SA-8v2 enclosure design help

[jokers10 19]

I have done a lot of searching and can't find anything in general to the problem I am having. I am ready to pull the trigger on the pre-order of the SA-8v2, but I cannot get the enclosure figured out.

I am not looking for a pure SPL, or a pure SQ enclosure. I want to be able to listen to it at normal volumes for most music, and then dial in the remote knob when the bass is pumping on certain songs. I want a small vented enclosure with 1 D4 SA-8v2. (I want a vented enclosure because I haven't heard any success stories with a sealed enclosure) I will be powering this sub with a SAX-1200D (I know it is overkill, but I want the option to add a second or a larger pair of subs at a different time).

The problem I am running into is this. I have set 2 internal dimensions, Height and Depth, at 10 inches, because I want the variable to be the width when adding for port length. This would make my internal width 12 inches to have an internal volume of .69444 cubes without speaker displacement. I am guessing the displacement would be about the same as the last version at about .1 cubes, making the internal volume roughly .6 cubes.

A 1"x10" port, tuned to 30 Hz would need to be just over 47" long. This would effectively increase the width of the enclosure to almost 25 inches, if the port was run up one side of the internal structure, across the back of the enclosure, and finally double backed on the other side of the enclosure. I could live with an enclosure with external dimensions of 24.75"x14.25"x11.5." But I have heard that a 1"x10" port would cause significant port noise to possibly include whistling.

A 2"x10" port, tuned to 30 Hz would need to be over 96" long. Now we are looking at a 36" wide enclosure which I am not even sure if it would fit in my trunk, and I might as well be running two SA-10s at that point.

Has anyone successfully designed a box for a single SA-8v2 tuned to the recommended frequency, while keeping the structure relatively small, without the use of an external port, or passive radiator?

[Duran 387]

Increase tuning and port area till you find a good balance that you have the space for.

[jokers10 19]

That is about the same response I seem to be getting from everywhere I ask the question. A box for two 10's or 12's is much easier to maintain a smaller footprint than one sa-8 while retaining the reccommended air space. I am almost wondering if a different style of enclosure would be better suited to get such a low tuning from such a small air space. I will measure the trunk tonight and see if a 2"x10" port will work.

As long as the corners are rounded would a 2"x10" port eliminate port noise?

[Shogen 325]

mount sub inverted to take up less cubic feet? just an idea

[dbsupra 69]

Jacob had good results with the v2 using a 10" psi passive radiator. Small footprint and could tune at different freq changing the mass

[jokers10 19]

Jacob had good results with the v2 using a 10" psi passive radiator. Small footprint and could tune at different freq changing the mass

I just researched it, and the PR costs about $75. As much as I want this one sub, I don't think adding $75 to the price tag os going to work for me. Right now I can get 2 SA-10s for $220. The box would end up being the same size or smaller than the one SA-8 enclosure, and would be able to get louder. The only way to compromise would be to go with a box tuned in the high 40s.

Back to the drawing board.

[dbsupra 69]

I have a bit of experience with single sa-8 boxes. Let me see if I can dig up something that will fit. But yes a single 8 tuned decent and small is not easy.

[dbsupra 69]

How about

25w x 14d x 7h?

Port is 5.5 x 2 tuned around 36hz. Is just a bit smaller port area than a 4" aeroport.

My first sa-8 box was very similar to this and ran off a 1200 at 2 ohm. Not huge output but it also was in a land cruiser. It did sound really good tho.

The port area could stand to be a little larger but working with that small of a box that's about the best I could come up with.

Maybe someone a little more crafty can come up with something else.

[jokers10 19]

All the math that I do keeps confirming my original issues. In order to make the SA-8 (an awesome and beefy small woofer) into a compact sub solution, I would have to compromise in one way or the another. The following are a list of compromises I have come up with:

Tune it to specs and end up with a box that compares to the size of a box designed for two SA10s.

Have a port area too small, and risk the possibility of port noise and/or whistling.

Have an external port, that would consume all the space of the correctly tuned box, and be ugly at the same time.

Increase the tuning of the port or woofer chamber and hope that it doesn't destroy the woofer or sound like crap.

Buy a passive radiator and spend hours tuning the mass to make it sound right.

Put it in a sealed box and live with the result.

Since I still want it to sound good, I am going with the first option, but dropping the idea of a single space saving SA-8 in favor of two SA-10s or 1 SA-12.

Lesson learned: This sub is awesome, and was designed to have a small woofer chamber, but the combination of the smaller woofer chamber and properties of its ultra low tuning, create an enclosure that would be better suited for 2 or more of the same woofer. The theory behind this is that as you increase the size of the woofer chamber the port doesn't need to be as long to acheive the same frequency, but if you increase the chamber size beyond the range of the woofers you are using, it will sound bad, and could destroy the woofer.

Good job Sundown on a good product, but it just doesn't fit the needs of my vehicle. Let me know when you build one that is better suited for a small sealed enclosure that acts like a nice ported one.

[SeductiveSounds 0]

What kind of a car is this going into?

If its a trunk car, chances are you're not going to hear a little bit of port noise. Smaller volumes require much longer ports, it just the way the physics work. Have you thought about doing round ports? They won't usually take up so much room thus keeping the final volume down.

I did a box with 2 SA-8's that was 36.5Wx13Hx9.5D almost half the box was port, port is 11.5Hx2W works just fine no noise and its in a hatch and is on a SAZ-2000D @ 2ohm

[jokers10 19]

Changed my mind and went with two Sundown SA-10s. The box is only a couple inches bigger all the way around. And two 10s from the same line as the 8 I wanted to use will be louder, and sound better.

[vanquish 0]

I'm having this same dilemma.

[jokers10 19]

I'm having this same dilemma.

It is just the way these SA-8s are designed. Perfect if you want to run 4 in a deep/wide low profile enclosure, but not really designed to save space if you use just one.

The two SA-10s are rocking my world though. Of course once the bass bug bites, you always want more. I am now thinking of upgrading to a third SA-10, or going with 12s next time.