Single SA-15 Build Questions

[mikebingham34 7]

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.

[StreetLegal 119]

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

[ricksi30 923]

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

[RAM_Designs 25]

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.

[ricksi30 923]

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.

[mikebingham34 7]

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".

[mikebingham34 7]

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.

[mikebingham34 7]

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?

[mikebingham34 7]

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!

[edouble101 314]

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.

[mikebingham34 7]

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.