I just bought a DD 3518

[90quattro]

Hello, my name is Thorbjørn, and I live in Norway. 34 years old, and have just rediscovered the joy of car audio..Haven´t had a proper system in my car for many years, but now I have started a new project.

I have a Audi 90 quattro ,which is under constant development.

Pioneer p99rs, orion hcca 250 amps, orion hcca 62 speakers, dual agm batteries etc.

Have lots of different subwoofers laying around, mostly 12"´s, and a few 15"´s.

Currently I have a RF T2d412, and it´s pretty good. The amp is a Dynabel (norwegian brand name) mono block which puts out 2500@1 ohm.

But now I want more, and just bought a DD 3518, d2. Should be quite a bit better than the RF...

And now I need some good advice about the box/port. Will try to end up at around 6 cu.ft, and sub will be facing upwards.

To save some space, I want to go for a round port, facing sideways. But how big port should i use? 6" aero is a bit to small, isn't it?

All I can find is specs for slot port, so any suggestions would be appreciated

[fecupe2001]

I tested the 3518 a lot, you need AT LEAST 2 6" round ports, 3 would be better but pretty sure you can´t fit them on 6 c/f and still play "lows" , what kind of music you like the most? are you sure you can fit a proper box for that sub on that trunk?

[90quattro]

Hello,

I think I can fit a fairly large box, the plan is to make a box that is appr. 43"wide, 22 deep",and 16" high, external. There is almost no steel left in the rear deck, the previous owner has cut out most. So there is no problem with the car being a sedan, it´s quite "airy", but I agree that the trunk is small. But I really want to do a more unusual project, I like to try things that not everyone else does.

I listen to almost all kinds of music, so i guess i need an "all-round" box...? Of course, i want "lows", that´s some of the reason why i went from 12" to 18"..

Here´s the specs of the amp btw, these are quite popular in Norway:

http://www.dynabel.no/Shop/Product/dynaBel-BF7501-1x750-2500-Watt-RMS-Bilforsterker/BF7501

[90quattro]

After some intense " googeling", I still haven't found anything about DD3518 and round ports. That makes me wanna go for round ports even more, problems are for solving.

But if I go for 2 6" aeros, how long should they be?

I only borrow a Mac for the time, so I can't download bassbox pro or similar programs

[stroupe79]

do you plan on having the sub face up toward the trunk lid?

you can run 2 6" aeroports and get tuning down to 32-35hz range and 6cubes using the dimensions you listed...not sure where you wanted to tune

[fecupe2001]

Well, here you have a video of my suzuki swift using 2 3518´s and low power, i was using 4 6" aeros and 11.5 cubic feet, i was burping a 148.5 @ 30 hz and 150.8 @ 40 hz, i still burped a 146.5 flat at 25 hz, i always knew i needed more port area but i didn´t have room for that, months later i installed one of those subs in my explorer with a 2K wired at 1 ohm, i tested 2,3 and 4 6´s aeros for a single 3518 on 7.5 cubic feet, that thing was NASTY with 3 6" aeros, burped a 147 @ 36 hz , you don´t have room for that but you do for a pair of 6" aeros, don´t go smaller than that!!!!!!

[90quattro]

Hello,

Yes, my plan is to build a box that´s wide (+/- 45") and rather low, 15-16". The sub will face the trunk lid, or more correct the rear deck, which is quite large/long on this car. And most of the steel in the rear deck is cut off/out, there is a large rectangular hole instead.

If I build a box that is only 16 "high, it will still be about 10" left up to the rear deck. Have previously tried an old CV 15" facing upwards, and it worked good.

I´m not sure where I want to tune, have little experience with different tunings in practice. Looking for a all-round/daily driver with nice "lows", so I guess I want it tuned rather low..?

[fecupe2001]

not necesarely, those subs can play very strong below tuning, if you want some nice lows on that size of box, you don´t need anything lower than 35 hz if you ask me, my box was tuned around 34 hz and i could play way lower than that

[90quattro]

NICE pics/vids, this type of project is "right up my alley", or what do you say?

Which brand is the drivers btw? Something "pro audio" I guess?

[fecupe2001]

yeah, i was using 4 powerbass 4xl 6.5" mids on the back and 2 on the doors along with 4 audiopipe tweeters, for the price it sounded very nice!

Yes i think you can do it , i mean, i haven´t looked at your trunk, but if it is as big as you say then it would get loud, just forget about a termlab if you are looking to compete since you are gonna be choking the airflow A LOT with that big ass box back there, but yes, you´ll get loud with 2 6" aeros and anything bigger than 5 cubic feet