I was playing with bass box, I have an Eclipse 88120.4 was playing with numbers tuned at 35hz and 40hz and the link below will show the graphs it gave me at 40hz but really this mean nothing at all to me I have no clue wether it's "correct" or screwd up... So thought you guys could let me know/fill me in on what's good and whats not, or hell even design a box for those with Bass Box or any other program.

https://img.photobucket.com/albums/v...tedBox40HZ.jpg

[ September 12, 2004, 11:12 AM: Message edited by: ChizzerZ24 ]

I want something that will sound sweet, but also can get damn loud... I have been messing with this thing for few weeks trying to figure things out but even if I "thought" I knew what's goin on could be totally wrong in the eyes of the "Pros"

Thanks Guys...

Normally I am a sealed fan, but as per the preachins of Dukk I figure what the hell give ported a try.

Link no work.

Damn thing, was working fine earlier.....cause I checked a few times...will fix it later..

This should work, created photobucket account.

sq is subjective.

People say tune low for sq.. which I think is wrong.

a nice ported box with a nice peak at 40-45hz
sounds the best to me.

When I think about it.. the peak does 3 things.

1.Loud.
2. Rolls off quicker in the lower feq regions which makes MUSIC sound more natural
3.Filters out the upper bass freq before your crossover. (to me bass above60hz shouldnt be reproduced by subs) less distortion due to phase issues between your mids

Am I rcazy?
prolly :D

things to consider..
group delay.. it should be smoth and not excessive (ms)

Smaller ported boxes provide better group delay.. but at the expense of stupid port lengths

the bigger the box the greater the groupdelay..


Still not cirtain how port area affects thing..

Comments?

[ September 12, 2004, 11:34 AM: Message edited by: Seahag ]

That's another thing, with ported in a trunk this case 03 Z24 does it matter where the port is where on the end of the box, then front/the back top/bottom?

Outta all you pros, I get 1 response woulda thought Dukk being the "Port everything" god woulda responded by now?

still nothing eh, hmmm good waste of time I see....

Ahhh... The blessings and burdons of box programs. I usually use WinISD myself, and I have to admit sometimes I get a little discouraged sometimes when it reccommends to me a sealed box of 25 cubic feet for a .707 Q. Ported boxes normally seem pretty accurate. Anyways, the main thing you should be concerned about is tuning frequency, amplitude response, and maybe group delay. Your amplitude response graph tells you where the "bump" in output occurs, which should be at about 40Hz. So at this point, output should be highest (which is what you're most concerned about), port velocity will be highest, driver excursion will be minimum, and the group delay will be worst. Port velocity is pretty self-explanatory. It denotes the speed in which air is moving through the port, which, at the tuning frequency, will be the highest. Group delay is the delay in milliseconds that it takes the port to react to the driver's excursion. And like was already mentioned here, this delay will be worse as the box gets bigger. I don't think this delay is really audible until you get into rediculously large boxes. Maximum acoustic power I'm assuming is an estimate of maximum SPL anechoically (which will obviously change when you drop it in a car), and maximum electrical input shows you why a subsonic filter is usually a good idea for ported enclosures. Below the tuning frequency, the driver will start to become unloaded very quickly which can lead to overexcursion and damage, so its actually a bit of a misnomer to call it maximum electrical input when its really mechanical power handling we're talking about. Phase response I'm assuming is an estimate of port phase relative to driver excursion. I wouldn't really pay attention to that, because in fact the port is never really 100% in phase with the driver. It comes close enough to increase output, but not 100%. Hope this helps!