Car; lancer GLX (sedan)i.e. with a boot

Speakers: 2x loaded Fi BL's 12's

box slot port common chamber

The goal is loud daily and I was told 32hz will work well. According to my dodgy calculater the below specs will give 31.44 Hz before a single 45 corner and a 1" front baffle. obviously the one side will have to be lengthened by .25'' ...i think

box with 36"

box height 14"

depth 22.5"

wood thickness .75" for most part of it(exept for front baffle -->other ideas welcome)

sq port height 12.5"

sq port with 4.5"

sq port L1 17.25"

sq port L2 5"

cheers

Car; lancer GLX (sedan)i.e. with a boot

Speakers: 2x loaded Fi BL's 12's

box slot port common chamber

The goal is loud daily and I was told 32hz will work well. According to my dodgy calculater the below specs will give 31.44 Hz before a single 45 corner and a 1" front baffle. obviously the one side will have to be lengthened by .25'' ...i think

box with 36"

box height 14"

depth 22.5"

wood thickness .75" for most part of it(exept for front baffle -->other ideas welcome)

sq port height 12.5"

sq port with 4.5"

sq port L1 17.25"

sq port L2 5"

cheers

BUMP please i need help with this and also what do you guys seggest for bracing ...stainless steel or Brass threaded rod

what thicknes in terms of mm>?

planning to start building next wknd. come on guys pls review my plans to see if they are any good...

Looks fine but remember tuning is going to raise when you add the subs, bracing and 45.

If those are external dimensions I get 5.25 cubes gross. Port displaces about 1 cube, let's say .3 cubes for the drivers. That leaves you with 3.95 cubes net. A port 12.5" tall, 4.5" wide and 26.75" long gives a tune of about 34 hz. You'll want to add about 6" onto the port to make it close to 32 hz.

At least that's why winISD alpha is telling me.

You forgot .75 inch in actual port length and then end correction also. The tuning he got is correct it will just raise to about 33 hz when he adds subs and everything.

I didn't forget the .75. He mentions his first port length being 17.25" long. Well, if his box is 22.5" deep externally, that leaves only 21" internally. since his port is 4.5" wide, the first port board would have to be 4.5" from the back wall. Add 17.25 + 4.5 + the .75" for the back wall, and you get 22.5". Therefore, his L1 includes the front baffle. Then 17.25 for the first leg + 4.5" for the corner from measuring down the center, plus 5" for the second leg = 26.75".

I didn't take end correction into account, I never think about it.

17.25" for the first leg + 4.5" for the corner + .75" for the L1 board + 5" for L2 = 27.5" You forgot .75" for the First port wall when you make the turn.

Edited December 8, 200816 yr by bromo

I assumed the 5" started from where the wood starts going that direction, just like the L1 length included the front baffle thickness. Not board cutout lengths. I guess that's something the OP would have to tell us.

Either way, it's only .75 inch. Not going to affect a thing.

im not sure if im miss understanding you guys but; are you asking the front baffle thickness? if so it will be 1" while the rest of the box will be .75"

ill be using threaded rod for bracing. the local shop call the thickness MT10 whatever that means. Looks to be about 10mm so maybe that is it.

mind sharing what the correction factor is and how it affects the settup?

is my port the right size? I have heard people saying to go for a 29" total lenght port.

thx for your input

just to add I used the SSA slotbox tool on here if that will help.

Edited December 10, 200816 yr by Punkeyboozter

I assumed the 5" started from where the wood starts going that direction, just like the L1 length included the front baffle thickness. Not board cutout lengths. I guess that's something the OP would have to tell us.

Either way, it's only .75 inch. Not going to affect a thing.

True is wont affect much but I like to be exact on calculating boxes.

im not sure if im miss understanding you guys but; are you asking the front baffle thickness? if so it will be 1" while the rest of the box will be .75"

ill be using threaded rod for bracing. the local shop call the thickness MT10 whatever that means. Looks to be about 10mm so maybe that is it.

mind sharing what the correction factor is and how it affects the settup?

is my port the right size? I have heard people saying to go for a 29" total lenght port.

thx for your input

just to add I used the SSA slotbox tool on here if that will help.

No we were discussing the port length. End correction is when your port uses a outside wall as one of the port walls, and it effects the perceived length of the port, as a general rule you add half the port width to the length of the port when calculate tuning frequency. After you add subs and bracing you should be tuned around 33Hz.

I assumed the 5" started from where the wood starts going that direction, just like the L1 length included the front baffle thickness. Not board cutout lengths. I guess that's something the OP would have to tell us.

Either way, it's only .75 inch. Not going to affect a thing.

True is wont affect much but I like to be exact on calculating boxes.

Well then we should discuss him using 1" on the front baffle, because apparently whoever designed the port didn't take that into account. The L1 length will be .25" off, and his L2 port won't be the right width. But really it just means his L1 length will be 17.5" instead of 17.25. No biggie.

I assumed the 5" started from where the wood starts going that direction, just like the L1 length included the front baffle thickness. Not board cutout lengths. I guess that's something the OP would have to tell us.

Either way, it's only .75 inch. Not going to affect a thing.

True is wont affect much but I like to be exact on calculating boxes.

Well then we should discuss him using 1" on the front baffle, because apparently whoever designed the port didn't take that into account. The L1 length will be .25" off, and his L2 port won't be the right width. But really it just means his L1 length will be 17.5" instead of 17.25. No biggie.

Regardless of the front baffle the port length would still be the same, panel dimensions would change but the length remains the same.

how can it stay the same if you're adding .25" onto the front baffle? The front baffle is still part of the port. His L1 would increase to 17.5" (since earlier I posted how his L1 must include the front baffle) and his L2 would decrease to 4.75" to keep the overall length the same 26.75" that I figured out earlier. So I guess yes, it would stay the same, but he'd have to realize how it will affect the port board lengths.

True, but regardless the box will work well for the BL's I think.

you guys are ridiculous. haha. i actually sat here and read every post, picturing the dimensions in my head with whatever you guys were talking about ..classic. i think the box will work well though

Good ol discussion gets the juices flowing.

True, but regardless the box will work well for the BL's I think.

Indeed. I've never had a discussion about quarters of an inch before! haha. I never get that in-depth with ports. If winISD recommends something like 17.68" long, I round up to 17.75" or something, maybe even to the half-inch. It's not like you'll ever hear the .04 hz difference in tuning frequency anyways.

Hahah you guys are indeed entertaining, but I have learnt a thing or two. So its safe to go with the specs as posted in the first post or should I make minor adjustments?

thanks for all your input