building box

Hi all in new to building boxes and i just need to know if it would work if i measure the internal dimensions of my trunk and i can fit the biggest box i can and i want to port it. does it matter what the volume of the box is as long as i get my port correct. I prefer to try to build my own box than to just buy a prefab one. im going to use 2 of these subs http://www.absoluteusa.com/cat-list.php?id=55&subdesc=VIAGRA%20SERIES 

i think they are fake imitation subs but i got them for free because my friend works for the company. has anyone ever heard of these

Internal volume is just as important as the port size. There is a much smaller margain of error when working with ported boxes.

I don't know about them being fake or imitation subs, but they seem to be on the "inexpensive" side. not top quality gear, but free is free!

so youre saying that it the internal volume does matter how can i find out what volume i need for a ported enclosure. is there a standard volume i can use for 10 inch subs?should i just give up and buy a prefab enclosure?

thank you very much for your help

These subs are called the Viagra series....

The link for the user's manual doesn't seem to work. This is where you will find all the specs you need. Sealed and ported air space. I would recommend against buying a prefab ported box, too many varaibles there. At least with a sealed box you will have a better chance of matching requirements. Besides, sealed boxes are generally cheaper.

my friend doesnt know crap hes just the delivery guy for the company thats how i got the subs. i looked around and found the specs but i dont know what to do with them. here they are

Fo(hz) 27

Qms 3.16

Qes 0.43

Qts 0.38

Vas(liters) 44

Vas(cubic feet) 1.5

EBP 57

Revc (2each@) Ohms   3.2

Spl(1w-1m)db   84

xmax (mm) Peak to Peak 26

Leve(mH) 1.6

minimum sealed (cubic feet) 0.4      &   max sealed 0.9                                      (BUT I WANT PORTED!!!)

I tried using Winl SD but i dont have all the info i need.

thanks for your help..

You can build a box to 3 cu ft net (after all displacements), single chamber.  Install the subs either normally or inverted, depending on whether you want to see all the chrome on the basket.  Use one port 4" round X 10" long for a tuning freq of 29.6 Hz.  A slight peak will be in the area of 40 Hz.  You probably won't need a subsonic filter on these, and the lowpass can be set at about 100 Hz to transition to your front drivers.  You should be able to provide this box with 500 - 1000 watts RMS total.

Buy a nice flared-end port to minimize port noise.  If you want to slot vent this, you'll still have to keep the slot on the small side because these drivers get into some really long port lengths if you increase the vent opening area.  Do a slot equivalent to the 4" round in that case, and round off the front edges.

And you'll want to make sure the mono amp is capable of a 1 ohm load if you'll be wiring these parallel/parallel.

Stevdart  thanks for your help. i decided to go with a slot port. thanks a lot but i still wonder how is it that you got the 3 cubic feet for the box. is this like a standard size one would use if you dont know what size to use?

Thanks to everyone who posted and i will get on my project as soon a possible.

Naw, bassrider, I modeled it in WinISD Pro.  That wasn't BS off the top of my head. (!!!)

Use a flared port like this one.  Those (Audiobahn clones) subs need all the help they can get in the port quality; as I said before, if you make the port opening too large the port length will be so big it will be difficult to construct.  All the info you need is in my previous post...