SSA Demon 12 new ported box questions

[Greg B]

I’m currently running a 2.13 cube box tuned to 30. I built it for another sub and it’s within ssa’s specs so I figured I’d give it a shot. Now I’d like to build something that will be the best for what I have. This will be in a santa fe. Current box is front to back along the passenger side sub up port about 4-6” from the hatch. I built it wide and short so a bigger box would take up about the same footprint. I listen to probably 60% late 90’s to mid 2000’s rap, 30% 80’s and 90’s hard rock and some miscellaneous
It’s got a nice sound but I’m not getting much kick drum punch, making me think it might be tuned too low. Ssa told me 1.8 tuned to 33 was optimal. I’ve run the parameters on bcae1 and speakerbox lite, which say 3.1 cubes at 32.1 hz and 3.3 at 33.8 respectively. Both give high 28 f3. I don’t think I have any need to go lower than that.
My main question is which way should I go with the volume but I’d also like to know how shape affects the sound.I plan to make the bigger ones 24l -16-18h & w aero port on the long end. I’m open to suggestions though. The smaller one I could make whatever shape sounds best. Also where should the sub be in relation to the port end?

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[Jeffdachef 5,000+ posts]

I’m currently running a 2.13 cube box tuned to 30. I built it for another sub and it’s within ssa’s specs so I figured I’d give it a shot. Now I’d like to build something that will be the best for what I have. This will be in a santa fe. Current box is front to back along the passenger side sub up port about 4-6” from the hatch. I built it wide and short so a bigger box would take up about the same footprint. I listen to probably 60% late 90’s to mid 2000’s rap, 30% 80’s and 90’s hard rock and some miscellaneous
It’s got a nice sound but I’m not getting much kick drum punch, making me think it might be tuned too low. Ssa told me 1.8 tuned to 33 was optimal. I’ve run the parameters on bcae1 and speakerbox lite, which say 3.1 cubes at 32.1 hz and 3.3 at 33.8 respectively. Both give high 28 f3. I don’t think I have any need to go lower than that.
My main question is which way should I go with the volume but I’d also like to know how shape affects the sound.I plan to make the bigger ones 24l -16-18h & w aero port on the long end. I’m open to suggestions though. The smaller one I could make whatever shape sounds best. Also where should the sub be in relation to the port end?

your musical tastes needs 35 to 40hz tuning tbh. even 33 is too low.

 

[hispls 5,000+ posts]

your musical tastes needs 35 to 40hz tuning tbh. even 33 is too low.

I was thinking about the same thing. I think you could tune at 38 and never miss anything in any of that music. <30hz tuning is for home theater movie sound effects type stuff and test tones.

3 cube should be efficient. As far as aiming/placement really it'll be trial and error. Sub up and port to back or into a corner is a safe guess most of the time.

 

[Greg B]

I was thinking 35 before I got into running it through the programs. I get hung up on the 41.6 hz fs and keep thinking I need to compensate for it. I had a little hatchback with a 10 tuned to 35 and it hit plenty low in there. Didn’t work as well in a larger vehicle though.

 

[Greg B]

Would the larger volume have any negative effects?

 

[Jeffdachef 5,000+ posts]

Would the larger volume have any negative effects?

peakier response but more efficiency. Also group delay shoots up so your accuracy suffers a bit. Slightly hard to notice those differences unless you are an extreme audiophile snob with a trained ear but you should notice efficiency increase.

 

[Greg B]

I haven’t messed with it but my hu can account for delay. Should the sub be centered? I have some head room on the spec’d 550 rms but ssa told me it could handle 1200 all day. From what I’ve read a larger box would be beneficial

 

[THATpurpleKUSH 5,000+ posts]

2.5 - 3cf @ 38-42hz for that kind of music

 

[Greg B]

I’m thinking about 3.15 tuned to 38. That gives me even dimensions to cut. I had a 4” pvc port in the old box and didn’t have any port noise. I’m thinking about going to 6 though unless that’s a bad idea

 

[hispls 5,000+ posts]

my hu can account for delay

Not the same thing, but again, should be inaudible.

As you go up in volume you will gain efficiency but it may start to get a bit peaky. Good news is it's much easier to shrink the box than to enlarge it if it doesn't play out the way you like once it is installed. You can't go wrong with more port area either, if you're using round it's simple enough to cut down or replace some PVC to adjust tuning to your tastes.

Going with a bigger box may start to sacrifice some mechanical power handling as well. Dunno how much power you're running but either way you'll need to keep an eye on over-excursion and make sure you use subsonic filter appropriately or just be careful what kind of music you really crank.

 

[Greg B]

I played a test tone in the upper 20’s (don’t remember the exact frequency) and turned up the ssf until it got quieter. I get to clipping around 750-800 watts and ssa told me their demo sub is run at 1200 rms daily. It’s plenty loud for daily listening but I wouldn’t mind just a little more once in a while.

 

[shredder2]

I played a test tone in the upper 20’s (don’t remember the exact frequency) and turned up the ssf until it got quieter. I get to clipping around 750-800 watts and ssa told me their demo sub is run at 1200 rms daily. It’s plenty loud for daily listening but I wouldn’t mind just a little more once in a while.

If you're tuned to 30 you will lose some punchiness for sure. Another thing you might try is your lp filter setting, if you have it crossed low it'll attenuate those frequencies you are after. I've seen guys with low tuned boxes that have their lp set 50hz or whatever then have to raise their lp to 90-100 before they find the response they want. Especially if the fronts are not strong.
Worth a try?...
Otherwise, ya... 2.5-3ft3 tuned mid-upper 30's is probably what you need.

 

[Greg B]

Thanks shredder2 the help you gave the user that built like 6 boxes for the same sub is what got my wheels rolling on a new box. I can’t think of his user name but he helped me out on another thread. I set my amp’s lpf the same way as the ssf. I got a new hu last week and set the lpf on there planning to not use the one on the amp but it slipped my mind. Just fixed it and it’s a huge improvement. I tried a variety of different music on my way home and it all sounded much better. I’m trying to figure out a good way to cut down my port. That might keep me happy for a while. I love to tinker though so I’m sure I’ll build another one sooner or later. I can also adjust the lpf slope if that would help

 

[Jeffdachef 5,000+ posts]

I haven’t messed with it but my hu can account for delay. Should the sub be centered? I have some head room on the spec’d 550 rms but ssa told me it could handle 1200 all day. From what I’ve read a larger box would be beneficial

this is not the delay i'm talking about, its how fast the sub plays the note and stops the note. Has nothing to do with your time alignment. All about accuracy.

 

[Greg B]

Got ya. I would assume that was the case. You all have mentioned a larger box being more peaky but I thought I had read that a flatter response was a benefit of going big.