Port Area

[BKOLFO4 29]

On the second part of your question.

A drop in comparison to me can be fair if the box is within the specs suggested for both drivers.

But you are also correct that some people do not consider it fair since they may not be in the same alignment.

You also have to look at the frequency they peak at. The true comparison would not be in a car where the cabin gain of the car may factor into the spl readings due to the two different drivers peaking at different frequencies. In one persons car on the same power in the same box, the BL might be louder than the BTL. In a different box or a different car, the opposite maybe true. A lower peak frequency may make one seem louder while really the other is louder on a meter.

There are a lot of factors when making comparisons. Another subject I hate. The assumption that the driver with rated power handling closest to the amount of power you have is the beat choice drives me insane!!

Brian

[thebiggmann12 14]

so bkolfo4, i should go with durans original recommendation? keep in mind that i will b running 1500 watts to it.

[jcarter1885 995]

On the second part of your question.

A drop in comparison to me can be fair if the box is within the specs suggested for both drivers.

But you are also correct that some people do not consider it fair since they may not be in the same alignment.

You also have to look at the frequency they peak at. The true comparison would not be in a car where the cabin gain of the car may factor into the spl readings due to the two different drivers peaking at different frequencies. In one persons car on the same power in the same box, the BL might be louder than the BTL. In a different box or a different car, the opposite maybe true. A lower peak frequency may make one seem louder while really the other is louder on a meter.

There are a lot of factors when making comparisons. Another subject I hate. The assumption that the driver with rated power handling closest to the amount of power you have is the beat choice drives me insane!!

Brian

This should be stickied, I used to think like that and being on this forum has opened my eyes up to a lot of things. When it comes to picking drivers I have to actually do some homework on them and there T/S Paramaters instead of just looking at price and if its rms is the same as my amplifier (how I used to be a year ago). I appreciate all the info and time your are putting aside to answer my questions.

OP(Brandon) I do apologize for getting your thread off topic.

[thebiggmann12 14]

On the second part of your question.

A drop in comparison to me can be fair if the box is within the specs suggested for both drivers.

But you are also correct that some people do not consider it fair since they may not be in the same alignment.

You also have to look at the frequency they peak at. The true comparison would not be in a car where the cabin gain of the car may factor into the spl readings due to the two different drivers peaking at different frequencies. In one persons car on the same power in the same box, the BL might be louder than the BTL. In a different box or a different car, the opposite maybe true. A lower peak frequency may make one seem louder while really the other is louder on a meter.

There are a lot of factors when making comparisons. Another subject I hate. The assumption that the driver with rated power handling closest to the amount of power you have is the beat choice drives me insane!!

Brian

This should be stickied, I used to think like that and being on this forum has opened my eyes up to a lot of things. When it comes to picking drivers I have to actually do some homework on them and there T/S Paramaters instead of just looking at price and if its rms is the same as my amplifier (how I used to be a year ago). I appreciate all the info and time your are putting aside to answer my questions.

OP(Brandon) I do apologize for getting your thread off topic.

lol it hasnt gotten off topic...lots of good info here

[BKOLFO4 29]

It is an 18, correct? Did I read you are putting it in 5 cuft? I think 80 to 100 sqin is enough for your application. If you can design a box with more, great. If not, don't lose sleep over it.

Brian

[thebiggmann12 14]

yea i can get the whole 145 that duran said, i already had my back seat out so its not a big deal to make a bigger box lol.

[BKOLFO4 29]

Why 5 ft? Is that what sundown recommends? Seems small for an 18, but I have never looked at that one.

[thebiggmann12 14]

yea they recommend 4-5. i figured 5 would be the best beings that im not running a ton of power so i would be more efficient.

[Don Ganso 13]

Eye opening thread here.

Tuned in fo sho.

[stealth 113]

brandon i told you approx 75-85..... also reason being that port area would be too much is his box would need to be hella big at a low tuning port would be a mile long and he has a small car. i just gave my insight as a reference. i also stated that you should retune from that point. i never said 15-17 per is the magic number, nor did i state that t/s specs dont come into play when building a box. all you guys rag on my because im from hawaii. GUESS WHAT MUTHAFUKAS I DO LIVE BY A VOLCONO DIAMOND HEAD FTMFW

[Duran 387]

Hawaii is a volcano. So you know for future reference.

[porkchop 304]

if i read this correctly, i found that i should increase my port area some as well, to be closer to the proper area.

i have not wrote the math out yet, so i do not know if the two answers will be the same, however i did see this Minimum Usable Vent Diameter calculator in my favorites.....

I will compare it to this formula to see if they hold the same results.......

it indeed does provide a larger port area than "the rule" would of suggested. lol

I agree, these debates bring out the good stuff, I only dream of a day, where all are grouped into one place, a bullet proof format , from start to finish, on enclosure design, with all the "good" info....

just re-checking myself on a few things.... my x-max was rated in inches....( .75" ) , one way..... so this is 19mm. , right? i mean that is what i plug in for the x-max value.

the calculater that i found suggest the diameter, would this be equal of the area of a slot port or sqaure port..... the area is.....the area?

thanks for the help.

chop

[Julian 641]

Hawaii is a volcano. So you know for future reference.

LOLZ

[///M5 2,833]

I only dream of a day, where all are grouped into one place, a bullet proof format , from start to finish, on enclosure design, with all the "good" info....

You've read before on here that you can just pick up Vance Dickason's Loudspeaker Design Cookbook and you will have "all" the good info, but that I guess you already knew.

[BKOLFO4 29]

if i read this correctly, i found that i should increase my port area some as well, to be closer to the proper area.

i have not wrote the math out yet, so i do not know if the two answers will be the same, however i did see this Minimum Usable Vent Diameter calculator in my favorites.....

I will compare it to this formula to see if they hold the same results.......

it indeed does provide a larger port area than "the rule" would of suggested. lol

I agree, these debates bring out the good stuff, I only dream of a day, where all are grouped into one place, a bullet proof format , from start to finish, on enclosure design, with all the "good" info....

just re-checking myself on a few things.... my x-max was rated in inches....( .75" ) , one way..... so this is 19mm. , right? i mean that is what i plug in for the x-max value.

the calculater that i found suggest the diameter, would this be equal of the area of a slot port or sqaure port..... the area is.....the area?

thanks for the help.

chop

As far as I can tell, that calculator uses the formula. I have never had a problem with it. It gives the minimum diameter for a round port, the minimum area, and the side length if your port happens to be a square.

As I said above, I design a lot of boxes with much less port area and they work great. . .In a car, it is normally a trade off due to size constraints.

Brian

[BKOLFO4 29]

I only dream of a day, where all are grouped into one place, a bullet proof format , from start to finish, on enclosure design, with all the "good" info....

You've read before on here that you can just pick up Vance Dickason's Loudspeaker Design Cookbook and you will have "all" the good info, but that I guess you already knew.

Great book. Read it cover to cover many times. Have it on my desk at work right now. Problem is that it is too technical for most people. They just want to know how it is done, not why it is done that way My guess - that is why all of these "close enough" estimates came to be. . .

Brian

[jcarter1885 995]

I only dream of a day, where all are grouped into one place, a bullet proof format , from start to finish, on enclosure design, with all the "good" info....

You've read before on here that you can just pick up Vance Dickason's Loudspeaker Design Cookbook and you will have "all" the good info, but that I guess you already knew.

Great book. Read it cover to cover many times. Have it on my desk at work right now. Problem is that it is too technical for most people. They just want to know how it is done, not why it is done that way My guess - that is why all of these "close enough" estimates came to be. . .

Brian

The next thing to get purchase on my car audio agenda, I need this book.

[///M5 2,833]

I only dream of a day, where all are grouped into one place, a bullet proof format , from start to finish, on enclosure design, with all the "good" info....

You've read before on here that you can just pick up Vance Dickason's Loudspeaker Design Cookbook and you will have "all" the good info, but that I guess you already knew.

Great book. Read it cover to cover many times. Have it on my desk at work right now. Problem is that it is too technical for most people. They just want to know how it is done, not why it is done that way My guess - that is why all of these "close enough" estimates came to be. . .

Brian

Its too bad, it really isn't that hard of a read. It will require you to think though, which of course is exactly what I would consider the "good info". If all you want are shortcuts, then you might as well never design anything yourself anyways.

[///M5 2,833]

I only dream of a day, where all are grouped into one place, a bullet proof format , from start to finish, on enclosure design, with all the "good" info....

You've read before on here that you can just pick up Vance Dickason's Loudspeaker Design Cookbook and you will have "all" the good info, but that I guess you already knew.

Great book. Read it cover to cover many times. Have it on my desk at work right now. Problem is that it is too technical for most people. They just want to know how it is done, not why it is done that way My guess - that is why all of these "close enough" estimates came to be. . .

Brian

The next thing to get purchase on my car audio agenda, I need this book.

Don't be afraid of an older version. The updates aren't worth extra. I doubt you'll ever build any of his speaker plans which have been added (and would even say you shouldn't).

[jcarter1885 995]

I only dream of a day, where all are grouped into one place, a bullet proof format , from start to finish, on enclosure design, with all the "good" info....

You've read before on here that you can just pick up Vance Dickason's Loudspeaker Design Cookbook and you will have "all" the good info, but that I guess you already knew.

Great book. Read it cover to cover many times. Have it on my desk at work right now. Problem is that it is too technical for most people. They just want to know how it is done, not why it is done that way My guess - that is why all of these "close enough" estimates came to be. . .

Brian

The next thing to get purchase on my car audio agenda, I need this book.

Don't be afraid of an older version. The updates aren't worth extra. I doubt you'll ever build any of his speaker plans which have been added (and would even say you shouldn't).

Thanks for the input, what editions do you suggest I shoot for.

[///M5 2,833]

Any. Just realize the older the cheaper. The math and ideas are all the same.

*I've never held a first edition, but 3rd and beyond I know covers more than you'll absorb in a sitting or 10

[porkchop 304]

i always kick myself in the rear when i spend the little extra cash i have on the wrong stuff....

i really looked forward to getting a hold of it. to be real honest, I had sorta forgot about it ,

you had mentioned it before,

i tell you what, i will make it my next goal/ purchase....

and when i get it, i will give you a shout out for the suggestion...

if i run into a area that i am truly stuck....

then yes, I Already Know where to come for usefull help...

thanks for the input fellas

chop

[porkchop 304]

looked around just for a sec,

the fifth edition can be had for $37 bucks......

the seventh is just a hair under $40 bucks....

what is the latest version, just curious?

hollar at you later...

chop

[///M5 2,833]

I believe 7th, think mine is 5th. I wouldn't save $3, but I have seen used earlier additions for less than $20.

[porkchop 304]

five, if you see one that comes up for a low price, let me know....

going to have mom grab one up for my birthday gift....end of april but she always shops early....

our, pm me a price for one of you older ones!

chop