Subthump Ported SA8 Ported Box Prototype

[Trancer 0]

Hey guys, I am in the talks with Steve, the owner of subthump.com. They make some of the best sealed prefabbed boxes I have ever dealt with. They are simply amazing, the prices are budget friendly. Their main focus are on sealed boxes, because they aim at the people who are on a budget and they can mass produce. So I have been throwing emails back and forth and emphazised how much pupularity there is out there for the Sundown Audio SA8's. Now we all know these things shine better in ported boxes. My box building days are over and subthump is nortorious for squeezing out as much air space and the deepest depth for subwoofers.

Here is my first subthump box. Ran this box in my 2003 Extended Cab Silverado with two TC Sounds TC1000's. They are both blown. Used the wrong type of screws so the subs kept getting lose and going free air. If anyone wants them, let me know.

http://subthump.com/Chevrolet-GMC-Sub-Boxes/Silverado-Sierra-Extended-Cab/99-06-GM-Extended-Cab-Ultra-Deep-Dual-1012-Downfire-Box.html

Then they came out with this. I wish I was able to get this box when I had my 03 Silverado.

http://subthump.com/Chevrolet-GMC-Sub-Boxes/Silverado-Sierra-Crew-Cab/07-Up-New-Body-Style-GM-Crew-Cab-Dual-Downfire-Box.html 7" mounting depth and 1.16 cuft of airspace! Ah GM Why cant you give us more room in the New Body Style trucks!?

Here is the box I am currently running. 2 RE SE 12's (Not the new RE SEx's)

http://subthump.com/Chevrolet-GMC-Sub-Boxes/Silverado-Sierra-Crew-Cab/07-Up-New-Body-Style-GM-Crew-Cab-Dual-Downfire-Box.html .83 cu ft airspace per chamber and 6.5" of mounting depth. This box is kinda suffucating my RE SE 12's. They want more air, they told me.

So Im thinking of going with 2 SA8's ported. It will be powered by the same amp I have been running and will probably be running forever. Phoenix Gold Tantrum 1200.1 @ 2 ohms. So with all of my wiring upgrade including the Big 3, Kicker 1/0 awg, one ground on each side of the truck, it should be doing whats on the birthsheet. I think the birthsheets @ 2 ohms are around 1350-1400 watts RMS. 1 Ohm is around 1550-1600 watts rms if I remember correctly. Correct me if I am wrong..

Here is what inspired me to talk to Steve about a Dual Ported 8" Box specifically for the SA8's, but I dont know what the mounting depth and what the optimum tuning would be. I like lower tuning; 31-33 hertz.

http://subthump.com/Chevrolet-GMC-Sub-Boxes/Silverado-Sierra-Crew-Cab/07-Up-New-Body-Style-GM-Crew-Cab-Quad-8-Front-Fire-Box.html

So this will be for the new 2007 New Body Style Silverado and Sierra Crew Cabs. I am sure he could probably make a design for the Extended cab trucks. Ironically, the extended cab trucks allow more room than the crew cabs. I dont get it GM.

So I am trying to get some feedback from you guys on here so I can relay this to Steve to see if there is any interest. If there is any interest, he may put his into production. I dont have much specs on this Subwoofer, just the specifcations I got from here;

Realized that I don't have them on the site or anywhere easy to find at the moment -- so here we go :

D2 Model :

RE: 3.28 ohms (series)

FS: 41.6 Hz

Qes: 0.513

Qms: 6.606

Qts: 0.476

Le: 2.778 mH

Vas: 3.285 L

BL: 17.138 N/A

Cms: 83.341 um/N

Mms: 175.654 g

Sens: 78.476 dB @ 1w/1m

BL^2/RE: 89.5

D4 Model :

RE: 6.08 ohms

Fs: 44.66 Hz

Qes: 0.594

Qms: 6.337

Qts: 0.545

Le: 4.26 mH

VAS: 4.44 L

BL: 21.20 N/A

Cms: 80.8 uM/N

Mms: 157 g

Sens: 80.06 @ 1w/1m

BL^2/RE: 73.92

- Jacob Fuller

- Owner, Sundown Audio

- Sundown Audio on FACEBOOK

- Associate, Stereo Integrity

and here

Box size has alot to do with mechanical power handling. If you are going to be pushing your woofer beyond it's rated RMS power you need to be very mindful of this fact and put the woofer in no larger than the minimum suggested enclosure for music program.

We design our woofers for very small enclosures and power ratings are there for a reason -- you can continue to push a driver like the SA-8 beyond RMS power and it will not be stressed whatsoever thermally by the time you can cause mechanical issues. The motor, especially on the SA-8, is VERY strong -- being an 8" driver there is limited mechanical throw available. The driver retains high motor force all the way up to the point where you can start breaking it.

In any event... based on my testing so far you can expect something like the following on mechanical power handling vs. ported box size on the SA-8 :

1.25 cubic feet = 300 watts

1.00 cubic feet = 400 watts

0.80 cubic feet = ~450-500 watts

0.60 cubic feet = ~500-600 watts

You may ALSO need a subsonic filter depending on box tuning. The rated RMS power is 400 watts RMS -- if you push past that you are voiding warranty coverage. We are bringing in re-cone parts and they can be fixed, though, for those of you who like to push things. If you have any doubts about your ability to monitor your listening habits just stick to the 0.60 recommendation.

To re-iterate... they are not fragile. I have ton ALOT of testing on them with enormous amounts of power -- the above considers full bandwidth music program that can drop to very low frequencies and is a safe suggestion.

If you are an SPL competitor then you probably already know this and these suggestions don't really apply for burps @ tuning. We have put in excess of 600% of RMS power on them for SPL burps.

- Jacob Fuller

- Owner, Sundown Audio

- Sundown Audio on FACEBOOK

- Associate, Stereo Integrity

Ok, so my questions are the following:

1. Does anyone have any interest in this build? If so, Please post her

2. What is the optimum space requirements?

3. What is the optimum tuning for an SA8?

4. Would I benefit from going from 24" of cone surface; sealed to only 16" cone surface, but ported?

I apologize for the long post, but we could really get something going here, if its worth it. I dont have much, well any at all with 8" Subs. So please help

[ap0352 0]

Any update on this? Looking at getting rid of my stealthbox for more output. This seems interesting!

[duanebrow 6]

I can model the box for you if you want. You should be able to fit 2 sa-8's under the seats.

[///M5 2,833]

Not sure I understand 2 8's in that application...and for that reason don't think it would be a big seller. Of course, the general internet boner over 8's makes no sense to me either. They do have a time and a place, but that IMO is when box size must be small. Ported and 8's is a joke, unless you are using multiples, but then its a waste of money over buying something with more cone area and a single one.

[duanebrow 6]

I put a 10" mtx (i don't remember the model) ported under the seat of a ext. cab 2500 about 4-5 years ago. He is still using it today. I'd think that two 10's downfiring sealed would be better than the 8s ported.