1999 BMW 323i

[wylekyote]

I just bought the BMW (listed in title) and I'm looking to move my subs from my old car to it.

I have 2 Kicker L5 solo baric's, and a 500watt pioneer amp. I really would like to build a bandpass box, but I couldn't find enough information to really build one competently, any ideas?

Dimensions, a rough drawing or anything would be a great help.

[sr20de4evr]

it's going to take a LOT of planning and calculation to do a bandpass box right....I would stick to ported personally

[wylekyote]

but would it sound as good and/or hit as hard?

Personally, I would prefer quality to quantity.

Currently I have them in a sealed enclosure in my Eclipse, but I thought that since I would have to build a new box anyway, I might as well do it right.

And if I do port it. . .what kind of spec's would I need to be considering? I plan on building the box myself. I built my other box with MDF, used screws and wood glue on the joints, and then caulked them afterwards. I assume a ported box is built the same way, but with a port hole cut or drilled?

[sr20de4evr]

Well a properly built bandpass box can sound just as good as ported and be slightly louder, but the problem is that it takes some serious designing to make one right, and there is zero room for error. A ported box will sound just as good or better, get almost as loud, and is infinitely easier to design and build.

If you're going to go ported, you would want to look at the manufacturer's recommendation for size and then come up with a tuning frequency. Kicker's tuning recommendations are ridiculous, they're for getting loud and that's about it. I would tune closer to 30-32hz in your case. You can play around with WinISD to find the needed port size and length for a 30-32hz tune. After you get that worked out, you need to figure out the volume that this port will take up, add the volume that the sub requires, add the volume that the sub itself takes up, and build a box that size. Then you can cut a hole in the front baffle and put in a PVC port or you can make a slot port (depending on how you designed it).

slot port:
http://www.edesignaudio.com/im/main/...REV5.10.04.pdf

pvc port:
http://www.adireaudio.com/Files/KIT81Plans.PDF (page 14)

they'll both behave the same way as long as the cross sectional area of the port and the length are the same, it's just 2 different ways of going about it.

[CBFryman]

i personally like slotted ports. what size are your L5's? 10? 12? 15?

4th bandpass is the only one that real world formulas exist for and its output is about the same as ported over its frequincy band. 6th order would show about a 3dB gain over all on ported but there are no real formulas so its trial and error to get it right.

[wylekyote]

The L5's are 10's. And what exactly is WinISD?

This is going to be my first time building a ported box, so any and all suggestions are welcome.

[CBFryman]

WinISD is a free audio program.

you basically choose your woofer from a very long list of woofers or input all of its specs. tell what type of enclosure you are placeing it in and how many you are going to have and it will show you estimated:

Responce
Sensitivity
Gain
Delay
Expected SPL w/o cabin gain.

and give you specs on what volume and what port would work most efficently for greatest SPL with flattest responce. then you can play around chaning box volume, port area, tuneing frequincy, etc...

added bonuses are things such as signal generators if you ever get serious and build yourself a teast bench.

there are other programs like this but they are slipping my mind at the moment. someone help me out.

however, WinISD is probably one of the best that is still free. though you should be nice and send the programmer a few bucks. i havent and probably never will but some one should...

Here is a link to the website where you can download it.

Here is Another link. this website is very helpfull. that link will take you to a whole list of enclosure CAD downloads and all. but there are otherthings on that website such as enclosure theory's and some DIY stuff.

[wylekyote]

I downloaded WinISD and the L5 isn't listed as one of the choices, so I chose the L7.

In the link provided above by sr20de4evr for slot ports, it shows multiple. . .I don't even know what they would be called. The dividers, basically. Would the length from beginning to end of that be considered the length of the port?

Also, the length of the port keeps showing up as something near .66in on WinISD. Is this possibly correct?. . .seems a bit short.

[bumpinstang77]

Originally Posted by wylekyote

but would it sound as good and/or hit as hard?

Personally, I would prefer quality to quantity.

Currently I have them in a sealed enclosure in my Eclipse, but I thought that since I would have to build a new box anyway, I might as well do it right.

And if I do port it. . .what kind of spec's would I need to be considering? I plan on building the box myself. I built my other box with MDF, used screws and wood glue on the joints, and then caulked them afterwards. I assume a ported box is built the same way, but with a port hole cut or drilled?

If you prefer quality over quantity I would go with something other then l5's. Those subs are definately not for sq. Consider a single brahma or xxx 12.

[wylekyote]

I already own the l5's, and I don't plan on spending any more money, except on the components for the box. I don't need them to be perfect, but I do want them to sound good.

[sr20de4evr]

Originally Posted by wylekyote

I downloaded WinISD and the L5 isn't listed as one of the choices, so I chose the L7.

In the link provided above by sr20de4evr for slot ports, it shows multiple. . .I don't even know what they would be called. The dividers, basically. Would the length from beginning to end of that be considered the length of the port?

Also, the length of the port keeps showing up as something near .66in on WinISD. Is this possibly correct?. . .seems a bit short.

that's not .66in unless you set the tuning frequency to well over 100hz, it might be .66m though

and for the link you're talking about, you would take the very center of the port and follow that from beginning to end and that would be the port length.

[wylekyote]

Would there be a downside to using the specs kicker has listed in the l5 manual for a box?

It has some useful illustrations for building a ported box, but I haven't found anything for two boxes =/ would I just build two completely seperate boxes? or could I integrate the two boxes where the top and bottom of both were the same piece, but other than that they are essentially seperate?


*edit* Also, where can I purchase a subsonic filter, and how much would a decent one cost?




If you haven't already noticed, I am completely clueless. But I assure you, there is hope.

[sr20de4evr]

Originally Posted by wylekyote

Would there be a downside to using the specs kicker has listed in the l5 manual for a box?

It has some useful illustrations for building a ported box, but I haven't found anything for two boxes =/ would I just build two completely seperate boxes? or could I integrate the two boxes where the top and bottom of both were the same piece, but other than that they are essentially seperate?

downsides?
well like I said above, they're designed for getting loud, you will have virtually no low end extension and there will be a gargantuan peak in the response if you use those boxes. Not sure how much worse it can get from a sq perspective.

as for the dual box thing goes, you could build one big box with one port, you could build 2 boxes that are sort of "joined" by the top, bottom, front and back baffles, or you could build 2 totally separate boxes, all up to you.

[CBFryman]

choosing the L7 will not work. you will have to insert specs yourself for the L5. once you have an idea about basic paramaters design your enclosure either on paper on in a CAD program.

after getting off my lazy ass and looking up the L5 10's specs.

i would go about 3.2cuft tuned to low 30's.

whis will give about the best SQL your going to get from a kicker.

other option would be to sell the woofers and buy to Adire Shiva 12's or even a single Brahma 10".

what do you need a subsonic filter for. most amps dont even respond to frequincies below 15-20Hz and most head units dont even send out frequincies below 20Hz and many tracks dont have frequincies below 25Hz. but if you want one all it is is a highpass cross over that does its work at low frequincies. i would imagine no more tha 6dB/octave would be needed.

[AndonD454]

i know the shiva/ brahma reccomendation was for SQ fryman.. but i was wondering also if the 2 shivas would get louder than the kickers too.. i havent heard shivas before and im kinda lookin for some spl subs for about 200-250 (and the shivas are 125 each i think)