Got some specs but don't know what to do

[mcsoul 10+ year member]

I'll do 4ft at 28hz ( lol just a tad ove 27hz)
Still got one question for you Mister Mcsoul //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I'll be using re l ported calculator for the volume and port dimension. I heard it's off 1-2hz in the tuning and maybe a little airspace wise. Any better enclosure calculator on the web?

I would have used the pre-made box, but i'll optimize my trunk space and when the time will come soon... i'll still have some space for the stroller //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Congrats about the new addition coming (needing a stroller).

RE calc fails to account for port wood and woofer displacement.

This box is 4.0 cubes net at 27hz

Force RE calc to build this box with the dimensions on the picture. This is our control box. Make sure that port piece 2 is the right length.

Take note of what recalc says the net displacement and tuning is (it will be slightly different than 4@27hz).

Now modify the dimensions in recalc to where you like them but try to keep the port area 56sqin, net displacement (as it said for our control box), and tuning (as it said for our control box)the same (just very close) but with your new shape.

 

[Xprime4 10+ year member]

thanks for everything again Mcsoul.

I was wondering also why do slot port need to be in "L" form? All my lastest box were build with a single port wall going inside the box. It never sounded akward and that helped me saving LOT of internal airspace.

is it bad or are we only doing them in L to get bigger port? any use to that?

 

[mcsoul 10+ year member]

thanks for everything again Mcsoul.

I was wondering also why do slot port need to be in "L" form? All my lastest box were build with a single port wall going inside the box. It never sounded akward and that helped me saving LOT of internal airspace.

is it bad or are we only doing them in L to get bigger port? any use to that?

Port length is determined by three main factors, airspace - tuning frequency - port area.

Whether you need a L or not is determined by the length.

The larger the the airspace, the shorter a port will have to be at a given port area.

3.75 cubes at 30hz and 50sqin of port area requires a longer port to archive than

4 cubes at 30hz and 50sqin of port.

The lower the tuning frequency, the longer the port for a given airspace and port area. So 4 cubes at 30hz with 50sqin of port will need a longer port than 4 cubes at 34hz with 50 sqin of port.

And finally, a port for a give airspace at a given frequency will be LONGER as the port area INCREASES. Somewhat counter intuitive. A 4 cube box tuned to 30hz with 50sqin of port will require a shorter port length than a 4 cube box tuned to 30hz with 60sqin of port.

You need to run the box recalc makes by me too, it will allow port piece 2 to be to

long and get to close to the right wall, I like to see 1.5 to 2 times the port width

between the internal end of the port and the right wall in an L.

 

[Xprime4 10+ year member]

ok here's what i'll be doing if everything is fine

Re calculator says I'm at 4.75 @ 29.6hz

Since it doesn't take in account sub displacement = 0.25 (estimated... no infos...tc out) service) x 2 = .5

+ bracing and port wall ( .25 estimate)

so i would be at around 4ft/cu with an tuning a little bit higher than what's written. Guessing around 31-32hz... which would be perfect for me

so is everything fine? can i start tommorow?

sub up port rear in hatchback btw //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[mcsoul 10+ year member]

ok here's what i'll be doing if everything is fine

Re calculator says I'm at 4.75 @ 29.6hz

Since it doesn't take in account sub displacement = 0.25 (estimated... no infos...tc out) service) x 2 = .5

+ bracing and port wall ( .25 estimate)

so i would be at around 4ft/cu with an tuning a little bit higher than what's written. Guessing around 31-32hz... which would be perfect for me

so is everything fine? can i start tommorow?

sub up port rear in hatchback btw //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Does not look right, your tuning should say about 26.5 hz and your

ft3 should be 4.4 cubes.

 

[mcsoul 10+ year member]

33w

19h

19d

3" port width

18" port 2

= 4.399 ft3

= 26.88hz fb

 

[Xprime4 10+ year member]

33w 19h

19d

3" port width

18" port 2

= 4.399 ft3

= 26.88hz fb

you just lost me //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

you told me re calculator wasn't taking the port wall / sub displacement. The subs may not take .3 but more like .03? so lost

anyway i'm pretty firm on the external dimension unless i'm really too big. Otherwise, i would cut in the deepness.

and i finally want the tuning a tad higher than 30hz... i'm afraid i'll lost too much in the upper end if i go lower

Mcsoul, thanks you so much for everything again...

 

[skmfkr 5,000+ posts]

try to talk to soundsplinter they are tc9 motors. but if it was me id do 4cubes tuned to 35hz

 

[Xprime4 10+ year member]

try to talk to soundsplinter they are tc9 motors. but if it was me id do 4cubes tuned to 35hz

I did looked, but haven't found any model with the the same specs.

35hz sounds a bit high... is this where soundsplitter users put them?

 

[mcsoul 10+ year member]

Subs are .15 each, you need recalc to show 4.4 net and tuned

to 26.5 hz for 4cubes actual and 28Hz.

What you have in the picture is 4.3 cubes net actual at about 31hz, it won't sound bad;

It's just not what you wanted.

 

[Xprime4 10+ year member]

Subs are .15 each, you need recalc to show 4.4 net and tunedto 26.5 hz for 4cubes actual and 28Hz.

What you have in the picture is 4.3 cubes net actual at about 31hz, it won't sound bad;

It's just not what you wanted.

ok i understand what i need to work on. But are you considering bracing displacement? I'll use atleast one mdf 2x4 between the subs for higher enclosure solidity. That might be only .05ft/cu tough....

I want my tuning at 30-31 hz. So falowing your logic i should look for around 28.5-29hz on re calc.

and around 4.4 before port wall /sub displacement

 

[mcsoul 10+ year member]

yep, 4.45ish at 28-29hz

 

[Xprime4 10+ year member]

yep, 4.45ish at 28-29hz

more like that

//content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

enough space so the second port wall won't be in the sub's way?

I'll make it as perfect as i can. with sanded port corner for sure

 

[mcsoul 10+ year member]

Could ya add an inch to that p2 length? Just to get it under 29hz?

If not, it's still good.

 

[Xprime4 10+ year member]

Could ya add an inch to that p2 length? Just to get it under 29hz?
If not, it's still good.

how could i refuse you that?//content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

thank you so much for everything again mcsoul. I'll let you know how it sound when they get here probably next week