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<blockquote data-quote="hispls" data-source="post: 8582066" data-attributes="member: 614752">.707 is considered the target for SQ and home theater.&nbsp; Of course IMO you really don&#039;t want it down 3dB until you get a bit lower.&nbsp; Of course you may well have some compelling reason to shoot for something different, but most modeling software shoots for .707 as optimum for sealed.&nbsp; Way back in the day when I ran sealed I preferred a little closer to 1.0.Sealed box is pretty forgiving on small changes, a smaller sealed would just push things to the right a little, slightly steepen the slope, and possibly give you a little bump where the curve hits the zero line.Smaller ported tuned low (where you started) picture adding a narrow hump around 26hz into the sealed box plot.&nbsp; This is exaggerated by your cabin&#039;s resonance (mid to high 50hz range) giving you a plot that looks like a two humped camel which I can say from experience sounds absolutely awful.I run winISD on a virtual machine on my Linux laptop so it&#039;s rather a chore to boot up.&nbsp; I may or may not have time to mess with it and save/upload the pic tomorrow morning while I&#039;m having my coffee.Win ISD is pretty easy to use really, just be careful to check your units (cubic feet vs. liters) as you input things.&nbsp; The ONLY specs you really need for this are Qts, Fs, and Vas.&nbsp; From there after you&#039;ve done a whole bunch of them you get a pretty good idea of what changes to size and tuning will do to change the shape of your graph.&nbsp; Once you&#039;ve seen enough and tested the boxes real-world you get a pretty good feeling about what to expect.Location and positioning of the subs/port in the vehicle is dramatic.&nbsp; Once again you&#039;re running &quot;voids warranty&quot; power to those subs so risking running into mechanical limits isn&#039;t unexpected.&nbsp;&nbsp; You are fortunate that loading those subs down firing keeps them under control.</blockquote>

[QUOTE="hispls, post: 8582066, member: 614752"] .707 is considered the target for SQ and home theater. Of course IMO you really don't want it down 3dB until you get a bit lower. Of course you may well have some compelling reason to shoot for something different, but most modeling software shoots for .707 as optimum for sealed. Way back in the day when I ran sealed I preferred a little closer to 1.0. Sealed box is pretty forgiving on small changes, a smaller sealed would just push things to the right a little, slightly steepen the slope, and possibly give you a little bump where the curve hits the zero line. Smaller ported tuned low (where you started) picture adding a narrow hump around 26hz into the sealed box plot. This is exaggerated by your cabin's resonance (mid to high 50hz range) giving you a plot that looks like a two humped camel which I can say from experience sounds absolutely awful. I run winISD on a virtual machine on my Linux laptop so it's rather a chore to boot up. I may or may not have time to mess with it and save/upload the pic tomorrow morning while I'm having my coffee. Win ISD is pretty easy to use really, just be careful to check your units (cubic feet vs. liters) as you input things. The ONLY specs you really need for this are Qts, Fs, and Vas. From there after you've done a whole bunch of them you get a pretty good idea of what changes to size and tuning will do to change the shape of your graph. Once you've seen enough and tested the boxes real-world you get a pretty good feeling about what to expect. Location and positioning of the subs/port in the vehicle is dramatic. Once again you're running "voids warranty" power to those subs so risking running into mechanical limits isn't unexpected. You are fortunate that loading those subs down firing keeps them under control. [/QUOTE]

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