Sundown 12" Neo Driver 4th Order Bandpass
I decided to move over here because I might as well build something this week.
I calibrated and tested this neo oddball with a WT3 woofer tester; do these specs look alright; does the box have any flaws I should be careful of falling into.
Trying out a 4th order bandpass design
Box Properties
Name:
Type: Bandpass Single-Tuned Box
Shape: rectangle, Bandpass
with two chambers
Chamber 1 - lower-freq.
Vb = 6.368 cu.ft
Fb = 39.39 Hz
QL = 5.207
F3 = 27.99 Hz
Fill = heavy
Chamber 2 - upper-freq.
Vb = 2.176 cu.ft
Fb = 45.89 Hz
QL = 6.239
F3 = 70.23 Hz
Fill = none
No. of Vents = 2
Vent shape = round
Vent ends = no flush
Dv = 6 in
Lv = 30 in
The box, the second smaller chamber will house about 14" of the port, they're 6" diameter and 30" long
http://i130.photobucket.com/albums/p...g?t=1312669498
I did more testing; here are the SS wt3 program:
Test Lead Calibration
http://i130.photobucket.com/albums/p...estleadcal.jpg
Test lead calibration with 1k ohm resistor
http://i130.photobucket.com/albums/p...hmresistor.jpg
Series Free Air
http://i130.photobucket.com/albums/p...iesfreeair.jpg
Series Vas Cal
missing
Parallel Free Air
http://i130.photobucket.com/albums/p...lelfreeair.jpg
Parallel Vas Cal
missing
Re: Sundown 12" Neo Driver 4th Order Bandpass
Re: Sundown 12" Neo Driver 4th Order Bandpass
Re: Sundown 12" Neo Driver 4th Order Bandpass
What were the woofer's specs? A flat response there wont quite be flat in car.. And you have fill set to heavy - Im pretty positive you want that set to none as no one in caraudio uses fill.
Edit - Qes of 4.x? Doesnt appear right.. Thats in QMS range..
Edit2 - 280grams? Thats like 45 quarters. You sure? A QES that high would be like super IB.
Re: Sundown 12" Neo Driver 4th Order Bandpass
Quote:
Originally Posted by
surreal 
What were the woofer's specs? A flat response there wont quite be flat in car.. And you have fill set to heavy - Im pretty positive you want that set to none as no one in caraudio uses fill.
Edit - Qes of 4.x? Doesnt appear right.. Thats in QMS range..
No that was 1 of two coils specs you seem to be mixing up. Yes, it has a high qts but jacob had this to say:
Quote:
Originally Posted by sundownz
As mentioned in the for sale all I could recall was high Qts on it -- we had good luck out of it in about 1 cube sealed despite what a box model program says that will do :)
Nick Lemons (Stereo Integrity) borrowed it for a while and reported that it was an enjoyable listen.
I noticed most of the specs were incorrect for the vas cals for the series and parallel wiring; must of mixed up when I was making screenshots and editing.
http://i130.photobucket.com/albums/p...g?t=1312669498
Re: Sundown 12" Neo Driver 4th Order Bandpass
I cant say Ive ever seen a sub with an EBP that low.. Might benefit from a tigher coil perhaps? Weird.
Ill tell you most people dont design 4ths for a flat response. Technically it is the way to do it for best sound, but people normally enjoy the peakiness of a larger front chamber.
Depending on what vehicle this is for and where it will be placed, within the passband, design it for an upward slope. 3-6db from bottom to top or so. This in-vehicle should still give you a good low end presence with a pleasing blend.
Re: Sundown 12" Neo Driver 4th Order Bandpass
I believe the cars resonance is around 40-45hz; based on what stratus01rt told me. This is going in a stratus.
Re: Sundown 12" Neo Driver 4th Order Bandpass
Ah, I would definitely slope it then if youre going for a flat response. You may get the peak there and youll normally get the biggest usable bump in the 30-40 range.
Is this facing back, or firing in cabin?
Re: Sundown 12" Neo Driver 4th Order Bandpass
it will be firing in cabin
Re: Sundown 12" Neo Driver 4th Order Bandpass
That sub is too pretty, yum.
Re: Sundown 12" Neo Driver 4th Order Bandpass
Alright well I just got two sheets of mdf; got my co worker to bring it home on his truck. Box will be done this weekend.
The Re-Stall will entail the following.
- Complete clean out of the car it's filthy
- Remove two remaining seats; possibly remove dash
- Repaint a silicone sound deadner in entire vehicle
- Rebuild amp wiring; and Low voltage electrical
- Install 3 Alpine PDX4.150s
- Install 1 Sundown 3000D
- Build 2 Chamber Fourth Order Bandpass; Will have two 6" x 30" long ports
- Build Car Puter
The Car Puter will likely replace the head unit; I want a touch screen to build into the dash.
P.S.
MDF is retarded now a days, back in 04 it was under twenty; Lowes got 35 a sheet out of me. :(
Re: Sundown 12" Neo Driver 4th Order Bandpass
Yeah, prices ****. Im starting to use birch but I really hate the splinters..
What were the official numbers you went with?
Re: Sundown 12" Neo Driver 4th Order Bandpass
I haven't started the box yet; but when I put it up in the program; I designed it to fit in the car; The flat frequency response was more of a coincidence but I'm not going to stress over it; because there is no real way to tell what it's going to do in the car.
So I'm just gonna build as is; and tweak ports and the small chamber as needed.
Got the car cleaned and painted with silicon to act as a sound deadner...took 4.5 hours.
THE MESS!
http://i130.photobucket.com/albums/p...8-13104745.jpg
http://i130.photobucket.com/albums/p...8-13104753.jpg
http://i130.photobucket.com/albums/p...8-13104800.jpg
http://i130.photobucket.com/albums/p...8-13110814.jpg
I sat there and vac'd every square in and it still looks dirty as hell
http://i130.photobucket.com/albums/p...8-13123234.jpg
http://i130.photobucket.com/albums/p...8-13123244.jpg
http://i130.photobucket.com/albums/p...8-13123224.jpg
One thorough coat applied in the skipped trunk and through out the car.
http://i130.photobucket.com/albums/p...8-13141615.jpg
http://i130.photobucket.com/albums/p...8-13141603.jpg
Re: Sundown 12" Neo Driver 4th Order Bandpass
holy ****...and i thought my truck was dirty. lol
Re: Sundown 12" Neo Driver 4th Order Bandpass
Quote:
Originally Posted by
treylittlefield holy ****...and i thought my truck was dirty. lol
x2. Wow.
