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View Full Version : I've done the seaching, yet still have questions



splitz
04-22-2003, 08:36 PM
Ok, I'm almost done with the aquisition phase of the system; now to the planning, I am trying to build my first ported box and need a few tips.

1. How far away from the inside wall should the opening of the port be ?

2. Does it matter what side of the box the port goes? (same side as the sub, out the side of the box, out the top of the box)

3. On WinISD the smaller the diamater of the port, the shorter the length...why?

4. Is there an advantage/disadvantage in using 2 ports vs. 1?

One more thing, I understand that rounding the edges of the port cuts down on the noise, so is this worth the money?

http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=12642857&St=4063&St2=-50759766&St3=-76403570&DS_ID=3&Product_ID=117897&DID=7

Thanks for the help

paikiah
04-22-2003, 08:42 PM
Originally posted by splitz
Ok, I'm almost done with the aquisition phase of the system; now to the planning, I am trying to build my first ported box and need a few tips.

1. How far away from the inside wall should the opening of the port be ?

A: as much as the diamter of the port for minimal turbulence.

2. Does it matter what side of the box the port goes? (same side as the sub, out the side of the box, out the top of the box)

A: This point has been debated about a number of times. SOme people say that it sounds a whole lot better when the port is on the same side as the cones. I say put it where you thiink looks best.


3. On WinISD the smaller the diamater of the port, the shorter the length...why?

More air pressure, I'd imagine. Remember, too small a diamter, you'll get port turbulence. 35~40m/s is the max, I think.

4. Is there an advantage/disadvantage in using 2 ports vs. 1?

Less port noise (turbulence) but the port will have to be considerably longer.


One more thing, I understand that rounding the edges of the port cuts down on the noise, so is this worth the money?

A: For slot port, you can easily do this with a dremel (hand grinder) or rough sandpaper. If circular, then you're talking about flared ports. These are supposed to reduce it somewhat, and I suggest it.. it won't cost you an arm and a leg.

bass_mekanik
04-23-2003, 06:29 AM
from my experience 25 m/s is the max i would allow for a daily enclosure cause my current boses have 31 m/s and all i get is a chuffing noise all the time

paikiah
04-23-2003, 07:26 PM
Originally posted by bass_mekanik
from my experience 25 m/s is the max i would allow for a daily enclosure cause my current boses have 31 m/s and all i get is a chuffing noise all the time

ah, 25...hmm, better make new calculations for my future ported box again. *sigh*

splitz
04-23-2003, 10:23 PM
m/s? not to sound like a complete idiot...what does that mean? I dont see that anywhere on WinISD.

paikiah
04-23-2003, 10:27 PM
Originally posted by splitz
m/s? not to sound like a complete idiot...what does that mean? I dont see that anywhere on WinISD.

you won't see it in the beta version, only on pro..

rear port velocity. :)

more_spl
04-24-2003, 06:02 PM
22m/s good for a daily driver tuned at 29hZ ?

i wasn't sure if you are supposed to be above or below 25

splitz
04-24-2003, 08:02 PM
Ok, I am dumb...I found m/s under the rear port velocity in WinISD after reading the posts(I had it in ft/s). Anyway, I did the default box (the one that is calculates for you then you tweek it from there) and the m/s is 56! Am I reading this wrong or something? Is the reading suppose to be taken at 1 watt or is it taken at the Max RMS your sub will be receiving?

Thanks!