I am needing some help with my port size. I built the box and figured the port on specs of one sub, so i realize its not correct. Also i am locked into a 3” port at roughly 18” max length.
I had conversation with a fella that recommended to go with 2 3” ports at 14” length each to tune to around 40hz, so i have 2 brand new 3” port kits sitting waiting to be installed. The box before displacement is 1.65ft^3. Im lost when it comes to porting as this is my first serup being ported.
So any help that can be given is greatly appreciated before i screw up anything else.
I had conversation with a fella that recommended to go with 2 3” ports at 14” length each to tune to around 40hz, so i have 2 brand new 3” port kits sitting waiting to be installed. The box before displacement is 1.65ft^3. Im lost when it comes to porting as this is my first serup being ported.
So any help that can be given is greatly appreciated before i screw up anything else.
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As a rule of thumb you'll need a port with at least 1/5th the area of the drivers Sd. So in your case that comes down to 1 x 3" port per 1 x 8" as a minimum. It looks like you have 2 x 8" drivers, so you will need 2 x 3" ports as a minimum as well.
In a (free) program such as WinISD Pro you could see the exact number of ports needed. In that case be sure to use the nett internal volume (and nett internal port area), so the internal volume of the cabinet, minus the volume occupied by the drivers and ports (about 1/14th ft^3 per 3" port in your case).
Best regards Johan
In a (free) program such as WinISD Pro you could see the exact number of ports needed. In that case be sure to use the nett internal volume (and nett internal port area), so the internal volume of the cabinet, minus the volume occupied by the drivers and ports (about 1/14th ft^3 per 3" port in your case).
Best regards Johan
Hi Regency,
Are you a Riddle Joker?
Who knows what Driver you are using? Dual 2 or Dual 4? From what Year? Do you have measured TS Data? In which Car are you installing your Sub? Do you have Cabin Gain Information* based on the suggested location of your Sub?
Knowing exact Box Dimensions(and the thickness of the Wood), is always mandatory, like the actual C-C Distance between the Drivers and the Ports and the in Car Installed Ports to Walls used Distances can make a FR difference if the Cabin Gain is not a submitted Design info.
* Easy to measure.. Measure the close Distance (~ 1") FR at Home preferably away from Room Walls, then at the intended place, Seal the Ports when doing the Measurement or not, I would make both for a complete References.
Calculate the Magnitude difference and Plot, Save the Cabin Gain FR to be used in a Program like Hornresp.
You be surprised on what suitable Port tuning that is returning a smooth FR in your Car.
b
PS: Use Collo's Flare-it Program to find out suitable Port Dimensions!
Flare-it - Free Speaker Design Software
By the way: This is the proper Forum for Your Questions:
http://www.diyaudio.com/forums/car-audio/
Are you a Riddle Joker?
Who knows what Driver you are using? Dual 2 or Dual 4? From what Year? Do you have measured TS Data? In which Car are you installing your Sub? Do you have Cabin Gain Information* based on the suggested location of your Sub?
Knowing exact Box Dimensions(and the thickness of the Wood), is always mandatory, like the actual C-C Distance between the Drivers and the Ports and the in Car Installed Ports to Walls used Distances can make a FR difference if the Cabin Gain is not a submitted Design info.
* Easy to measure.. Measure the close Distance (~ 1") FR at Home preferably away from Room Walls, then at the intended place, Seal the Ports when doing the Measurement or not, I would make both for a complete References.
Calculate the Magnitude difference and Plot, Save the Cabin Gain FR to be used in a Program like Hornresp.
You be surprised on what suitable Port tuning that is returning a smooth FR in your Car.
b
PS: Use Collo's Flare-it Program to find out suitable Port Dimensions!
Flare-it - Free Speaker Design Software
By the way: This is the proper Forum for Your Questions:
http://www.diyaudio.com/forums/car-audio/
Hi Regency,
Are you a Riddle Joker?
Who knows what Driver you are using? Dual 2 or Dual 4? From what Year? Do you have measured TS Data? In which Car are you installing your Sub? Do you have Cabin Gain Information* based on the suggested location of your Sub?
Knowing exact Box Dimensions(and the thickness of the Wood), is always mandatory, like the actual C-C Distance between the Drivers and the Ports and the in Car Installed Ports to Walls used Distances can make a FR difference if the Cabin Gain is not a submitted Design info.
* Easy to measure.. Measure the close Distance (~ 1") FR at Home preferably away from Room Walls, then at the intended place, Seal the Ports when doing the Measurement or not, I would make both for a complete References.
Calculate the Magnitude difference and Plot, Save the Cabin Gain FR to be used in a Program like Hornresp.
You be surprised on what suitable Port tuning that is returning a smooth FR in your Car.
b
PS: Use Collo's Flare-it Program to find out suitable Port Dimensions!
Flare-it - Free Speaker Design Software
By the way: This is the proper Forum for Your Questions:
http://www.diyaudio.com/forums/car-audio/
I can give some of those questions answers but some of them im lost.
From one of those pictures, it looks like the vents are going to be pretty close to the doors, which is going to lower their tuning a little. To be honest I'd just use the two 3" vents as suggested, and make them as long as possible, making sure that there's at least 4" clearance between the internal entrance to the vent and any internal walls.
The "secret" to getting a vented subwoofer right in a car is to have EQ, with bands above, at, and below the resonance frequency of the box, e.g. 50 Hz, 32 Hz, 20 Hz. Use the one below the resonance frequency to cut any input to the subwoofer, as it can run into problems trying to reproduce any signals below the resonance frequency. Then use the other two to adjust the response of the subwoofer to taste.
The "secret" to getting a vented subwoofer right in a car is to have EQ, with bands above, at, and below the resonance frequency of the box, e.g. 50 Hz, 32 Hz, 20 Hz. Use the one below the resonance frequency to cut any input to the subwoofer, as it can run into problems trying to reproduce any signals below the resonance frequency. Then use the other two to adjust the response of the subwoofer to taste.
I am building the vents out to 14”, which is 15” per precision paperwork. This will give me 3.5” from the step in the middle of the box thats about half the depth of the box.
Its very hard working with minimal space and keeping everything tucked so the kids dont stick their foot in them.
WOW, what a difference the extra port made! Pulled the single 3” x 11.63” and installed two 3” x 14”...!!
Now just to find the right amp to power them good! Only pushing 75w each with sub output on hu at 12 of 15. Im looking to find a jl500/1 and adjust output level accordingly so i can put the 300/4 on the highs where it belongs
Now just to find the right amp to power them good! Only pushing 75w each with sub output on hu at 12 of 15. Im looking to find a jl500/1 and adjust output level accordingly so i can put the 300/4 on the highs where it belongs
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