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soldiermedic
04-18-2010, 11:25 PM
I'm working on yet another design, and I was wondering if anyone had pictures of an internal box with a long port that resembles a maze design before closing. Just trying to get an idea of a box that will have a total port length of about 60 inches will look like.

ascitiesburn69
04-19-2010, 12:24 AM
Why the hell do you need 60" of port length.....100sqin of port on a 1cuft net box tuning to 28hz???

jdawg
04-19-2010, 12:29 AM
Why the hell do you need 60" of port length.....100sqin of port on a 1cuft net box tuning to 28hz???

true, what box size and tuning? Yes it has been done, a L would be better if you could fit it. An aeroprt may be a better solution though.

RAM_Designs
04-19-2010, 12:49 AM
I do 40"+ a lot...what are you looking for exactly?

Louisiana_CRX
04-19-2010, 12:51 AM
20hz :confused:

jdawg
04-19-2010, 12:56 AM
20hz :confused:

If I wanted to tune 20hz it would be HT with an 18 or 15 and Im sure it would require a large enough box that I wouldnt need a 60" long port lol

RAM_Designs
04-19-2010, 01:04 AM
I did a box for a single 10"er recently. 1.5ft^3 tuned to 28hz with a 10.5"x2" port...43" long I think. 20hz would have been 90". :eek:

jdawg
04-19-2010, 01:09 AM
I did a box for a single 10"er recently. 1.5ft^3 tuned to 28hz with a 10.5"x2" port...43" long I think. 20hz would have been 90". :eek:

thats what I mean, honestly I would have done an aero for that

RAM_Designs
04-19-2010, 01:13 AM
thats what I mean, honestly I would have done an aero for that

Stock aeros aren't long enough, and I don't feel like buying extra pipe...or spending the money in the first place, really.

jdawg
04-19-2010, 01:28 AM
Stock aeros aren't long enough, and I don't feel like buying extra pipe...or spending the money in the first place, really.

alot of that depends on power also, they "golden rule" that everyone goes by here (on this forum) about so many cubes requires so much port is bullshit. Yea on large boxes with thousands of watts of power it may apply but really its power depending. No way a pyramid 18 with 500w of power needs a port area as large as a BTL on 2000w of power. More port area almost never hurts but in some cases its just total overkill and all you do is scratch your head and try to figure out how you can fit some huge *** port in a teeny box when it does not need it in the first place.

Supergumby5000
04-19-2010, 01:35 AM
I did a box for a single 10"er recently. 1.5ft^3 tuned to 28hz with a 10.5"x2" port...43" long I think. 20hz would have been 90". :eek:

the difference between 43" and 60" is huge.....

soldiermedic
04-20-2010, 04:07 PM
Wow..so many responses...yet so little help. Anyway, I am planning to do a box for a single 10" sub tuned to 26hz for a flat response from 30hz and up. Box size will be 1.75cu. Low pass will be set at 125hz. Also, I have a question as to whether winISD calculates displacement for the sub and port or do I have to do that myself.

soldiermedic
04-20-2010, 04:14 PM
And what is an aeroport?

CRXBMPN
04-20-2010, 04:24 PM
all you need to know is that an aeroport is not long enough lol
its just pvc with flared ends to reduce cancellation etc

soldiermedic
04-20-2010, 04:25 PM
Why the hell do you need 60" of port length.....100sqin of port on a 1cuft net box tuning to 28hz???

Close...1.5cu at 26.

Ronny
04-20-2010, 04:34 PM
You could try placing the driver on one extreme of the enclosure and doing an S-port.. Or even add another wall to make it an.. Actually I don't know what that would be called. A winding tunnel like port :p

Brian Owens
04-20-2010, 04:38 PM
I normally do something like this. . .

http://i183.photobucket.com/albums/x24/bkolfo4/Skipsbox.jpg

RAM_Designs
04-20-2010, 06:27 PM
^^^that looks like a lot of work.

soldiermedic
04-20-2010, 06:48 PM
Yeah. But he's the only one that has given me anything close to a picture of what I am trying to get an idea about.

RAM_Designs
04-20-2010, 06:52 PM
http://i45.photobucket.com/albums/f92/RyanM923/RandomBoxDesigns/Single12-2ft3-at-32hz.png

audio_phill
04-21-2010, 01:44 AM
Wow..so many responses...yet so little help. Anyway, I am planning to do a box for a single 10" sub tuned to 26hz for a flat response from 30hz and up. Box size will be 1.75cu. Low pass will be set at 125hz. Also, I have a question as to whether winISD calculates displacement for the sub and port or do I have to do that myself.

WinISD does not account for any displacement, volume given is net, you have to figure out port displacement and add it to the net volume. The Box Shape/Size option uses golden ratio FYI. heres one way I fold my ports. 32Hz in 1 cube net. 57.75" of port compound folds .

http://i386.photobucket.com/albums/oo310/AudioPhill/Enclosure/DSC02234.jpg

audio_phill
04-21-2010, 01:49 AM
Finished Raw Box. 1/64" tolerances, $90. lol.
http://i386.photobucket.com/albums/oo310/AudioPhill/Enclosure/DSC02375.jpg

audio_phill
04-21-2010, 01:50 AM
Heres another, 1.4 @ 34Hz with 36"sq port, ~53.25" long port. $55

http://i386.photobucket.com/albums/oo310/AudioPhill/Enclosure/DSC02780.jpg
http://i386.photobucket.com/albums/oo310/AudioPhill/Enclosure/DSC02783.jpg

Brian Owens
04-21-2010, 09:47 AM
The golden ratio does not matter for a subwoofer unless you have a length over ~5.5 ft long inside the box. . .

I am curious, why not round over or 45 the inside edges of the turns on those ports? It would allow you to have a larger 45 on the outside while maintaining the required port width.

Brian

soldiermedic
04-21-2010, 06:01 PM
Awesome. Thanks for all the visuals. I would have missed putting the blocks to ensure consistency of the port width throughout had I not seen them in yours. I also see that I need to increase the planned depth of the box for displacement of the sub as well as the port walls (which was the only thing I accounted for).

audio_phill
04-21-2010, 06:28 PM
The golden ratio does not matter for a subwoofer unless you have a length over ~5.5 ft long inside the box. . .

I am curious, why not round over or 45 the inside edges of the turns on those ports? It would allow you to have a larger 45 on the outside while maintaining the required port width.

Brian


Golden ratio effects the sound and efficiency of the enclosure as well as increase upper freq roll off and lessen output deviation. These boxes were slap together few hour jobs, and as low as the Vas was on the driver, the vent mach was so low it wouldn't have benefited in any way since 45's don't remove standing waves. As for maintaining proper port width, 45'ed corners dont allow for nominal width anyway, only nominal radius (1/4 turn corners/edges do,) lol. geometry people, lol.

soldiermedic
04-21-2010, 07:21 PM
Oh yeah...I forgot that I am a little slow when it comes to that. Speaking of geometry, how do I calculate displacement for my port and speaker? I figure that I have to get the speaker mounting depth measurements, but what of the port?

soldiermedic
04-21-2010, 07:56 PM
Also, is there a reason to offset the vent for a box mo less than 3" from the side of the box? Just a suggestion that I wanna check.

audio_phill
04-21-2010, 08:41 PM
Oh yeah...I forgot that I am a little slow when it comes to that. Speaking of geometry, how do I calculate displacement for my port and speaker? I figure that I have to get the speaker mounting depth measurements, but what of the port?

port displacement is (port width + board thickness) x height x length, divided by 1728
sub displacement can be found by using the sub displacement calculator in WinISD Pro Alpha and a measuring tape.


Also, is there a reason to offset the vent for a box mo less than 3" from the side of the box? Just a suggestion that I wanna check.
No need to offset the port. Ports like in the boxes above are perfectly fine. Design it to have a vent mach .05 - .03 and you're good to go.

soldiermedic
04-21-2010, 10:28 PM
port displacement is (port width + board thickness) x height x length, divided by 1728
sub displacement can be found by using the sub displacement calculator in WinISD Pro Alpha and a measuring tape.


No need to offset the port. Ports like in the boxes above are perfectly fine. Design it to have a vent mach .05 - .03 and you're good to go.

Ouch...a vent mach at that range is difficult right now...is 0.08 ok?

outsideshot23
04-21-2010, 10:31 PM
word

Brian Owens
04-22-2010, 11:13 AM
. . . .since 45's don't remove standing waves. As for maintaining proper port width, 45'ed corners dont allow for nominal width anyway, only nominal radius (1/4 turn corners/edges do,) lol. geometry people, lol.

My comment had nothing to do with 45's and standing waves. What I was saying is to 45 the inside edge of the port along with the outer edge, like in the picture below. . .Helps maintain nominal width. geometry, lol.

http://i183.photobucket.com/albums/x24/bkolfo4/port.jpg

iamamp3pimp
04-22-2010, 11:19 AM
http://i35.photobucket.com/albums/d177/iamamp3pimp/Worklogs/Doliver84%203/FINAL-1.jpg

http://i35.photobucket.com/albums/d177/iamamp3pimp/Worklogs/Doliver84%203/SAM_3540.jpg

http://i35.photobucket.com/albums/d177/iamamp3pimp/Worklogs/Doliver84%203/SAM_3544.jpg

Brian Owens
04-22-2010, 11:21 AM
^^^^ nice!

audio_phill
04-22-2010, 11:50 AM
Ouch...a vent mach at that range is difficult right now...is 0.08 ok?

if its in a trunk it would be okay, lol. .08 is quite noisy.

slim2fattycake
04-22-2010, 12:02 PM
http://i222.photobucket.com/albums/dd246/slim2fattycake/10%20iXL/th_IMG_0006.jpg (http://i222.photobucket.com/albums/dd246/slim2fattycake/10%20iXL/IMG_0006.jpg)

audio_phill
04-22-2010, 12:13 PM
"Got standing wave?" lol