Enclosure size too big for today's speaker requirements

[Poorha 10+ year member]

Here is the actual internal dimensions of the main box = 12.5x18x18.25=4106.25/1728=2.38 ft^3, then I build the two smaller boxes and I glued them inside the box to occupy air space, so the outside dimensions are

10x5x5=250in^3/1728=.14 ft^3

6.75x17x5=573.8 in^3=.33ft^3

So, The main box minus the smaller boxes the net gross box volume is 2.38 - .14 - .33 = 1.91 ft^3, now the speaker displacement=.1ft^3 and the port = .07 ft^3, So the net box volume= 1.91 -.1-.07 = 1.74 ft^3

Please let me know if you have any questions. Thanks again for your time.

 

[disturbed471985 5,000+ posts]

whoa something does not add up.. U said in the OG post box was 2.3cf correct??? I assume thats before port and sub displacement? Any idea on the tuning?

 

[pro-rabbit 5,000+ posts]

Main box 14.75 H x 19.75 W x 19.75 D

If those are outer dims you listed then you have this for internal dims with 3/4" wood

13.25 x 18.25 x 18.25 which gives you 2.55ft^3

Inner Box#1 = 6.75 H x 5 W x 17 D

5.25 x 3.5 x 15.5 = .16ft^3

Inner Box#2 = 5 H x 5 W x 10 D

3.5 x 3.5 x 8.5 = 0.06ft^3

Port 4" x 13.5 = 0.1ft^3

So

2.55 - .16 = 2.39 - .06 = 2.33 - 0.1 = 2.23ft^3

This is with out sub displacement (which will more then likely take you down to around 2.1 or so)

 

[disturbed471985 5,000+ posts]

Main box 14.75 H x 19.75 W x 19.75 D
If those are outer dims you listed then you have this for internal dims with 3/4" wood

13.25 x 18.25 x 18.25 which gives you 2.55ft^3

Inner Box#1 = 6.75 H x 5 W x 17 D

5.25 x 3.5 x 15.5 = .16ft^3

Inner Box#2 = 5 H x 5 W x 10 D

3.5 x 3.5 x 8.5 = 0.06ft^3

Port 4" x 13.5 = 0.1ft^3

So

2.55 - .16 = 2.39 - .06 = 2.33 - 0.1 = 2.23ft^3

This is with out sub displacement (which will more then likely take you down to around 2.1 or so)

The master has spoken... That box is fine for the alpine.

 

[Poorha 10+ year member]

Why would you use the inside dimensions for the filler boxes, I used the outside dimensions of the filler blocks for the calculation since they are taking up space(or air volume) so the outside dimensions are the critical dimensions. So the 2.4 ft^3 box ( I actually get 2.4 ft^3 this calculation is based off of actual internal dimensions) minus 6.75x5x17=.33 ft^3 and minus 5x5x10=.14ft^3 = 2.4-.33-.14= 1.93 ft^3. This is gross and based on the your port volume displacement of .1 ft^3 and the speaker displacement of .1ft^3 the net volume is = 1.93-.1-.1=1.73 ft^3. Not sure how to calculate the tuning frequency of the box the Vas for the speaker is 1.5ft^3 and Fs=31 hz. What is the recommended tuning box frequency for heavy metal and some hip/hop type of music. Thanks

 

[Poorha 10+ year member]

Yes, I added filler boxes to decrease the internal box volume. thanks

 

[disturbed471985 5,000+ posts]

got pics of said box?

 

[pro-rabbit 5,000+ posts]

Ah, I didn't catch that I used the inside dims for the enclousre of the filler boxes. I'm on my phone so I'm doing math from there.

With that in mind...

2.55 - .1= 2.45-0.33=2.12-.14= 1.98ft^3

with out the sub displacement that tunes to around 32hz or so.

After sub will be around 34hz or so... and around 1.85ft3

should work fine

 

[pro-rabbit 5,000+ posts]

Why would you use the inside dimensions for the filler boxes, I used the outside dimensions of the filler blocks for the calculation since they are taking up space(or air volume) so the outside dimensions are the critical dimensions. So the 2.4 ft^3 box ( I actually get 2.4 ft^3 this calculation is based off of actual internal dimensions) minus 6.75x5x17=.33 ft^3 and minus 5x5x10=.14ft^3 = 2.4-.33-.14= 1.93 ft^3. This is gross and based on the your port volume displacement of .1 ft^3 and the speaker displacement of .1ft^3 the net volume is = 1.93-.1-.1=1.73 ft^3. Not sure how to calculate the tuning frequency of the box the Vas for the speaker is 1.5ft^3 and Fs=31 hz. What is the recommended tuning box frequency for heavy metal and some hip/hop type of music. Thanks

How do you get .1 less then I do on your enclosure volume? Is the wood that off on the inside or on the outside?

 

[disturbed471985 5,000+ posts]

How do you get .1 less then I do on your enclosure volume? Is the wood that off on the inside or on the outside?

U know it is its not a rabbit built and approved box!!!//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Poorha 10+ year member]

must be the way i built it, not quite sure. But thanks for your time. Is it possible to adjust the length of the port to get different box tunings.

 

[pro-rabbit 5,000+ posts]

U know it is its not a rabbit built and approved box!!!//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

lol

must be the way i built it, not quite sure. But thanks for your time. Is it possible to adjust the length of the port to get different box tunings.

If it is an actual precision port you can buy a new center section from parts express. There is not a good way to extend the port with out bulding a new one.

 

[Poorha 10+ year member]

cool thanks again

 

[pro-rabbit 5,000+ posts]

cool thanks again

No problem, sorry on the confusion. I'm trying to build/cut enclosures and post on the forum at the same time haha...