amature clam shell design

[germandark 10+ year member]

okay here is my pos sketch up # 1

each port has (rounded up) 85in^ of port area.

each is tuned to 36 hz.

each side is 8.125ft cubed.

______

My port area is a bit small, I know.

I would glass corners/etc. and use threaded rod for bracing. I was thinking of double baffle for the subs.

this is my first mock up...I am not too happy with it but I will keep on.

ALSO I plan on dc level 4 15's

questions & comments?

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[germandark 10+ year member]

ttt

 

[Jeremy M 10+ year member]

looks identical to supergumby's....

 

[rollinonD's 10+ year member]

I would try and tune a little lower within the 30-34hz range as thats where those subs are most comfortable at. Overall looks good and should thump.

 

[germandark 10+ year member]

who is supergumby? think he/she would mind if I asked a few questions?

edit: that's the guy with the avalanche!....I was really impressed with his design, I tryed to base mine the same way but obviously smaller for my little ranger.

 

[Jeremy M 10+ year member]

who is supergumby? think he/she would mind if I asked a few questions?
edit: that's the guy with the avalanche!....I was really impressed with his design, I tryed to base mine the same way but obviously smaller for my little ranger.

makes sense

 

[germandark 10+ year member]

#2 here.

6.73ft cubed each side, 6.93 before guesstimated displacement.

99in^ of port area for each side, total of 198in^

effective port length is 24.5in so Ill just say 24in.

tuned to 35 hertz, actually 35 point something.

questions & comments?

 

[18inchjeepin 10+ year member]

2 looks stronger, but sacrafice some box

would firing 2 subs into each other cause problems?

 

[germandark 10+ year member]

2 looks stronger, but sacrafice some box
would firing 2 subs into each other cause problems?

both enclosures would be braced with glass, and threaded rod.

about the subs firing together...could cause and issue. I've seen people get 4 deep like that before and it sounded just fine. I wouldn't think cancellation would be too much of an issue, the dc level 4's have a bit over an inch of travel for xmax, if I remember correctly, so with the space between them I don't think their will be too much compression to cause cancellation. I could be wrong tho.

 

[TnT_Sounds 10+ year member]

No problems with the subs firing like that.. it would only cancel if the subs are moving in OPPOSITE directions. They are moving the same direction and are all pressurizing the middle chamber at the same time. Being "in phase" is more important then the direction they are aiming, even if its at each other.

Looks great man. Although it does look like a 6th order quasi tuned bandpass

 

[germandark 10+ year member]

ttt for suggestions.

 

[TnT_Sounds 10+ year member]

Why 4 15's?

 

[germandark 10+ year member]

I was favoring 8 12's originally, or 6. I am just planning right now.

 

[DBBOOM 10+ year member]

Firing against each other doesnt hurt anything, it really just acts to load the subs. I have 4 15''s in a tunnel blowthrough 4th order bandpass. All four of mine sit squarely though, no flare, been told that it also raises the power handling ability of the sub. I have 2.5 cu ft for each sub and 10 cu ft in the front chamber. My port is tuned to 30hz, i have great response from around 30-65hz. And by having the rear chambers sealed it has a nice low end extension with a very accurate sound. Also, nice that i only had to cut a 14''x14'' hole for the port and not a huge hole in the back of the cab.

 

[Supergumby5000 5,000+ posts]

the two inner subs (that arent angled) are going to fight against the port a wee bit, but it probably wont make an audible difference.

If you can, slant all four subs. It will help with that a little bit. Your setup pretty much has the sub IN the port.

Also, with that type of setup, im guessing your port length is as long as the end of the middle board? You may have taken this into account already, but that box design will treat the whole length (including those first subs) as port. if you havent taken that into account, tuning will come out much lower.