Alright, so... I plan on buying a SA-15 D4. I currently have a 500W @ 2ohms Rockford Fosgate amp that is powering a 12. I do not plan on getting rid of it, considering I just got it. But i realized I want a 15 instead of a 12. The 12 I have is a Rockford Fosgate P2D412 (2011 model). So, the jump to Sundown its self is a great upgrade I'm assuming. I plan on building a box that's 3.5 cubes, tuned at 27Hz with a 4"x11" aero port. That gives me a port area of ~12sq. in./cu. foot. From what I hear that is sufficient for a SQ setup. But it seems a bit too short. Any opinions? I want a tune between 25Hz and 28Hz.... That brings me to another question, is that too low of a tune for a SA-15? Oh, and some notes to take into account... I really dont want to do a slot port. Second, this is a SQ build... I think that's it. I appreciate any help I can get! Thanks.

use this tool by psp to determine port lenght for respective tuning >>>http://www.psp-inc.com/tools.html

Why are you tuning so low? I'd do a bit more port area and tune a little higher.

The way you're figuring out your port area is not correct. A single 4" aeroport has a port area of just 12.5in^2. So with a 3.5ft^3 box you're looking at a measly 3.5in^2 of port per ft^3. If you're wanting to tune that low, you're going to have to custom make your aeroports longer than the stock length they give you. This is why a low tuning is so much easier to do with a slot port.

The way you're figuring out your port area is not correct. A single 4" aeroport has a port area of just 12.5in^2. So with a 3.5ft^3 box you're looking at a measly 3.5in^2 of port per ft^3. If

you're wanting to tune that low, you're going to have to custom make your aeroports longer than the stock length they give you. This is why a low tuning is so much easier to do with a slot port.

I didn't catch that he meant aero I thought he meant a 4x11 slot. Ram is correct in everything he stated. If you can't figure it out on your own have Ram design it for you.

use this tool by psp to determine port lenght for respective tuning >>>http://www.psp-inc.com/tools.html

Well, i gave that a try, and I still wound up with the same port length... 11.75".

Why are you tuning so low? I'd do a bit more port area and tune a little higher.

I have used WinISD beta to do all the designing, and I would do say a 30hz tune, because the F3 is at ~25hz. but, it becomes a little peaky for my liking around 52hz. I don't want a curve to exceed +3db. So, the lower tuning helps it become more flat.

The way you're figuring out your port area is not correct. A single 4" aeroport has a port area of just 12.5in^2. So with a 3.5ft^3 box you're looking at a measly 3.5in^2 of port per ft^3. If you're wanting to tune that low, you're going to have to custom make your aeroports longer than the stock length they give you. This is why a low tuning is so much easier to do with a slot port.

If the port was long enough, I am more than happy to go out and just buy some pvc and duct tape some port flares to the ends... Could you tell me how to find port area for a tube? I have just been doing W x H. Also, should I use more than one port?

If it is easier to just do a slot port for the tuning I want, I'll do it. If you guys think I should, any suggestions/ways to calculate/things to consider? Thanks for all the help so far!

Alright, so... I plan on buying a SA-15 D4. I currently have a 500W @ 2ohms Rockford Fosgate amp that is powering a 12. I do not plan on getting rid of it, considering I just got it. But i realized I want a 15 instead of a 12. The 12 I have is a Rockford Fosgate P2D412 (2011 model). So, the jump to Sundown its self is a great upgrade I'm assuming. I plan on building a box that's 3.5 cubes, tuned at 27Hz with a 4"x11" aero port. That gives me a port area of ~12sq. in./cu. foot. From what I hear that is sufficient for a SQ setup. But it seems a bit too short. Any opinions? I want a tune between 25Hz and 28Hz.... That brings me to another question, is that too low of a tune for a SA-15? Oh, and some notes to take into account... I really dont want to do a slot port. Second, this is a SQ build... I think that's it. I appreciate any help I can get! Thanks.

A low tuned enclosure is often misunderstood. You do not need a low tuned enclosure to achieve a flat FR. A properly adjusted EQ can do that. Another note to consider, SA-15 for SQ? There are better options available, not saying a SA-15 is a fart cannon.

Why are you tuning so low? I'd do a bit more port area and tune a little higher.

I have used WinISD beta to do all the designing, and I would do say a 30hz tune, because the F3 is at ~25hz. but, it becomes a little peaky for my liking around 52hz. I don't want a curve to exceed +3db. So, the lower tuning helps it become more flat.

Once you place your "finely tuned enclosure" into a vehicle FR anomalies will be nothing compared to what you planned. Tame those peaks an dips with an EQ.

The way you're figuring out your port area is not correct. A single 4" aeroport has a port area of just 12.5in^2. So with a 3.5ft^3 box you're looking at a measly 3.5in^2 of port per ft^3. If you're wanting to tune that low, you're going to have to custom make your aeroports longer than the stock length they give you. This is why a low tuning is so much easier to do with a slot port.

If the port was long enough, I am more than happy to go out and just buy some pvc and duct tape some port flares to the ends... Could you tell me how to find port area for a tube? I have just been doing W x H. Also, should I use more than one port?

Vc = π×r²×h r^2 from outside of tube

Do some research brah. This shit is all over the net.

If it is easier to just do a slot port for the tuning I want, I'll do it. If you guys think I should, any suggestions/ways to calculate/things to consider? Thanks for all the help so far!

Tons of tips all over the net.

Alright, so... I plan on buying a SA-15 D4. I currently have a 500W @ 2ohms Rockford Fosgate amp that is powering a 12. I do not plan on getting rid of it, considering I just got it. But i realized I want a 15 instead of a 12. The 12 I have is a Rockford Fosgate P2D412 (2011 model). So, the jump to Sundown its self is a great upgrade I'm assuming. I plan on building a box that's 3.5 cubes, tuned at 27Hz with a 4"x11" aero port. That gives me a port area of ~12sq. in./cu. foot. From what I hear that is sufficient for a SQ setup. But it seems a bit too short. Any opinions? I want a tune between 25Hz and 28Hz.... That brings me to another question, is that too low of a tune for a SA-15? Oh, and some notes to take into account... I really dont want to do a slot port. Second, this is a SQ build... I think that's it. I appreciate any help I can get! Thanks.

A low tuned enclosure is often misunderstood. You do not need a low tuned enclosure to achieve a flat FR. A properly adjusted EQ can do that. Another note to consider, SA-15 for SQ? There are better options available, not saying a SA-15 is a fart cannon.

Why are you tuning so low? I'd do a bit more port area and tune a little higher.

I have used WinISD beta to do all the designing, and I would do say a 30hz tune, because the F3 is at ~25hz. but, it becomes a little peaky for my liking around 52hz. I don't want a curve to exceed +3db. So, the lower tuning helps it become more flat.

Once you place your "finely tuned enclosure" into a vehicle FR anomalies will be nothing compared to what you planned. Tame those peaks an dips with an EQ.

The way you're figuring out your port area is not correct. A single 4" aeroport has a port area of just 12.5in^2. So with a 3.5ft^3 box you're looking at a measly 3.5in^2 of port per ft^3. If you're wanting to tune that low, you're going to have to custom make your aeroports longer than the stock length they give you. This is why a low tuning is so much easier to do with a slot port.

If the port was long enough, I am more than happy to go out and just buy some pvc and duct tape some port flares to the ends... Could you tell me how to find port area for a tube? I have just been doing W x H. Also, should I use more than one port?

Vc = π×r²×h r^2 from outside of tube

Do some research brah. This shit is all over the net.

If it is easier to just do a slot port for the tuning I want, I'll do it. If you guys think I should, any suggestions/ways to calculate/things to consider? Thanks for all the help so far!

Tons of tips all over the net.

Alright, after some research, I am deciding to go with the slot ported enclosure. You also mentioned an EQ, I don't know why, but I never would have thought of that, so thanks... I'll pick one up after some looking around.