Stereo & Electronics - Car Audio Expert's I Need Your Help! Thanks!

Which Box Will Perform Better? Notice How Close The Driver's Are To The Port.. Is There A Certain Distance They Need to Be Apart From Each Other? or does the distance from the drivers & port doesn't matter.. please make comments on the two box's i have displayed thanks! I am trying to find out which design will perform better...once again THANKS!

1st box or 2nd Box Better? Don't Judge By Looks Judge By Performance from experience! thanks!

http://i136.photobucket.com/albums/q198/Zcustoms28/scan0002-1.jpg

Either will do fine, as long as the airflow in the box is good.

Theres really no difference between those 2 boxes. I would place the speakers over the tallest part of the box so they have enough room to flex and breathe. This would be the "trunk" area with the little gully. Then just put the port in between them and the amp. I would also use 2 or 3 circles, not a big "cut" too much air and you wont even hear those subs. I personally prefer no ports :)

Just so you know, speaker flex means loss of bass. You don't want the speaker, or box for that matter, flexing.

Just make sure the port is tuned to the right frequency and either of those designs will work.

actually, a slotted port will reduce port noise over a round one. If you do use round ports, you want to use flared port ends on both ends of the ports. Port noise is one of the reasons many people do not like ported enclosures.

id do the port right behind the back seats and have it "L" rear ward. Then the subs furthest back, amp in the middle if u want. Would probably promote the best air flow. But what do i know :P

I would base my design on the airflow reaction based on the first design and the effective reflection of the subs ....2nd design...

Will I benefit by having the port firing at the window?

which design is better on airflow? how do ensure the air flow the enclosure is right?

You're making far too big a deal out of it.

which design is better on airflow? how do ensure the air flow the enclosure is right?

Since all the port does is reinforce the output from the front of the speakers, "airflow" isn't going to matter. What IS going to matter is the size and tuning of your enclosure. Just make sure that your math is right on calculating the area of the port, and try to round the port edges a little to reduce any port noise. Also, as with any box, rigidity is paramount. Brace the hell out of the box internally so it won't flex.

I know when I was designing sub enclosures and competing in IASCA in the '80s and early '90s it was generally thought not to put a port within 2" of any surface, whether it be speaker or side of the enclosure.

I would also move the subs to the deepest part of your enclosure. And you may have to build a transmission line (think Bose) for that port to work properly.

Check all your math too. Don't just design something that looks good and throw in a set of speakers and expect them to perform as they were meant to.

so should i keep the subs in the deep end & run the port behind the seat? would i lose bass quality from not having the port firing at the glass?

Just to clearify, the Transmission Line style of porting has been around for decades. It is mostly used in higher end home speakers or studio reference speakers because of the cost involved with creating them the right way (both research and materials).

The idea was made popular most recently by Bose. This image shows how their wave radio uses the technology in order to create great sound using a small space. This is achieved by making the speaker think it is in a much larger enclosure than it really is in and, ideally, you should taper the line (making sure to eliminate all 90* angles) as it progresses. Thus the higher cost of the materials.

http://ws6.hpstudios.com/bose wave transmission line.jpg

I apologize for the picture quality but it was the best one I could find.

it was generally thought not to put a port within 2" of any surface, whether it be speaker or side of the enclosure.

Check all your math too. Don't just design something that looks good and throw in a set of speakers and expect them to perform as they were meant to.

Yes, I forgot about that. I usually don't do ported enclosures due to the music I listen to, and usually space constraints. Depending on the tuning of your enclosure, you might need to fold the port into the box like a "L" shape, should the port need to be too long. Again this is dependent on your tuning.