my box

wait ranger i'm lost now. i thought a lower tuning would allow the sub to play lower. my box that i had made for my orion 12's was tuned to 40. how do i know.well anything below 40 has no output and the subs flop like fish.

the sucky part is that not only does it affect my rap/bass music it also affects how my jazz,blues and r&b sounds. no deep bass.

and my kicker has more deep bass output at 35 hz than the 2 12's. i did a side by side comparison,but anything over that is rediculously loud. more than my 10 can do. 47hz is a monster in that big box.

 

Thing is tuning to 40Hz will still be able to play the lows...the output down low will just be not as loud relative to above tuning.

Ranger...I was thinking the other day...the article you wrote about loud boxes and about your truck...the principal behind that is basically a 1/4 wave pipe...lol so basically you had a walled transmission line in your van.

Guess you didn't realize that did you??

 

well then mine must be tuned way higher. cause like i said anything lower than 40 sucked.BAD!

 

if anything below 40 sucked that bad than it was the enclosure lol...maybe some miscalculations

 

Not much below 40 hz, you sure you don't have the signal cut with crossovers?

 

If you cut the faceboard down on each side then the end pieces of the port should be shortened, by how much? I don't know lol, hard to figure out, but roughly i'd say cut off the ends of the ports about 4 inches each side

 

I need full dimensions of your box right now with the wrong cuts and i'll recalculate it for you

 

nope. only lowpass signals.80hz and down @18 db per octave.

when i plug in the kicker its night and day. so it deff the box.

 

Typically, this happens when a ported box is too small. Also if the box is too big we also run into problems.

Plug in your speaker specs in WINISD and pick a box size. Look at the peak above 0. Now tune it up and down and watch the peak. It will move up and down. Now frequency will be effected, but not significantly.

Now pick a tuning and change the box size. Watch what happens.

AZN, the box in the van was well over 12 cu ft for each speaker. The size coupled with the length made for a super loud box. Yes I was using 1/4 wave tuning ideas. For your truck I was using 1/2 wave principles.

 

but the box was built to the subs specs of 2.25 cu ft per sub ported.

doesnt matter anyways its not even in the truck anymore.

live and learn.

 

Let me ask one question. Did you have one sub in one box or two subs, one each in its own box?

Here is what I would have done, for a single sub, I would have increased box size to 3 to 3.5 cu ft and tuned around 40 hz. (I would use software to determind the correct sizing)

Now for two subs, I would build one enclosure (no dividers) around 3.5 to 4 cu ft and again the tuning would be around 40 hz.



This box was tuned to around 45 Hz. This guy listened to Rap. He never complained about it not hitting low enough. This box was around 5 to 6 cu ft. and it was built about 4 or 5 years ago.

It barely fit in that Impala

 

Here are some stats for a Polk Audio EX12 subwoofer. This data was generated using WinISD

The top row shows the tuned frequency, I used 20, 30, and 40 Hz
The first column is the box size in cu ft



The data shows the f3 point, the point or frequency where the woofer is down 3dB or rolling off.

Notice, for example, that at 2 cu ft, and tuned to 20 Hz, the woofer is barely able to get to 31 Hz. No where near the 20 its tuned to. But as the size gets larger, it gets lower.

Also notice that frequency gets much lower as size increases, than it does with tuning changes.


Typo, 37 should be 27, my bad

 

Now I'm hungry. Thanks ranger

 

when i seen him design it on the RE site http://www.reaudio.com/speaker_box/LPort_Box_Calc.html

he made it as a single enclosure with 4.5? cuft. tuned to 29 then when i came out to watch him build,he already had it as two separate boxes.

with the subs out( when i put in my polks in it) i did some measuring. on the same RE site. each box has a tuning freq of 45 hz.




7/8 in think mdf. did i figure it right at .88 thick?

 

O.K, 45 Hz in a 2 cu ft isn't a good idea. The box is too small for that tuning.

Remember that I am generalizing, different woofers perform differently. But as a general rule, if I was building a 2 cu ft ported box, I would tune around 36-40 Hz. Again I use software to see what is going on.

In my car I have a Polk Audio EX 12. Polk recommends a 1.75 cu ft box tuned to 36 Hz. My box is 2.0 cu ft tuned to 38. No real difference. But for sound Q this thing sounds great. It handles low frequencies extremely well. Never had a problem. But it will never win an SPL contest. Thats not what it was designed for.

Do you have one or 2 subs? Be honest, you want loud or SQ? If you want SQ change the tuning on your box. With out knowing the specs on your speakers, I would suggest around 35 - 36 Hz.

If you want louder you need bigger

 

this box IS loud,but again its a moot point as i took it out and just went back to my kicker in the 2cf probox. it has the best of both worlds for me. good clean bass and it can get loud too.



this is it. cost me 100.

 

went back to this.

 

RANGER thank you for your input on this subject. it sucks tho that i lost some money on this.

who knows it may sound ok in my house for HT use.