4th order low end question

[DylanBunch]

All of the t/s parameters are factors not just the size of the sealed chamber

Yeah but I'm asking like if anyone knows specifically?

[hecta187]

Think I might know what your asking

to put it simple different woofers have different suspension and motor size/resistance.

Which in turn they react different because theyre built different. Each kind of woofer has its own unique reaction to certian pressure nd wattage.

Excluding the fact of enclosure design and cabin resistance for simplicity at the moment.

4th orders atleast in my experience are something that is learned by experiences with enclosure building. 4th orders can be tempermental as sh** under certian circumstances.

In this craft

experimentation is key

I built and remodified my first 4th a good 10 times

so I would just follow what info you can get from manufacturer nd keep your ratio dependable

[RAM_Designs]

FS, Vas, and Qts are going to be the big indicators as far as how a sub will react in a given box. All specs play a role but those three will give you a good idea of what the F3 is going to be in a given box. For a good sealed box sub you want a low FS and a Qts value in the .4-.6 area. Just try to keep Vas reasonable so that you don't need too big of a box to get the good low-end output. The DC Level 4 and Obsidian 15" and 18" woofers make great 4th order BP subs.

[DylanBunch]

Im not asking my question clear enough sorry guys lol what im trying to say is, for example, say i want a low end cut off of 25hz. Now take a high qts woofer and a low qts woofer, would the low qts woofer need a bigger sealed side to reach 25hz and the higher qts woofer being more sealed friendly need a smaller sealed side or is there something more to it than simple stuff like that? That was just an example and i picked qts because that mainly determines whether the sub likes sealed or ported but you catch my drift? I appreciate the help but i keep getting things back that i already i know haha i understand what determines whether the sub likes 4ths or not but Im dialing in on the lower end specifically and how to decide on my sealed space for lows I want with the sub I choose. Understand where im goin with it?

[RAM_Designs]

Too high of a Qts and/or Vas and you're going to need a pretty large box to get a low F3 point in the sealed box. Low Qts subs will have a high roll-off in a sealed box unless they have a very low FS...TC Sounds subs come to mind where you can couple low Qts with very low FS and still get good sealed results. But most low Qts subs are not low FS subs by nature, which is why they tend to not work well in 4th order BP's.