A little mis-calculating, need yalls opinions ASAP.

[Spud2388 10+ year member]

Ok, I finally have finished putting my box together, and its volume is 5.898 cuft after sub displacement. I put that figure into the forluma and to reach my goal of 32 hz, I got 2 6" round ports at 20.88" long. After port displacement, the final volume is 5.218 cuft. Is that too much for 2 12" Type R's ('06 versions)? It's not a SPL box my any means, I'm just afraid its going to be real boomy and not sound as good as a 4 cuft box would, which is what I was aiming at but somehow my calculations got messed up //content.invisioncic.com/y282845/emoticons/blush.gif.99bc659ee2012b7d826165e26fb5eebe.gif . What's yalls opinions? Should I add some wood in the inside to decrease the volume or leave it alone? They're going to be powered off of a nine.1 if ED ever gets some in. I still have to put braces in it, so that should knock the volume down a little, but not 1 cuft.//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

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[jd_man_90 10+ year member]

just wondering, why don't you just redo your calculations to make a smaller box?

 

[jd_man_90 10+ year member]

My bad just re read it and realized you allready built it

 

[wilzyx 5,000+ posts]

no its fine 2 12"s

 

[xluben 10+ year member]

Correct me if I'm wrong, but I think you need to use the box volume with port displacement removed when calculating tuning frequency.

With 2, 6" ports, 20.88" long and a 5.218 cu.ft. box Win ISD is telling me 34Hz tuning frequency.

 

[Fast1one 10+ year member]

Correct me if I'm wrong, but I think you need to use the box volume with port displacement removed when calculating tuning frequency.
With 2, 6" ports, 20.88" long and a 5.218 cu.ft. box Win ISD is telling me 34Hz tuning frequency.

He already factored in ports....re-read the thread....
SHould be fine for two type Rs. Put them in and see how they sound //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[xluben 10+ year member]

He already factored in ports....re-read the thread....
SHould be fine for two type Rs. Put them in and see how they sound //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

My understanding is he took the net internal volume and used that to calculate the port length, and then subtracted the port volume. That also corresponds to my quick type-in's with WinISD. But I could be wrong or have misunderstood, either way it doesn't really answer his question.

 

[Spud2388 10+ year member]

Correct me if I'm wrong, but I think you need to use the box volume with port displacement removed when calculating tuning frequency.
With 2, 6" ports, 20.88" long and a 5.218 cu.ft. box Win ISD is telling me 34Hz tuning frequency.

I thought about that too, but got to thinking and couldn't figure out how. You'd be trying to find the port length using the volume of the port, which the port length is needed to find, so you'd get nowhere. Kinda confused. I think I found everything right, didn't I?

 

[xluben 10+ year member]

I think your problem was building a box without first calculating the port lengths!

If you did it the other way around you could just use WinISD to do it.

If you have the actual equations for calculating tuning frequency I would think that through some kind of substitution you could solve for the variable in question.

 

[Spud2388 10+ year member]

I think your problem was building a box without first calculating the port lengths!
If you did it the other way around you could just use WinISD to do it.

If you have the actual equations for calculating tuning frequency I would think that through some kind of substitution you could solve for the variable in question.

I agree, but you learn form your mistakes:crying: . So, with a box that is 5.898 cu ft after sub displacement, and I plan on using 2 6" round ports, what length would I need to make them to get the 32hz I'm looking for? 20.88" as I said before? What would be the final volume and tuning the subs would see after port and sub displacement?

 

[xluben 10+ year member]

With the ports you're thinking of it should be tuned to ~34Hz according to WinISD.

 

[Spud2388 10+ year member]

so what length ports do I need to make to make it 32 hz?

2 6" round fyi

 

[Spud2388 10+ year member]

Ok, I guess I need to go back to the origional question. Do yall think I should lower the volume to around 5 cu ft after sub displacemnet and make my port off of that, which in turn should give me a final volume of around 4 cu ft? The reason I ask is because I have mostly read people recomending 2 cu ft per sub tuned to around 28-33 hz, so with 2 subs, 4 cu ft would be ideal. I really dont want boomy bass, i want something what will appeal to all styles of music.

And in a way, I'm kind of glad I made the box bigger than what I wanted, cause you can always make a box's volume smaller by adding things on the inside, but its a little harder to make a box bigger, without starting over.

 

[Spud2388 10+ year member]

bump, bump, bump

 

[Spud2388 10+ year member]

ur killing me guys!!!//content.invisioncic.com/y282845/emoticons/crying.gif.ec0ebefe590df0251476573bc49e46d8.gif//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif i'm ready for BASS!!!!!