Box build for a friend

[jolly_26 10+ year member]

Just whipping up a 12" temporary box with a friend, he had been pretty difficult to design for as I'm definitely no expert at box design and he wants a very small box but still tuned low, but I'm always up for a challenge.

He plans to sell the car (05 Mondeo) in March, so we're just keeping it simple

Even though we have both left school, the teachers welcomed us back to use the wood working room, so we have been building it there!

Cut and glued yesterday, but we managed to **** up one of the sides when attaching it so there will be some sanding and filling for sure, there's no way it's coming back off now.

Should have it painted and installed today or tomorrow!

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Click to read more...

 

[jolly_26 10+ year member]

Oh and that's not me in the photo

EDIT: If you want me to post up pics of finished product, please comment, cbf posting up stuff if nobody cares haha

 

[Ninesvnsicks 10+ year member]

I like it the slot seems small in width but I'm sure the height makes up for that hopefully.

 

[jolly_26 10+ year member]

I like it the slot seems small in width but I'm sure the height makes up for that hopefully.

It's a pretty small port actually, just over an inch by just under 12 (31mmx294mm) so that we could keep size down in general. My main concern is port noise, but it's not a very powerful sub anyway.

 

[jolly_26 10+ year member]

Did a test run this morning, hits very low and pretty **** hard for what it is, we're both pretty happy with it. About to go do some final touches, will have photos of finished setup up later on.

 

[Ninesvnsicks 10+ year member]

Did a test run this morning, hits very low and pretty **** hard for what it is, we're both pretty happy with it. About to go do some final touches, will have photos of finished setup up later on.

Congratz it's always good when a project works out. What is the boxed tuned too anyways?

 

[THATpurpleKUSH 5,000+ posts]

Port is too small and you exceeded the 9:1 ratio of height to width. It will have excess port noise and tuning will be shifted. Don't play it too loud or it wont sound good.

 

[jolly_26 10+ year member]

Port is too small and you exceeded the 9:1 ratio of height to width. It will have excess port noise and tuning will be shifted. Don't play it too loud or it wont sound good.

I have played it loud and it does sound good. Oh, and there is absolutely no noticeable port noise, it's only a Pioneer 12 at 400rms (yeah, go ahead, but in NZ these are the best value for money subs short of importing from the US), so not pushing huge amounts of air. And the 9:1 ratio? Can be used to alter the tuning of the box intentionally as well //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I'm no expert but I'm no noob either, didn't just throw this together without doing some research.

What is the boxed tuned too anyways?

Should be about 31 //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[jolly_26 10+ year member]

Sanding

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Painting

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The sub

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Boxed

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Installed

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[pro-rabbit 5,000+ posts]

Nice enclosure, I agree on the port area being small though. I won't go into huge details here, but if you want more info on issues/results of those ports and why we avoid them PM me and I will help fill you in.

Other then that, nice build and it looks small once installed lol.

 

[hispls 5,000+ posts]

Looks good. Back in the day we used 4" round ports on 12" low powered woofers with fine results....not optimum, but certainly no audible chuffing, and that's about the same port area.

Rule #1 of this hobby is if it puts a smile on your face it's all good.

 

[pro-rabbit 5,000+ posts]

Looks good. Back in the day we used 4" round ports on 12" low powered woofers with fine results....not optimum, but certainly no audible chuffing, and that's about the same port area. Rule #1 of this hobby is if it puts a smile on your face it's all good.

What we are discussing is the limited width of the port not the overall port area. Also a single 4" typically very nice with a 12" sub. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

As for your rule... Agreed //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[jolly_26 10+ year member]

Yeah that port on my box gives an area of 14.1 square inches, and a 4" aeroport would give about 12.5. This woofer should get away with 12 square inches easily, and with 31x250 I could have kept within the 1:9 and had exactly 12 square inches. This means the smaller port dimension, 31, shouldn't cause any port noise, and extending the width of the port to 294 would only decrease the velocity of the port, correct? This is what I based my "I should be fine to step outside that ratio" thinking on. I had also read that in doing so you may lower the tuning of the box slightly, which would have been handy, so I went ahead with it.

Hopefully pro-rabbit can let me know if my thinking on this matter is correct. And sorry for the mess of metric and imperial together!

 

[jolly_26 10+ year member]

Rule #1 of this hobby is if it puts a smile on your face it's all good.

Yeah man, and now I have a 10 day road trip up the length of the country in this car! Should be mean