Soundqubed hdc4 port help

[jar1zx 10+ year member]

I know the math for cubic foot.

I'm good on taking out sub displacement and wood to get internal volume.

I've just learned how to get two of the port height and width by using cubic foot of box times 17-18 depending on if I overpower them........think i Will a bit.

So I need 2.25-2.5 per sub think I'll go with 4.5x17 to get port, maybe 5x17. Port volume.

Both subs will be close to .4 cubic displacement. So I've almost got this.

My Q is what is the math to get port length? Think I want box tuned at 32hz.

I've looked for answer to this for over a week now, and besides a program I can't find anything.

Math to take port volume out to get net volume of box should be same as getting box volume. Just add port displacement like I would sub displacement.

So if I can ever get the magic formula to get port length I'm good.

Sorry if this is kinda turning into a rant........I've been watching YouTube vids...reading everyplace I can think of and I can't find it.

Click to read more...

 

[jar1zx 10+ year member]

Let's make this easy.....that was way to long of a read.

What is the math to determine port length for tuning?

 

[BOOMINGRANDPA 5,000+ posts]

I know the math for cubic foot. I'm good on taking out sub displacement and wood to get internal volume.

I've just learned how to get two of the port height and width by using cubic foot of box times 17-18 depending on if I overpower them........think i Will a bit.

So I need 2.25-2.5 per sub think I'll go with 4.5x17 to get port, maybe 5x17. Port volume.

Both subs will be close to .4 cubic displacement. So I've almost got this.

My Q is what is the math to get port length? Think I want box tuned at 32hz.

I've looked for answer to this for over a week now, and besides a program I can't find anything.

Math to take port volume out to get net volume of box should be same as getting box volume. Just add port displacement like I would sub displacement.

So if I can ever get the magic formula to get port length I'm good.

Sorry if this is kinda turning into a rant........I've been watching YouTube vids...reading everyplace I can think of and I can't find it.

Port Length Calculator

 

[Popwarhomie 5,000+ posts]

torres box calculator

 

[hispls 5,000+ posts]

https://www.ajdesigner.com/phpsubwoofervented/port_length_equation_fb.php

All formulas are here.

 

[jar1zx 10+ year member]

https://www.ajdesigner.com/phpsubwoofervented/port_length_equation_fb.php
All formulas are here.

Thx bro!

 

[jar1zx 10+ year member]

So how does this look

51.5 width 14.5 tall 20.25 deep

Port is 13x5.875 by 41 long. Tuned to 30hz and port is 1.8 cubic foot.....hum?

Should be close to 4.5 after port and sub are taken out. .18 cubic foot displacement per sub. Think I rounded off to .40 for both.

Maybe I should add a lil more for 45's and bracing

 

[jar1zx 10+ year member]

I went with the port calculator for port length

 

[shredder1]

So how does this look51.5 width 14.5 tall 20.25 deep

Port is 13x5.875 by 41 long. Tuned to 30hz and port is 1.8 cubic foot.....hum?

Should be close to 4.5 after port and sub are taken out. .18 cubic foot displacement per sub. Think I rounded off to .40 for both.

Maybe I should add a lil more for 45's and bracing

2-12's?

 

[jar1zx 10+ year member]

Yes two hdc4 12

Might be over powering the sub's rated rms just by a little

Soundqubed 7k on bass with northstar 480 northstar 34/78 on starting with a mechman 320 elite

Plan on running 3 runs of 2/0 ofc and will have a dual alt bracket, see how that goes and may add 2nd mechman to replace factory alt.

 

[jar1zx 10+ year member]

I have mechman alt, the 2/0 ofc wire, the subs, the 7k amp.

Battery's are ordered and at least one has shipped.

Probably order the dual alt bracket for my truck soon.

And need to buy a lot of fuses

 

[hispls 5,000+ posts]

So how does this look51.5 width 14.5 tall 20.25 deep

Port is 13x5.875 by 41 long. Tuned to 30hz and port is 1.8 cubic foot.....hum?

Should be close to 4.5 after port and sub are taken out. .18 cubic foot displacement per sub. Think I rounded off to .40 for both.

Maybe I should add a lil more for 45's and bracing

Looks OK. You could probably do with a little less port if you want to pick up more volume or if 40" deep port is tough to fit. Why are you tuning so low?

 

[jar1zx 10+ year member]

Looks OK. You could probably do with a little less port if you want to pick up more volume or if 40" deep port is tough to fit. Why are you tuning so low?

Thought it would be cool to hit some lows.

32hz is 34 inch port, 35hz is 27 inch port.

I don't have a problem fitting any of the ports, what you think would sound best?

I'm not really going for all out spl or I would be tunning higher

 

[shredder1]

If you're gonna power those to the max... say 4000+... this is port velocity at 4000 watts modeled in Winisd... close to 30 m/s is where it should be... this is in the current box you've come up with... 76 in2 of port area... lemme know if you want me to find the optimum port area... for 4000 watts...

I'm just playing around and adding drivers to my database here... tryin' to help

 

[jar1zx 10+ year member]

Thx shredder1

I don't have a pc so I'm using my iPad.

Nice to have programs like port calculator that just work without having to download.

I really don't know much about my subs or amp, but subs are rms 2000 watts, amp does 7k at 14 volts 1ohm, at most I'll be pushing 15 cold to 14.7ish hot. So not much power increase.

I have no clue on box rise but I'm going to guess I will not get full 7k, if I pushed subs at 3k each I would be happy, heck I'll even take 2500rms. But until box is made and amp is clamped I guess I won't know.

Maybe other people with these subs will know how they do with box rise. I haven't seen any amp dyno test or clamp test with this soundqubed 7000 watt amp. Amp seems built well and it's power hungry so buying a 2nd 7k will be more than I want to put into alts and batts.

Kinda wish I was smart enough to make a 6th order box and have two tuned points and a bigger bandwidth.

Guess I'll be happy with a low tune box hopefully catching a good bit of the bandwidth.