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View Full Version : Box design help 2 18" RE Audio SX18's



Trill
02-05-2014, 08:02 PM
Hey everyone I'm hoping to get some help designing and tuning a box for 2 18" RE audio SX18's
What I really need is the correct type of port and size and location of it. I'm ok with subs up with port up but also subs up and port forward between the seats.

It will be going into my 2007 dodge ram 1500 quad cab.
Plan on using a single Hifonics BRX 2400.1 @ 1ohm unless I decide on a more powerful woofer and will use 1 for each woofer.

I have made this in sketchup as it will be close to my max size I want to fit in the back of my truck.

Max OD W=60" H=24" D=26-27"
Material Thickness will be dual layer 3/4" so 1.5"
Looking to tune it to 34hz
Will be playing mostly music but want it to be loud and low

Woofer = If you can recommend a better woofer in this price range let me know!
RE Audio SX18D2 (SX18-D2) 18" Dual 2 ohm Car Subwoofer (http://www.sonicelectronix.com/item_27322_RE-Audio-SX18D2.html)
SX 18" T/S Parameters:
Electrical Q Value (Qes): 0.53
Mechanical Q Value (Qms): 6.1
Total Speaker Q Value (Qts): 0.48
Free Air Resonance (Fs): 33.2 Hz
Equivalent Compliance (Vas): 159 liters
One-Way, Linear Excursion (Xmax): 22 mm
Efficiency (SPL 1W/1m): 92.7 dB SPL
Effective Piston Area (Sd): 1210 cm2
DC Resistance (Re): 1.9 ohm
Nominal Impedance (Znom): Dual 2 ohm
Thermal Power Handling (Pe): 1000 W
Force Factor (Bl): 21

This box will have a 3" baffle to get my 24" height but could change it to 1.5" if it improves performance with more volume by increasing Height.

ID H=19.5"-21"(21" if 1.5" baffle) W=57" D=23"-24" (24" makes me scoot my seat up an inch :))
http://i92.photobucket.com/albums/l21/surfstylez/DualRE18NoBaffle_zpsb12a2be0.png (http://s92.photobucket.com/user/surfstylez/media/DualRE18NoBaffle_zpsb12a2be0.png.html)

And thanks in advance for anyone bored enough to help me design my port for this box!

Trill
02-05-2014, 08:06 PM
A member of another forum suggest this design but I was told it may not be the best for the sub closest to the port and that the port is also too small.

http://i92.photobucket.com/albums/l21/surfstylez/DualRE22_zps7c688e41.png (http://s92.photobucket.com/user/surfstylez/media/DualRE22_zps7c688e41.png.html)

http://i92.photobucket.com/albums/l21/surfstylez/DualRE222_zpsf758f3c0.png (http://s92.photobucket.com/user/surfstylez/media/DualRE222_zpsf758f3c0.png.html)

bgowdy31
02-05-2014, 08:11 PM
Hey everyone I'm hoping to get some help designing and tuning a box for 2 18" RE audio SX18's
What I really need is the correct type of port and size and location of it. I'm ok with subs up with port up but also subs up and port forward between the seats.

It will be going into my 2007 dodge ram 1500 quad cab.
Plan on using a single Hifonics BRX 2400.1 @ 1ohm unless I decide on a more powerful woofer and will use 1 for each woofer.

I have made this in sketchup as it will be close to my max size I want to fit in the back of my truck.

Max OD W=60" H=24" D=26-27"
Material Thickness will be dual layer 3/4" so 1.5"
Looking to tune it to 34hz
Will be playing mostly music but want it to be loud and low

Woofer = If you can recommend a better woofer in this price range let me know!
RE Audio SX18D2 (SX18-D2) 18" Dual 2 ohm Car Subwoofer (http://www.sonicelectronix.com/item_27322_RE-Audio-SX18D2.html)
SX 18" T/S Parameters:
Electrical Q Value (Qes): 0.53
Mechanical Q Value (Qms): 6.1
Total Speaker Q Value (Qts): 0.48
Free Air Resonance (Fs): 33.2 Hz
Equivalent Compliance (Vas): 159 liters
One-Way, Linear Excursion (Xmax): 22 mm
Efficiency (SPL 1W/1m): 92.7 dB SPL
Effective Piston Area (Sd): 1210 cm2
DC Resistance (Re): 1.9 ohm
Nominal Impedance (Znom): Dual 2 ohm
Thermal Power Handling (Pe): 1000 W
Force Factor (Bl): 21

This box will have a 3" baffle to get my 24" height but could change it to 1.5" if it improves performance with more volume by increasing Height.

ID H=19.5"-21"(21" if 1.5" baffle) W=57" D=23"-24" (24" makes me scoot my seat up an inch :))
http://i92.photobucket.com/albums/l21/surfstylez/DualRE18NoBaffle_zpsb12a2be0.png (http://s92.photobucket.com/user/surfstylez/media/DualRE18NoBaffle_zpsb12a2be0.png.html)

And thanks in advance for anyone bored enough to help me design my port for this box!

im going to add that if i were you i would go with a bigger amp now if you have the funds. yea they are rated "1k rms each" but they will want more also after rise and voltage drop you may only be giving the a total of 1200-1500 rms split between the 2 subs

Trill
02-05-2014, 08:29 PM
What would you suggest for an amp? Also I'm planning on having an XS Power D6500 to replace my factory battery and I am able to install a 2nd battery under the hood so could have 2 6500's but that may be too much for my alt. Don't know if I will be able to afford a HO Alt right away. Should I also put like a D3100 in the back? Should I plan on using a capacitor?

Have 2-3k to spend but will also be adding damplifier pro w/ luxury liner pro and upgrading my front stage. All still to be decided.
Thanks

Currently have Alpine IDA-X305s HU with Imprint PXA-H100 connected to a JL JX360/4 running Alpine SPR-60c components.

bgowdy31
02-05-2014, 10:04 PM
What would you suggest for an amp? Also I'm planning on having an XS Power D6500 to replace my factory battery and I am able to install a 2nd battery under the hood so could have 2 6500's but that may be too much for my alt. Don't know if I will be able to afford a HO Alt right away. Should I also put like a D3100 in the back? Should I plan on using a capacitor?

Have 2-3k to spend but will also be adding damplifier pro w/ luxury liner pro and upgrading my front stage. All still to be decided.
Thanks

Currently have Alpine IDA-X305s HU with Imprint PXA-H100 connected to a JL JX360/4 running Alpine SPR-60c components.

Amp wise i would aim about 3k atleast if you have the money. The Brx2400 is a good amp but will do closer to 2100rms then the rated 2400, which still isnt bad. you may be able to find a good 3k amp pretty cheap floating around the classified.

I would honestly get the alt first, you shouldnt need 2 of those up front. i would get 1 good batt to fit under the hood, then the alt. with your budget you should be able to fit a alt into your budget.

As far as back batteries, look into like Deka g31 batts, they are just as good and they are cheaper, also the sams club duracell agms will save you money. you can probably get 2 of the sams club g31 agms for the price of 1 xs-d3100, yes the xs-power will be better then 1 of the sams club batts by a small margin but the not even close to 2 of the sams clubs ones.

Trill
02-08-2014, 10:14 PM
This is what I came up with.

http://i92.photobucket.com/albums/l21/surfstylez/NewBox1_zpsfaca7413.png (http://s92.photobucket.com/user/surfstylez/media/NewBox1_zpsfaca7413.png.html)

http://i92.photobucket.com/albums/l21/surfstylez/Torres6_zps8f4c4ed8.png (http://s92.photobucket.com/user/surfstylez/media/Torres6_zps8f4c4ed8.png.html)

With a Q1-3500D.1 Amp
Q1-3500D.1 Amplifier (http://www.soundqubed.com/Q1-3500D1-Amplifier_p_32.html)

Think this will work for me?