2 18s 4th order help or oppinion

[joshy629 10+ year member]

ok so i just did my first 4th order. im only doing a 149 at the head rest but that is at 27 hrtz....lol i have 2 dc xl 18s and a soundstream xxx 10000d amp. plenty of batt power. the subs are in a 8.5 cube sealed box firing to the side into a 16 cube ported box. the ports are 2 8inch flared ports. i have 38 inchs of width available. 28 heigh and 50 depth and thats to leave just enough room for all my equipment to fit. look at the pics and tell me what you would do diffrent to get a higher score say maybe a 152 out of it.

basic of the box

the ports front view

looking into the ports

and the back just for looking =]

Click to read more...

 

[813thumper 10+ year member]

increase port area

shrink sealed chamber

 

[bgowdy 5,000+ posts]

id like to do one but i have a blazer no need. one of my friends has a single fi btl in a 4th order with 4 4" aeros and is doing 150+ playing music.

ive never seen or heard of him burp it seeing we compete in a daily driver type comp.

 

---------- Post added at 03:36 PM ---------- Previous post was at 03:35 PM ----------

 

but yea i would have probly went with maybe 3 8" or 4 6" aeros tho

 

[Ninesvnsicks 10+ year member]

Geez those 2 dc's can take 10k rms?

 

[bgowdy 5,000+ posts]

ha together on a burp maybe. probly not to many times tho. lol...

but now that i think. i dont see how they can take that honestly...

 

---------- Post added at 03:46 PM ---------- Previous post was at 03:46 PM ----------

 

well unless his gain is down a bit

 

[joshy629 10+ year member]

The sealed box causes a lot of impediance rise. I've clamped it at 1.4 ohms with 3x impediance rise and it was doing 6k and these 2 are wired to 1. So idk what it is putting out. But the amp gets hott quicker than the subs lol. I love these subs. But would adding another port tune it higher? And what do you think the results of making the sealed box smaller would do? I'm taking oppinoins here. Help me out?

 

[joshy629 10+ year member]

anybody? anyhelp at all?

 

[hispls 5,000+ posts]

Geez those 2 dc's can take 10k rms?

Those amps won't do 10KW on 18V system (there's a guy around here who uses 4 on a pair of 18s and breaks glass....mid 165's 67's at kick). That being said LV5 softparts can take 5KW for half a song or so.

 

[813thumper 10+ year member]

i bet it slams the low end and that is mainly because you have a huge sealed section. if you shrunk everything up then you would end up getting the response that you want. right now i am running 2 18s in a 4th order. about 4.5 cubes sealed and 14 ported off of about 2000 watts and i can tell you that i am in the very high 40's. the XXX seems to like a larger box so what i would recommend is that you shrink it about 2 cubes and see where that gets you. also increasing the port area is going to change your tuning. what did you tune it at?

 

[hispls 5,000+ posts]

anybody? anyhelp at all?

Have you attempted just a big ported box? Seems to me that would probably get louder.

 

[joshy629 10+ year member]

its peaking at 28 hrtz. would adding another port raise the peak?

 

[joshy629 10+ year member]

and yes its doing a 149 at 28 hrtz but i want atleast a 52 out of it

 

[813thumper 10+ year member]

your truck peaks at 28 hz? thats nasty lol. sometimes it will sometimes it wont. you really have to test it on order to know. what is the 4th order tuned to right now

 

[joshy629 10+ year member]

no clue man just threw it together 8.5 cubes sealed 16 cubes ported. 2 8 inch aeros that are 11inchs long each. lol u tell me idk. and yeah 28 hrtz pretty good flex. but i know that it has alot more potentual in it for sure

 

[RAM_Designs 5,000+ posts]

increase port areashrink sealed chamber

This