Re-tuning a box with slot port *pic*

[Xprime4 10+ year member]

I installed the box in my car few days ago and i'm not too sure i love the sound of my sd2.5. They were hitting much clearer and less boomy in a similar ported box with a smaller port area. They now don't sound flat but are def louder.

The box is ported 7.2 after subs but before port displacement. tuned around 37 in a slot (wall going in.. that's it) box. Anything i could do (now that the box has been glue and carpeted) to change my tuning? I was thinking about sealing the slot (there would still be a mdf sheet getting in, but seal) and adding a 8inch sonotube (50ish in/sq round compare to my actual 131 square). Any other idea?

little picture of the box. I won't be building another one since i'm broke //content.invisioncic.com/y282845/emoticons/greedy.gif.5a53e6246569d7ab79867170f3b06629.gif

Click to read more...

 

[Xprime4 10+ year member]

now that i think about it, there won't be space for the tube because the port will be in the way //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif What to do?

 

[Xprime4 10+ year member]

I just checked some more calculator and if i want to add a 8inch sono, it only got to be 9-10 inch long for a 34-36 hz tuning with 7.3ft/cu? accurate or not? that sound like a small port to me

 

[mlstrass 5,000+ posts]

what is the NET enclosure size? Seems like a lot of port area, like over 20^2 per cube which is pretty high for a daily box.

And "assuming" those are 15's then your box is WAY too small. I'd want at least 3.75cubes NET per sub with 4 - 4.25 per sub even better with 16^2 of port per cube tuned at 38Hz.

 

[mlstrass 5,000+ posts]

You could try laying MDF in the port to take up port area, but you'll also lower tuning some. That would at least give you an idea if the port is the issue.

I ran a DD 9515 in 4cubes with 80^2 of port area and tuned to 42Hz and it actually sounded pretty good on all types of music.

 

[Xprime4 10+ year member]

Yeah the box is on the low side, but the last one i had was too , yet still sounding a lot better to me...

Like i said, box is 7.2 after sub displacement. The port atm 17height 6.75 wide.

From my calculs, that gives 114.75 then divide by 7.3 ( or is it after port displacement???) = on the 16ish per ft/cu... my last one was more like 12-13 , yet sounding a lot sharp and better transitient response on fast kick bass

also the idea of trowing mdf in it... how do i do that? cut smaller and silicone ? i'm not sure this would be easy

 

[jmanpc 5,000+ posts]

slide a piece of wood in the same height and length as the port and glue it up against one of the walls. it will make the port 3/4" narrower. repeat if necessary.

 

[Xprime4 10+ year member]

slide a piece of wood in the same height and length as the port and glue it up against one of the walls. it will make the port 3/4" narrower. repeat if necessary.

well sound simple by the way you say it. I may try that.

What about the sono? 8inch diameter x 9-10 inch long and sealing the port (the airspace won't be lost that way right?)

also, if I take jmanpc idea, this will higher the tuning not lowering it? It's ok for my if it's lowered... not sure about getting it even higher

 

[mazdakid 5,000+ posts]

Putting a piece of mdf in there will lower the tuning. If you're going with a sono, just get a 10". Id use the old slot as a brace and cut windows out of it.

 

[Xprime4 10+ year member]

Putting a piece of mdf in there will lower the tuning. If you're going with a sono, just get a 10". Id use the old slot as a brace and cut windows out of it.

all i got is a jumping saw and no talent using it a 10inch sono would need to be longer than the 8inch one right?

 

[mazdakid 5,000+ posts]

A 10" needs to be longer than an 8" to be tuned the same. The sono will take up less airspace too

 

[Xprime4 10+ year member]

so my 9.5-10inch with a 8inch sono for 34-35hz sound accurate? i wouldn't too much job to do if that sound cool. I love sono //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif and smaller port area = less peaky sound right?

 

[Xprime4 10+ year member]

I'm bumping this coz i want some more change

I was thinkign about sealing the port... and putting a 8 inch sono facing the box top. Box pic is in signature

There won't be as much clearance between the port and the hatch. But i'd like to experiment. Would it works? The 8 inch sono would be 10 inch long for a 36hz tuning.

 

[Xprime4 10+ year member]

sry if the draws aren't clear.

The first one is box top

Second one is side view... with the hatch closed (showing the clearance)

I know the port area is small, but i like the sharpiness of smaller port area

maybe that pics would be more representative

 

[DonH 5,000+ posts]

jesus man just re do the box bro! no money? just go fuck sum fat chix for sum $$!

re do the box with the 8" sonotube with the length at ~9.5" or so for a 35hz tuning

make sure that the tube has at least 8" behind the end of the port though bro!!