Jump to content
coltpurdy16

is the SP4 for ported or sealed boxes?

Recommended Posts

They have their respective pro's and cons..

Share this post


Link to post
Share on other sites

Sealed as it is less efficient than a typical 4th order box.

Share this post


Link to post
Share on other sites

You will get more output, all else being equal, with a vented alignment.

Sounds like that is all you want.

Share this post


Link to post
Share on other sites

You will get more output, all else being equal, with a vented alignment.

Sounds like that is all you want.

I see that Fi recommends ported enclosure sizes for a 15" SP4 from 3^3ft to 5^3ft.

What will be the differences between a 3^3ft ported enclosure and a 5^3ft ported enclosure with a single 15" SP4? Tuning freq and power (2k-2.5k) the same.

Share this post


Link to post
Share on other sites

You will get more output, all else being equal, with a vented alignment.

Sounds like that is all you want.

I see that Fi recommends ported enclosure sizes for a 15" SP4 from 3^3ft to 5^3ft.

What will be the differences between a 3^3ft ported enclosure and a 5^3ft ported enclosure with a single 15" SP4? Tuning freq and power (2k-2.5k) the same.

Your options are, high efficiency, low end extension, small enclosure size; pick two.

Apply that law to Fi's recommendations and you'll answer your own question.

Share this post


Link to post
Share on other sites

What do you mean "most power"? You want to just put a lot of power just cause. Or to be loud?

Share this post


Link to post
Share on other sites

You will get more output, all else being equal, with a vented alignment.

Sounds like that is all you want.

I see that Fi recommends ported enclosure sizes for a 15" SP4 from 3^3ft to 5^3ft.

What will be the differences between a 3^3ft ported enclosure and a 5^3ft ported enclosure with a single 15" SP4? Tuning freq and power (2k-2.5k) the same.

Your options are, high efficiency, low end extension, small enclosure size; pick two.

Apply that law to Fi's recommendations and you'll answer your own question.

That is a good general summary.

Specifically what will be the difference between 3^3ft and 5^ft? I.e. 3^ft offers small enclosure size and...... I.e. 5^ft offers high efficiency and....

Low end extension is derived from tuning frequency. Or am I missing something?

...so......

3^3ft offers a small enclosure size and low end extension?

5^3ft offers high efficiency and low end extension?

What is the difference in efficiency between the two enclosure sizes and 2k-2.5k power?

Share this post


Link to post
Share on other sites

the larger the ported box, while maintaining the same tuning, the higher the SPL output will be testing the same low end note(s).

Make a ported enclosure too large, you can tune in the 40s, for example, and still peak BELOW tuning due to the enormous volume in use.

I had to experience this before with a friend's install and it was interesting to see and watch how the enclosure was able to alter the peak the way it did.

After talking with others about it, i found out it wasn't so uncommon either as one of my other competitor friends had won finals where his design was tuned in the low 40s yet peaked in the high 30s.

You do not not the box to be too large or the low end will peak higher over the 40hz+ range.

Likewise, too small and the low end will just be audible vs felt quite well, :)

Share this post


Link to post
Share on other sites

the larger the ported box, while maintaining the same tuning, the higher the SPL output will be testing the same low end note(s).

Make a ported enclosure too large, you can tune in the 40s, for example, and still peak BELOW tuning due to the enormous volume in use.

I had to experience this before with a friend's install and it was interesting to see and watch how the enclosure was able to alter the peak the way it did.

After talking with others about it, i found out it wasn't so uncommon either as one of my other competitor friends had won finals where his design was tuned in the low 40s yet peaked in the high 30s.

You do not not the box to be too large or the low end will peak higher over the 40hz+ range.

Likewise, too small and the low end will just be audible vs felt quite well, :)

I have wondered how that worked well. Arent subs suppose to reach/exceed their mechanical limit below tuning?

Share this post


Link to post
Share on other sites

suppose to?

Nobody wants it too.. the reality is anything is possible, you can control this if you really want to.

Share this post


Link to post
Share on other sites

suppose to?

Nobody wants it too.. the reality is anything is possible, you can control this if you really want to.

(shhhhhh..they are already confused enough as it is. leave well enough alone please because stuff like that will cause people to go out and try it and shred their soft parts to hades and back.)

Do not tune a box to 40+Hz and intend on playing music with it with a high excursion long coil woofer and no subsonic filter. You are asking for trouble.

Share this post


Link to post
Share on other sites

You will get more output, all else being equal, with a vented alignment.

Sounds like that is all you want.

I see that Fi recommends ported enclosure sizes for a 15" SP4 from 3^3ft to 5^3ft.

What will be the differences between a 3^3ft ported enclosure and a 5^3ft ported enclosure with a single 15" SP4? Tuning freq and power (2k-2.5k) the same.

Your options are, high efficiency, low end extension, small enclosure size; pick two.

Apply that law to Fi's recommendations and you'll answer your own question.

That is a good general summary.

Specifically what will be the difference between 3^3ft and 5^ft? I.e. 3^ft offers small enclosure size and...... I.e. 5^ft offers high efficiency and....

Low end extension is derived from tuning frequency. Or am I missing something?

...so......

3^3ft offers a small enclosure size and low end extension?

5^3ft offers high efficiency and low end extension?

What is the difference in efficiency between the two enclosure sizes and 2k-2.5k power?

Download WinISD or Unibox.

Input SP4 parameters.

Load the sub into both enclosures.

Look at graphs and compare differences.

Arrive at the answer to your question.

Share this post


Link to post
Share on other sites

suppose to?

Nobody wants it too.. the reality is anything is possible, you can control this if you really want to.

(shhhhhh..they are already confused enough as it is. leave well enough alone please because stuff like that will cause people to go out and try it and shred their soft parts to hades and back.)

Do not tune a box to 40+Hz and intend on playing music with it with a high excursion long coil woofer and no subsonic filter. You are asking for trouble.

lol. Don't be scured. :dancing:

Share this post


Link to post
Share on other sites

×