Hi, I am playing with the specs of this powerful little driver, but I think something is wrong with these numbers. Look, this is the recommended ported enclosure for 39hz:
Ported Volume : 1.00 ft^3
Port Area : 13 sq.in.
Port Length : 19"
I think something is not right with these number, because in the calculator that I use, I am getting around 26hz with 1 cubic foot and a port that should be 13 sq in and and extreme length of 45.4 inches, which obviously I think is totally wrong, which put me to think that some of the values may be wrong. Any help? I want a total space enough to throw it down to 30hz, which considering the amazing specs of the sub, I can get that ending with a enclosure still smaller than 2 cubic foot. Please any help? thanks so much.
Ported Volume : 1.00 ft^3
Port Area : 13 sq.in.
Port Length : 19"
I think something is not right with these number, because in the calculator that I use, I am getting around 26hz with 1 cubic foot and a port that should be 13 sq in and and extreme length of 45.4 inches, which obviously I think is totally wrong, which put me to think that some of the values may be wrong. Any help? I want a total space enough to throw it down to 30hz, which considering the amazing specs of the sub, I can get that ending with a enclosure still smaller than 2 cubic foot. Please any help? thanks so much.
https://www.skaraudio.com/products/vvx-8v3?variant=18135438593
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It's valid for a small, tightly sealed car 'enclosure', which has a massive amount of 'room gain', so always ignore any car audio driver's recommended cab alignments for home, etc., systems.
Because of its high power handling [if accurate], high Qts, you can safely tune it at least down to 32 Hz and even lower if there's a decent amount of room gain, though even with a large BR cab it will still need a huge vent, so better to load it with a TL or TH.
GM
Because of its high power handling [if accurate], high Qts, you can safely tune it at least down to 32 Hz and even lower if there's a decent amount of room gain, though even with a large BR cab it will still need a huge vent, so better to load it with a TL or TH.
GM
Thanks both GM, bjorno. I am still confused about the numbers that I got from my enclosure calculator (30 liters, 26.5hz, with a port 4"x 42inches.). Are these the real numbers ignoring the fact of the cab gain? because as you can see, I can get 32hz even with a smaller enclosure (of course excluding displacements) (16.5 liter, 32hz, port: 4"x53.4") Do these numbers make sense?
Btw bjorno, I was not able to understand that sheet, too much science.
Btw bjorno, I was not able to understand that sheet, too much science.
You're welcome!
Hornresp says 26 Hz, so plenty close enough.
FWIW, the BR I did was 16.8 L, 4" x 47.25" vent/31 Hz to conclude that it's best to morph the small cab, large/long vent into some form of TL to maximize acoustic gain over the BR [several dBs based on his sim], which will have a lot of vent pipe harmonics that will need stuffing.
Another option would be to replace the vent with a 12" PR, but the tapered TL or even a simple straight pipe vented [ML] TL at the same 46 L is a better performer overall IME.
GM
Hornresp says 26 Hz, so plenty close enough.
FWIW, the BR I did was 16.8 L, 4" x 47.25" vent/31 Hz to conclude that it's best to morph the small cab, large/long vent into some form of TL to maximize acoustic gain over the BR [several dBs based on his sim], which will have a lot of vent pipe harmonics that will need stuffing.
Another option would be to replace the vent with a 12" PR, but the tapered TL or even a simple straight pipe vented [ML] TL at the same 46 L is a better performer overall IME.
GM
I think that I simply will bend the port in few parts, in order to keep a compact form factor. As long as I keep rounded corners, I think I should have no problem with that? and note that the port is not adapted to a bigger size taking all the width of the enclosure, so this port will have 2 dedicated walls, one for each side, and ending with something like this once mounted in the front baffle. (pic 2, that's a draw I did for another sub.) It should keep compact factor, keeping port area at the minimum (just a little more than enough). I can also try to throw it around the 3 walls "sides and back board", but I like the idea of the picture, so it end as an one piece dedicated module. Hope to leave a better draw later, I did that quickly just to show the concept without measuring anything.
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What a such snake this port hehe, still working on the enclosure, so far I think I am almost done designing the port according to my critic. After founding that port area was actually pretty big, I decided to adapt it, so it actually fit between the main walls.
I think that I kept the port displacement low for a such long section it has (47"). It takes only half cubic feet of displacement for a tune of 26hz, driver chamber needs around 32.55 liter including driver displacement, so the total finish space, including some bracing, will take around 1.7 cubic feet, which I think is wonderful for such marvelous deep tune. Hope to get this done soon, any critic with the port or advice, please let me know, thanks.
I think that I kept the port displacement low for a such long section it has (47"). It takes only half cubic feet of displacement for a tune of 26hz, driver chamber needs around 32.55 liter including driver displacement, so the total finish space, including some bracing, will take around 1.7 cubic feet, which I think is wonderful for such marvelous deep tune. Hope to get this done soon, any critic with the port or advice, please let me know, thanks.
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Out of curiosity, i simmed it with WinISD in a vented box & was also surprised how low it could go in a Very small box, & without exceeding Xmax ! In fact larger boxes looked worse ! Not often that happens
bjorno's TL design looks nice too
Yeah, this 8" sub seems to be amazing, I remember when I thought that the ts values were incorrect. I am trying to design an enclosure that seat on these two big facts.
1 - Smaller possible form size factor
2 - louder and powerful at an impressive level (impressive because of its sound and the surprise of someone getting impressive after discovering that the huge sound is actually not coming from a very huge enclosure with couples of speakers on it, but just a single 8" subwoofer mounted in a small enclosure that does not seems to be proportional to the sound heard. Big technology is here and we have things that do miracles, for example the "little" speaker of this thread, that thing performs so amazing, and surely that's rms power handling, is true, I have seen videos where some techs do some tests, in some cases they go far beyond and the unit still seems able to easily hold it, for example this speaker is 400w rsm, in some tests, this speaker reached a 600w load with no problem, many of you already know that these things exist, but there should be some people that don't know that is possible getting an impressive sound level in a small size form factor, which still is cheap, and won't take you too much of room.
I don't know if sacrifice some hz, and gain in less weight and space in advantage, for example maybe 32hz are more than enough, if you instead get that, you still have amazing sound, and because it's more compact, you can carry it out with no much problem and it won't take too much of the room as well. for brazing across the walls, I would rather use some threaded rods and bolts, so it does not displace too much, which is the case using 2x2 sticks or hardwood dowels, with a 5/16 threaded rod, you have an unbeatable way to brace with taking minimum possible space.
There are some other 8" models who handles more rms power around, a thousand or even more, for its price, $90, its an unbeatable option, in some cases, founding that it's more convenient one of these instead of those 15" subwoofers that just take half of what the 8" can.
Hey guys,
Some of the Skar Audio drivers model extraordinarily well for their price (but i am reluctant to get too excited YET because that is based on simulations using the published T/S parameters, i am curious to see the actual measured parameters on the Skar drivers) .....
Skar does have the published parameters conveniently listed at their website ..
Some of these car audio drivers seem to be good decibel per dollar values (for subbass) ... I wrote about it just the other day over here http://www.diyaudio.com/forums/subw...d-series-tuned-6th-order-200.html#post4953276
and i have also discussed it over at the facebook group in multiple posts during the last several months as well (feel free to join, we are working on building up the group)
https://www.facebook.com/groups/bassaz/
Some of the Skar Audio drivers model extraordinarily well for their price (but i am reluctant to get too excited YET because that is based on simulations using the published T/S parameters, i am curious to see the actual measured parameters on the Skar drivers) .....
Skar does have the published parameters conveniently listed at their website ..
Some of these car audio drivers seem to be good decibel per dollar values (for subbass) ... I wrote about it just the other day over here http://www.diyaudio.com/forums/subw...d-series-tuned-6th-order-200.html#post4953276
and i have also discussed it over at the facebook group in multiple posts during the last several months as well (feel free to join, we are working on building up the group)
https://www.facebook.com/groups/bassaz/
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Has anyone tried this? yesterday was thinking about proportions according to the compact form factor, and decided to give 12x24" to the sides, so there you can screw a whole 12x24" standard size of plexiglass/polycarbonate sheet, letting see the interior to see the woofer and port labyrinth, it should look nice with some RGB led straps mounted back along the other side controlled by those cheap led controller that are sound activated.I think that a 1/2" thick plexiglass window is more than enough, only weak point will be the woofer chamber area, but there we can put a cross brace touching up, down and sides, I think that it would be more than enough for bracing such small enclosure. I will need to threat all the contact areas where plexiglass seats, and insert a dowel where every screw of plexiglass will land, mdf is not screw friendly. Then I thought I can use a 12x24 thin foam sheet instead, and draw and cut the lines, then gluing it as a whole piece, so the chance of leaking is vanished once everything properly mounted.
What do you think it would be better? the foam sheet or to apply silicon gasket? I think that the foam sheet is more convenient, avoiding the irregularities we can get while manually applying the silicon gasket.
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