder highs, given the same airspace as the 15". the new BTLs are complete horse sh** according to the t/s parameters. i'd never buy one unless it was for an spl application. just my $0.02. keep in mind, you're just asking about airspace. if both subs were in the same box (example 3ft^3) the 18 would require a different amount of port area (usually more) and a higher tuning (due to box size and a larger diaphragm). ANYONE who says one size of sub needs one size of box is full of crap. every sub has a different set of t/s data, and can vary greatly. i've seen 15"s in sealed boxes that can have a 40hz -3dB point in 2ft^3, where some have a 70hz -3db point in the same airspace. before you think you know anything, take a hand in learning a bit about enclosure design, how enclosures work, and an understand of t/s specs. but to answer your question, if you got the proper port specs for a new btl 18" in a box of that size, i would expect +3dB somewhere in the 50-70hz range. Good read! Chevy astro 2 18s and 9k rms Walled!http://www.stevemead...rms-42-inch-tv/JEEP GRAN CHEROKEE SRT8 BUILD!2 JL AUDIO 15s trunk buildDC XL 15 buildDC level 3 18 buildhttp://www.stevemead...verunner-build/ http://www.facebook....hp?id=646651228 Link to comment Share on other sites More sharing options...
soundsystemaniac Posted July 7, 2011 Report Share Posted July 7, 2011 Also, I want to ask, how much port area do I need for an 18? depends on the airspace you have, and the tuning the box wants. but for an example, in 3ft^3 that sub would need 135in^2 of port area with a tuning of 33hz. You also want between 12 and 16 square inches of port per cubic foot....and correct me if I'm wrong but doesn't the box size and port size also correlate with the amount of power you give the sub? Chevy astro 2 18s and 9k rms Walled!http://www.stevemead...rms-42-inch-tv/JEEP GRAN CHEROKEE SRT8 BUILD!2 JL AUDIO 15s trunk buildDC XL 15 buildDC level 3 18 buildhttp://www.stevemead...verunner-build/ http://www.facebook....hp?id=646651228 Link to comment Share on other sites More sharing options...
flashlight_65 Posted July 7, 2011 Report Share Posted July 7, 2011 Check my sig under friends impala. I built a box for an 18 in my lil homies '06 impala and it looks large in his trunk and had to squeeze it in. I think the dimensions were about the same. My builds: my caddy my 'hoe friends impala Link to comment Share on other sites More sharing options...
OldsBoomer Posted July 7, 2011 Report Share Posted July 7, 2011 Depends I have 2 12's in a 8.6+ cube box right now and its loud lol But that's more cone area.. Wrong and its meant for 4 12's Suburban Coming Soon Link to comment Share on other sites More sharing options...
SkylarDunn Posted July 7, 2011 Report Share Posted July 7, 2011 Also, I want to ask, how much port area do I need for an 18? depends on the airspace you have, and the tuning the box wants. but for an example, in 3ft^3 that sub would need 135in^2 of port area with a tuning of 33hz. You also want between 12 and 16 square inches of port per cubic foot....and correct me if I'm wrong but doesn't the box size and port size also correlate with the amount of power you give the sub? designing a box around power is like designing a car around its exhaust. just my 2 cents. i use raw driver data. subs need different port areas depending on the suspension specs, how much travel the suspension has, and how much area the cone displaces. you would shit yourself if you knew how much port area decent 8"s need if you want to tune them to anything reasonable. if you dont use the proper port area, the sub will only have reasonable phase and output till the xmax and cone surpasses how big the port is, then the sub just steadily goes out of phase and has a sharp drop off in output. theres a reason SPL guys have huge ports. heres my 2 old fi 12"s, in a box designed for the subs, but i built the box with a jigsaw lol (skilsaw was broken and couldnt afford one at the time), the port didnt have a 45' like it needed because i ran out of MDF, and there was so many internal gaps in the port that im suprised the box didnt sound like a whistle, the subs blew because they were both unloading into the port because i had them mounted on the wrong axis in the box. roof had 2 layers of dampening, hatch had 8 layers, side panels had 4 layers, and floor had 5 layers, and look at all that flex, on only 500w rms. THAT my friend, is a box designed around the subs. >: ) tell me this shits weak. $65 subs, btw. that box has 1" of allthread sticking out of the bottom, and when i started that little demo, the box was against the hatch. thats how much air it moved. alot of people say in full of sh** but every box i have ever built as absolutely destroyed for what got put in it. Getting bass into the cabin of a W124 mercedes is impossible. Current setup: Temp 1999 panasonic HU rockford 300.2 for fronts rockford 200.2 for rears rockford 400.1 for sub Leaning towards a 8" in an exponential horn DAMN YOU GERMANS AND YOUR 5" SPEAKERS! Link to comment Share on other sites More sharing options...
Shigshwa Posted July 7, 2011 Author Report Share Posted July 7, 2011 Interesting. I will take all of this new info into account then. Quite a lot to learn! Link to comment Share on other sites More sharing options...
STL Posted January 10, 2012 Report Share Posted January 10, 2012 Also, I want to ask, how much port area do I need for an 18? He's basically saying whats the difference in db if he put a 15 btl in a 5cuft enclosure & and 18 btl in a 7cuft enclosure. Basically saying if a 15 & 18 were in their own enclosure both built to company specs. how much of a db increase would it. I would say not much possibly 2-3db I don't got that bad of a mouth, do I? Fuck Shit Ass Bitch Cunt, Shooby-de-doo-wop.Skibbedy-be-bop,a-Christopher Reeves! THE FUNNIEST U WILL EVER HEAR!!: Bak in 2010 my old neighbor gave me a demo of his 2 cvr's. It wasn't LOUD and I told him that. Guess what comes out his mouth? "Idk bro its usually louder, I guess it still has an ATTITUDE, It tends to get mad @ me every now & then when I turn it up too much!" What the fuck! I was like.. " R u serious u CRAZY DUMB MOTHERFUCKER!" Ahh, I luv the Forum & the Forum luvs me!!(STL) Link to comment Share on other sites More sharing options...
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