When I modeled (WinSID Pro) two vented 3015s with four 4 round ports against one 3015 with two 4 round ports the 215 seems to have a smoother freq curve with less bumps and dips expressly with the 215 cab tuned to about 51Hz. Im new at playing with WinSID and still learning so I may be missing something - but if not, can anyone explain why this is? Thanks
Joe, what are the respective cab volumes you are modeling? I'd be happy to run the sims myself and see what I can suss (if anything).
Thank you. Im not sure I understand the question exactly but I just went with the first vented 3015 on-axis box size that came up and only changed the # of drivers, ports, and cab tuning.
If all else is the same and all you did was double driver count and box volume, the curve should look the same, just 3 db louder. If they look different, you may have something other than exactly double, or different levels of input power between the 2 models. If you see bumps on the right side of the chart, the listening position is set to some degrees off axis.
Thanks Will, no bumps on the right but the 115 has a low end bump where the 215 doesn't -and I'll check levels and etc - thank you.
A higher port tuning and/or smaller box size per driver will give you that bump. You can also apply eq to the model, check you don't have one eq'd and not the other.
Maybe, but I’m not sure. I download WinISD Pro Alpha from LinearTeam and on Windows 7 I have to use “Task Manger” to shut the program down - so there are some glitches/bugs.
That will leave you with either one or two drivers in the same size box. And that in turn will give you very different alignments and frequency response curves. So now try starting from scratch for each iteration, or alternately start with one driver, then double the box volume when you switch to two drivers. The curves should be very similar once you do that. WinISD doesn't really "suggest" box sizes, instead it gives you a few classic alignments to get started with. Read on Joe...
Thank you very much - yeah, I've still got much to learn, but this is way cool. EDIT: Oh, and for anyone who would like to checkout WinISD Pro Alpha it’s free software and I downloaded it form http://www.linearteam.dk/default.aspx?pageid=winisd - I’m using version 0.50alpha7.
Actually, I think it was last update in 2004? I’m running it with Windows 7 and it works - and version Pro Alpha 0.50alpha7 is what the experts here on TB suggested.