12w6v2 enclosure

I think that using a 2 cubic feet

the subwoofer works with more freedom,  I mean, like if the subwoofer could use more properly the air to push and suction itself.

First I tried the 1.5 cubic feet, it worked really fine.

I Liked more this just recently made of 2 cubic feet considering your instructions, so thank you.

I really had troubles to envolve the slot port, I dont like just to paint it... i like to envolve the port with the fabric or anyway its called in english.

As i said before, i'll try to show you a picture of the installation by tomorrow or so.

thanks, and I hope i can keep in touch,.

cloak the size of the enclosure has absolutely nothing to do with it.  The amount of air being forced through the port does.  The airspace in the enclosure does not impact this... the size of the woofer and the amount of power the woofer is getting do.

Now, if we had a *pair* of 12's in that same box, it would whistle like starving coyote.

Admittedly, I'm actually not sure of the relationship between the t/s parameters, but I modeled the box in WinISD and the box I described will have a vent mach of .1 .... whatever that is its like half again less than the audible range of port noise. 

mezzaricardo, both you and cloak need to start modeling this stuff on a computer and your understanding here will leap 100x over.  I designed that enclosure with WinISD in about 20 seconds and it takes care of all that aggrevating math with port calculations and what-not.  Read stevdarts sticky on the top of this forum and give it a try.

http://www.linearteam.dk/default.aspx?pageid=winisd

This is actually what happens.. but the woofer loses some cone control when it loses a tight air suspension behind it...

You also must be *VERY* careful about how much power you are running to that sub in a box that big.  You can get away with it, but like you said, the subwoofer works with more MECHANICAL freedom, which brings its effective power handling down.  You should assume your 12w6 is probably only going to handle ~300watts or so.. be very careful with your gain and back off of it considerably if you hear any distortion coming from that box.  You can kill that sub very quickly in a box that large.

Huh?  blame? What?  Freedom is a perfectly fine word to use there.  You are actually doing a better job of communicating on this board than half of our new posters.

Tu englias es muy bein?

I dunno my spanish is awful.  I just don' t want you to hurt that beautiful woofer.

Hmm.  Read the 'setting your gain' sticky on the top of the forum.  This is a really important point..

I can't answer that question. It depends on you deck's preamp voltage as well as your paticular amplifier.  75% is probably a bit high, but I really have no way of quantifying that for you.

Well there is no gain setting sticky.

Okay look dude I really can't in good concious tell you to do it by ear.  You're gonna have to do a little research here.  Start with the search function on this forum if you want.  People go over this stuff all the time.

I always set my gains by ear and that's really kinda careless *especially* if your running that sub in a box that large.  That requires great care okay?

okay, I will take care, believe me... I don't wanna kill that sub..... I paid too much to a Numptee Seller for it.

Well, I misunderstood the deal about that word. You know, sometimes there are words in spanish that if you translate them LITERALLY means nothing in english.

thanks for your valuable time and attention.

I'll search a lil' bit more about the gain stuff.

But in the beginning I remember you said there was no problem about using that subwoofer on that cubic footage., Although I guess that would be because of the slot ported design, in this case, of course.

As a comment let me tell you that  A friend of mine is running 2 alpine subwoofers SVC type E on a slot ported box with a V12 mono amplifier 600 Watts RMS, gain to TOP on an enclosure of two chambers of 3.5 cubic feet EACH).... that's being a murderer subs

Question:... Does WinISD or some webpage the calculus of slot ports?...

Well not in theory and it shouldn't affect the sound quality of the sub.  Still, you have to set your gain properly.  It really wouldn't matter what sort of box you put the sub in you still don't want to overrun the thing.

Yea I have abosolutely no idea how his subs are even working.  I couldn't imagine speakers that would last very long being treated like that.  I wonder how long his amp will last.

Like I was trying to explain, large ported boxes do not have the 'air spring' that a sealed enclosure provides.  Any ported enclosure is going to make the sub more sensitive to power (because the air isn't providing resistance to the woofer cones' movement) and thus more prone to mechanical overexcursion at higher power levels. 

This is why you have to carefully set your gain. 

That's clear

You can convert easily to slotted using WinISD but you have to learn the program well enough first to enter your driver's parameters into into it and get it up and running.  It doesn't have a quick and easy app that will just do a conversion for you.  But the following is an answer I wrote about this and saved in my docs folder:

pi r^2 to find the area of a circle

pi is 3.14

r is radius, or half the diameter of a circle

^2 is squared, or the number times itself

pi r^2 is 3.14 X the result of radius squared

pi r^2 gives you the square inches of a circle

You want to change the shape of the opening but keep it the same square inches.  The length of the port is not a factor and you will leave it exactly the length it already is.

Find the square inches of your circle using pi r^2 (ex. a 6 inch diameter circle yields 28.26 square inches)

Decide on the longest side you want your square or slotted port opening to be

Divide the total square inches of the circle by that long side, in inches (ex. 28.26 / 11.5 = 2.46)

The result is the measurement of the shorter side of the port opening

In the example, the 6" round port equals a slotted port 11.5 X 2.46 inches.  Round measurements to the nearest Imperial or metric value.  2.46 would be  2 7/16 to 2 1/2.

You should keep the ratio of length to width of the slotted opening at no greater than 8:1.

Use this math to convert your round port to a slotted port.  Square is best, while long and very skinny is worst, although both can comprise exactly the same square inches.  That is what I mean by keeping it less than 8:1 ratio.

Also, here is a list of web help and calcuators.  You might want to save the list to refer to.

Information links, calculators, and other online help:

http://www.bcae1.com/

https://www.the12volt.com/installbay/forum_posts.asp?tid=74558&PN=1

https://www.the12volt.com/caraudio/boxcalcs.asp

http://www.sound.westhost.com/tsp.htm

http://sound.westhost.com/site-map.htm

http://sound.westhost.com/articles/cscaling.htm

http://www.diysubwoofers.org/faq.htm

http://home20.inet.tele.dk/kou/ubmodel.html

http://www.soundandvisionmag.com/idealbb/view.asp?topicID=47166

http://www.vikash.info/audio/diy_audio_search/index.asp

http://www.thielesmall.com/database.asp

http://www.linkwitzlab.com/

http://www.linkwitzlab.com/design_of_loudspeakers.htm

http://www.pvconsultants.com/audio/frdgroup.htm

http://scienceworld.wolfram.com/physics/HelmholtzResonator.html

http://www./help2/Articles.cfm

http://www.partsexpress.com/resources/crossover/xoverhelp.html

http://www.users.bigpond.com/bcolliso/port-flares.htm

http://www.hometheaterhifi.com/volume_1_1/v1n1spk.html

http://www.realtraps.com/test-cd.htm

http://www.soundandvisionmag.com/idealbb/view.asp?topicID=37023

http://www.clubknowledge.com/Car_Audio_FAQ/?t29

http://diyaudiocorner.tripod.com/formula.htm

http://www.linearteam.dk/default.aspx?pageid=winisdpro

http://www.crownaudio.com/apps_htm/designtools/elect-pwr-req.htm

http://www.avsforum.com/avs-vb/printthread.php?t=759083&p=9024043

http://www.users.bigpond.com/bcolliso/freesoft.htm

http://www.mhsoft.nl/conv1.htm

http://www.apicsllc.com/apics/Misc/filter2.html#fourth

http://www.users.bigpond.com/bcolliso/driver-conversions.htm

http://www.users.bigpond.com/bcolliso/flare-it.htm

http://www.subwoofertools.com/forum/ported-box.asp

http://www.mkprofessional.com/freq.htm

http://www.gomath.com/geometrycal.html

http://www.falstad.com/mathphysics.html

http://www.opamplabs.com/cfl.htm

http://www.opamplabs.com/rfc.htm

http://www.subwoofertools.com/forum/portlength.htm

http://www./help2/Articles.cfm?id=31

http://www.1728.com/pythgorn.htm

http://www.hometheatershack.com/roomeq/

http://www.subwoofertools.com/forum/sag.htm

http://www.users.bigpond.com/bcolliso/sonosub.htm

http://www.mhsoft.nl/spk_calc.asp

http://www.mhsoft.nl/spk_calc.asp#top

http://www.cvs1.uklinux.net/calculators/

http://www.linearteam.dk/default.aspx?pageid=unitconverter

http://ourworld.compuserve.com/homepages/Bill_Bowden/r2.htm

http://www.danmarx.org/audioinnovation/theories.html

http://www.audioholics.com/techtips/setup/loudspeakers/subwooferplacementguide.php

http://www.ht-audio.com/audio.htm#Driver%20Manufacturers

 

Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.