4th Order Design Help

[SlamminBeats]

Looking to build a 4th order with an external port butted up against the ski hole opening. The entire trunk is sealed off including rear deck. Max dimensions are 16" H x 34" W x 12" D (Can maybe go a bit deeper, but looking to max out width and height here before adding more depth). The external port opening max dimensions are 9" x 7"

The sub will be likely be a dd1510 or DD2510 but open to any other options in the under $200 range. Can someone guide me to creating this? Do I put dimensions into Torres for both the sealed side and ported side separately and tune the ported size to ~45-50 hz? What should the port area per sq ft be(12-16)?

If anyone wants to throw a design together for me that would be alot of help. I have never made a 4th before.

[Triticum Agricolam]

How much power are you going to be running? What kind of bandwidth do you want to have?

With just a single 10" I hope your expectations are fairly modest.

[SlamminBeats]

How much power are you going to be running? What kind of bandwidth do you want to have?

With just a single 10" I hope your expectations are fairly modest.

There will be power headroom on which ever sub i do run. I'd like to be able to play down to 25hz and as high as I possible can. Id prefer bandwidth over loudness.

[Joe X]

The fourth order will play as high as your tuning, the larger the rear chamber the better the low end, larger front chamber the peakier it will get around your tuning frequency. model your prospect drivers before buying or building anything.

[SlamminBeats]

The fourth order will play as high as your tuning, the larger the rear chamber the better the low end, larger front chamber the peakier it will get around your tuning frequency. model your prospect drivers before buying or building anything.

so youre saying if i want to play to 60hz, i tune to 60hz

[Triticum Agricolam]

so youre saying if i want to play to 60hz, i tune to 60hz

Your output will begin to roll off once you get much above your tuning frequency, just how fast it rolls off depends on the size of the front chamber. You should be able to get good output to 60 Hz with a 45-50 Hz tuning.

I played around with the numbers a bit trying to find something that will work well for you. These small bandpass boxes can be very difficult things to design. There are a lot of conflicting goals that have to be balanced out. Things like keeping the port area high enough for good performance, without it require the port to be so long as to be impractical, etc. I haven't had a lot of luck finding something that looked good, but I'll keep working at it.

How much power do you want to run? I know you said you will have plenty of power no matter what sub you choose, but if I had an idea of where you wanted to be, it would help narrow down which subs will work well. Unfortunately I don't think either of the DD subs you were looking at are going to do what you want to do well.

[SlamminBeats]

so youre saying if i want to play to 60hz, i tune to 60hz

Your output will begin to roll off once you get much above your tuning frequency, just how fast it rolls off depends on the size of the front chamber. You should be able to get good output to 60 Hz with a 45-50 Hz tuning.

I played around with the numbers a bit trying to find something that will work well for you. These small bandpass boxes can be very difficult things to design. There are a lot of conflicting goals that have to be balanced out. Things like keeping the port area high enough for good performance, without it require the port to be so long as to be impractical, etc. I haven't had a lot of luck finding something that looked good, but I'll keep working at it.

How much power do you want to run? I know you said you will have plenty of power no matter what sub you choose, but if I had an idea of where you wanted to be, it would help narrow down which subs will work well. Unfortunately I don't think either of the DD subs you were looking at are going to do what you want to do well.

thanks man.

ill have at least 1000 rms and i dont need to use DD either.

[Joe X]

The fourth order will play as high as your tuning, the larger the rear chamber the better the low end, larger front chamber the peakier it will get around your tuning frequency. model your prospect drivers before buying or building anything.

so youre saying if i want to play to 60hz, i tune to 60hz

Not exactly, to give you an idea here's the DD 1510 in a 4th bandpass Vr = 0.7 cf, Vf = 1.2 cf @ 45Hz:

If you see it will peak a little below tuning and then roll off from there, I'd say you have about half an octave to decide where to crossover, this is a typical peaky loud design that is not very musical so more an example than something you want to follow.

[SlamminBeats]

which overall sub and port orientation is better below? One on the right is for 1 sub but could be place on either side. Remember the port is external will butt up to ski hole opening. also sub can be an 8 if that fits better.

[Cj Kumz]

Based on your dimensions you have slightly under 3 cubes to work with which should be fine for two 8s, one 10 or maybe even one 12. The sub orientations you have posted look ok though personally I would do the single sub setup exactly like the double setup but with 1 sub.