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FISP418 Sub Subwoofer Box size help in building correct size sub box. Help!

LOWSUB

Active Member
I was looking at all these threads and it seems people on here are going crazy building sub woofers for themselves & angliaboy seems to be building the box that I would like to have a go at myself as i'm looking for for a cube box of H20'' W X 20'' D X 20'' this size is critical I would prefer no bigger because of aesthetics my only problem is how do you tune this sub woofer so it dosent break itself apart and is tuned to the right frequency so this is what I had in mind.

1 X FI CAR AUDIO SP418 or would the SP415 be a better driver for my build as I have herd that mooted

1 X XTi 2 Crown 6002 PA POWER AMPLIFIER Output Power 4 ohms Bridged-Mono: 3200W

Would the SP418 fit in this size box, and I would like a rough idea of what I should be aiming towards with sub box, Also briefly how do you set the amplifier to the required EQ for the subwoofer so it is set as accurately as possible.. Any help would be appreciated.. Thank you
 

scottthehat

Distinguished Member
The 18 will fit in a 20inch cube. Look in the gecko thread thats what they have just done and iu sounds impressive but of the top of my head it will need good eq to get the best from it.
 

LOWSUB

Active Member
The 18 will fit in a 20inch cube. Look in the gecko thread thats what they have just done and iu sounds impressive but of the top of my head it will need good eq to get the best from it.
Hey thank you very much for pointing me in the right direction all the info I can get will be very much appreciated, I will ahve a look at Gecko 's thread so I would also need a good EQ. Ahh well must plod on this will happen will sound awsome when done cant wiat to read Geckos reaction to his build and ask some pesky questions.. All the advice I can get will be very much needed and required. Thank you scottthehat for the heads up.
 

LOWSUB

Active Member
The 18 will fit in a 20inch cube. Look in the gecko thread thats what they have just done and iu sounds impressive but of the top of my head it will need good eq to get the best from it.

Hey tried looking for this gecko thread and can not find it any chance you can throw us a link to access the thread as it is something I would love to read. Thank you..
 

scottthehat

Distinguished Member

LOWSUB

Active Member

Thank you scottthehat for the link it seems those guys are into designing sub woofers themselves where as I'm going to do this myself even though this is a steep learning curve for me all I need is a bit of assistance with EQ for this sub is there anyone here who can assist with the EQ & sub box design I do not want a massive coffin of a sub box something around 20 H X 20 D X 20 W. Any replies would be very much welcome.

Thanks
 

scottthehat

Distinguished Member
Thank you scottthehat for the link it seems those guys are into designing sub woofers themselves where as I'm going to do this myself even though this is a steep learning curve for me all I need is a bit of assistance with EQ for this sub is there anyone here who can assist with the EQ & sub box design I do not want a massive coffin of a sub box something around 20 H X 20 D X 20 W. Any replies would be very much welcome.

Thanks
if you want it in a 20" cube it will go with no problems but the qtc will be 0.9(recomeded is around 0.707 which gives the flatest response) but with good eq on the sub there will be no problem, so all depends on what your gonna use for eq, the behringer amps are great value and have costom eq built so its worth looking at.

lets say you go for a
option 1=
20" cube you can stuff it with polifill which will gain you upto 30% increase in box volume so should give you around a 120l internal volume,
so with 2000wrms and will hit 109.7db at 20hz with a qtc of 0.8349so will need some eq)

option 2 use a fi sp4 15" this will go nicely in a 70lbox and with 2000w rms of power it will hit 106.7db at 20hz, with a qtc of 0.704.

option 3 same as above but build a 20" cube and use the 15" driver which will give you a little more low end bass so will hit 107.6db at 20hz with 2000wrms and a qtc of 0.659.


box wise i would use a double front baffle all mdf 25mm and 50mm front, and maybe a couple of braces.
 

LOWSUB

Active Member
if you want it in a 20" cube it will go with no problems but the qtc will be 0.9(recomeded is around 0.707 which gives the flatest response) but with good eq on the sub there will be no problem, so all depends on what your gonna use for eq, the behringer amps are great value and have costom eq built so its worth looking at.

lets say you go for a
option 1=
20" cube you can stuff it with polifill which will gain you upto 30% increase in box volume so should give you around a 120l internal volume,
so with 2000wrms and will hit 109.7db at 20hz with a qtc of 0.8349so will need some eq)

option 2 use a fi sp4 15" this will go nicely in a 70lbox and with 2000w rms of power it will hit 106.7db at 20hz, with a qtc of 0.704.

option 3 same as above but build a 20" cube and use the 15" driver which will give you a little more low end bass so will hit 107.6db at 20hz with 2000wrms and a qtc of 0.659.


box wise i would use a double front baffle all mdf 25mm and 50mm front, and maybe a couple of braces.

So I could use a 20'' cube to house the SP4 15'' I was thinking of using the Crown XTi 2 4002 PA power amplifier or would that be overkill so apart from deciding on speakon connectors or bare wire & of course XLR to phono thats all there is to it would there be anything else I would need? On a separate note the above mentioned amplifier would that amplifier be capable of running two of these sub woofers..

I think the 15'' is the better option for me to be truthful less fuss and smaller sub box well 20'' cube & it will sound fantastic.

Thank you for this information that is what I needed to hear and you have no idea how helpful you have been.
 

LOWSUB

Active Member
Hey on the Behringer amps they see to be very complicated to set up I mean there are that many parameters to set up would there be an easier way of setting this amplifier to suit my build using this amplifier with above 15 SPI Drive unit as I do not think I would be able to sit and take my time in setting this amplifier up so would you have a fast track way of advising how this would be done as I imagined it would be as simple as setting the crossover on the amplifier rather using intricate computer based software which seems to be very intricate..

Thank you
 

scottthehat

Distinguished Member
Im not sure on the dsp side of things but there is alot of guys on here that would help you out, all i know is the software is very good and well worth having, and nu3000dsp(bridged mode 2200wrms) will run one of the sp4 15" as long as you get a dual 2ohm sub, if you want to run 2 sp4 then get an nu6000 dsp which has 2x2200w rms

the recomended size for asp4 15" is 70l(so say a 19" cube) but if you stick it in a 20" cube(which is what i would do) as i said with some bracing it will be about 90l give it the 2200wrms and it will sing very nicely like 108db at 20hz and if you had 2 in the own boxes 114.1db at 20hz which is pretty darn good.
 

LOWSUB

Active Member
Im not sure on the dsp side of things but there is alot of guys on here that would help you out, all i know is the software is very good and well worth having, and nu3000dsp(bridged mode 2200wrms) will run one of the sp4 15" as long as you get a dual 2ohm sub, if you want to run 2 sp4 then get an nu6000 dsp which has 2x2200w rms

the recomended size for asp4 15" is 70l(so say a 19" cube) but if you stick it in a 20" cube(which is what i would do) as i said with some bracing it will be about 90l give it the 2200wrms and it will sing very nicely like 108db at 20hz and if you had 2 in the own boxes 114.1db at 20hz which is pretty darn good.

Dear Scottthehat

I can only thank you for pointing me in the right direction as I am new here I did not think anyone would respond with the wealth of information I have gathered from this thread, can I ask you to recommend anyone who you think is capable of preparing a sound file for my particular needs as you would know better than I or if anyone reading this thread knows their way about doing this it would be very much appreciated as I would not like to do this myself without first spending days if not weeks trying to figure this all out and it seems a nightmare to configure everything.

I will write a separate post maybe to see if anyone would be kind enough to offer their services.

Again thank you for all your help and pointers..
 

mhuk05

Well-known Member
The XTi is a good amp and also has DSP, well spoken of on some of the USA forums. AN iNuke 3000DSP or 6000DSP are cheaper alternatives.
 

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