Enclosure Size Calculation

Okay, now we are starting to get somewhere.

The reason that the program computed 9hz is probably because there were 2 parameters missing.  Ill show you what I got

Qts 0.38                           Qms 10.13

Qes 0.4                             Xmax 0.157" (4mm)

Pe RMS 175W (575W max)               Re 3.49ohms

Sd 64.3"   (415cm2)                   Cms   0.257 x 10^-3 M/N

Mms 2.43 oz  (68.79g)

Bl   12.03 Tm                     SPL 91db

Ill keep playing with it, but I want to start building this unit in the next couple of days.  Id like to do it right though...

Right

Im missing the Le & Z values.

Also Im unsure as to which diameter to input

Nom Dia  9.02" (229mm)  or   VC dia.  2"  (51mm)

Also, the Usable Frequency Response is 20Hz-1KHz.  Would i set the graph cut-offs to these values?

Its interesting that the program wants all the values in meters!

I appreciate all the help.  One of the reasons I went with cheaper hardware is to learn how to do it right, with my girls car as the guinea pig.  That way when my own ride gets out of the shop...

I'll look at this later when I have more time, but meanwhile:  if the program shows l for liters, and you want to input cu.ft., place the curson on top of the l, click through the measurement changes....so in reality all conversions will be done for you by the program.  That is in the parameter input dialog box.  Also, the cursor changes can be made when you bring your project up in its own box.

Don't worry about Le, and Znom is the nominal impedance of the driver ( e.g. 4 ohms).  That sub has a 4 mm Xmax??  That's the typical excursion of a 6" driver!  Just see what size sealed box you can make for it.

Set the program low to 20 Hz, and the high can be anywhere 500 Hz and above for subs.

LOL

Before everyone starts cruising on my crappy components, just remember that the idea here was to use this as a learning experience & ive been learning heaps already.  Not to mention coming in well within budget.

I recalculated everything for a sealed box & came up with 0.982 ft^3, so it should be right around 1ft^3 when I take the volume of the speaker into account.  I dont plan on bracing it as it probably wont need it!

Ive heard some different theories on deadening material, but I was gonna use dynamat or something similar & line 3 adjacent sides with it.  Would packing in fiberglass be better?  If so, would I pack the box up with it, right next to the speaker, or just use a bit?

EBP?  Where do you find that & what does it represent?  Can you tell me how you got those values for volume, ports, etc?  I havent gotten anything close to that!

Maybe you could send me the save file?

By the way, im using WinISD beta, if that makes any difference.

EBP is Fs / Qes which gives you a value that determines what type of enclosure works best.  38.10 / 0.4 = 95  . The EBP comes up in the center of the second dialog box after you select your driver from the scroll down list.  That box gives you the program's determined type of enclosure and shows EBP=95.3  Generally, an EBP of 50 and below is best sealed, and 90 and above is best vented.  In between numbers, which a lot of subs fall into, can go either way.

To edit your driver database, pull down Utilities, database editing.  Select your Jensen from the scroll list and go to parameters...change whatever in it is entered wrong.  You'll notice the values you enter are a different color than the ones that the program determines (BTW, there is a check-off box to let the program determine values, check it).  When you enter parameters, there are some you should leave out...QTS and BL are two that I know the program wants to figure, because if you enter a value that is not identical to what it figures, you get an error box.  The parameters you listed in the above posts are all you need to enter, (leave out QTS and BL)  which is what I did.  The best enclosure and size came up automatically when I brought up the Jensen driver, and all I had to do was look at the graph and approve it and look at the port size and see if it was workable, which is with this sub.  The small Xmax allows for a small port length, so this is a pretty easy one.  And I'm using the same version as you.  You'll get it, take your time.  In fact, I have learned it better by helping out guys like you.

When working with the port size, you can change the port diameter to be exactly the inside diameter of whatever port tube you could find to purchase (e.g. PVC pipe, etc.).  You'll see the length change to accomodate the different diameter you entered, but the box tuning and size will remain the same.  And you can use the cylinder calculator on this site under Port Length calculators..to find the displacement of the port tube.  Make sure you add it to the overall air volume along with driver dispacement so that you get a net air space of 2 ft^3.

Oh btw, I just entered the Re, and not the Znom.  The program figured it to be 6 ohms.

So Ive gone through again & my EBP does come out to 95.3.  There are a few differences though.

For Volume I get 1.806ft^3  & for Tuning I get 40.5Hz.  Ql = 7 (?)

The Port is 4.02" x 8.38,  & the Vent Mach=0.08

All of my inputs seem right, however, when trying to edit them & leave out Bl & QTS, I do not have a box which allows the program to calculate the numbers.  This must be making the difference.

If I manually input 2ft^3 & tuning of 38.67hz like you said, the port length is 8.27 instead of your 8.35"

Im gonna try to download a different version to see if it makes a difference.  I want to have the box designed today so that I can get the materials tomorrow.