Contour Enthusiasts Group Archives Forums Modifications Audio need help

im going to bulild a new box but i cant decide on seald or vented,both the seald and vented hae a decent flat response (which is what im looking for) but the seald box has a cut off of about 50hz and the vented has a cut at about 30hz ,do you think i would be able to relly tell a diffrence. im using WINisd to build it,take a look at the graph and tell me you think.

p.s. can any one tell me what delay is and what efect it has on how the sub would sound.
group delay chart

Both pictures give me a page with this picture:

[img]http://members1.clubphoto.com/_cgi-bin/getImage.pl?imgID=5990612-7fa8&trans=[/img]

But, 50Hz is plenty good enough in a car. There is a cabin gain of about 12dB per octave below 50-100Hz, depending on the car. So, I think the vented will give you a little more output in the 30-50Hz range, at the cost of under 30Hz frequency response. Vented also requires a larger box. Those are the fundemental differences. Sealed is easier to build as well. I guess you must determine if the output with sealed in the 30-50Hz range is going to be enough for you.

Aaron

sorry : try this pic1
delay chart
thanks for the info.

Just checked out the graph. The sealed looks much better than the ported graph for in car use. THe ported will have a huge rise in response under 50 hz. The sealed, in car, would be very flat down to the mid to low teens.

Yeah, what Dave said.

In a car due to the cabin gain, you'll end up with way too much bass in the 35-50Hz range.

time to stat buliding thanks to you guys I now know a little more about car audio; thanks for your help

BTW, group delay isn't easy to explain, so i found this link if you want to read about it.
http://www.trueaudio.com/basslst2.htm

How are you mounting your box? I have a bottom fired box with a JL 12w3 and it slides all over. NOT acceptable. Any ideas? I thought about brackets holding it to a rear strut tower brace > now to get the brace!