box tuned to 2 frequencies
11-11-2009, 10:22 PM
#1
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box tuned to 2 frequencies
I was experimenting with differening frequencies to tune my box to. When I make a change like a different box or tune it always takes me a couple weeks of listening to decide whether I like it or not.
On my most recent box I was experimenting with the recommended tuning frequency of 30hz as per JL specs. I also wanted something a little higher to see whether the SQ drop would be worth it.
I decided to use pvs pipe for the ports. I used two for a 30hz tune and then added two more for a 36hz tune. Which ever frequency I am testing with I have blocked the other port tubes.
Is there anything inheritantly wrong with this?
On my most recent box I was experimenting with the recommended tuning frequency of 30hz as per JL specs. I also wanted something a little higher to see whether the SQ drop would be worth it.
I decided to use pvs pipe for the ports. I used two for a 30hz tune and then added two more for a 36hz tune. Which ever frequency I am testing with I have blocked the other port tubes.
Is there anything inheritantly wrong with this?
11-12-2009, 12:05 AM
#3
That's a great idea. Should the airspace in the port that's blocked be accounted as airspace for the subs? Just to get a precise tune. What happends when all ports are uncovered, bandpass or 120hz? I'd like to do 32hz and my cars resonant frequency.
11-12-2009, 10:21 PM
#5
I'll make an example for you.
You have a 4 cubic foot enclosure with three 4" aeroport. All three of the ports are 12" in length. For daily use, you choose to plug one port and run two of the three aeroports, which gives you a 35hz tuning. When your at a comp, you choose to run all three ports open, which should raise your tuning to around 42hz as well as increasing your total port area
You have a 4 cubic foot enclosure with three 4" aeroport. All three of the ports are 12" in length. For daily use, you choose to plug one port and run two of the three aeroports, which gives you a 35hz tuning. When your at a comp, you choose to run all three ports open, which should raise your tuning to around 42hz as well as increasing your total port area
11-12-2009, 10:31 PM
#6
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I'll make an example for you.
You have a 4 cubic foot enclosure with three 4" aeroport. All three of the ports are 12" in length. For daily use, you choose to plug one port and run two of the three aeroports, which gives you a 35hz tuning. When your at a comp, you choose to run all three ports open, which should raise your tuning to around 42hz as well as increasing your total port area
You have a 4 cubic foot enclosure with three 4" aeroport. All three of the ports are 12" in length. For daily use, you choose to plug one port and run two of the three aeroports, which gives you a 35hz tuning. When your at a comp, you choose to run all three ports open, which should raise your tuning to around 42hz as well as increasing your total port area
11-12-2009, 10:42 PM
#7
PVC pipes = major port noise. that could be whats making the enclosure sound bad.
you must also remember that when you plug or unplug a port, that the cubic footage in the enclosure changes, usually around .1-.15 cubic feet
you must also remember that when you plug or unplug a port, that the cubic footage in the enclosure changes, usually around .1-.15 cubic feet
11-12-2009, 10:45 PM
#8
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thanks for the info. My plan was to get some aeroports however the are rather impossible to find in my home town. My thought initially was that due to the box being in the trunk behind seats that port noise would not be audible. Thoughts?
11-13-2009, 08:55 AM
#10
50 Watt CAFz'r
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JL 2 x 12w3v3. They sound fine as it is. Although I haven't really listened with the seats down to notice if there is any port noise or not. The box is actually one that you provided me a couple months back. There were a couple construction problems I had and will be rebuilding soon. In the mean time I am experimenting with different tuning to see what I will like. By then i'll hopefully have the tuning figured out. I'll probably end up going with a slot port. The round was easier to experiment with.
