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kfx450r
02-20-2009, 10:07 PM
Well, had my (1) type R tuned to about 32hz in my big box, hit the lows great. Well I threw in another type R in the box today and it doesnt seem to hit the lows as good anymore but hits the highs a little better. All the port calculators ive seen dont say anything about number of subs so wut gives.

squeak9798
02-20-2009, 10:18 PM
When you increase the number of subs, you need to increase the volume of the enclosure accordingly.

kfx450r
02-20-2009, 10:21 PM
When you increase the number of subs, you need to increase the volume of the enclosure accordingly.

The box is a 7cu ft ported box..I really dont thin i need mre than that for 2x 12" type rs

boomzilla
02-20-2009, 10:24 PM
7 Cubes for two 12's?

boomzilla
02-20-2009, 10:27 PM
Anyways, when you add a sub to an enclosure made for 1 woofer, and add another woofer, you're displacing more air in the box, making the tuning higher. When you change airspace, you need to change tuning also, which can really only work with aeropoorts, or if you built a removable slot port.

kfx450r
02-20-2009, 10:27 PM
7 Cubes for two 12's?


Ya dont ask. I got crazy..the single type r slammed in it..i throw the 2nd in and the tuning just totally changes. I just ordered a third for it also..so itll be a good box.

How do I change the port to tune it lower then.

boomzilla
02-20-2009, 10:31 PM
You can't. Once you build a standard slot port, it's done. Unless you're really **** good with woodworking, then maybe you can get away with adding/ taking away port length. You'll need to build a new box. A box about 5 cubes would probably be better, tuned to anywhere from 30-34hz would be good IMO.

kfx450r
02-20-2009, 10:33 PM
You can't. Once you build a standard slot port, it's done. Unless you're really **** good with woodworking, then maybe you can get away with adding/ taking away port length. You'll need to build a new box. A box about 5 cubes would probably be better, tuned to anywhere from 30-34hz would be good IMO.

Its a simple round port..I can change it very easily..

squeak9798
02-20-2009, 10:38 PM
Anyways, when you add a sub to an enclosure made for 1 woofer, and add another woofer, you're displacing more air in the box, making the tuning higher. When you change airspace, you need to change tuning also, which can really only work with aeropoorts, or if you built a removable slot port.

A 1% change in enclosure volume won't affect the response or tuning nearly as much (or audibly at all, really) as reducing the effective volume per sub in half.

squeak9798
02-20-2009, 10:40 PM
The box is a 7cu ft ported box..I really dont thin i need mre than that for 2x 12" type rs

If you want to maintain the same response characteristics you need to.


I'm not saying that you need a 14cuft enclosure for 2 12" Type R's.

But don't toss a 2nd sub in an enclosure and expect the response characteristics to remain unchanged.

kfx450r
02-20-2009, 10:41 PM
A 1% change in enclosure volume won't affect the response or tuning nearly as much as reducing the effective volume per sub in half.


Hm, I really only like subs for low bass around 30-32...but i like it to get real deep and loud..do u think i shuld make a smaller box?..also..1 type r is a old version the other is a new.and the other one i ordered is a new version..so i may kep this box for when i get the 3rd one ad see how it sounds. Also..longer round port = lower frequency..so I think i will add .1-2" and see how it sounds.

kfx450r
02-21-2009, 12:17 AM
Alright used RE's box calculator thing for a box for my 3x type Rs and anyone think this would be a good box. in a ext cab midsized truck firing all 3 toward front. It says a 50x22x15, counting in port and all 3 sub volumes, 6.6cu/ft tuned to about high 29/low 30hz. Im going for deep ear rattling bass, but also want it to be nice and clean. Gives each sub about 2.2cuft. Slot Ported

Or I can use every space i have an build a 9.2cu ft ported box ported to the same hz but giving each sub about 3 cu/ft each

Or i can make it a little easier to build and get 8.5 out of it and have 2.7 cu/ft for each sub..

This is all with the possibility of adding a 4th down the road. So if I built one that was 50x27x16..counting sub displacements..i would get 8.5cu/ft which gives 3x subs 2.8cu/ft eac and 4x 2cu/ft each..still more or equal to spec. Goofy lookin box tho, all tuned to about 30hz

Random1010
02-21-2009, 04:33 PM
how big is the port?

kfx450r
02-21-2009, 05:12 PM
how big is the port?


I always left it about 4-5" wide..and it filled in the rest which changed with every box..i just modified the length to get high 29-low 30hz


Oh if u mean on my current box..its a roung port i forget was like around 2 inches at 4" diameter..tuned to either 32 or 34 i forget.

sikcavy
02-21-2009, 08:39 PM
u have only 1 4" port for two 12's? good luck with that lol

kush-divinity
02-22-2009, 10:40 AM
I always left it about 4-5" wide..and it filled in the rest which changed with every box..i just modified the length to get high 29-low 30hz


Oh if u mean on my current box..its a roung port i forget was like around 2 inches at 4" diameter..tuned to either 32 or 34 i forget.


Although this was hard to read and comprehend, am I reading right, you have a 4" port 2 inches long?

Hmmm, interesting concept.

Rashaddd
02-22-2009, 11:10 AM
oh boy..

badvlvo
02-22-2009, 05:44 PM
I'm a noob to frequency tuning but I understand the failure here.

kfx450r
02-23-2009, 01:00 AM
Thanks for the absolutly pointless posts.

The port is a pvc 4" diameter about 2" deep into the box.

kfx450r
02-23-2009, 01:39 AM
If someone could help me with this box itd be appreciated..instead of pointless criticism posts. For now the box will be for 2x new style type Rs..ported..I made a design in re's calculator.. width50xheight18xdepth15 wood thickness .75 square port height 16.5 port width 4", length 1 10.25, length 2 16", total port lngth 33". square port area is 66, box volume is 4.98 before sub displacements, tuning frequency is 29.98. I was aiming for 30hz but i guess with the subs it raises it? IS there anything wrong with this box.

Xprime4
02-24-2009, 09:47 PM
Thanks for the absolutly pointless posts.

The port is a pvc 4" diameter about 2" deep into the box.

:rolleyes: that's not a port, that's an hole

Xprime4
02-24-2009, 09:50 PM
by the way do you got pics? i'll sign you up in a failure contest