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View Full Version : MJ-18 questions about 3rd, 4th, -8th order BP boxes.



generalGOTCHA
05-21-2007, 07:32 PM
I like to create programs in c++ to do all the calculations for my boxes, but I am in serious need for knowledge to build something that keeps a nice flat responce, very very high DB output, and without a great deal of SQ sacrifice which has brought me to consider a multiple order band pass box of some sort.

Could anyone link me to resources for building one.
I dont mind the easy route either, but if I have to calculate it all myself, then thats fine too. I just want to know what I have to work with to achieve what I am wanting.

If someone could please just provide me with resources I would ve very Greatfull. As I am going to go from my pair of 10" Orion P series (134db's) at the DASH in my VAN !!! to a pair of 18's or a single 18 in hopes to prove my cousins and family wrong who dont know jack about the differences of drivers.

I argue all the times about box sizes, and I get into arguements about 10's hit lower notes than 12's and 15's wont hit as hard as 10's etcetera.. they think the size of the woofer will make it hit different notes.. I argue that a 15 will hit any same note a 10" sub can, and do it louder because of the cone area pushing more air pressure. So please assist in helping me show that knowledge ROCKS over " this hits better than that, and pyramid might be cheap but it bumps" kind of crap.

Ive already shown them a pair of 10's hitting 8db's harder then their 4 visonik 10's off my Orion HCCA 250 lol :) They just dont grasp that it says 250, but it can do 800WRMS.

SO now I am out to show that a larger sub can hit the same lows, mid and higher range subsonic frequencies and still move **** in your car doing it.

jeremiah
05-21-2007, 07:53 PM
(134db's) it that on the TL? O and we are mj-18 brother's now


http://i200.photobucket.com/albums/aa157/mj-18/051707_15001.jpg

mtlhead
05-21-2007, 07:56 PM
talk to 80INCHES about bandpass...he's definitely your man

jeremiah
05-21-2007, 08:13 PM
X2^^

jeremiah
05-21-2007, 08:17 PM
.......O and Thar's no 3rd order bandpass box right?

jeremiah
05-21-2007, 08:24 PM
O and if I war you I would just do a 10cu.ft @30hz box my mj-18 box is tuned to 33hz and it gets LOW try

http://www.subwoofertools.com/forum/ported-box.asp?Ew=45&Eh=17&Dia=11&Xmax=12&Vd=0.43&NumW=2&Vb=10&Fb=30&Qts=&Vas=&Fs=&CE=0

dvrmstrng
05-21-2007, 08:25 PM
talk to 80...you wont regret it....

80INCHES
05-21-2007, 08:33 PM
.......O and Thar's no 3rd order bandpass box right?

box types
1st order(free air)
2nd order(sealed)
3rd order(ported)
4th order(bandpass with 1 sealed chamber playing into 1 ported chamber)
5th order(4th order bandpass with a low pass filter)
6th order parallel tuned(bandpass with the rear chamber ported while the sub is playing into another ported chamber...both ports are seen)
6th order series tuned(bandpass with the rear chamber ported playing into a front ported chamber...one one port is seen and its fron the front chamber)
7th order(bandpass with the rear chamber using a passive radar while the sub is playing into a ported chamber..only the passive radar and the front chamber port are seen)
8th order( bandpass with both the front and rear chamber ported and both ports playing into another ported chamber...only 1 port is seen but theres 3 ports all 2gether)

if u want high output and still be able to hit the lows go 4th order
try 4 cubes sealed playing into 3 cubes ported with 120square inch port tuned to 70hz
or throw it in 5 cubes tuned to 32 hz and u should be fine

80

jeremiah
05-21-2007, 08:41 PM
70hz?

80INCHES
05-21-2007, 09:09 PM
70hz?

yes , i wouldnt go lower than 40hz
he will still hitthe lows tuned at 70hz his =3db rolloff will be in the low 30hz area

80

helotaxi
05-22-2007, 09:21 AM
70hz?

The tuning of the front chamber of a bandpass is nothing like the tuning of a regular ported box in regards to higher tuning limiting the low end. The sub doesn't unload below the front port tuning.

jeremiah
05-22-2007, 03:05 PM
O Ok....

generalGOTCHA
05-22-2007, 10:03 PM
(134db's) it that on the TL? O and we are mj-18 brother's now


http://i200.photobucket.com/albums/aa157/mj-18/051707_15001.jpg

Yeah, me and my cousins were going to watch a movie but on the way there we were gonig to settle who hits harder lol. So we paid 10$ each to have a local audio shop meter us. I have a cheapy wal-mart DB meter but shows my 10" Orion P series hitting at the highest 127Db's mind you this is at the dash, and the subs are nearly 12 feet away LOL. Those subs flex my van !!!! I dont dog on the new orion equipment whether owned by DEI or not, they bang like hell !
Anyhow, the TL meter also at the dash showed 134.6Db's for my pair of 10" Orions . It didnt have the nicest flat responce lol, but from 30-45hz it was peaking then rapidly dropped on the slope.
My cousins dont know that my amplifer puts out more power than what it says it can. They dont get the ohm's law theorum, and dont care to, but will argue with me until I am blue in the face about subwoofers hit better in this or that or smaller sub punches better and gets louder on the lows etc.. Bullshit that irritates me so much so I buy subs and **** I dont need to show how wrong they are heh.., and im pretty sure you who reads this has been in this type of arguement lol.
After 2yrs of all this I finally got my HCCA 250 Cheater amp I told them about for years, and my pair of Orion 10's that I said Ide promise would hit harder because I would build them a box to make sure of it.
Heh.. it felt good as hell when those 4 Visonik 10's didnt even come close.
They saw how much it takes to rise 1 DB lol .. to hit 8DB's harder felt great.


Anyhow, Jerimiah I am going to get a pair of MJ-18's :) power them with only 400WRMS@12v when my Vans on im at 14.3volts so Im assuming im around the 500WRMS area, and Im going to port the box to respond at close to that power level.

I recently proved myself wrong by un-bridgeing my amplifier from a 1ohm load @ 800 Watts.. LOL I ran each sub 2ohms each to each channel on the HCCA 250 and with those numbers it says it only puts out 2x 100Wrms @ 2ohms. I was experimenting.. and check this.. with 2 batteries and a capacitor to feed the amp at 800WRMS.. and then unbridging it and wiring each sub to each single channel at 2ohms = 100WRMS in the same ported box both channels set to mono from the amplifier so their not hitting seperate notes the output was 1db lower than my highest recorded output.

AINT THAT SOME **** ??? Efficiancy is everything !

So now if I can hit 1db less, off such small amount of power, then 2 MJ-18's bridged together on 400Wrms(prolly 500+WRMS when van is on) then with the right box, Im predicting far more output.

generalGOTCHA
05-22-2007, 10:14 PM
box types
1st order(free air)
2nd order(sealed)
3rd order(ported)
4th order(bandpass with 1 sealed chamber playing into 1 ported chamber)
5th order(4th order bandpass with a low pass filter)
6th order parallel tuned(bandpass with the rear chamber ported while the sub is playing into another ported chamber...both ports are seen)
6th order series tuned(bandpass with the rear chamber ported playing into a front ported chamber...one one port is seen and its fron the front chamber)
7th order(bandpass with the rear chamber using a passive radar while the sub is playing into a ported chamber..only the passive radar and the front chamber port are seen)
8th order( bandpass with both the front and rear chamber ported and both ports playing into another ported chamber...only 1 port is seen but theres 3 ports all 2gether)

if u want high output and still be able to hit the lows go 4th order
try 4 cubes sealed playing into 3 cubes ported with 120square inch port tuned to 70hz
or throw it in 5 cubes tuned to 32 hz and u should be fine

80





**BOWS** to mr 80 inches !

Seriously dude, thanks for summarizing this information !

Since I am getting 2 MJ-18's , and I do have a van :) so space isnt to much of an issue ! How could I use the second 18 into my system to help with output.
before you blessed me with your presence of knowledge in the subsonic science .. I was thinking of building one big *** infinite baffel to hold both subs with only one port .... eg big 3rd order.

I am going to use you as a refference since you know so much about this topic because I really want to try a little more advanced box than a 3rd order so im very very interested in a 4th order , but how do i impliment the second 18" subwoofer ?

btw whats a low pass filter ?? I understand electronics and what a low pass filter is, but in subwoofer enclosure terms I am ignorant to this.

Also , whats the bennefits of having a higher order box ? Would the second 18" sub being used as a passive radiator also increse overall DB output without sacrificing to much SQ ??

generalGOTCHA
05-22-2007, 10:45 PM
O Ok....

Hey are you still bumping that 18 with that vr3 amp ?? LOL LOL LOL

sorry thats just funny.. that little amplifier is what I use on my 6x9's lol.


Anyhow.. Nice box man :)

if all goes well with 80" inches knowledge and assistance I am going to fit two MJ-18's in my van to see what they can do vrs my pair of 10" Orions.
Im dying to know if I am going to hit harder or not.
If your reading this 80 , what do you think ???

my Orion P series 10's hit nice and hard, but have a 17mm Xmax , will the pair of MJ-18's with your box plan and my Orion HCCA 250 amplifier supplying ONLY 500WRMS to the pair @ 2ohms get louder than my two Orion P series 10's ???

80INCHES
05-23-2007, 10:40 PM
if all goes well with 80" inches knowledge and assistance I am going to fit two MJ-18's in my van to see what they can do vrs my pair of 10" Orions.
Im dying to know if I am going to hit harder or not.
If your reading this 80 , what do you think ???

my Orion P series 10's hit nice and hard, but have a 17mm Xmax , will the pair of MJ-18's with your box plan and my Orion HCCA 250 amplifier supplying ONLY 500WRMS to the pair @ 2ohms get louder than my two Orion P series 10's ???

if u want to be louder bassed off the power u have
do 6th order parallel tuned box
have the rear chamber in 10 cubes tuned to 35hz with a 120 square inch port
playing into a 5cube ported chamber tuned to 75hz with 280 square inches of port area
u should see a big difference

80

jeremiah
05-24-2007, 03:48 PM
Hey are you still bumping that 18 with that vr3 amp ?? LOL LOL LOL

sorry thats just funny.. that little amplifier is what I use on my 6x9's lol.


Anyhow.. Nice box man :)

if all goes well with 80" inches knowledge and assistance I am going to fit two MJ-18's in my van to see what they can do vrs my pair of 10" Orions.
Im dying to know if I am going to hit harder or not.
If your reading this 80 , what do you think ???

my Orion P series 10's hit nice and hard, but have a 17mm Xmax , will the pair of MJ-18's with your box plan and my Orion HCCA 250 amplifier supplying ONLY 500WRMS to the pair @ 2ohms get louder than my two Orion P series 10's ???

yes:crying: but iv only bin bumping that amp on that sub for a week

jeremiah
05-24-2007, 03:54 PM
O and my scosche SPL1000 says 125.6 on the dash:) sub is not broke in yet and barley moves :) ha ha ha! I love it

jeremiah
05-25-2007, 01:01 AM
make that 126db now :)

SHiZNiLTi
06-17-2007, 05:31 AM
if u want to be louder bassed off the power u have
do 6th order parallel tuned box
have the rear chamber in 10 cubes tuned to 35hz with a 120 square inch port
playing into a 5cube ported chamber tuned to 75hz with 280 square inches of port area
u should see a big difference

80

like this...

http://i113.photobucket.com/albums/n228/SHiZNiLTi/th_REMT18.jpg (http://s113.photobucket.com/albums/n228/SHiZNiLTi/?action=view&current=REMT18.flv)


http://img237.imageshack.us/img237/9241/toppaintsketched8.jpg

http://img83.imageshack.us/img83/3447/corneranglewq2.jpg

80INCHES
06-17-2007, 12:24 PM
yup exactly....but his box wont be nearly as big as urs

80