well lets see ....sealed?

[ollie 0]

gooday ladies and gents

wonderinging if anyone can help me with an inquiry i have. i plan on buying a single 15" mag when they arrive (preorder) and am also planning on building the box on my lonesome. to start off i drive a 94 maxima gxe with a fairly spacious trunk. due to the fact that it will soley be used for daily driving and for personal use (don't plan on showing it off to anyone) i guess you could consider me a SQ guy but the magnum is the best of both worlds hence it will get loud for me but have phenominal reproduction capabilities....im not a rap guy but i like a good bit of tribe called quest once in awhile and a whole bunch of other stuff prog rock (liquid tension (faaaaaast bass drumming)) and also a good bit of metal and were talking fast here now im sure the sub can keep up and thats not the question....on to the goods..

my maxima has a taper in its trunk that is approximately 36X17X18 inches of space that i'd like to use for an enclosure. my wood working skils aren't terrible, and im sure pops would be willing to lend me a hand (you think that id be better being that i sell all of the equipment at work (hardware store)) so anyways... im trying to keep this short.

SEALED would be easier for me to do im sure and i know that i could pull it off. also, i can get anything hardware within reason AT COST and i want to use 3/4" MDF. BUT....which would be better for that fast paced bass drum reproduction, ported or sealed? because out of all the reading that i have been doing, a lot of people are saying ported 28hz etc... im open to ideas and i know that i could expand my dimensions with the ported enclosure. im up to doing some prototypes or something to get it right but im more concerned about the physics of the woofer in general. (the restriction of a sealed box may not offer as fast of reproduction, as you can tell i really dont know it could be the other way around.

so in short gentlemen, the big question is, the faster the bass, which enclosure is better suited? maybe someone can help me plan something out as WINISD is jibberish to me (not entirely)i appreciate your bearing with me and ive learned alot from many of you on other forums etc... im doing this for the first time, and im doing it right....

BTW HIFONICS bx1500d planned on being the amp, other sugguestions welcome...

you have no idea how much i appreciate your help in this matter.

[djjdnap 78]

sealed is just fine, its easy also lik eyou said but with ported you could be louder.

[Electrodynamic 2]

I would go with a sealed enclosure. Ported will still sound good, but a sealed alignment will aid with the fast bass kicks like you want.

[ollie 0]

thanks guys always appreciated your wisdom shows

[sundownz 197]

I am with Nick. I have fallen in love with sealed boxes, especially larger sealed boxes stuffed with polyfill and fiberglass for a really low Qtc. Mmmmm... large sealed boxes...

[Electrodynamic 2]

...especially larger sealed boxes stuffed with polyfill and fiberglass for a really low Qtc. Mmmmm... large sealed boxes...

YES! I'm finally starting to rub off on Jake! The combo of polyfil and fiberglass insulation is hard to beat fellas.

[ollie 0]

so for one 15, when we say big, how big are we talkin? ft^3

[sundownz 197]

I would do between 2.25 and 3 ft^3 sealed... stuffed with 3 - 4.5 pounds of polyfill and fiberglass insulation mixture. What do you think Nick?

[I8apony19 0]

2.1 cubes NET yields a Qtc of .707

So I'm in agreement with Jake...anything 2 cubes up until space becomes an issue..then poly fill it to get that Qtc a lil lower for better transients...

[ollie 0]

sounds like a good plan. i need to get my dimensions final and nick and jake, youll probably see a money order from me soon for a 15". is the total price for me $350? live in michigan. thanks buds. i wanna get it to you before the 27th.

do you expect to run out of driveres from preorders ONLY or still have some left after preorders because people are sure talking....

Edited February 8, 2004 by ollie

[Electrodynamic 2]

Jakes suggestion will work just fine, and Clarke showed how small of a box it will take to get the coveted .707 alignment, so you can choose whatever you want. I would definately mix fiberglass insulation and polyfil inside the enclosure.

As of now we will have plenty of drivers remaining even after the drivers show up. And yes, $350 will cover the driver and shipping up to you.

[hoss 0]

I am with Nick. I have fallen in love with sealed boxes, especially larger sealed boxes stuffed with polyfill and fiberglass for a really low Qtc. Mmmmm... large sealed boxes...

yeah, youre weird...

[I8apony19 0]

The man goes to bed at 10 o'clock every night...regardless what night of the week it is......

"yeah, youre weird... "

DUH!

[ollie 0]

man i can't wait!

[I8apony19 0]

I'll give Jake a

Hollis....you can settle with.....

Edited February 9, 2004 by I8apony19

[hoss 0]

clarke... i am the

best recognize foo!!

[I8apony19 0]

Ollie....if you want to get a good idea about how winISD works....

go to a manufacturer's site and write down all the T/S parameters...

enter winISD and click on the new project tab...

some drivers are already on the list..but if you don't find what you are looking for you'll simply create a new driver by clicking "new" and enter all the T/S parameters you wrote down...you won't be able to fill in all of them..but some of the parameters you enter will self calculate others..so don't worry...

Save it and then load the driver you want in sealed, vented...etc..box environment....

Simply enter the NET box volume and tuning (if you chose a ported box)...

If you choose a sealed box, obviously no tuning will be available, but a Qtc below will be shown....increase the box for a lower Qtc alignment (.707 is considered perfect I believe and .5 is perfect for transients)..correct me if I'm wrong...

Things to look for in an SQ application....

1) How flat the graph is..the flatter the graph at 0db, the better...

2) A ported box has a steeper roll of, but rolls off closer to 0hz...

3) ported boxes have a hump (or a peak) in the graph...the longer the hump is...the better (or flatter)

4) F3 and F10

SPL application

1) How high that ported box hump is..and where that hump peaks at as far as frequency is concerned)

You can find the F3 and F10 of a box by simply clicking on the curve and tracing it to the -3db mark on the graph (the horizontal line turns purple at -3db) ...then...look at the upper right hand corner of the graph and locate the corresponding frequency....

Same can be done for the F10..just at -10db

That is the basic way of using WinISD...there are other graphs to look at...but for most of us..that's all we use...

REMEMBER...WinISD is NOTHING more than a PROGRAM....it does not represent the in-car environment once so ever...it's more or less a good idea of what to expect...but not always 100% of the time...

There are a few drivers out there that model up HORRIBLY..but do not sound that way at all...

Ultimately...it just comes down to which driver you use, and more importantly, the characteristics of your box and car

[Electrodynamic 2]

Magnum's have never been very good with WinISD, Boxplot, or any of the other programs. What they are good with, however, is music. Like Clarke said, WinISD will only give you an idea of how it will plot out...not sound.

[sundownz 197]

That is correct... anyone SI.net members know I am "The Master of WinISD" but it really won't give you a representation of what the sub will do in your car

[ollie 0]

sounds like a good plan. i was coming up with some volumes today that looked decent so ill have to plug them in. im looking at anywhere between 3-4 cubes as i have about

36 length x 18 depth x 17 height so the length looks like it with be shortened depending on displacement etc...

thanks for all of the help guys. i hope this forum stays this way. keep any new ideas coming!