A posting on acurazine about ported enclosures...

[96MaxGLE 10+ year member]

A member over on acurazine was showing off his new Type R's in a sealed enclosure. I made the comment that he should port the subs, and after a few post saying...yea drill a hole in the box type comments...one user posted this. It just sounds like to me he really knows NOTHING about ported enclosures...

"actually u hit lower bass notes with a sealed box....sealed gives you a more dynamic range of sound. ported has to be tuned very very very differently and in a car its not practical....the port would be huge.

SQL doesnt exist its SPL and ported is recommended for SPL because you are tuning the port to a note you want to hear....it doesnt mean your going to have a good range of sound being put out through it.....it just means you have a less dynamic range of sound...your box was tuned to 28hz inside or outside of the car??? the roll off is where your range starts so if the tune was set to 28hz lets say your roll off was at 39hz...from 39hz up you would have a range of sound that was produced for you to hear....anyuthing below that sounded like ***** pu*** flapping in the wind.

the resonant frequency of the inside of the car is how you tune a ported box or even sealed for that matter to a frequency you feel is good. I have 3 10inch jl w6v2's in a a sealed enclosure producing 148dB at 1280watts"

BTW...the JL bandwagon is big over there

DISCUSS...

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[jmanpc 5,000+ posts]

Yep. Pretty much a moron. Care to poast a link so we can crash it?

 

[jmanpc 5,000+ posts]

I think I'll troll saying JL sucks.

 

[thorshammer1 10+ year member]

Link plz!

 

[IDSkoT 5,000+ posts]

Well, I think we should first address the things he's right about. Tuning drops when the box is put into a car. I believe an employee at DD (Not sure who, don't ask me) said that if you tune the box to 38, and put it in a car, the tuning will drop to 33-34 depending on the car. I can't verify this, nor do I know if there's any sort of formula that can tell you how big of a drop it is. But, much like impedance rise, we choose not to address it.

And while ported enclosures are tuned to a specific frequency, that just means the enclosure is most efficient at said frequency. But, as we all probably know, the rest of the notes should roll off and act almost identical to a sealed box. (Almost.)

But, other than that, he's full of crap.

 

[dman4486 5,000+ posts]

boy needs an edj0omication

 

[thorshammer1 10+ year member]

Well, I think we should first address the things he's right about. Tuning drops when the box is put into a car. I believe an employee at DD (Not sure who, don't ask me) said that if you tune the box to 38, and put it in a car, the tuning will drop to 33-34 depending on the car. I can't verify this, nor do I know if there's any sort of formula that can tell you how big of a drop it is. But, much like impedance rise, we choose not to address it.And while ported enclosures are tuned to a specific frequency, that just means the enclosure is most efficient at said frequency. But, as we all probably know, the rest of the notes should roll off and act almost identical to a sealed box. (Almost.)

But, other than that, he's full of crap.

Agreed. My last box was tuned to 47 and peaked at 43 once in the vehicle.

 

[jmanpc 5,000+ posts]

Agreed. My last box was tuned to 47 and peaked at 43 once in the vehicle.

in my van my box was tuned to 34 and peaked at 42 //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[audioholic 5,000+ posts]

Placing the enclosure inside your vehicle does not change where its tuned, it merely changes where the peak frequency will be in terms of output intensity. If you tune your enclosure to 35hz for example, it will start to unload below 35hz, be it anechoic or placed in a vehicle.

Some of you guys seem to be confusing these two issues.

 

[gunz4me 10+ year member]

Yep, they are mixing up the vehicle transfer function, or cabin gain as it is better known. My 1997 Civic coupe peaks in the 50 Hz range, around 54 or 55 Hz IIRC, and my dd1010 is tuned @ 35 Hz!

 

[Seth_3515 10+ year member]

Well, I think we should first address the things he's right about. Tuning drops when the box is put into a car. I believe an employee at DD (Not sure who, don't ask me) said that if you tune the box to 38, and put it in a car, the tuning will drop to 33-34 depending on the car. I can't verify this, nor do I know if there's any sort of formula that can tell you how big of a drop it is. But, much like impedance rise, we choose not to address it.And while ported enclosures are tuned to a specific frequency, that just means the enclosure is most efficient at said frequency. But, as we all probably know, the rest of the notes should roll off and act almost identical to a sealed box. (Almost.)

But, other than that, he's full of crap.

BAMM!!! DD recommends 40 hz enclosures because the tuning drops quite a bit when put into a car... my box i built for a 9515 to DD spec dropped 5hz when its in my car. i do not know the formula either (would probably be different for every car) but DD knew it would drop and adjusted their boxes accordingly..

 

[dragnix 5,000+ posts]

I could have sworn that the reason that DD and AQ recommends the higher tuning because their suspension is really stiff and will not unload when playing a lot lower than tuning.

 

[Seth_3515 10+ year member]

even still it is higher than normal tuning.. normal tuning will drop also when in your car because of obstructions... yes they like higher tuning and you are still giving it to them

 

[Buck 5,000+ posts]

I could have sworn that the reason that DD and AQ recommends the higher tuning because their suspension is really stiff and will not unload when playing a lot lower than tuning.

That must be a safety just in case your tuning doesn't change as much as it's supposed to when it's in the car.

And, DDs and AQs can take some power......

Btw, I hit 24 hz on my HDC318 in my box. It was scary.

 

[ramos 5,000+ posts]

BAMM!!! DD recommends 40 hz enclosures because the tuning drops quite a bit when put into a car... my box i built for a 9515 to DD spec dropped 5hz when its in my car. i do not know the formula either (would probably be different for every car) but DD knew it would drop and adjusted their boxes accordingly..

I could have sworn that the reason that DD and AQ recommends the higher tuning because their suspension is really stiff and will not unload when playing a lot lower than tuning.

even still it is higher than normal tuning.. normal tuning will drop also when in your car because of obstructions... yes they like higher tuning and you are still giving it to them

That must be a safety just in case your tuning doesn't change as much as it's supposed to when it's in the car.
And, DDs and AQs can take some power......

Btw, I hit 24 hz on my HDC318 in my box. It was scary.

read //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Placing the enclosure inside your vehicle does not change where its tuned, it merely changes where the peak frequency will be in terms of output intensity. If you tune your enclosure to 35hz for example, it will start to unload below 35hz, be it anechoic or placed in a vehicle.
Some of you guys seem to be confusing these two issues.