Port length and a few box ?'s

*Mbrooks420* · 07-30-2002, 12:05 AM

It's time to build a new box for my single 12. I am thinking about building a ported box his time instead of another sealed. I am looking to either tune it to 30 or 35hertz. The inside diameter othe the box will be
22'wX 14't X 9'd. I was planning on using a 4in port. I need to know how long the port needs to be cut to tune it to 30 or 35hertz.
Also I have read on a box building site that you should have the sub counter sunk to be EXACTLY level with the outside of the box. Something to do with the traveling of the sound waves. Is this true? I was going to put an extra front plate on the box to protect the sub, so it was maybe 1/4 to 1/2 inch sunk into the box.
I was also wondering if you can brace a box with dowel rods? I was thinking you could run them across thr box and use long wood screws and glue. This sound practical? If I don't do that I will brace the back with an mdf X cutout. The front will likely have to plates so it will be fairly strong. The sides are are fairly shallow and it isn't all that tall.
Thanks in advance....

Explorer94GV · 07-30-2002, 01:48 AM

Well if i were you ask leenjen about the exact specs for the box he will whip up some dimensions for ya. As far as bracing goes just build it 1.5 mdf thick basically making 2 boxes. Im not sure you will really need it for your sub but trust me that box will be leak free. Yes countersink your box to make it flush every screw hole you drill countersink them than go back and putty the hole after. Im not to sure about internal bracing but with 1.5 mdf you wont need it.

leenjen · 07-30-2002, 03:56 PM

Quote:

22'wX 14't X 9'd

and what kind of vehicle is this HUGE enclosure going to fit in:p

22 ftX14ftX9ft !!!!! not even a tractor trailer can hold that

leenjen · 07-30-2002, 04:00 PM

assuming you meant 22"X14"X9"

a 4" diameter port tuned to 35HZ would need to be 14.4" long

if you wanted it tuned to 30HZ, the port would have to be 20.6" long

i think 35HZ would work better in your situation

*Mbrooks420* · 07-30-2002, 04:05 PM

The port should be on the same side as the sub and should face the rear, right? I was going to build it 9in out from the seat so the port wouldn't fit. I may have to redesign my box, but that will be difficult. And will the SQ suck if its tuned to 35?

*Mbrooks420* · 07-30-2002, 04:13 PM

Oh yeah and I hope that your back is feeling a little better, man.

leenjen · 07-30-2002, 08:40 PM

you could have the port on the same side as the subwoofer facing the rear, but it will stick out a few inches. if you dont like that idea, either have the port on one side or have it sticking out the top.

or you could redesign the enclosure.

the sq will be fine at 35HZ.

*Mbrooks420* · 07-30-2002, 10:40 PM

Well I decided it wasn't really possible to redesign the enclosure and keep the layout that I wanted. So I built it NEAR what I wanted. One sheet of MDF was
23 3/4 wide and 2 were 24 1/4. Gotta love quality control.
I am happy with the box and it is drying in the clamps now. All I have to do is cut the sub hole. And do A LOT of bracing. I seem to have a bit to much air space.
Well that, and start the second enclosure. And layout the wires.
Would countersinking the sub cause any sound problems?

leenjen · 07-31-2002, 12:43 AM

Quote:

Would countersinking the sub cause any sound problems?

nope

07-30-2002, 12:05 AM	#1
Mbrooks420 High Voltage. Erie, Pennsylvania 1998 Mountaineer Join Date: Feb 2002 Posts: 5,090 Vehicle Specs (Original Poster)	Port length and a few box ?'s It's time to build a new box for my single 12. I am thinking about building a ported box his time instead of another sealed. I am looking to either tune it to 30 or 35hertz. The inside diameter othe the box will be 22'wX 14't X 9'd. I was planning on using a 4in port. I need to know how long the port needs to be cut to tune it to 30 or 35hertz. Also I have read on a box building site that you should have the sub counter sunk to be EXACTLY level with the outside of the box. Something to do with the traveling of the sound waves. Is this true? I was going to put an extra front plate on the box to protect the sub, so it was maybe 1/4 to 1/2 inch sunk into the box. I was also wondering if you can brace a box with dowel rods? I was thinking you could run them across thr box and use long wood screws and glue. This sound practical? If I don't do that I will brace the back with an mdf X cutout. The front will likely have to plates so it will be fairly strong. The sides are are fairly shallow and it isn't all that tall. Thanks in advance.... __________________ 1998 Mounty 5.0 AWD TT/Shackles/rear AirLift springs 31x10.5 Kelly TSR's 1995 Subaru Legacy AWD Sedan RIP---Killed by an suicidal deer 1972 El Camino---Project Dirty Old Chevy---Fresh Marine Longblock .060 over, Forged crank RV Cam 454/th400 swap, Hooker Headers, fresh coat of white 1999 KTM 300exc RaceTech Suspension, Rekluse Slipper Clutch, single track killer

07-30-2002, 01:48 AM	#2
Explorer94GV Wannabe Elite Explorer Springdale, Arkansas 94' XLT 97' XLT AWD V8 Join Date: Jan 2002 Posts: 558 Vehicle Specs	Well if i were you ask leenjen about the exact specs for the box he will whip up some dimensions for ya. As far as bracing goes just build it 1.5 mdf thick basically making 2 boxes. Im not sure you will really need it for your sub but trust me that box will be leak free. Yes countersink your box to make it flush every screw hole you drill countersink them than go back and putty the hole after. Im not to sure about internal bracing but with 1.5 mdf you wont need it. __________________ 97' Explorer XLT V8 AWD http://www.cardomain.com/member_page...page_id=392990 94' Explorer XLT V6 2WD http://www.cardomain.com/member_page...make%3DFord&am

07-30-2002, 04:05 PM	#5
Mbrooks420 High Voltage. Erie, Pennsylvania 1998 Mountaineer Join Date: Feb 2002 Posts: 5,090 Vehicle Specs (Original Poster)	The port should be on the same side as the sub and should face the rear, right? I was going to build it 9in out from the seat so the port wouldn't fit. I may have to redesign my box, but that will be difficult. And will the SQ suck if its tuned to 35? __________________ 1998 Mounty 5.0 AWD TT/Shackles/rear AirLift springs 31x10.5 Kelly TSR's 1995 Subaru Legacy AWD Sedan RIP---Killed by an suicidal deer 1972 El Camino---Project Dirty Old Chevy---Fresh Marine Longblock .060 over, Forged crank RV Cam 454/th400 swap, Hooker Headers, fresh coat of white 1999 KTM 300exc RaceTech Suspension, Rekluse Slipper Clutch, single track killer Last edited by Mbrooks420; 07-30-2002 at 04:14 PM.

07-30-2002, 04:13 PM	#6
Mbrooks420 High Voltage. Erie, Pennsylvania 1998 Mountaineer Join Date: Feb 2002 Posts: 5,090 Vehicle Specs (Original Poster)	Oh yeah and I hope that your back is feeling a little better, man. __________________ 1998 Mounty 5.0 AWD TT/Shackles/rear AirLift springs 31x10.5 Kelly TSR's 1995 Subaru Legacy AWD Sedan RIP---Killed by an suicidal deer 1972 El Camino---Project Dirty Old Chevy---Fresh Marine Longblock .060 over, Forged crank RV Cam 454/th400 swap, Hooker Headers, fresh coat of white 1999 KTM 300exc RaceTech Suspension, Rekluse Slipper Clutch, single track killer

07-30-2002, 10:40 PM	#8
Mbrooks420 High Voltage. Erie, Pennsylvania 1998 Mountaineer Join Date: Feb 2002 Posts: 5,090 Vehicle Specs (Original Poster)	Well I decided it wasn't really possible to redesign the enclosure and keep the layout that I wanted. So I built it NEAR what I wanted. One sheet of MDF was 23 3/4 wide and 2 were 24 1/4. Gotta love quality control. I am happy with the box and it is drying in the clamps now. All I have to do is cut the sub hole. And do A LOT of bracing. I seem to have a bit to much air space. Well that, and start the second enclosure. And layout the wires. Would countersinking the sub cause any sound problems? __________________ 1998 Mounty 5.0 AWD TT/Shackles/rear AirLift springs 31x10.5 Kelly TSR's 1995 Subaru Legacy AWD Sedan RIP---Killed by an suicidal deer 1972 El Camino---Project Dirty Old Chevy---Fresh Marine Longblock .060 over, Forged crank RV Cam 454/th400 swap, Hooker Headers, fresh coat of white 1999 KTM 300exc RaceTech Suspension, Rekluse Slipper Clutch, single track killer

07-30-2002, 04:00 PM	#4
leenjen Wannabe Elite Explorer in the poconos, PA 2001 sport Join Date: May 2001 Posts: 5,529 Vehicle Specs	assuming you meant 22"X14"X9" a 4" diameter port tuned to 35HZ would need to be 14.4" long if you wanted it tuned to 30HZ, the port would have to be 20.6" long i think 35HZ would work better in your situation

07-30-2002, 08:40 PM	#7
leenjen Wannabe Elite Explorer in the poconos, PA 2001 sport Join Date: May 2001 Posts: 5,529 Vehicle Specs	you could have the port on the same side as the subwoofer facing the rear, but it will stick out a few inches. if you dont like that idea, either have the port on one side or have it sticking out the top. or you could redesign the enclosure. the sq will be fine at 35HZ.