akuma4u Posted April 28, 2016 Author Report Posted April 28, 2016 is the sa 12 a low qts low vas sub? It's QTS is around .5, which is pretty moderate. A .5 QTS should be fine for 4th order band pass. The Vas is about 24 liters, which is on the low side for a 12" sub. This is going to make the output more peaky and will make it harder to get a wide bandwidth. ok cool thanks for that info the guy in the video that i posted above used the same subs and said this "Bandpass boxes have a great sound to them IMO. They have a wide bandwidth and are not as peaky as a normal ported box. Ported boxes have most of their output around port tuning and this bandpass played all frequencies from 25-55 within 2db of each other so the response was rather flat...which is what I wanted " so he was able to hit 25-55 that is plenty wide for me..
Triticum Agricolam Posted April 28, 2016 Report Posted April 28, 2016 Just something to think about, what the guy in the video is saying isn't wrong, but it's a huge over-generalization. It's basically like saying all Fords are fast. Some are, some aren't. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds:
akuma4u Posted April 29, 2016 Author Report Posted April 29, 2016 Just something to think about, what the guy in the video is saying isn't wrong, but it's a huge over-generalization. It's basically like saying all Fords are fast. Some are, some aren't. so if i copied his design , it doesnt mean that i will also have the same results as he did.
Triticum Agricolam Posted April 29, 2016 Report Posted April 29, 2016 Just something to think about, what the guy in the video is saying isn't wrong, but it's a huge over-generalization. It's basically like saying all Fords are fast. Some are, some aren't.so if i copied his design , it doesnt mean that i will also have the same results as he did.No, not unless you were using the same subs in the same vehicle. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds:
akuma4u Posted April 29, 2016 Author Report Posted April 29, 2016 Just something to think about, what the guy in the video is saying isn't wrong, but it's a huge over-generalization. It's basically like saying all Fords are fast. Some are, some aren't.so if i copied his design , it doesnt mean that i will also have the same results as he did.No, not unless you were using the same subs in the same vehicle.same subs yes, more powerful amp, same car no.
Triticum Agricolam Posted April 29, 2016 Report Posted April 29, 2016 I got a chance to watch that video and plug the box specs into WinISD and see how it looks. With 2 cu ft sealed and 2.5 cu ft ported it didn't look too bad. The guy in the video is keeping the front chamber size on the smaller side, which definitely helps give the box wider bandwidth. How much power are you going to be running? If you have the space you may be able to increase the sealed chamber size some, which would improve low end performance and help flatten out the frequency response more. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds:
akuma4u Posted April 29, 2016 Author Report Posted April 29, 2016 I got a chance to watch that video and plug the box specs into WinISD and see how it looks. With 2 cu ft sealed and 2.5 cu ft ported it didn't look too bad. The guy in the video is keeping the front chamber size on the smaller side, which definitely helps give the box wider bandwidth. How much power are you going to be running? If you have the space you may be able to increase the sealed chamber size some, which would improve low end performance and help flatten out the frequency response more. i will be running the sa 12s on a crescendo bc2000. I will try to increase the sealed chamber more if i can, my trunk is kinda tight as it is but if i do happen to increase the sealed size by lets say .5 cubes does that mean the ported side must also be increased .5 cubes?
Triticum Agricolam Posted April 29, 2016 Report Posted April 29, 2016 No, the chambers are sized independently. Ratios are dumb. Leave the front chamber at 2.5 cu ft. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds:
akuma4u Posted April 29, 2016 Author Report Posted April 29, 2016 No, the chambers are sized independently. Ratios are dumb. Leave the front chamber at 2.5 cu ft. ok so 2.5 to 2.5.. and tune it to the resonant freq of the front chamber. This will design will make for a musical box and not a peaky one.. but there will still be plenty of SPL, more than a ported box, right?
Triticum Agricolam Posted April 29, 2016 Report Posted April 29, 2016 With 2.5 cu ft sealed, the sealed resonance is going to be about 48 Hz. Tuning there will give you the flattest response, it may not play as low as you would like though, so you may want to tune more like 44 Hz. I'd suggest making your port adjustable so you can tweak things once you get the system playing in your vehicle. I think that box should perform well for you, buts not going to beat a ported box, either for max output or smooth frequency response. For use in vehicles 4th order bandpass boxes have one advantage over a ported box, they let you push all the output through the port, which when you need that ability its a very handy thing to have. When it comes to performance though, ported boxes are better at turning space into bass. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds:
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