Old faithfull!
Moderators: P3g4sus, Daniel, rat, Draco, Riekert
I did them both about 2 years ago. The 156.4 was for the show, demo car, and the speakers were wired in parallel. The 150.9 was a comp, I just entered to see what the difference was when wired in series, as they are now. I changed from parallel to series because the mids couldnt keep up with the subs. My brother now is saving up to get 4 more mids and anoth amp.
Let me cut to the chase....
at first I didn't want to comment or give my opinion but it got the better of me, I am sorry if I am going to offend anyone with the following.....
In my years of competing, I heard alot of stories, stories meaning there was always this someone that have seen a reading and make a comment that his or hers did this higher reading....normally I and other competitors who was in the game got this grin...the BS grin....I got this grin when the post was made.
For someone to hit a 150db is extremely difficult, you need some serios equipment and a very well built car, a car very close to the resonant frequency of the car and so forth, in a serios spl car with all the goodies 150 is moderately easy....for a normal street car...not so easy.
I am not an expert on spl, but I have been in that game for about 5 years or so, I do not believe the setup in the picture you provided will do 150 db's, on certain unofficial meters that is heavely out on calibration maybe but not likely.
That looks like 2 to a 2.5 cubic feet box, I don't see any ports, if there are any they are facing the wrong way, to the point, for that setup to do a 150 it had to be at least a 4 cubic feet box with 2 x4" ports facing to the back, I'd gues a tuning frequency of around 60hz, the power you had to give would have been around at least 800 w rms into 1 vc, that meens 1600rms per sub.
I would guess that setup would do around a 146dB at the most on an iasca meter. for you to do a 156 you had to at least have a 6 cubic feet box with a 10" port or 4X 4" ports tuned at about 55 hz with the box all the way back from the back window just behind the front seats, at least 2 big batteries and ad some 2v sells to get a voltage of about 16 volts, you have to at least push a 1000 or 1500 w rms into each vc, that means 2000w rms per sub at least.
For this you had to have at least 2 class D amps 1per sub or 1 huge amp in 1ohm, or obviosly more digitals daisy chaned to give the power.
Some facts....
in stock 261+ the highest dB's in the class is 154.6,
in stock pro which you should not be in unless you made some changes the highest was 153.3.
These scores are the highest in the class and these cars was built putely for spl, this meens you trashed them with your spl box(156) whitch makes you the SA champ in both classes.....I find this hard to believe.
at first I didn't want to comment or give my opinion but it got the better of me, I am sorry if I am going to offend anyone with the following.....
In my years of competing, I heard alot of stories, stories meaning there was always this someone that have seen a reading and make a comment that his or hers did this higher reading....normally I and other competitors who was in the game got this grin...the BS grin....I got this grin when the post was made.
For someone to hit a 150db is extremely difficult, you need some serios equipment and a very well built car, a car very close to the resonant frequency of the car and so forth, in a serios spl car with all the goodies 150 is moderately easy....for a normal street car...not so easy.
I am not an expert on spl, but I have been in that game for about 5 years or so, I do not believe the setup in the picture you provided will do 150 db's, on certain unofficial meters that is heavely out on calibration maybe but not likely.
That looks like 2 to a 2.5 cubic feet box, I don't see any ports, if there are any they are facing the wrong way, to the point, for that setup to do a 150 it had to be at least a 4 cubic feet box with 2 x4" ports facing to the back, I'd gues a tuning frequency of around 60hz, the power you had to give would have been around at least 800 w rms into 1 vc, that meens 1600rms per sub.
I would guess that setup would do around a 146dB at the most on an iasca meter. for you to do a 156 you had to at least have a 6 cubic feet box with a 10" port or 4X 4" ports tuned at about 55 hz with the box all the way back from the back window just behind the front seats, at least 2 big batteries and ad some 2v sells to get a voltage of about 16 volts, you have to at least push a 1000 or 1500 w rms into each vc, that means 2000w rms per sub at least.
For this you had to have at least 2 class D amps 1per sub or 1 huge amp in 1ohm, or obviosly more digitals daisy chaned to give the power.
Some facts....
in stock 261+ the highest dB's in the class is 154.6,
in stock pro which you should not be in unless you made some changes the highest was 153.3.
These scores are the highest in the class and these cars was built putely for spl, this meens you trashed them with your spl box(156) whitch makes you the SA champ in both classes.....I find this hard to believe.
I agree being class records I highly doubt it but the car made those figures twice, maybe I wasnt in pro stock or this wasnt a sanctioned event.
There are 2 port hole 120mm diameter and yes you cant see them, they are the bottom of the box. A little bit of maths, 2 x 120mm diameter port holes give you a area of 226cm^2, which is about 2 x 4".
150Db is very difficult I know that, but with a system of R19 000 its not so difficult. The box is much bigger than 2 cubic feet I would guesstimate it to be around 4 cubic feet, it is a bit deceiving because the box follows the back of seat so the bottom is about 25cm bigger than what you can see.
The box was designed on some software program that gave the length of the port tubes, I didnt do this so cant vouch for it.
I hope I answer most of the question you asked.
There are 2 port hole 120mm diameter and yes you cant see them, they are the bottom of the box. A little bit of maths, 2 x 120mm diameter port holes give you a area of 226cm^2, which is about 2 x 4".
150Db is very difficult I know that, but with a system of R19 000 its not so difficult. The box is much bigger than 2 cubic feet I would guesstimate it to be around 4 cubic feet, it is a bit deceiving because the box follows the back of seat so the bottom is about 25cm bigger than what you can see.
The box was designed on some software program that gave the length of the port tubes, I didnt do this so cant vouch for it.
I hope I answer most of the question you asked.
.I wipped guys with full Rockford Fosgate systems...MTX worth 20grand or more with my R4000 system, price does not always mean anything.
1" is 25.4 mm or 2.54cm, that means 4" port is 101.6 mm, 5" port is 127 mm, you have 2x ports of about 5"....not sure of the 120mm.
You say the box follows the seat, that means it is a wedge box, Vol=LengthxDepthx(Width1+Width2)/2, specs for a 4 cubic feet box...
Vol = 70x33x(30+70)/2 in cm
=70x33x50
=115500/1000 to get it liters
=115.5 liters/28.3 to get cubic feet
=4.08 cubic feet
That meens that box must be about 700mm long, 330mm deep and about 500mm wide....my eyes might be deceving me but that looks a bit small.
in anyway, that install looked good
1" is 25.4 mm or 2.54cm, that means 4" port is 101.6 mm, 5" port is 127 mm, you have 2x ports of about 5"....not sure of the 120mm.
You say the box follows the seat, that means it is a wedge box, Vol=LengthxDepthx(Width1+Width2)/2, specs for a 4 cubic feet box...
Vol = 70x33x(30+70)/2 in cm
=70x33x50
=115500/1000 to get it liters
=115.5 liters/28.3 to get cubic feet
=4.08 cubic feet
That meens that box must be about 700mm long, 330mm deep and about 500mm wide....my eyes might be deceving me but that looks a bit small.
in anyway, that install looked good
Last edited by Draco on Mon Apr 23, 2007 2:47 pm, edited 1 time in total.
Take the width of a boot in a car, probably about 1.4m - length of box. The box is 550mm on the bottom and prob about 600mm high. But the center of the box wedges in (just for looks) but the bottom of the box also comes out. As I said I am not sure on the volume of the box but these dimensions look far bigger than what you says.
