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  • WinISD not modeling right

    WinISD works fine for some speakers but not for others . The Dayton RSS315HO-4 show a vented box of 1.58 cu.ft. with a 4" vent 24" long and a sealed box of .58 cu.ft. The Ultramax 12" shows a 5.8 cu.ft. box sealed and over 8 cu.ft. vented . Not anywhere near the published specs for enclosure size. The input data is correct in the data base .I am using the beta version , the alpha version was worse . I'm running Windows 8 . Anybody else have these kind of problems .My old computer had Windows XP and never had a problem with either version . The RSS315HF models correctly but not the HO .

  • #2
    Re: WinISD not modeling right

    Don't use Beta, it's not accurate. Use the W7 version of Alpha Pro, in W7 mode. If you're still way off you probably do have bad data, make sure you're not entering cu ft Vas instead of liters, for instance.
    www.billfitzmaurice.com
    www.billfitzmaurice.info/forum

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    • #3
      Re: WinISD not modeling right

      Well, computer software kinda just doesn't (can't) run like that, and it SEEMS like your value "units" are OK. These box sizes and tunings aren't BAD, and I wouldn't necessarily be using PE's box recommendations as gospel. I think when you get into these large drivers (especially with large vented boxes) the realm of design possibilities gets much, MUCH wider. There's a tradeoff between size (and F3) and power handling (limited by Xmax).

      WinISD's alpha and beta versions have NEVER spit out EXACTLY the same results for me, but then, the alpha ("Pro") version can pick from between maybe 4 or 5 different vented box alignments. Currently I'm running BOTH versions on 2 different machines: about a 5 year old desktop under Vista Home, and a new notebook under Windows 8. The alpha versions match each other, and the beta versions match each other, but the 2 different versions don't agree EXACTLY (maybe +/-5% variation on Cb, Vb, and Fb), but all that's normal AFAIC.

      Also, Dayton may have changed their published specs on older drivers over the last few years. I've never checked, but do the box sizes/tunings on the product page exactly match the recommendations in PE's "Woofer Selection Guide"?

      Also (and I find this to be a bit odd), WinISD Pro would NOT exit gracefully under Vista (I got used to closing it down under "Task Manager"), but there's no discernible problem with it closing in Windows 8.

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      • #4
        Re: WinISD not modeling right

        Originally posted by Chris Roemer View Post
        Also (and I find this to be a bit odd), WinISD Pro would NOT exit gracefully under Vista (I got used to closing it down under "Task Manager")
        That's because it's not Vista compatible. Run it in W98 mode and it's fine.
        www.billfitzmaurice.com
        www.billfitzmaurice.info/forum

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        • #5
          Re: WinISD not modeling right

          THANKs Bill.

          I had tried running it under XP/SP2 before (I THOUGHT under your advice?), but that never cleaned it up for me.

          I just switched it to W98, and it works great (now - why didn't I think of that?).

          Chris

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          • #6
            Re: WinISD not modeling right

            Originally posted by wlb View Post
            WinISD works fine for some speakers but not for others . The Dayton RSS315HO-4 show a vented box of 1.58 cu.ft. with a 4" vent 24" long and a sealed box of .58 cu.ft. The Ultramax 12" shows a 5.8 cu.ft. box sealed and over 8 cu.ft. vented . Not anywhere near the published specs for enclosure size. The input data is correct in the data base .I am using the beta version , the alpha version was worse . I'm running Windows 8 . Anybody else have these kind of problems .My old computer had Windows XP and never had a problem with either version . The RSS315HF models correctly but not the HO .
            Hi, a couple things:

            1) WinISD does not account for stuffing density. The recommended sealed enclosures for the Ultimax drivers includes a prescribed amount of stuffing. Other design tools, such as BassBox Pro, can account for the effect of stuffing and you'll see that the numbers work out in those programs when the stuffing density is set correctly.

            2) Be sure to use the provided Sd parameter. If this is off, then the box model won't come out right.
            Best Regards,

            Rory Buszka
            Product Manager, Dayton Audio

            The best way to predict the future is to create it.

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            • #7
              Re: WinISD not modeling right

              Originally posted by [email protected] View Post
              1) WinISD does not account for stuffing density.
              It does, in the Advanced section of the Box tab. Parameter Qa, absorption losses. These are produced by losses in enclosure. Any stuffing will increase the absorption loss. With no stuffing inside the box, 100 is typical. Heavily stuffed enclosure has this about 3-5.
              The default value is 100. I use 40 for a lined enclosure, 5 for stuffed. As is always the case you never get something for nothing. Stuffing can tame a response peak, the result of a box that's too small, but it also reduces broadband sensitivity. When you change Qa you will see a shift in the box Qtc with a sealed cab.
              www.billfitzmaurice.com
              www.billfitzmaurice.info/forum

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              • #8
                Re: ARRRGH - Oh NO00000oooooo !

                Sorry Bill, I thanked you too soon.

                Once I changed CM to Win98 (on my Vista machine) I could run sims with WinISD Pro (alpha) till the cows came home, and it would exit gracefully (w/out me having to resort to Task Manager).

                Then . . . I entered in data for a new driver, and as soon as I hit "Save", not only did my data entry screen fold, but the entire WinISD app disappeared. I opened it back up, thinking my new driver would be there, but I thought wrong.

                So, once again, it'll be back to TM for me. :-(

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                • #9
                  Re: ARRRGH - Oh NO00000oooooo !

                  Originally posted by Chris Roemer View Post
                  Sorry Bill, I thanked you too soon.

                  Once I changed CM to Win98 (on my Vista machine) I could run sims with WinISD Pro (alpha) till the cows came home, and it would exit gracefully (w/out me having to resort to Task Manager).

                  Then . . . I entered in data for a new driver, and as soon as I hit "Save", not only did my data entry screen fold, but the entire WinISD app disappeared. I opened it back up, thinking my new driver would be there, but I thought wrong.
                  I never had that happen. At any rate it's time to leave Vista in the rear view.
                  www.billfitzmaurice.com
                  www.billfitzmaurice.info/forum

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                  • #10
                    Re: ARRRGH - Oh NO00000oooooo !

                    FWIW, I got all three versions to work fine in Win7 Home Version Premium or XP Pro on my new re-built 'puter. I have it set-up with both OS on separate HD's so it doesn't care. I ran about thirty drivers in all three versions in both OS and got so nearly identical answers, I'm not going to worry about it. It's pretty neat that I can run both OS at once on a split screen and crunch stuff simultaneously. Quad core processors rock!

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                    • #11
                      Re: ARRRGH - Oh NO00000oooooo !

                      I was able download WinISD Alpha pro ok ,seems to be working well . I do have a question with the 12" ultramax . WinIsd says it needs a 5 cu.ft. box for a .707 qtc. but it starts to max out quickly after 30 hz. If I put it in a 2cu.ft. box it holds up good down to below 25 hz . but the qtc is 1.025 .PE sells a 2cu,ft. box for that speaker . Is that a problem with a qtc that high ?

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                      • #12
                        Re: ARRRGH - Oh NO00000oooooo !

                        I got the same answers. P-E "recommendation" using Bass Box suggest a 2.8 Cu. ft. box with an F3 of 34Hz. I guess this driver is designed for REALLY small enclosures. It seems all wrong though...

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                        • #13
                          Re: ARRRGH - Oh NO00000oooooo !

                          Originally posted by wlb View Post
                          If I put it in a 2cu.ft. box it holds up good down to below 25 hz . but the qtc is 1.025 .PE sells a 2cu,ft. box for that speaker . Is that a problem with a qtc that high ?
                          Compare the two charts. Qtc of .7 has a flat response with f3 at 30Hz, Qtc of 1 has a hump centered at 60Hz and f3 of 36Hz. The larger cab is down 8dB at 20Hz, so with cabin gain it's still useful there. The smaller is down 16dB at 20Hz, so it's not.
                          www.billfitzmaurice.com
                          www.billfitzmaurice.info/forum

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                          • #14
                            Re: ARRRGH - Oh NO00000oooooo !

                            Well, there's more.

                            The "Pro" version has a tab that'll let you simulate a low pass filter (like on a sub's plate amp, or an AVR's LF output). If you set it to whatever freq (or freqs) you might want to use, you'll see the top end roll off (at 50 or 80Hz, or whatever). You'll end up with just a "hump" curve showing you how wide the bandwidth of your sub will be. Just find the top of the peak, and go down -3dB on either side, and that's how much the sub will play in your final setup. The lower F3 point shows how low it'll go, and the upper shows where you should roll your mains in. If you're happy with the range (an F3), then (in THIS situation) I'd say that's the prime decision maker, regardless of what the Qtc ends up at.

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                            • #15
                              Re: ARRRGH - Oh NO00000oooooo !

                              Originally posted by Chris Roemer View Post
                              Well, there's more.
                              The "Pro" version has a tab that'll let you simulate a low pass filter
                              Equally useful is the high pass filter, which shows how excursion and, in the case of ported, port velocity are affected.
                              www.billfitzmaurice.com
                              www.billfitzmaurice.info/forum

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