port size?

what size port do you think would be the best. 

The box is 1.21ft3 for a single kicker comp vr 10.  I'm not sure what size port to use.  i have built this box before and used a 2" port tuned to 30 hz but it didn't have enough backpressure and the sub bottomed out a lot.  Now i am thinking about a 1.5" port tuned to 30 hz. i haven't been able to find any info or general rules of thumb  on port size compared to sub size.  I have heard before that for 12's and 15's don't use anything smaller than 2" but i've never heard anything about 10's.  any advice would be appreciated.

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what!?!?! you want some??

You'll see a lot of small diameter port sizes spec'd out and used because the smaller the port diameter, the shorter the length will have to be.  But the trade-off is the sound of air rushing through the small diameter.  Try to work out a diameter of 3.5 to 4" for a SPL 10" sub.  Keep in mind the port length will grow much longer.  I've heard someone say a general rule is 1/4 cone diameter, but the minimum vent size calculators will tell you to make the port diameter much larger.  You must find a compromise somewhere in between according to how much space you have available.  Get to know the free enclosure design program WinISD Pro and you'll be able to figure it out using the woofer T/S parameters.

4" seems a little big for a single 10 don't you think

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what!?!?! you want some??

In a 1.21 cuft enclosure, 4" will require too long a port (28" approx.)  If you really want to try and port that small an enclosure, I suggect using 2.5" diameter at 10" long.  It will have lots of port noise, though.  A larger enclosure size and a larger port would probably work better.

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but the specs call for a 1.25ft3 enclosure, plus i have a mustang so my trunk isn't exactly the easiest place to squeeze a large box, would a 1.5" port sound like ass?? right now it's sealed and bangs it's ass off but i want a little more, i was told buy a man who owns a stereo shop that the reason the box i built with the 2" port sounded bad was because the port was to big and wasn't holding enough back pressure on the sub, that is why i was wondering if i should step it down to a 1.5" port.

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what!?!?! you want some??

Well, whoever told you that was... err, wrong.

Your Kicker Comp VR10 requires a vented enclosure size between 1.25 and 1.75 CUFT with a rather large slot port.  When vented, it is rated at only 200 watts RMS.  The preferred mounting for these wooferes is in a 0.8 CUFT sealed enclosure, and when sealed it can handle up to 300 watts RMS.  So, if you must stay at 1.25 CUFT, I recomend you remove the round vent and either seal up the enclosure, or rebiuld it with the recomended 2" X 10.5" X 20" slot port.  HERE's your owners manual with recomended enclosure information.  Your amp is too large for this woofer, and you will need to add a subsonic filter (your Kenwood does not have one) at around 30Hz.

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i don't have a kenwood amp, where the HELL did you get that.  I have a MA Audio HCA1302 on 2 vr 10's. i was just wondering the enclosure size for one because i was thinking of just doing SQ with 1 sub.  besides, you can never have to big of an amp, the more head room you have the cleaner the sound.

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what!?!?! you want some??

Sorry, got my posts mixed up.  And yes, as long as you know what you're doing and don't crank the system, head room is a good thing.  :)  If you want SQ, use a sealed enclosure.

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DYohn's point regarding the subsonic crossover remains the same. Woofers frequently bottom out / distort in ported enclosures when asked to play too loud below their ported frequency.

If you don't have one on your amp or deck you can use these: https://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=266-248


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New Project: 2003 Pathfinder