WinISD converted to Cubic Feet?? (1 Viewer)

[Ches Campbell]

Is there a way to convert the WIndISD Measurements to cubic feet rather than litres? I cannot comprehend litres as well as cubic feet. Or, is there anothe program like WinISD that uses cubes rather than litres?
Thanks.

 

[Brian Bunge]

Ches,

Right next to the box labeled "Volume" there is a little "l" for liters. Place your cursor there and click one time. It will change to a different type of measurement. Keep clicking until you see "ft^3".

Also, to convert yourself, divided liters by 28.3. This will give you equivalent ft^3.

Brian

 

[Chris Carswell]

Ches,
That is funny. I wasn't the only one:b I just downloaded Win ISD as well and had no idea how to get cu. ft. I was doing all the conversions by hand all day :frowning: I actually still have a port question for someone......
When checking the port size & length what does the vent mach. mean? Is that the air speed of the port? A lower # would then be preferred. For my tempest I would either go with:
1 4" port, 6" long w/ a .18 vent mach (written in red)
1 6" port, 12" long w/ a .10 vent mach (written in green)
2 4" ports, 14" long w/ a .05 vent mach (written in green)
So, which do I use & why? What about this flared port thing?
Thanks to all.
Chris

 

[Brian Bunge]

Chris,

I just delivered a 175L DVC 15" sub tuned to 17.5Hz. I used one of the 4" dual flared ports and it worked fine. We didn't notice any port noise at all. Simply rocked the entire house!

The lower the vent mach the better. What volume and tuning frequency are you using to get these numbers?

Brian

 

[Ches Campbell]

The vent match is the level of port noise. The higher the number, the worse. If it is green, you are fine, but once it turns red, you need to go with a wider diameter port.

Thanks guys for the quick responses.

 

[Chris Carswell]

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[Chris Carswell]

Hi Brian,
I was using 262L tuned to 21hz.
What do you think?
I was also thinking of using an NHT 1259 instead of the tempest b/c it plays 1 db louder accross the board and has a lower F3 16hz comp to 20hz for the Tempest. This being in the same 8.9 cu. ft. box. I want to use a 15" b/c I think I would "feel" more punch (move more air) with the 15" tempest. I already have a loud boomy sub, now I want something that will thump you in the chest and not pop and distort. The thing is, I don't think I want to build a box that big (8.9 cu.ft.) I can use a smaller box with the NHT and it looks like it would still out perform it on paper, but in real life not sure??? There are a ton of happy tempest owners out there. Oh ya, I will be using an older PE #300-800 150 watt plate amp with the boost disabled.
LMK if ya got any advise or tips for me.
Thanks
Chris C
HTF Member

 

[Brian Bunge]

Chris,

I would definitely go with the Tempest. It'll move much more air than the 1259. There's absolutely no way the 1259 will outperform a Tempest. Even a Shiva would outperform the 1259. Also, if you're going with 262L I'm assuming you're building a sontube based sub? If so, then the 1259 cannot be mounted downfiring. If this isn't the case then disregard.

Anyway, I'm looking at the 262L enclosure tuned to 21Hz and it looks very good. If you tune to 18Hz instead you get a little bit more extension but you lose a dB or two in the upper 20's. Either way looks like a good system though, with an anechoic response of 108dB at 20Hz with 150W and just over 110dB from 22Hz up if you go with the 21Hz tuning.

Also, if you have the latest version of Excel, you might think about trying Unibox as a simulation program. I like it a lot better than WinISD, but everything is metric. There is a help sheet at the bottom that you can click and it will give you the English meaurements though.

Brian

 

[Janne Ahonen]

Hi everyone,
have you tried WinISD pro?
http://www.linearteam.dk/winisdpro.html
If you haven't then I suggest that you try it (nothing to loose, at least!)
I would check port velocity calculations with WinISD pro, it shows peak air velocity vs. frequency at your desired power level.. 15-17 m/s is safe limit for port velocity, generally..
Regards,
Janne

 

[Chris Carswell]

Hey Brian,
Thanks for the tips. I have heard form others that anything over 3.5 cu. ft for the NHT 1259 and,sounds bad, no good. Plus I want a little more THUMP!!! SO........ tempest it is
The box will be a Frustum Pyramid / obelisk finished in a high gloss piano type black. I hope to have some pics up soon as I start this bad boy this weekend.
I do have a few more ??? for ya if ya don't mind:
1.How many liters/cu.ft. should I subtract from the total volume for the Sub? Port? Amp?
2.It will be down firing and I want to use 6" legs. Is this ok or should I use 4" or 5". I read something about sub loading but forgot what it said exactly.
3.What about insulation or polly-fill for it? How much?
4.If using a flared port, add 1" to total length, correct?
Thanks for all the help. Without people like you, people like me would be lost!!!! :star: :star: :star: :star: :star:
5 stars to you guys!!!
-Chris

 

[Brian Bunge]

Chris,

1. I think a good general rule is to just add approx. 10L to the box to account for the Tempest, a single 4" dual flared port and the amp. I a 262L enclosure a couple of liters difference should be negligible.

2. 6" legs should be fine. The 175L DVC 15" sub I just delivered had 4" legs and it worked great as well.

3. You could get away with just adding 2-3 layers of sheets of dacron batting to the walls.

4. Yes, add 1" to the length.

Brian

 

[Chris Carswell]

Thanks again Brian. You too Ches and sorry about all the qusetions I had on your post. I was too lazy to start my own