FINALLY, i need some help designing

[paulie 0]

i got a local guy that has a 2.5 cube box tuned to 32Hz and he will sell it to me for the same price as building my own. how would it sound in that box?? is it too big?

[Eldorado 0]

to big

[CBFryman 2]

the biggest difference in 1.5 @ 30 and 2 @ 30 is going to be the low end extension. the larger box will reinforce it a bit better. the larger box will also be more efficient, requireing less power. the smaller box should give ya more punch has the frequencies rise. and lastly, the larger box has the potential to be the louder of the two.

with tuning that low, your not going to notice much of a difference between 28hz and 30....and, i'd shoot for the larger of the two boxes. IME, when you start tuning like that, small boxes just don't sound as good.

also, once you start tuning that low, you might as well go sealed. a 1.25-1.35ft^3 sealed box would give close ot the low end of the 1.5 ported one, sound crisper and not lose a whole bunch of output. IMHO anyway..

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

<{POST_SNAPBACK}>

Not always. Generally, in daily tuned low applications that is the rule of thumb. SPL boxes seem to get smaller and smaller. Solo X 12's with ~1cuft before speaker displacement, rear side of walls keep moving more and more forward.

Larger boxes are more efficent watt for watt but smaller ones give more mechanical powerhandleing above tuning.

You can have a massively large box that will allow the driver to reach full excursion with half its RMS power and be 2dB more efficent than a smallerone that takes roughly the RMS power to reach full excursion. However the smaller one can sitll take double the power so in the end it will be 1dB louder.

Not challenging your statement, just that alot of things that are rule of thumb in the audio industry somehow become an undenyable audip physics fact to people just understanding ported enclosures, which later on can cause a headache of argument or sudden embarassment.

Best idea is to design a daily enclosure that will allow the most excursion with an acceptably flat responce with the power you have on tap.

LEAP, Term Lab (i think), and a few others can modle this for you. WinISD Alpha Pro can to a less accurate extent as well.

[dave_Edwards 1]

and why is a "Snail-Shell" enclosure the best?----I always wondered why those guys acted like they re-invented the wheel or something.

[CBFryman 2]

i would geuss because it gradually gets smaller and smaller to a point. This means no reflections back at the cone of the driver and no parallel walls. The sealed airspace acts as an additional suspension and nothing more no matter the frequincy.

Think of it as a reverse horn with no outlet. Horns take small sounds and amplify them many times, that enclosure takes loud sound and cancels any wave activity out by the end.

my geuss.

[Eldorado 0]

I just thought they looked cool

[bobby_7 0]

ok, had a guy that helped me with the design, name is Tempe, dunno if you guys know him around here, but here is what he designed, and i had to draw it out, cuz i have to see it before i build it. just wanted to check and make sure everything looks right....its a crappy paint drawing, i know, but thats all i could get to work right.

http://h1.ripway.com/Bobby_7/BOX2.JPG

it is supposed to be 2 cubes tuned to 32Hz. in WinISD, im getting that with that setup it would be tuned to like 35Hz, but i know WinISD sux compared to others and Tempe is probably right. i figured up the internal volume size and it comes up like 2.4ft^3, the sub and port wouldnt take up that much room would it? either way, is this enclosure gonna work well? sub will be facing upwards and port will be towards the rear of the car.

[mrray13 30]

Not always. Generally, in daily tuned low applications that is the rule of thumb. SPL boxes seem to get smaller and smaller. Solo X 12's with ~1cuft before speaker displacement, rear side of walls keep moving more and more forward.

Larger boxes are more efficent watt for watt but smaller ones give more mechanical powerhandleing above tuning.

You can have a massively large box that will allow the driver to reach full excursion with half its RMS power and be 2dB more efficent than a smallerone that takes roughly the RMS power to reach full excursion. However the smaller one can sitll take double the power so in the end it will be 1dB louder.

Not challenging your statement, just that alot of things that are rule of thumb in the audio industry somehow become an undenyable audip physics fact to people just understanding ported enclosures, which later on can cause a headache of argument or sudden embarassment.

[mrray13 30]

ok, had a guy that helped me with the design, name is Tempe, dunno if you guys know him around here, but here is what he designed, and i had to draw it out, cuz i have to see it before i build it. just wanted to check and make sure everything looks right....its a crappy paint drawing, i know, but thats all i could get to work right.

http://h1.ripway.com/Bobby_7/BOX2.JPG

it is supposed to be 2 cubes tuned to 32Hz. in WinISD, im getting that with that setup it would be tuned to like 35Hz, but i know WinISD sux compared to others and Tempe is probably right. i figured up the internal volume size and it comes up like 2.4ft^3, the sub and port wouldnt take up that much room would it? either way, is this enclosure gonna work well? sub will be facing upwards and port will be towards the rear of the car.

yeah, sub and port can and will eat up 4 tenths of a cube very easily. hell, most low tuned ports will eat up 4 tenths....

but sounds good to me!!

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

[CBFryman 2]

wasnt argueing, just stateing that, ive soon SOOO many n00bx's on the AF forum and a few others think large SPL boxes are always best.

[bobby_7 0]

yeah, sub and port can and will eat up 4 tenths of a cube very easily. hell, most low tuned ports will eat up 4 tenths....

but sounds good to me!!

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

<{POST_SNAPBACK}>

ok, i think i figured up that with the sub and port displacement that the box will be about 2.145ft^3 and with a 22.75" port, will be tuned to 33.37 (according to WinISD). now if i take an inch off the height of the box, i get a net volume of 1.97ft^3 and with a 22.75" port i get a tuning of 34.82. i like the first box, will it work good for daily driver street bump? will it have good SQ and be able to hit all the double bass kicks?

[mrray13 30]

wasnt argueing, just stateing that, ive soon SOOO many n00bx's on the AF forum and a few others think large SPL boxes are always best.

but again, we aren't talking about spl, but daily driver. and a low tuned one at that. and in that situation, 98% of the time a large box will win and have the potential to be louder.

there was simply no need to even bring up spl oriented enclosures.

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee