I'm going with 4 - 12" alpine type R's my total net box area is 8cu.ft. and I can have about 9.6 gross MAX.
I came up with 2 options thats i'm thinking of using. My MAX size box dimensions are 50.5 x 18 x 22 (outside dimensions)
Option #1 4 - 4" ports that are 14" long tuned at 32 hertz
Option #2 3 - 6" ports that are 23" long tuned at 32 hertz
Now i'm wondering if there will be any noticeable difference between the 2 since they have very different port areas yet tune at the same frequency. Option 1 allows me to have a smaller box which I prefer but i'm worried there may not be enough port area. Option 2 gives me more port area but also makes my box quite a bit larger.
Which do you think will give better output? I was staying away from a slot port because it seems to take up too much box area, but if you have a idea for a slot or any other design please let me know. (i had started asking this in a different thread but the title wasn't about this so I started a new one, hope thats cool)
All help is greatly appreciated cause I wanna build this weekend
Thanks
How'd you determine that those port configuraion options are the best for your enclosure? Did you model it? If so, look at which gives you the least port velocity and use that one. If not, then you need to.
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Support the12volt.comnow I may be off, and I havent modeled 4 12 r's but I might later, I believe you really have to much port area for those subs.
Low mach on the port is a good thing, but too much area of port can also cause the sub to free air around the tuning frequency or below.
I can get a reading of .0001 vent mach is I use a 12" port on a single 12" sub, but I know the results would be very dangerous.
I would consider the 4 4" ports well before the 3 6" ports
2 6" ports alone have more port area then 4 4" ports
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
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Yes, good point Jeff. You also need to look at excursion of the woofer in the enclosure with the target power. Most good modeling software will tell you that too.
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Support the12volt.comDYohn] wrote:
ow'd you determine that those port configuraion options are the best for your enclosure? Did you model it? If so, look at which gives you the least port velocity and use that one. If not, then you need to.
My WinISD program keeps giving me error messages when I try to enter in the driver parameters, I may have a corrupt program. So I was just using various port calculators that took into account the xmax of the speaker, volume of the box, and tuning frequency. They kept giving me huge port areas - 6.6 equivilent round ports per 12" woofer with extremely long ports. I came up with the 4 - 4" ports because it was similar to old boxes I used to build, but that was 10+ years ago and speakers were much different then.
Ok I ran this in Uni-Box (cool program) and they are recomending 4 - 6" ports at 34" long with 750watts. With those ports it keeps the air speed below 26 m/s. I would really like less port if possible.
What is the MAX air speed that I can have without too much port noise?
Thanks
Just to clarify its 750 watts per woofer not total.
The spec sheet says 18.1mm of XMAX, does that sound correct because that number is whats spiking the port velocity I think. Sorry for all the questions and appreciate the help