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WinISD - help

Discussion in 'Miscellaneous [BG]' started by MAGUS®, Jan 6, 2006.

  1. MAGUS®


    Dec 23, 2004
    Shame there's no SPEAKER / CABS forum - wasn't sure where else to put this thread.

    does anyone know how to use this WinISD programme to calculate volume of a cab and the optimum port size ?

    I'm interested in building a cab to house 2 Eminence Delta 12LF units. Also, if the results say that a port of 6" diameter is required, can i fit 2 x 3" ports or does it have to be 1 x 6" port ?

    Heres a link to a UK company selling Eminence - the link is to the Delta12LF but the spec is ever soooooo slightly different to the spec on the Eminence site. ( the resonancy Hz rating is 45hz on the UK sellers site and 51hz on the Eminence site )



    PS i've heard that Eminence have made mistakes on their website before, but i wouldnt know who was right regarding this particular Speaker Chassis
  2. Passinwind

    Passinwind I Know Nothing Supporting Member

    In that screen there's a drop-down box for number of ports. Choose 2 and see what it tells you. :cool:

    There are many places where you can manually enter values, and other values will change accordingly. Play with that for a while then get back to us. Which version of WinISD are you using? What speaker alignment did you choose? Do you understand the various possible alignments?

    Most of these threads end up in Amps, bet this one will eventually too.
  3. MAGUS®


    Dec 23, 2004
    I must be using it wrong - which is why i've posted here , but i cant see any drop down box. There's the option to use well known speakers from WinISD database, but it doesnt have an option that i can see where you want to use 2 of the same speakers.

    I thought i would try the one speaker, then just double all the values. EG if the results for 1 speaker was 2 cubic feet, and 4" port, as i was using 2 speakers i would make it 4 cubic feet and 8" port

    I've since been told that its not how speaker builds work.

    If anyone else can just guide me through the process of using the porgramme - please post or PM me ! Cheers
  4. Passinwind

    Passinwind I Know Nothing Supporting Member

    Open "New Project".
    Select the Delta 12LF, click "next" at the bottom right.
    Do you now have a drop down box for number of drivers?

    I'm using the Pro version, but I think I have the other one kicking around somewhere if you need me to look at that instead.

    If you want to take this to PM, I'll try to get you started on the right foot.
  5. MAGUS®


    Dec 23, 2004
    Thanks dude -
    Oh , i appear to have version 0.44 if that helps. I'm going to tiptoe off and try it again with your advice, then report back !

    I dont mind you posting here - i dont care if i look like a dork cos i cant figure it out ! :)
  6. MAGUS®


    Dec 23, 2004
    Whoa !

    Passin - you're so right ! There was a drop down box - damn my eyes man. Ok, heres the results ...

    Front chamber / Volume ( inches ?? millilitres ?? ) = 436.6

    Tuning Freq = 31.9 hz ( is that something to do with the port length ? ) How do " TUNE " to 31.9hz and how will i know when i've done it ...


    number = 1

    diameter = 0.102m ( meters ? )

    Vent length = too short m ??

    Vent match = 0.31 ?

    Can you decipher for me ? Much obliged !!! :D
  7. Passinwind

    Passinwind I Know Nothing Supporting Member

    The units of measure can be changed to whatever you're comfortable with, by double clicking on the m, l, in^3, or whatever.

    That tuning frequency is critical, and sounds pretty low for those drivers. If you change it, the port dimensions will change though, and vice versa. Try it, it's pretty educational. You can see the frquency response curve change as you fiddle with the tuning and box size.

    I just tried (very briefly) modeling the cab in both the Pro Alpha .50a7 version and in Beta v0.44. Neither one looked reasonable, and the database T-S parameters are wildly divergent between the two. In that case, I've had acceptable results from creating a "new driver" database, and manually entering all the parameters. It's kind of a pain, but try that.

    Maybe someone else will jump in this evening. I have to go mix a club show pretty soon, but I'll try to unravel things tomorrow at some point if you still need a hand. There are lots of Talkbassers who are better at this than me though.

    Don't go crosseyed!
  8. MAGUS®


    Dec 23, 2004
    So are you thinking that the choice of Speaker Chassis is getting the non favourable results ?

    We dont get much choice of 12" Eminence speakers that are also 4ohm in the UK. I need 2 x 4ohms to get the amp to run full power.
    That is, the amp is 250 watts per channel @ 4 ohms. The speakers would be seperate ( not parallel or Series ) but in the same cab. That way i can run a channel per speaker.

    Its neary time for bed here - but i will be back for some advice. You're doing ok so far, as far as i'm concerned ;)
  9. Passinwind

    Passinwind I Know Nothing Supporting Member

    I managed to get some better looking results with a little effort, but it all still looks a little goofy to me right now. I like the 12LF, and it would actually be potentially useful to me to have this sorted out. This is a software/operator issue; the speaker is a perfectly fine choice, although an additional tweeter and/or midrange driver may be useful to many of us.

    I you haven't done so already, download Bgavin's musician's reference spreadsheet. I know he has some nice Eminence designs on that site (http://www.ofgb.org/) too. Parts Express has some on their website as well.

    Off I go now to something I actually know a bit more about. :cool:
  10. MAGUS®


    Dec 23, 2004
    A couple of persons on this side of the lake have suggested that running 2 x 12LF's might leave the response a tad short on top end sparkle, but i'm not really after that anyways. In my rig setup, i always back the treble right off, hi mids too ( if the amp has such a control ) ...have the low mids up midway, and 3 quarters bass. All treble backed off on the guitar too.

    OK mate - thanks for your time - appreciated :)

    Gonna go have a looksie at that link and see whats what !!
  11. Passinwind

    Passinwind I Know Nothing Supporting Member

    I took another stab at it this morning, using T-S parameters from Parts Express. I edited the parameters in the WinISD database, which were totally whacked for some reason. Things looked much more reasonable at at that point. :cool: As I said before, I've had best results just entering all the parameters into a new driver database. I could email you the results if that would help.

    There are a ton of threads on this very subject though, as it turns out. Start with searches on "Delta 12LF WinISD" and "Cabinet Building 101" for starters. There are more links in the stickied FAQ thread at the top of the Amps forum as well.
  12. MAGUS®


    Dec 23, 2004
    Hi mate - well i wouldnt mind those results. Glad its not the speakers, cos i had my mind settled on that pair.

    Strangely, i had a go at the WinISD plot, using just 1 Emmy 12LF and i got cab volume around 218, port diameter 3.9, but port length was given as 0.036 of a meter ? Doesnt that sound real short to you ?

    I then went through it again using 2 12LF's and all it did was double the volume to 436 but left the port vol and length identical - its a confusing thing

    Anyways - can you forward your efforts to fat-bass@hotmail.co.uk ?

    Cheers !!!
  13. Passinwind

    Passinwind I Know Nothing Supporting Member

    No, 3.6 cm could be a perfectly reasonable port length. Look at all the cabs that just use the 3/4" thickness dimension of the baffle as the port depth.

    Anyways - can you forward your efforts to fat-bass@hotmail.co.uk ?

    Done! :cool:
  14. MAGUS®


    Dec 23, 2004
    yeah you're right. Someone else had a stab at it, and got the same results and advised that port length was very reasonable !

    Thanks for email mate

    Bargain !