I need advice from the gods... ("experts" please)

[k_schutte 10+ year member]

PLEASE! Do not post in here if you are a newbee, I am looking for advice from people who compete regularly and have are deep into this shit!! Once my car gets out of the body shop (thanks to some *** hole for the hit an run) I am going to finally get started on the cadillac again! However, I am basically just completely lost on what I should do. I have enough money into this setup now that I want to squeeze every little bit out of it that I can! my best so far is a 144 with a single 15" on like 3Kw in a REALLY horrible box that was sub/port both rear facing. Although unlikely I think, I would REALLY love to try and come close to the magical 150dB.

I have:

300A alt

pair of C&D 350's (93ah each)

Big 3 done in 2/0

Fully Loaded 18" BTL with D2 coils

Digital Designs Z1 amp

I am willing to do pretty much anything EXCEPT A WALL! I cannot do a wall, well, I could do a wall but I don't think I would be competitive enough in that class and I don't want another 2-seater. I would like to run these classes: Local 3, Advanced no wall, and Basic 5 (Midwest Street Division) what do you guys think my best choices would be for highest numbers.

With the 18" sub I can only run it facing up I think. My rear deck is only like 18.5" tall so squeezing I won't be able to fit it any way other then facing up. Some may have seen my plan at the moment is just facing the sub UP and porting through the rear deck. That box would end up being 7ft^3 @ 40hz for the comps, 32hz daily.

Another option would be making a box that "flares" upward at the rear which would allow me to do a rear facing subwoofer with the port up and through the deck. It wouldn't be a "stepped" box but rather like a quarter pipe... OR, do you think I would be better off ditching the 18" and getting a 15"

Click to read more...

 

[audioholic 5,000+ posts]

I dont see 150 from a trunked car with rear facing sub reflecting off the back. Wall the trunk. If you have a problem with height, angle the sub upward slightly. Sub and port forward from trunk, walled. Then... maybe... you have a lot of air space in that car to compress.

 

[k_schutte 10+ year member]

I dont see 150 from a trunked car with rear facing sub reflecting off the back. Wall the trunk. If you have a problem with height, angle the sub upward slightly. Sub and port forward from trunk, walled. Then... maybe... you have a lot of air space in that car to compress.

really not wanting to wall but I might look into it. I guess if I build the wall a couple inches back I could still put the rear seat in there is i needed to. however then I won't be able to run the classes I want to and with a wall I don't think I would stand a chance of being competitive in that class! Ruggles is doing a 150+ with and HDC315 and a XXX-6500D from his trunk. He is the reason for my 2nd place trophies LOL... However, now that I am running an 18" I am not in his class anyways but, now that I seen it can be done with a 15" and only a couple thousand watts (clamped, max of 2Kw in that class) I am just thinking with an 18" and twice the power I should be able to get fukkin close to that LOL...

I wish there where a couple experts around here to help me out with this build! Doing everything by myself sucks after a while...

 

[k_schutte 10+ year member]

Actually, looking over the rules... If I build the "wall" behind the B-pillar and under the rear deck I don't think that would be counted as a wall so I would still be in the "trunk" class. I mean, that would basically just be a forward facing ported box and the rear seat would be "folded down". My seat back doesn't fold but it says you can just remove the seat back and lay it on the seat bottom as if it where folded down...

Can anyone Verify that would not be considered a wall? Rules

7-10 A speaker wall is any subwoofer enclosure that is taller than the top of the rear seat (not including head rests) or taller than the bottom of the rear side or rear glass, which ever is lower.

 

[audioholic 5,000+ posts]

Actually, looking over the rules... If I build the "wall" behind the B-pillar and under the rear deck I don't think that would be counted as a wall so I would still be in the "trunk" class.

Correct. Think of it more as sealing off the trunk to avoid needing to pressurize it. Trunks can help, as they act as a quasi-6th order BP, but results are unpredictable without a lot of testing.

Im not a big SPL guy, maybe Tommy or one of the other respectable SPL guys can chime in with more specific advice.

 

[Mr. Slate 10+ year member]

It's a Caddy?

BTW, no man is GOD.

 

[k_schutte 10+ year member]

It's a Caddy?BTW, no man is GOD.

It is a cadillac, '99 Eldorado to be more specific. Also, I know no man is God.

God (with a capitalized G) is defined as: 1 capitalized : the supreme or ultimate reality: as a : the Being perfect in power, wisdom, and goodness who is worshipped as creator and ruler of the universe b Christian Science : the incorporeal divine Principle ruling over all as eternal Spirit : infinite Mind

gods is defined as: a person(s) or thing(s) of supreme value

there knowledge/opinion is of supreme value to me so... //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Mr. Slate 10+ year member]

Never intended to get into a religious discussion with you.

Anyhow, you may or may not reach that number. In that vehicle it would be pretty differcult as a lot of variables come into play. Best of luck though.

 

[T3mpest 10+ year member]

I drive the exact same car, but I'm not an SPL guy lol. Getting an 18 in there would be a trick as you already mentioned, you'd probably have to build the box in the trunk and the actual clearance getting in is very hard to deal with. Behind the rear seats there are a bunch of electronics too lol. The car is also an absolute PITA to get loud and thats coming from a SQ guy lol. Maybe a 6th order bandpass using the rear deck? That would force all the output into the cabin which is the hardest thing to deal with in these cars. Then you could simply seal the trunk off the rest of the way except for the port hole. As deadened as they are it might be easier to keep bass from going back into the trunk than it would be to get the sound to leak into the cabin from the trunk, just a thought....

edit: A question for you since you compete. Do you know where the Eldo's resonant frequency is? Going by ear I think it's around 45hz, but I've never actually done any in depth on it and was curious.

 

[slam 5,000+ posts]

Ohmmmmmmmmm

Ohmmmmmmmmm

Ohmmmmmmmmm

 

[k_schutte 10+ year member]

I drive the exact same car, but I'm not an SPL guy lol. Getting an 18 in there would be a trick as you already mentioned, you'd probably have to build the box in the trunk and the actual clearance getting in is very hard to deal with. Behind the rear seats there are a bunch of electronics too lol. The car is also an absolute PITA to get loud and thats coming from a SQ guy lol. Maybe a 6th order bandpass using the rear deck? That would force all the output into the cabin which is the hardest thing to deal with in these cars. Then you could simply seal the trunk off the rest of the way except for the port hole. As deadened as they are it might be easier to keep bass from going back into the trunk than it would be to get the sound to leak into the cabin from the trunk, just a thought....
edit: A question for you since you compete. Do you know where the Eldo's resonant frequency is? Going by ear I think it's around 45hz, but I've never actually done any in depth on it and was curious.

Good ear! it is indeed 45hz!

 

[TaTonka 10+ year member]

I dont see 150 from a trunked car with rear facing sub reflecting off the back. Wall the trunk. If you have a problem with height, angle the sub upward slightly. Sub and port forward from trunk, walled. Then... maybe... you have a lot of air space in that car to compress.

Dave pulled a 151.9 yesterday in the trunk of his mustang with the sub reflecting off the back...

OP, the thing is is going to hurt you the most is that your seats don't fold down. You can try to build loud, but you are most likely going to brickwall in that car whenever you reach 145-146db.

 

[audioholic 5,000+ posts]

Dave pulled a 151.9 yesterday in the trunk of his mustang with the sub reflecting off the back...

Yes, he says he did... in a much smaller car, with a DD Z series and, what, 8kw?

 

[TaTonka 10+ year member]

Yes, he says he did... in a much smaller car, with a DD Z series and, what, 8kw?

Actually in a saleen (not too small)

Equipment was a DDz12 and only 4k. The box took me and my coworker 30 minutes to build out of scrap wood. It has potential to be louder after a little testing.

Fine, I'm doing 151.x with two DD2510s in a 4 door alero....

 

[Canaan 10+ year member]

Hard to do 150+ in a trunk???

Well, if your back seat folds, not really.

We got Madison's Charger up to 149.x w/ 1 Omega 18" and an Orion XTR2400. That was w/ a daily box tuned to ~37hz, peaked in the mid-40hz range. Sub up, port to passenger wall, ~6cuft.

Given an SPL box, 151+ would have been there w/ ease.

We also just did a Cadillac Centennial with 2 DD2512's on an M2a (rated 1600w @ 11.9v) and 1 optima yellow top that is easily doing 146-47 daily in 4cuft tuned to 36hz. Thats subs up, port back. And again, w/ an SPL box 150+ would be very attainable.