X 15 6th order help...

[dsw422]

Hey guys..

I need help designing a 6th order for a single Sundown X15 on 1500 watts. This will be for a customer of mine. I already built a ported box 5 cuft tuned to 28 hz and he wants a different style and sounding box so he asking for a 6th.. he'd like it to be more musical and play low and higher notes well..

I came up with a design, I'd like input on what I have come up with and any changes you'd recommend. This box is for a parallel 6th (since that's all WinISD will allow)...

Rear chamber: 2.75 cuft tuned to 20hz, square port 5.5"x5.5" (this leaves my port super long though)

Front chamber: 4.5 cuft tuned to 42hz, slot port 4"x16"

Thanks for any help

[Triticum Agricolam]

I think your idea of a parallel 6th order bandpass sounds good. I'm not sure about your chamber specs though. With such a large front chamber and such a small, low tuned rear chamber the rear chamber isn't going to be contributing much output and I don't think it will keep up with what you are having coming out the front chamber.

When it comes to a bandpass box its a good idea to keep in mind what frequency you will want to be crossing over to the mids at and make sure you have good output from the subs to at least as high as that.

Just playing around with it quick in WinISD I'd shoot for something more like a 4.5 cu ft rear chamber tuned to 25 Hz and a 2 cu ft front chamber tuned to 50 Hz, both chambers using a 50 sq in slot port.

As with any bandpass box, having some kind of adjustable ports would be a REALLY good idea.

[dsw422]

Thanks for your input Triticum. After posting last night, I did realize there was better response and output by swapping the tuning frequency like you said. I think my new design (almost like urs) give the guy more response like he wants and will give a little more output than the current ported box he has. And the 50sqin of port area was perfect at keeping the air velocity below 30m/s..

New design:

Rear chamber: 4.5 cuft tuned to 22hz, port area 50sq in

Front chamber: 2.5 cuft tuned to 50hz, port area 50sq in

Only question is with an adjustable port for the rear chamber. With this design, it's length will be 56" long which means it has to turn. How would I make it adjustable being so long?.

Also, what program would u recommend me getting to try designing a series tuned 6th cuz I'd like to see the difference between a series and parallel 6th..

Thanks for any help

[notorious97200]

28 Hz on a ported box for one X15 in a 5ft3 enclosure ? I'm sure it was getting down low !
Big box and low tuning on a X : from what I've listened, it shouldn't play high to blend with the midbass.

Did you tried a higher tuning, or a smaller box ?

Obviously volume is not a factor, this 6th order bandpass box will be huge !

Good luck.

[Triticum Agricolam]

Thanks for your input Triticum. After posting last night, I did realize there was better response and output by swapping the tuning frequency like you said. I think my new design (almost like urs) give the guy more response like he wants and will give a little more output than the current ported box he has. And the 50sqin of port area was perfect at keeping the air velocity below 30m/s..

New design:

Rear chamber: 4.5 cuft tuned to 22hz, port area 50sq in

Front chamber: 2.5 cuft tuned to 50hz, port area 50sq in

Only question is with an adjustable port for the rear chamber. With this design, it's length will be 56" long which means it has to turn. How would I make it adjustable being so long?.

Also, what program would u recommend me getting to try designing a series tuned 6th cuz I'd like to see the difference between a series and parallel 6th..

Thanks for any help

The 56" long port is one reason I'd raise the tuning on the rear chamber a bit. Just going up to 25 hz will shorted the port by more than a foot. Also cabin gain is going to boost the low end anyway, so with a 25 Hz tune there should still be good output to nearly 20 Hz.

As far as the adjustable port goes, the front chamber is really the one I'd be concerned about tweaking the tuning on. The front chamber port should be short enough that making it adjustable shouldn't be as much of a challenge.

[dsw422]

Thanks for your input Triticum. After posting last night, I did realize there was better response and output by swapping the tuning frequency like you said. I think my new design (almost like urs) give the guy more response like he wants and will give a little more output than the current ported box he has. And the 50sqin of port area was perfect at keeping the air velocity below 30m/s..

New design:

Rear chamber: 4.5 cuft tuned to 22hz, port area 50sq in

Front chamber: 2.5 cuft tuned to 50hz, port area 50sq in

Only question is with an adjustable port for the rear chamber. With this design, it's length will be 56" long which means it has to turn. How would I make it adjustable being so long?.

Also, what program would u recommend me getting to try designing a series tuned 6th cuz I'd like to see the difference between a series and parallel 6th..

Thanks for any help

The 56" long port is one reason I'd raise the tuning on the rear chamber a bit. Just going up to 25 hz will shorted the port by more than a foot. Also cabin gain is going to boost the low end anyway, so with a 25 Hz tune there should still be good output to nearly 20 Hz.

As far as the adjustable port goes, the front chamber is really the one I'd be concerned about tweaking the tuning on. The front chamber port should be short enough that making it adjustable shouldn't be as much of a challenge.

That makes sense.. thanks. If and when I start the build, I'll post pictures of the progress..

P.s. do you know of a program I could use to model a series tuned 6th?

[Triticum Agricolam]

That makes sense.. thanks. If and when I start the build, I'll post pictures of the progress..

P.s. do you know of a program I could use to model a series tuned 6th?

HornResp can model series tuned 6th order boxes and its free. It has a bit of a steep learning curve though.

[DLHgn]

HornResp can model series tuned 6th order boxes and its free. It has a bit of a steep learning curve though.

^^^This. It is a very powerful program able to simulate many kinds of enclosures with more variables than I can find a use for. Think of WindIsd on steroids. The only issue I have with it is that I find it to be very difficult to work with. The more I do the easier it gets but it is still difficult even with some experience under my belt. You will most likely have to read tutorials on how to setup whatever box style you want.