JBL monster build

[tangmonster]

the one that is straight down to 30hz

[undefined.za]

the one that is straight down to 30hz

Ah, thanks!

Wasn't sure if the graph had the EQ applied. 10db is a lot of power and excursion!

[tangmonster]

if you have 2 woofer it halves the power and boost needed for each driver.

Also at 30 hz is only 5db eq. Normally material at 20hz is lower in volume anyway.

So each woofer will see 2.5db boost at 30hz and 5db boost at 20hz

[BiZKiT]

sealed needs eq!!! else it will not like it much!

Look at the below simulation. the yellow are two of them sealed with 200L box. needs around 10db EQ at 20hz then you are solid down to 20hz.

The green is 225L vented with one 100mm wide 124.2mm long vent. (happy down to 30hz)

Tang is that 225 vented for both or each sub? Want to try build a big box...

[tangmonster]

that is 2 woofer in 225L with one port. You can get it a bit lower by playing with the tuning frequency and box size and ports.

please double check my data inputs. Even better you got a option from jimgore to measure the actual drivers!! Which is better than just taking a google search specs of the drivers.

use winisd en do the experiment yourself!!

[Timber_MG]

Also check airspeed at rated power and dimension the port to avoid chuffing.

[Steerpike]

When messing with WinISD, I find that changing Ql and Qa (leakage and absorbtion) for the box can make big differences, yet I can find no quantitative techinical info that tells how Ql and Qa relate to practical issues. How you actually MAKE your box have a specific Qa or Ql seems to be a bit random, or indeed knowing what these parameters are for a particular built box.

[BiZKiT]

jeeez guys i dont get this stuff...give me wood and i can make anything but this

please help me out...was thinking of building a box about 800-1000mm high and 450x480mm and port i have is 80mm but we can play with the lenght?

Going to use 20mm mdf with alot if bracing so will never flex...EVER!!! and then going to cover with some 18mm veneer board and solid pieces(cherry) then the foot i will have a 500x500m granite slab!

[tangmonster]

please help me out...was thinking of building a box about 800-1000mm high and 450x480mm and port i have is 80mm but we can play with the lenght?

Then rather change this thread name then to: "taking 2 woofers and bliksem them into a box and hoping for the best"

[JimGore]

+1.

We are trying to apply tough love to you here.  It means you need to go through some suffering, but the flip side is that you will emerge on the other side actually knowing what you are working with.

Anyone can build a wooden box, but not everyone can make it sound good.

Tell you what - if you bring those drivers for me to measure, I will give you a 20 minute overview of how WinISD works and what to look out for.

Ian.

[BiZKiT]

Then rather change this thread name then to: "taking 2 woofers and bliksem them into a box and hoping for the best"

tough love hey   so if i stick to 110l each i should be fine? that is what i will have internaly if i do it the way i just gave it...then just tune with port size?

[BiZKiT]

+1.

We are trying to apply tough love to you here.  It means you need to go through some suffering, but the flip side is that you will emerge on the other side actually knowing what you are working with.

Anyone can build a wooden box, but not everyone can make it sound good.

Tell you what - if you bring those drivers for me to measure, I will give you a 20 minute overview of how WinISD works and what to look out for.

Ian.

guess you are right bud...yes i think i must take you up on this offer! want this one to be awsome

[Abu]

When you going bizkit?

Ian has offered his expertise to me too so maybe we can do a 2 for 1 special and visit him at the same time 

[BiZKiT]

Guess it will have to be a saterday morning...Ian are you going on leave?

[BiZKiT]

heeeehaaaaa....i got it!!!!!!! thanx for the support and pressure guys 

how do i post my findings!