Sundown 12" Neo Driver 4th Order Bandpass

[Rawr-DQ 10+ year member]

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

I did more testing; here are the SS wt3 program:

Test Lead Calibration

Test lead calibration with 1k ohm resistor

Series Free Air

Series Vas Cal

missing

Parallel Free Air

Parallel Vas Cal

missing

Click to read more...

 

[Rawr-DQ 10+ year member]

Coil a free air (individual coil)

Coil a vas (individual coil)

Coil b free air (individual coil)

Coil b vas (individual coil)

Polarity Reversed (one coil) Parallel Free Air (trouble shooting)

 

[Rawr-DQ 10+ year member]

forgot to post woofer p0rn; here ya go; can anyone say back plate p0rn?

 

[surreal 10+ year member]

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.

 

[Rawr-DQ 10+ year member]

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:

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 //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

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.

 

[surreal 10+ year member]

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.

 

[Rawr-DQ 10+ year member]

I believe the cars resonance is around 40-45hz; based on what stratus01rt told me. This is going in a stratus.

 

[surreal 10+ year member]

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?

 

[Rawr-DQ 10+ year member]

it will be firing in cabin

 

[The_Grimy_One 10+ year member]

That sub is too pretty, yum.

 

[Rawr-DQ 10+ year member]

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. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[surreal 10+ year member]

Yeah, prices ****. Im starting to use birch but I really hate the splinters..

What were the official numbers you went with?

 

[Rawr-DQ 10+ year member]

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!

I sat there and vac'd every square in and it still looks dirty as hell

One thorough coat applied in the skipped trunk and through out the car.

 

[treylittlefield 10+ year member]

holy ****...and i thought my truck was dirty. lol

 

[Buck 5,000+ posts]

holy ****...and i thought my truck was dirty. lol

x2. Wow.