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View Full Version : Enclosure size too big for today's speaker requirements



Poorha
08-25-2011, 07:56 PM
:confused:
I have an ported 2.3 cubic foot enclosure, I ran an older 12" JL 12W4-4, and this was the recommended size for a ported box design for this speaker. I recently shredded the speaker's surrounding rubber and I'm the market for a new speaker, but non of the speakers that I research require such a big box. Can i run these speakers for example the Alpine type R, which only requires up to 2 cubic feet of air space. If not how could reduce the volume of my box without actually building a new box, Way back in the day, I was told to add foam material to inside of a box, but I not sure if this effectively adds or reduces the box volume. Thanks for reading and I will take any advice that you have to offer.

The_Grimy_One
08-25-2011, 07:58 PM
You should be just fine with most 12s (the Type R will before well in it)... The box sizes havent changed much...

As for making it smaller, add some bracing to the inside. Fill doesnt change the volume much, but is used to make the sub think the box is bigger than it is.

Poorha
08-26-2011, 09:25 AM
Thanks for time.

subzero
08-26-2011, 09:42 AM
:confused:
I have an ported 2.3 cubic foot enclosure, I ran an older 12" JL 12W4-4, and this was the recommended size for a ported box design for this speaker. I recently shredded the speaker's surrounding rubber and I'm the market for a new speaker, but non of the speakers that I research require such a big box. Can i run these speakers for example the Alpine type R, which only requires up to 2 cubic feet of air space. If not how could reduce the volume of my box without actually building a new box, Way back in the day, I was told to add foam material to inside of a box, but I not sure if this effectively adds or reduces the box volume. Thanks for reading and I will take any advice that you have to offer.

do you have an idea of what sub you are going to replace it with?

pro-rabbit
08-26-2011, 10:08 AM
Actual specs of your current enclosure would help us determine the size/tuning and it may work for.

Jroo
08-30-2011, 03:43 PM
I used to run the old solobarics and started seeing these smaller box size for the newer woofers. What I found out by looking at the custom designs not the manufacture sizes is the boxes are usually way bigger. To be honest, the box sizes have changed that much. Find a woofer that like the tuning your box has and you should be good.

Poorha
08-31-2011, 10:54 AM
Alpine Type R => SWR-1243D

Poorha
08-31-2011, 10:55 AM
I'm also currently running a 4" port at 13.5" long.

pro-rabbit
08-31-2011, 11:09 AM
I'm also currently running a 4" port at 13.5" long.

With out knowing the actual size ( h x w x d ) and what wood was used (1/2" or 3/4" or what ever), we can not determine what the actual air space or tuning is. I would be glad to help, but can not do so with out that info...

wickedwitt
08-31-2011, 11:12 AM
There is no such thing as an enclosure that's too big:up2somet:

Poorha
08-31-2011, 02:23 PM
It's 3/4" plywood, and I now have the box down to 1.9 cubic foot from 2.3 cubic feet, I ended up making a couple of smaller boxes and I glued them into the existing enclosure to take up some air space, and my port size is 4" in diameter and 13.5" long.

pro-rabbit
08-31-2011, 02:35 PM
I hate to say it, but that does not even come close to answering what I asked for lol.

Now you would need to give us the height, width, and depth.

Then the sizes of the enclosures you build to put in side the enclosure.

Like I said, I would be glad to help, but you would need to give me/us the info we asked for us to help. Other wise not much we can do or offer.

budahbuddy803
08-31-2011, 03:08 PM
2 liter bottles will consume airspace pretty easily

Poorha
08-31-2011, 03:13 PM
Its 3/4" MDF, the dimensions provided are all outside dimensions.
Main box 14.75 H x 19.75 W x 19.75 D
Inner Box#1 = 6.75 H x 5 W x 17 D
Inner Box#2 = 5 H x 5 W x 10 D

I'm trying to achieve a good tight heavy metal double bass sound, and currently I feel that transient time is a little lagging, the single bass drum sound is chest pounding, but the double bass sound is lacking some oomf. I also listen to hip/hop and I would like to keep some boom. Thanks for your efforts.

pro-rabbit
08-31-2011, 03:17 PM
Do you have any bracing or anything? My numbers are not coming close to matching yours right now

Poorha
08-31-2011, 03:42 PM
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
08-31-2011, 03:45 PM
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
08-31-2011, 03:50 PM
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
08-31-2011, 03:53 PM
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
08-31-2011, 04:05 PM
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
08-31-2011, 04:06 PM
Yes, I added filler boxes to decrease the internal box volume. thanks

disturbed471985
08-31-2011, 04:10 PM
got pics of said box?

pro-rabbit
08-31-2011, 04:11 PM
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
08-31-2011, 04:14 PM
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
08-31-2011, 04:15 PM
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!!!:D

Poorha
08-31-2011, 04:24 PM
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
08-31-2011, 04:28 PM
U know it is its not a rabbit built and approved box!!!:D

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
08-31-2011, 04:30 PM
cool thanks again

pro-rabbit
08-31-2011, 04:33 PM
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...