Oddball Neo Specs

[Totalnewbie007 4]

I calibrated and tested this neo oddball with a WT3 woofer tester; jacob or anyone knowledgeable; do these specs look alright; and to any bandpass enthusiast, does the box have any flaws I should be careful of falling into.

Driver Properties

Name: Neo 12" driver

Type: Standard one-way driver

Company: Sundown

No. of Drivers = 1

Dual voice coils = series

Fs = 35.66 Hz

Qms = 5.591

Vas = 1.429 cu.ft

Cms = 0.11 mm/N

Mms = 177.6 g

Rms = 7.257 kg/s

P-Dia = 10 in

Sd = 0.0507 sq.m

Qes = 1.855

Re = 3.634 ohms

Le = 4.268 mH

Z = 14.59 ohms

BL = 8.829 N/A

Qts = 1.393

no = 0.0943 %

1-W SPL = 81.84 dB

2.83-V SPL = 85.32 dB

-----------------------------------------

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

[Totalnewbie007 4]

bump, anyone think that the qts is reading high, the highest I've seen in literature is .7 or so.

this subwoofer is one that will like sealed boxes, and dislikes vented, anyone know how a 4th order will react?***

sp*

Edited August 7, 2011 by Rawr-dq

[Totalnewbie007 4]

To help make this more interesting here is the bbp6 design

[95Honda 486]

That is a high Q. Are you sure both coils were hooked up?

What do you mean by 1st order? Are you refering to a 4th order box? If so, most drivers that behave well sealed will work OK for 4th order bandpasses if they have sufficent Vas to allow for proper vent sizes...

[Impious 1,476]

That Q looks really high. I'd try to double check your measurement.

[Totalnewbie007 4]

That Q looks really high. I'd try to double check your measurement.

I have and done different masses, re calibrated, retested, this motor has a huge shortening ring and huge back-plate.

Was wired in a series and parallel during testing, but I will wire it in a series to a 3000D Sundown. Results are from series calculations.

Edited August 7, 2011 by Rawr-dq

[Totalnewbie007 4]

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

Parallel Free Air

Parallel Vas Cal

Coil a free air

Coil a vas

Coil b free air

Coil b vas

Polarity Reversed (one coil) Parallel Free Air

Polarity Reversed (one coil) Parallel vas

Yup thats it

[Totalnewbie007 4]

[Duran 387]

One of Jacob's prototypes, it just has a high Q.

[Totalnewbie007 4]

Do you know anything about this sucker, all I can tell is it will probably do best in a sealed enclosure.

[Totalnewbie007 4]

http://www.bcae1.com/#116

Qtc

Qtc is the total Q of the speaker in an enclosure including all system resistances. A Qtc of .707 is the most common and generally produces the flattest frequency response with approximately a 6dB/octave rolloff. Higher values of Qtc will give a peak in the output with a sharper rolloff. A lower Qtc will start to roll off earlier and will roll off at a slower rate. If you don't know what Qtc you need, start with a Qtc of .707.

Qts

Qts is the total Q of the speaker. It is defined as 1/Qts = 1/Qes + 1/Qms.

Edited August 7, 2011 by Rawr-dq

[sundownz 197]

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.

[Totalnewbie007 4]

ok well I'll let you know how the bandpass goes this week

[Totalnewbie007 4]

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.

[Totalnewbie007 4]

Ok well the sheets got cut today; I had to clean the porch to work to mess it up again.

However with a skill saw I still manage to get cuts within 1/8th of an inch;

My method of measuring is meticulous I use the factory cut edges of the boards in order to setup a guide. I lined the corners up flush to the guide; the cut board; and the support directly on the chairs I used as saw horses.

From there I do the following:

Measure the saw blade to the rim of the saw to determine the distance of the blade to the guide depending on which side of the board I'm on (I account of the thickness of the blade)

Basically if I'm cutting from the 4x8 sheet and the guide is on the outside the cut. I need to factor in the thickness of the blade plus the distance to the guide from the rim of the saw. If the guide is sitting on the board and I'm trimming it to size; I factor out the blade and just use the distance of the blade to rim.

I make two markings on the cut sheet the guide arrows and cut arrows using a tape measure.

I place the guide down and line the board on the center of the arrows and clamp down.

Here is the tedious part:

I use a block to nudge the board into alignment before while and after clamping it in place; Then I cut a test notch; measure my board; adjust if necessary; then rip it in a few seconds maintaining and even level pressure perpendicular to the cut.

Spend 10-20 minutes measuring; and a few seconds cutting.

I speed things up as I get going I will assembly with minimal screws tomorrow.

I've already figured how the box is going in; I will have to take off my passenger door to do it; along with the seats out. I will have some more interesting pics tomorrow.

The guide is on the outside of the cut here. To keep the saw from binding, the support is at the guide; this will pull the board away from my blade to keep it from pinching; another chair that is slightly smaller is there to keep it from bending too far and from falling.

Here is a picture of the test cut and measurement; This one was spot on at 34"

Note the guide was on the inside of the cut here; the blade is on the outside; distance of the blade to the rim was 1 1/8th inch plus 32 and 7/8" (the guide position)

Thanks for looking

Edited August 14, 2011 by Rawr-dq

[Totalnewbie007 4]

Look ma no screws!

I love my corner clamps for sure; I also love clean even cuts; very few gaps.

I line up my clamps; test fit; rub my finger at the seems and adjust the clamps till I don't feel any edges; tighten one side of the corner clamps; raise the board; brush glue; drop; clamp corners; add big clamps near corners and tighten each back and forth; add center clamp and tighten; then finish cranking all three down till the glue completely fills the voids.

[Shogen 325]

looking good... :popcorn:

[Totalnewbie007 4]

Ok well I'm going to cut the ports and put elbows on them!

Just wanted to make that clear; However 6" elbows are harder to come by than I thought; so I'm gonna visit a sewer guy I know or order them online.

Today I'm going to wire the amps and cut the ports; going to leave it sealed.

I've found out that my engine battery (a kinetik 6800?) went bad; doesn't charge.

Using a Optima d3100? as a start battery; then disconnect it; engine runs without; tried charging it at 2k rpms for 20 min; but unless it's totally dead; it wont even put the windows down or unlock the doors.

On to the {PICS!}

Edited August 15, 2011 by Rawr-dq

[Totalnewbie007 4]

Ok well I got to cut the ports; then it rained and lightninged, so I went inside. I got back out and went ahead and painted it with the same silicone I had before. I figure it will seal better when I put the cover on.

The ports are 15.5 inches; changed the peak; but I have enough room for some elbows which should give me 6-7" longer port; still a cry from the 30" planned, but we'll see what happens. I'm going to test it sealed first; then bandpass w/ 15.5" ports; then with ~21-22" ports; and so on.

Legend:

Red is the 30" port

Orange is the 22" port

Yellow is the 15.5" port

Green is a 6.83 Cubic Ft sealed box

It was a tight fit!

[Totalnewbie007 4]

Painted with silicone