Need help with WinISD designs

[scooter99]

So I was just playing with WinISD Pro last night and trying to figure out where I want to be with this enclosure. I have a few pictures to show.

So my plan is to have tweeters, 6.5" mids, this 10" sub as mid bass, and then I'm planning a pair of DC Audio XL 15's in a 4th order band pass blow through.

The plan is to have a pair of mids and tweets in each door (4 doors). That means rear fill. I'm not 100% sure where to cross them yet. They're all ampere audio components and equipment except the 15's. Unfortunately I don't have much in the way of the frequency ranges of the components. There's a 5khz crossover that comes with the tweets, but other than that I don't have a range.

I've been doing some reading, which isn't always a good thing lol, and came up with these as my crossover starting points.

Tweeters - 2-6khz

6.5" Mids - 2khz - 450hz

10" Mid bass - 500hz - 40hz

15" Sub bass - 45/50hz - ???

I was just doing this model on the 10" sub for mid bass. I currently have it in an enclosure that I started at 1.15cu ft with a 2" x 10.5" x 28" port. I quickly found out it was too much air space. Through talks with Andrew at Ampere, we decided that .80-.75cuft was where it should be built. So I shrunk it and noticed an immediate difference.

So plotting here are my pictures.

This is the Transfer Function Magnitude. The first selection that shows up.

Yellow - current enclosure. Approx .80 cu ft, port 2" x 10.5" x 28" shows a tuning of 47hz (2000 w @ 1 ohm, LPF 100hz, HPF 40hz)

Red - New Plot. .80 cu ft, port 1.5" x 10.5" x 17.86" tuned at 50hz (2000w @ 1 ohm, LPF 500hz, HPF 40hz)

Green - New Plot. .80 cu ft, port 1.5" x 10.5" x 29.75" tuned at 40hz (2000w @ 1 ohm, LPF 500hz, HPF 30hz)

These are the rear port velocity readings. My understanding after reading is that anything under 110 m/s is good. So I'd think these are well within the range of good.

Yellow current - Peaks at 47.44hz at 35.195 m/s peak

Red - Peaks at 50.49hz at 51.454 m/s peak

Green - Peaks at 40hz at 47.611 m/s peak

Then there's the transfer function magnitude (EQ/Filter)

So I'm not sure if these are good readings or not. Am I way off on these or am I in the ballpark? What am I aiming for? A flat curve with no hump in it? For example, these show a spike in the beginning and then a smooth flow after that. Should that "spike" be eliminated, and how would i do that? What does that represent?

Maybe you all can give me some insight as far as that goes, and I can maybe play with it from there.

Thanks for any help. I appreciate it.

Scott

[Triticum Agricolam]

Just one thing that jumped out at me. You want your port velocity to be under 110 feet per second, not meters per second. 110 FPS works out to about 33.5 m/sec. Less would be better though since once you get much over 20 m/sec you start to get more significant amounts of port compression.

[diegoclass2010]

nice topic.. something different, im in....

the only thing i dont get is why 2,000 watts at 1 ohm? seams like alot to me for midbass with only one driver

[scooter99]

nice topic.. something different, im in....

the only thing i dont get is why 2,000 watts at 1 ohm? seams like alot to me for midbass with only one driver

Well, it wasn't going to be originally. I was planning on doing about 10 10's in a blow through and I was going to test a single 2k per sub and per pair, but I couldn't ever sell my 15's. Now I have them and I wanted to do a 10 in the console and so no need to get anymore equipment. Use what I have.

There are a lot of systems out there with 1-2k watt midbass. It's just spread over a pair of drivers in doors. Mine is just centralized and one driver.

Plus I can use it as a dual purpose driver. Midbass with the subs in, and as a sub bass when I have to remove the 15's.

I'm still experimenting.

Triticum, sorry it wouldn't let me multi quote on mobile. Thand you, I'm going to play with it some more. Is the best way to lessen the port velocity to shrink the port or make it bigger? Seems like shrinking it would choke it off more, but if you think in the sense of a water valave, the more you open it the more it let's through. But I don't know if that way of thinking works here.

[ckeeler11]

Larger port for lower velocity.