12s in 4th order VS 15s ported

[Bryan90 0]

I have 2 sa 12s in a ported box and I've been thinking of trying to build a 4th order or just buying some sa 15s and building a ported box for them. So my question is could the 12s be louder in a 4th order than the 15s in a ported box tuned to say 30hz? They would both be ran on a saz1500 and space isn't an issue for either and they would be ran in the same vehicle

[lithium 358]

12s in a bandpass wont gain output over a conventional ported box. 

[Bryan90 0]

I thought 4th order were suppose to be louder or is it more about having a broader frequency range but equal output? Idk that's why I'm asking

[lithium 358]

I thought 4th order were suppose to be louder or is it more about having a broader frequency range but equal output? Idk that's why I'm asking

nope just some bullshit that spread around the internet. 

[95Honda 486]

Your 12s are already in a 4th order enclosure.

 

Are you wanting to build a bandpass?  They are more complicated and only potential gains in output over a small range of frequencies.  If you aren't really good at designing and building enclosures now, I would suggest building your knowlege base or hiring out the work.

[Bryan90 0]

Yea I want to build a bandpass I'm just used to referring to them as 4th orders but I have a decent knowledge of box building. I've built multiple ported boxes but never a bandpass but I've been reading about designs and different ratios. I believe the hardest part is tuning. I've built my last couple boxes with interchangeable ports so I could do that to test out which frequency would work best for me.

[lithium 358]

Yea I want to build a bandpass I'm just used to referring to them as 4th orders but I have a decent knowledge of box building. I've built multiple ported boxes but never a bandpass but I've been reading about designs and different ratios. I believe the hardest part is tuning. I've built my last couple boxes with interchangeable ports so I could do that to test out which frequency would work best for me.

 

the ratio business is also BS. what are you trying to achieve? 

[Bryan90 0]

In this thread I was wanting to know if it's worth my time to try and build a bandpass for the 12s or just save up for 15s but overall just a loud daily setup

[lithium 358]

In this thread I was wanting to know if it's worth my time to try and build a bandpass for the 12s or just save up for 15s but overall just a loud daily setup

nope, either try a high tuning in the current box or save for 15s. 

[Bryan90 0]

I already went from 30hz to 36hz and currently 45hz port... High tuned ports aren't really my thing I like my lows

[Tenacious 32]

SAs are very 4th order bandpass friendly. It can't hurt to try if you already have the subs - and if you don't like the output you can always go with the two 15s.

 

They do well with around 1 cube sealed and anywhere from 2-3 cubes ported each, and port area should be around half of your total cone area. This puts your sealed resonance around 45-47, and tuning the ported section to that number yields good results.

[Bryan90 0]

That's kinda what I was thinking I might as we'll try. So your saying for 2 12s 2 cubes sealed and between 4-6 cubes ported. What would be the benefit of going with 6 cubes I want to be able to play 25hz to atleast 40hz.

[Tenacious 32]

 

Yea I want to build a bandpass I'm just used to referring to them as 4th orders but I have a decent knowledge of box building. I've built multiple ported boxes but never a bandpass but I've been reading about designs and different ratios. I believe the hardest part is tuning. I've built my last couple boxes with interchangeable ports so I could do that to test out which frequency would work best for me.

 

the ratio business is also BS. what are you trying to achieve? 

 

 

The ratio business is actually not BS. Changing the ported size affects the response greatly, with higher ratios generally having a more peaky output and lower ratios generally having a wider, flatter response.

[Tenacious 32]

That's kinda what I was thinking I might as we'll try. So your saying for 2 12s 2 cubes sealed and between 4-6 cubes ported. What would be the benefit of going with 6 cubes I want to be able to play 25hz to atleast 40hz.

 

If you're wanting to play that low, moving up to about 2.4 cubes sealed may benefit you. You would probably see more efficiency from 6 cubes ported, but you may start to lose some high and/or low end response. 

 

For what it's worth, I know someone who did a forward firing 4th order with 2 SA-12s in a Tahoe. He used 2 cubes for the sealed chamber and had around a 4:1 ratio. It played flat within 2dB from 25-60Hz and was doing very respectable numbers when measured with a TermLab.

Edited June 28, 2014 by Tenacious

[frogcase2002 393]

What are all the measurements of your current enclosure? How are you doing your changeable ports?

[Bryan90 0]

I'm at work so I can't get the dimensions but I remember it being around 3.8 cubes after displacement. I use a rubber weather stripping and just bolt it on. It seems to work I can't feel any leaks

[frogcase2002 393]

I'm at work so I can't get the dimensions but I remember it being around 3.8 cubes after displacement. I use a rubber weather stripping and just bolt it on. It seems to work I can't feel any leaks

I mean how are you changing the tuning? Like are you just putting different length ports in the enclosure?

[Bryan90 0]

Oh.. Yea that's how

[frogcase2002 393]

Well that will be changing the internal volume also. . How did you figure out your gross and net volume?

[Bryan90 0]

I got the net from a kicker u app length x width x height and I kinda guessed on what the net is from the displacement of each sub and what I think is the displacement of the port but I made this box awhile back so I don't remember exact numbers plus I I'm not a math wiz so i don't know how to figure out the ports displacement anyways

[ssh 924]

I got the net from a kicker u app length x width x height and I kinda guessed on what the net is from the displacement of each sub and what I think is the displacement of the port but I made this box awhile back so I don't remember exact numbers plus I I'm not a math wiz so i don't know how to figure out the ports displacement anyways

So you don't know where the enclosure is tuned to.

If it were me I'd go with more cone area and ported box.

[frogcase2002 393]

I got the net from a kicker u app length x width x height and I kinda guessed on what the net is from the displacement of each sub and what I think is the displacement of the port but I made this box awhile back so I don't remember exact numbers plus I I'm not a math wiz so i don't know how to figure out the ports displacement anyways

Your current enclosure mite not be what you think it is so I would probably figure all that out first. . Because who knows, it could be way off and you mite really be happy with a regular ported enclosure designed right. . . . .

When you get a chance post the dimensions of the enclosure and port area and length. .and Type/thickness of wood

[Bryan90 0]

I have a general idea. I just can't for sure say a exact number and I will measure it when I get home and post it

[Bryan90 0]

It's 3/4 in mdf

32 width

15 1/4 height

20 1/4 depth

[frogcase2002 393]

Port size?