4th order/ sealed bandpass discussion

[flastrongman 8]

Saw a similar post on ****, but it seems like everyone has an opinion without any real experience to back it up. Why do people in car audio hand out info so freely when they have no clue on the subject? I've been building boxes for over 10 years now and I feel like I've just scratched the surface of enclosure design. But if you post a question on boxes on just about any forum you'll get a flood of advice from kids that have never even built a box. Pretty frustrating. Is there any forums for just box builders? If not, there should be. Kirby get on it.

Anyways, sorry for the rant. On to the question

In your experience with 4th orders, what ratio sealed/ported do you think works the best and why? Also, the trend seems to be tiny sealed sections, why is this? I know it has a lot to do with power handling, but is that all?

Please do not respond to this if you have not designed and built at least 3 4th orders yourself. I will verbally "tar and feather" you if you come on here knowing all the answers without any experience.

[slim2fattycake 85]

just passing through cus I'd like to know too.

[95Honda 486]

Why don't you just read up on the ratios and expected ripple? You obviously have the experience.....

[Impious 1,476]

Someone who understands the physics involved would be more than capable of answering your questions without necessarily having to have built any (or 3) themselves. The physics doesn't change and results can be predicted pretty easily if the individual is competent.

The only thing that will change is the subjective perception of the "sound" and personal preference which is going to be different from person to person so any answer you receive to that end will essentially be meaningless.

And on the reverse side, someone could have built a dozen bandpass enclosures themselves without having the slightest clue of what is actually going on and why. Those responses would be essentially meaningless as well.

Your first question lends itself to being subjective. What one finds works for them may not be what works for you or me. It depends on the goals of the individual and the system. So you want people to come in and give you a consensus on a subjective topic? Good luck with that. Personally I'd rather have the objective information from someone who actually understands the concept rather than rely on someone with an arbitrary number of feathers in their cap who may or may not have an actual understanding of the topic, but who can easily give a quick (but useless) subjective opinion of what "worked for them".

It sounds to me like it's time for you to pick up a good book on enclosure design so that you can answer the objective questions yourself, which will allow you to arrive at the subjective answer of what works best for you.

[KU40 173]

When you say the trend is tiny sealed enclosures, who are you talking about? What people want tiny sealed enclosures? Certainly not SPL guys. But people with more quality and space-saving oriented systems, maybe, because power is cheap these days. According to Hoffman's law you can have two of three- small enclosure size, low frequency extension, or efficiency. Well, with power becoming so cheap these days, why get a woofer that's efficient when you can throw gobs of power at it and still have LFE and small enclosure size?

[REVpuggie 23]

When you say the trend is tiny sealed enclosures, who are you talking about? What people want tiny sealed enclosures? Certainly not SPL guys. But people with more quality and space-saving oriented systems, maybe, because power is cheap these days. According to Hoffman's law you can have two of three- small enclosure size, low frequency extension, or efficiency. Well, with power becoming so cheap these days, why get a woofer that's efficient when you can throw gobs of power at it and still have LFE and small enclosure size?

Not entirely true , wanting that small sealed setion would depend on how high you'd want the tuning to be ...so in bassracing or european ESPL that will definatly work with a very big vented side.

[///M5 2,833]

When you say the trend is tiny sealed enclosures, who are you talking about? What people want tiny sealed enclosures? Certainly not SPL guys. But people with more quality and space-saving oriented systems, maybe, because power is cheap these days. According to Hoffman's law you can have two of three- small enclosure size, low frequency extension, or efficiency. Well, with power becoming so cheap these days, why get a woofer that's efficient when you can throw gobs of power at it and still have LFE and small enclosure size?

Not entirely true , wanting that small sealed setion would depend on how high you'd want the tuning to be ...so in bassracing or european ESPL that will definatly work with a very big vented side.

How is Hoffman's Iron Law not 100% true??

[REVpuggie 23]

When you say the trend is tiny sealed enclosures, who are you talking about? What people want tiny sealed enclosures? Certainly not SPL guys. But people with more quality and space-saving oriented systems, maybe, because power is cheap these days. According to Hoffman's law you can have two of three- small enclosure size, low frequency extension, or efficiency. Well, with power becoming so cheap these days, why get a woofer that's efficient when you can throw gobs of power at it and still have LFE and small enclosure size?

Not entirely true , wanting that small sealed setion would depend on how high you'd want the tuning to be ...so in bassracing or european ESPL that will definatly work with a very big vented side.

How is Hoffman's Iron Law not 100% true??

wasn't debating on Hoffmanns iron law ...its an iron law .....

In a 4th order bandpass enclosure efficieny is not determined by the size of the sealed side but the size and tuning of the vented side

[UpGradde 7]

I've only built one 4th order bp, so I guess my opinion is invalid.

[Duran 387]

When you say the trend is tiny sealed enclosures, who are you talking about? What people want tiny sealed enclosures? Certainly not SPL guys. But people with more quality and space-saving oriented systems, maybe, because power is cheap these days. According to Hoffman's law you can have two of three- small enclosure size, low frequency extension, or efficiency. Well, with power becoming so cheap these days, why get a woofer that's efficient when you can throw gobs of power at it and still have LFE and small enclosure size?

Not entirely true , wanting that small sealed setion would depend on how high you'd want the tuning to be ...so in bassracing or european ESPL that will definatly work with a very big vented side.

How is Hoffman's Iron Law not 100% true??

wasn't debating on Hoffmanns iron law ...its an iron law .....

In a 4th order bandpass enclosure efficieny is not determined by the size of the sealed side but the size and tuning of the vented side

A sealed enclosures efficiency chanced based on internal volume as does a vented enclosure, I think. Lol

[Aaron Clinton 2,372]

Saw a similar post on ****, but it seems like everyone has an opinion without any real experience to back it up. Why do people in car audio hand out info so freely when they have no clue on the subject? I've been building boxes for over 10 years now and I feel like I've just scratched the surface of enclosure design. But if you post a question on boxes on just about any forum you'll get a flood of advice from kids that have never even built a box. Pretty frustrating. Is there any forums for just box builders? If not, there should be. Kirby get on it.

Anyways, sorry for the rant. On to the question

In your experience with 4th orders, what ratio sealed/ported do you think works the best and why? Also, the trend seems to be tiny sealed sections, why is this? I know it has a lot to do with power handling, but is that all?

Please do not respond to this if you have not designed and built at least 3 4th orders yourself. I will verbally "tar and feather" you if you come on here knowing all the answers without any experience.

:lol:

But on a serious note, what is your goal from the 4th order other then their obvious strengths?

[REVpuggie 23]

When you say the trend is tiny sealed enclosures, who are you talking about? What people want tiny sealed enclosures? Certainly not SPL guys. But people with more quality and space-saving oriented systems, maybe, because power is cheap these days. According to Hoffman's law you can have two of three- small enclosure size, low frequency extension, or efficiency. Well, with power becoming so cheap these days, why get a woofer that's efficient when you can throw gobs of power at it and still have LFE and small enclosure size?

Not entirely true , wanting that small sealed setion would depend on how high you'd want the tuning to be ...so in bassracing or european ESPL that will definatly work with a very big vented side.

How is Hoffman's Iron Law not 100% true??

wasn't debating on Hoffmanns iron law ...its an iron law .....

In a 4th order bandpass enclosure efficieny is not determined by the size of the sealed side but the size and tuning of the vented side

A sealed enclosures efficiency chanced based on internal volume as does a vented enclosure, I think. Lol

not sure I'm reading this right because my english is slightly challanged , maybe I'm going mad ,

small sealed side = higher tuning on the sealed end , big sealed side = lower tuning on the sealed end , to me that is far more important than the gain in efficiency you'd get from it ....how broad you want the band the sub is playing in / if and where you'd want it to peak