rjh8589 Posted October 17, 2014 Report Posted October 17, 2014 Im sorry to even post but everything I read dances around what im looking for. Ive got 2 sa12's d4 in approx 3.5 cubes before displacement. Subtract .28 for subs. Ive been doing a ton of trial and error porting trying to make it sound as clean and loud as possible. Its in a 2001 gmc sierra extra cab back seat raised 2" flipped up 95% of time. Powered by a ct sounds 1400.I amp. Big 3 done 1/0 welding cable ran with 2 batteries under hood. I tried 6- 2"ports firing forward which sounded ok but I know it could do better. Ive now got 2 4" ports firing up sounds slightly better but still not as clean as I would like when I put power to it. The 4" are 6" internal 6" external to not give up much airspace. Subs are currently firing up. This box is temporary as im trying to just see what works best in this so after I see best results I will build new using what my trial and error taught me. With my given power and box size sub setup what would be my next step? Ive tried every calculator but all say something different slightly. If I start putting 90's in ports does it add additional length like hvac 3'? Hate asking for help but its my first ported box and im port dumb(actually dumber after reading for the past 3 weeks). Any tips are appreciated. Next upgrade is alternator after I figure out which gm trucks came with kw5 option 220 amp alternator. Be easy on me ive tried looking for a long time before asking. Since im running a little bit of power what should that do do my ports in my given enclosure?
Joe X Posted October 18, 2014 Report Posted October 18, 2014 Your port area is rather low, your current box should be about 3.1 cubes net to about 38Hz with 2 4" 6" external length , 6 internal. Don't exactly know what you mean by "clean" but if your gains or electrical are bad, no matter what you do to the box there will be distortion.
rjh8589 Posted October 18, 2014 Author Report Posted October 18, 2014 So would 2 5" ports be a better match? My gain on amp is currently between 1/2 and 3/4 and my bass knob I never turn up past half. I never go past 75% of my headunit volume my mids and highs are not even close to distortion and also ran through another amp. 4volt preouts on kenwood head unit. I guess I think it should be hitting harder than it is. Once I go past a certain point it just sounds like sheet metal bouncing which could I guess be my roof but I cant really see much of anything when out of truck. Back wall of truck and doors are deadened. I just was assuming that the major flaw was port area but didn't want to keep guessing by hacking more holes.One calculator said I need a minimum vent diameter of 9.63 but thats no standard size and lots of people seem to post a couple 4" ports work fine. Ive also read that port and power handling go hand and hand so I guess I just want to not assume its my roof flexing and be cautious that its more likely sub port power issues. I always turn down whenever my bass knob, dash mounted digital and factory get down to low 13's voltage because they all read about identical and I dont want to chance burning up anything by starving it for power. To clarify clean sounding I meant that sheet metal bouncing sound that could possibly be my roof but I doubt. I guess also looking for people with similar trucks to see what tricks worked well for them.
rjh8589 Posted October 18, 2014 Author Report Posted October 18, 2014 Yea im stupid my roof is making the noise I just did something very simple, I pushed up on roof when noise started and it stopped. Question remains what is most effective port or combination of ports to not mess up anything?
snyderd758 Posted October 19, 2014 Report Posted October 19, 2014 "rule" of thumb for aeros is 9-13 cu ft per ft3 of the enclosure if i read your specs right your enclosure is 3.22ft3 before port displacement? so i pick a number in the middle 3.22x11=35.42 cu ft total port are you need 2 5' ports give you a total area of 39.25 cu ftstill within your range. keep in mind this is before port displacment. both of the ports need to be 24.1 drastically changing the volume of the enclosure.
rjh8589 Posted October 20, 2014 Author Report Posted October 20, 2014 That kinda why Im trying to keep a lot of the port external. Every part of this truck is a pain because im keeping back seat. I appreciate the input . Im pretty sure im gonna yank this box out and cut down tranny/driveshaft tunnel(has a 6" lift) to get easier airspace so ports wont be so intrusive in my interior. I would rather cut hump than do a blow through because I need my bed for work. If I can get the room would it be better to fire subs to rear? Not sure if possible yet, just seems in past its always worked or sounded better rear facing. If I do what I think I can with floor I think I can get real close to 4 cubes and without humps everywhere running ports gets a lot easier. Also I thought I was having a sound quality issue when it was actually my tin canning roof will dynomat help or fix this or when I repaint my truck Again this spring should I weld in some braces on roof to stop the floppy metal sound?
Recommended Posts
Archived
This topic is now archived and is closed to further replies.