why are aero ports better than any other?

[audioholic 5,000+ posts]

Yes, that makes sense. However, I still have yet gotten a concrete answer as to why a low frequency and strong throw is more likely to break a joint opposed to a higher frequency and lower throw. What if both produce the same SPL inside the box? What's the most likely outcome?

SPL stands for sound pressure level. If both situations create the same amount of pressure within the box, the same amount of stress is placed on the walls, and therefor the outcome should be the same in either case.

 

[tooloud4tv 10+ year member]

Yes, that makes sense. However, I still have yet gotten a concrete answer as to why a low frequency and strong throw is more likely to break a joint opposed to a higher frequency and lower throw. What if both produce the same SPL inside the box? What's the most likely outcome?

well kota even @ the same spl level the Lower note will always need to have twice the energy@ force to even be @ the same level of the higher note with less throw. therefore IMO thats why the lower note with strong throw would likely blow an box apart vs the higher note with less throw. even @ the same spl levles. its proven that lower notes need more power/energy to be @ the same spl level as an higher note. ex: it may take 400 watts to reach an 141@ 60hz but it may take 2000 watts to do an 141 @ 20hz and not to mention even more cone area

 

[Lakota 5,000+ posts]

SPL stands for sound pressure level. If both situations create the same amount of pressure within the box, the same amount of stress is placed on the walls, and therefor the outcome should be the same in either case.

But what about resonance? Many things in nature will flex more more at a lower frequency compared to a higher one. Resonance has been the cause of many engineering failures. Does MDF not resonate more at a lower frequency?

 

[audioholic 5,000+ posts]

But what about resonance? Many things in nature will flex more more at a lower frequency compared to a higher one. Resonance has been the cause of many engineering failures. Does MDF not resonate more at a lower frequency?

Okay now were are venturing into different territory. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
When building a speaker cabinet, its resonant freq MUST be designed to be outside the operating range of the speaker system. Otherwise when playing this frequency, as you suggest, the enclosure itself will resonate... at best creating non-intended sounds. At worst, yes it will lead to premature deterioration of the enclosure itself.

When building a speaker box, you have 2 choices.. try to raise the res freq of the box above the operating range of the speaker, or you can try to lower it below this range. Most people think you only work to go below it, discussing how heavy their boxes are, how dense and massive etc... not realizing their box's res freq is actually ABOVE their speaker's operating range.

Lowering res freq generally happens by adding mass/weight. The heavier it is, the lower the freq it takes to make it resonate. This is much more common in home audio than car audio. People whoi biuld concrete speaker enclosures are going for a very low res freq, for example. But you dont find many heavy concrete enclosures in car audio.

Raising res freq happens by increasing rigidity. This is generally done by using internal bracing. The box can be infinitely light, so long as it is rigid enough to not flex until it encounters a note above the operating range of the speaker system placed in it. This is, by far and away, the most popular design type in car audio. Even those guys with double wall boxes and triple wall baffles, stiffen it all up with internal bracing. This is what happens when you dont understand what Ive described here... building a box while moving in both directions (adding mass AND increasing rigidity). Although double-walls have other advantages too (added strength through a simple type of lamination). But generally speaking both methods need not be applied.

Quick recap. Adding weight/mass lowers res freq, adding bracing increases rigidity and raises res freq. Either method can acheive the goals you want, so long as you understand this.

Cheers.

 

[Lakota 5,000+ posts]

Okay now were are venturing into different territory. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
When building a speaker cabinet, its resonant freq MUST be designed to be outside the operating range of the speaker system. Otherwise when playing this frequency, as you suggest, the enclosure itself will resonate... at best creating non-intended sounds. At worst, yes it will lead to premature deterioration of the enclosure itself.

When building a speaker box, you have 2 choices.. try to raise the res freq of the box above the operating range of the speaker, or you can try to lower it below this range. Most people think you only work to go below it, discussing how heavy their boxes are, how dense and massive etc... not realizing their box's res freq is actually ABOVE their speaker's operating range.

Lowering res freq generally happens by adding mass/weight. The heavier it is, the lower the freq it takes to make it resonate. This is much more common in home audio than car audio. People whoi biuld concrete speaker enclosures are going for a very low res freq, for example. But you dont find many heavy concrete enclosures in car audio.

Raising res freq happens by increasing rigidity. This is generally done by using internal bracing. The box can be infinitely light, so long as it is rigid enough to not flex until it encounters a note above the operating range of the speaker system placed in it. This is, by far and away, the most popular design type in car audio. Even those guys with double wall boxes and triple wall baffles, stiffen it all up with internal bracing. This is what happens when you dont understand what Ive described here... building a box while moving in both directions (adding mass AND increasing rigidity). Although double-walls have other advantages too (added strength through a simple type of lamination). But generally speaking both methods need not be applied.

Quick recap. Adding weight/mass lowers res freq, adding bracing increases rigidity and raises res freq. Either method can acheive the goals you want, so long as you understand this.

Cheers.

We need more threads like this where I actually learn something.

So can box resonance be both a positive and negative thing? I've read about CRX's losing sound pressure when a double baffle was applied to their fart box. Supposebly it is good for their small/high tuned boxes to resonate.

 

[audioholic 5,000+ posts]

Well, resonating does imply adding sound. But remember, it also means the enclsoure volume is constantly changing. Box flex being a positive may be normal in SPL worlds (although ive never heard of it), but generally speaking you want your box's resonate frequency to remain outside the speaker system's operating range.

 

[the727kid 10+ year member]

Going back to the basic question.. what are dis-advantages of the aero? I am considering building a new box with aeros to possibly gain some airspace for subs, they are starved right now for airpsace.

 

[audioholic 5,000+ posts]

Going back to the basic question.. what are dis-advantages of the aero? I am considering building a new box with aeros to possibly gain some airspace for subs, they are starved right now for airpsace.

Price mostly.

 

[Lakota 5,000+ posts]

Price mostly.

That and it's more difficult to get an accurate port area unlike a slot port where you can get nearly any port area that you want. However, it's not really that big of a deal.