10" TC OEM with 104sq in of port

[Rashaddd 5,000+ posts]

Follow-up of this thread: http://www.caraudio.com/forum/showthread.php?t=368391

Gave the same box 104 sq in of port now. Calculated tuning is in the high 30's, the amount of leakage dropped it to about 33hz (lots of leaking especially around the port hole, because I just quickly freehanded it with a router from the original 8" hole to the new 11.5" hole

so:

single 10, getting 800 watts rated power

3 cubes net before sub disp

104 sq in of port @ 33hz tune/test tone (more than double the 45sq in of cone area)

enjoy:

http://www.youtube.com/watch?v=gyOiiR-R0Rw&feature=channel_page

Click to read more...

 

[Rashaddd 5,000+ posts]

vid is working now //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[dman4486 5,000+ posts]

vid is working now //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

lies

edit: there it is....same as the other thread

 

[Rashaddd 5,000+ posts]

lies

edit: there it is....same as the other thread

shouldn't be, idk youtube is bein wierd right now....took 3 tries and like an hour to upload a 20mb 2.5min vid...//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Edit: OK Vid is officially fixed now, or at least its working properly on my computer...

 

[bhsdriller 10+ year member]

cool

 

[Rashaddd 5,000+ posts]

fvck youtube...i need to start using photobucket

anyway...point is...

people seem to have the idea that the amount of air moving through a port is directly proportionate to the air displacement of the sub (based on cone area x excursion). If this is true, shouldn't port excursion = less than half of sub excursion here? Hmmm..............

 

[audioholic 5,000+ posts]

fvck youtube...i need to start using photobucket
anyway...point is...

people seem to have the idea that the amount of air moving through a port is directly proportionate to the air displacement of the sub (based on cone area x excursion). If this is true, shouldn't port excursion = less than half of sub excursion here? Hmmm..............

What exactly do you mean by 'port excursion'? There is no such thing. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
Im really not sure what we are to conclude from your video. Yes you have more port area than cone area, and yes it still makes noise... I dont think anyone said otherwise in the previous thread. What WAS debated was whether or not cone displacement is directly proportional to the amount of air moved, with a little argument over port velocity thrown in to confuse things. I dont see any evidence that proves for, or against, any of those issues. Furthermore, since the sub is ultimately the device creating the air displacement, I dont see how anyone could argue air displaced through the tube is not proportional to cone movement.

Thanks for the vid tho, interesting seeing a setup with so much port area. Now try an experiment, let us know just how quickly it unloads below tuning. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif//content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

 

[dman4486 5,000+ posts]

What exactly do you mean by 'port excursion'? There is no such thing. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
Im really not sure what we are to conclude from your video. Yes you have more port area than cone area, and yes it still makes noise... I dont think anyone said otherwise in the previous thread. What WAS debated was whether or not cone displacement is directly proportional to the amount of air moved, with a little argument over port velocity thrown in to confuse things. I dont see any evidence that proves for, or against, any of those issues. Furthermore, since the sub is ultimately the device creating the air displacement, I dont see how anyone could argue air displaced through the tube is not proportional to cone movement.

Thanks for the vid tho, interesting seeing a setup with so much port area. Now try an experiment, let us know just how quickly it unloads below tuning. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif//content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

time will not measure it:laugh:

 

[Rashaddd 5,000+ posts]

What exactly do you mean by 'port excursion'? There is no such thing. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
Im really not sure what we are to conclude from your video. Yes you have more port area than cone area, and yes it still makes noise... I dont think anyone said otherwise in the previous thread. What WAS debated was whether or not cone displacement is directly proportional to the amount of air moved, with a little argument over port velocity thrown in to confuse things. I dont see any evidence that proves for, or again, any of those issues.

Thanks for the vid tho, interesting seeing a setup with so much port area. Now try an experiment, let us know just how quickly it unloads below tuning. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif//content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

Port excursion would be referring to the distance air moves in the port, similar to the distance the cone moves being cone excursion

I think its pretty clear this doesn't just "still make noise", based on yours and a few others statements, and the general understanding of port area vs cone area that seems to be thrown around here, we should've expected port velocity/movement to be pretty minimal, shouldn't we? How do you explain the ridiculously high port velocity in comparison to the relatively small amount of cone excursion, and the ratio of port area to cone area?

Tbh it looks just silly seeing the port that big next to the tiny little sub, and except for my understanding of how a port works at tuning frequency, I would have thought there's no way that port is going to be doing a **** thing except acting like a fat hole in the box

and yes it unloads below tuning like no other...that was assumed and I've always said that would happen, obviously, however, above tuning, it plays very solidly and loud, just with less air movement in the port. It can play down to about 29-30hz before bottoming out off this much power

 

[Rashaddd 5,000+ posts]

If you can't tell...overall amount of pressure being created and air being moved FAR exceeds anything I've ever seen out of a single 10 on 800 watts...I'm confident this would meter very impressively if the box was designed to actually fit in a car...

audioholic, one of your statements actually is what made me realize wtf is going on here

when you said "air compresses, water doesn't"

 

[tommyk90 5,000+ posts]

I fail to see the purpose of this vid.

Yes, you have a lot of air movement going on without a lot of excursion, but that will hold true with any amount of port area you have.

The one thing you fail to mention is that power handling will be decreased because of such a large enclosure and an asston of port area. Sure, the sub is moving less, but the coil will be getting just as hot (if not hotter).

FYI, I'll put $10 on that thing not metering worth a damn.

 

[Rashaddd 5,000+ posts]

I fail to see the purpose of this vid.
Yes, you have a lot of air movement going on without a lot of excursion, but that will hold true with any amount of port area you have.

The one thing you fail to mention is that power handling will be decreased because of such a large enclosure and an asston of port area.

FYI, I'll put $10 on that thing not metering worth a damn.

Power handling is ~the same actually...except for below tuning where it steeply rolls off (like I said)

Above tuning yes it is decreased somewhat, but because of the fact that higher frequencies have less excursion anyway, its really just increasing power/excursion efficiency at those frequencies without any chance of bottoming out or reaching mechanical limits.

Eitherway this is up for discussion, and that is why I even shared it.

Edit: and once more...perhaps you know better, but I know the majority of the people here including audioholic would have guessed that this would bottom out with its thermal rating going to it, and/or port velocity would have been extremely low...its really the exact opposite.

 

[dman4486 5,000+ posts]

Power handling is ~the same actually...except for below tuning where it steeply rolls off (like I said)
Above tuning yes it is decreased somewhat, but because of the fact that higher frequencies have less excursion anyway, its really just increasing power/excursion efficiency at those frequencies without any chance of bottoming out or reaching mechanical limits.

Eitherway this is up for discussion, and that is why I even shared it.

Not a fact. excursion depends on tuning frequency.

in my enclosure, 38hz is extremely close to mech limits, and approaching 24hz is minimal excursion

 

[Rashaddd 5,000+ posts]

Not a fact. excursion depends on tuning frequency.
in my enclosure, 38hz is extremely close to mech limits, and approaching 24hz is minimal excursion

Regardless, if you tuned higher, you'd have even less excursion at tuning. Yes I know that excursion is reduced at tuning lol //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

This also further is part of the point that a big *** port will not turn into a big *** hole in your box. A port functions the exact opposite as a hole would. Rather than decreasing pressure, it increases it. (though its hard for me to believe that this would apply infinitely, so for now I can only assume that eventually you would get TOO big, and the sub wouldn't even be able to excite the air in the port enough to get it to behave like a port).

Next I'll see what it can do with a pair of these ports:wow:

 

[mobeious 10+ year member]

excursion is biased on the tunning of the port and Fs of the actual box and i dont know if i would say box size affects powering handing as it does to control the sub below/above tunning i guess u could say u could have more power to a sub below tunning in a box that is smaller then recomened from the back pressure on the cone do to the small area the sub is compressing