The 4th order thread

[RangerDangerV2 5,000+ posts]

I'm sorry //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif
So those are sa-12's you are running? What's the specs of the box now?

yes, sa12s, rear chamber is 2 cubes. thats all im giving out lol

 

[RangerDangerV2 5,000+ posts]

heres the innards though lol

 

[Buck 5,000+ posts]

Yes, that's what I've used on them as well.

 

[RangerDangerV2 5,000+ posts]

Yes, that's what I've used on them as well.

id go smaller, but the tahoe peaks so low, theres not point to it. and if one were to go smaller, the woofers would be getting beat on fur sure... I doubt the surrounds would hold up lol. but 1-1.2 is optimal.

 

[Buck 5,000+ posts]

There is a certain trust or faith you have to have with people when it comes to mechanical failure. I say that because you have to assume people will test the limits of that box, so it's fair to give a little over-excursion room, as in more cone control. So I think long and hard about the size of my chambers.

If you know what I mean //content.invisioncic.com/y282845/emoticons/naughty.gif.94359f346c0f1259df8038d60b41863e.gif

 

[RangerDangerV2 5,000+ posts]

There is a certain trust or faith you have to have with people when it comes to mechanical failure. I say that because you have to assume people will test the limits of that box, so it's fair to give a little over-excursion room, as in more cone control. So I think long and hard about the size of my chambers.
If you know what I mean //content.invisioncic.com/y282845/emoticons/naughty.gif.94359f346c0f1259df8038d60b41863e.gif

******, the way I like it.

 

[Buck 5,000+ posts]

One guy was running almost 8 cubes with 4 12's to achieve the Fc he wanted. I understand that, but for most I wouldn't feel comfortable doing that even if the numbers did match up. If it was my box, wouldn't be a second thought about it because I know how to spot problems. That's why bandpasses are fun. Trying to get the best performance while trying not to mechanically destroy your woofer. Maybe that's the name of the game.

 

[RangerDangerV2 5,000+ posts]

One guy was running almost 8 cubes with 4 12's to achieve the Fc he wanted. I understand that, but for most I wouldn't feel comfortable doing that even if the numbers did match up. If it was my box, wouldn't be a second thought about it because I know how to spot problems. That's why bandpasses are fun. Trying to get the best performance while trying not to mechanically destroy your woofer. Maybe that's the name of the game.

one thing I learned, small rear chamber=more port larger rear=less port. Im as small as I want to go rear chamber wise, but I still only have like .25" of excursion, now, since I have a large ratio, the woofers arent pressurizing the enclosure as I wish they were, thats why im chopping the port down. That will give me a higher tuning, and more excursion at my peak.

 

[Buck 5,000+ posts]

one thing I learned, small rear chamber=more port larger rear=less port. Im as small as I want to go rear chamber wise, but I still only have like .25" of excursion, now, since I have a large ratio, the woofers arent pressurizing the enclosure as I wish they were, thats why im chopping the port down. That will give me a higher tuning, and more excursion at my peak.

smaller chamber = higher Fc. The higher you tune, the higher your vent mach is given same power and port area. So it makes sense why your port velocity would increase when you shrink the rear chamber based on that logic.

 

[noble brown]

ok so vas:46/Vb:2.2=20.9 + 1 = 21.9, sqrt = 4.6 x Fs:27 = 126, which should be my Fc of my rear chamber right? it seems really high. am i messing something up?

 

[RangerDangerV2 5,000+ posts]

ok so vas:46/Vb:2.2=20.9 + 1 = 21.9, sqrt = 4.6 x Fs:27 = 126, which should be my Fc of my rear chamber right? it seems really high. am i messing something up?

vb needs to be in liters. you have to convert it from cu ft.

 

[noble brown]

specs claim the 46 is in liters. a missprint?

 

[RangerDangerV2 5,000+ posts]

specs claim the 46 is in liters. a missprint?

vas is in liters. you need your Vb to be in liters as well.

 

[noble brown]

wouldnt that give me an even larger number, 46 cuft is 1302 liters

 

---------- Post added at 11:21 PM ---------- Previous post was at 11:21 PM ----------

 

oh ok

 

---------- Post added at 11:22 PM ---------- Previous post was at 11:21 PM ----------

 

duh

 

[noble brown]

ok so Fs of rear is 35hz. i multiply this by my desired ratio... whats my next step