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New to audio. Building ht ported enclosure.


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Looks good!

The only change I would make would be to make your 45 pieces in the corners of the port a little bigger. The goal is to keep the cross sectional area of the port as constant as possible. See below:

rb6QTCF.png

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

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I figured they needed to be larger. I'll go and change that tonight after dinner. Thank you again for all of the help. I really can't thank you enough. Made my life easier and saved me time/money

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I have a question. What are the equations y'all use to figure out tunning frequency of a port, lenght of a port and volum of box needed? I can't seem to find them. Also, what is the general rule of thumb for port cross sectional area?

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I have a question. What are the equations y'all use to figure out tunning frequency of a port, lenght of a port and volum of box needed? I can't seem to find them. Also, what is the general rule of thumb for port cross sectional area?

I use two formulas for determining port tuning, the first is listed here:

http://www.troelsgravesen.dk/vent_tuning.htm

The second is from JL's website. I have both put into a spreadsheet so they are really quick and easy to use.

There is an online port calculator here:

http://www.carstereo.com/help/Articles.cfm?id=31

As far as port area goes, the best rule of thumb is to NOT use any rules of thumb, seriously. For determining port area there is a calculator on the same page as I linked above for port tuning. Its very conservative and often will tell you you need more port area than you really do, but its better to error on the high side vs the low side. If you want a more precise answer you can use box modeling software like WinISD, BassBoxPro, Hornresp, etc. Modeling software combined with experience is how I come up with port area requirements.

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

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I've tried using WinISD and it wasn't working right for me. I was probably doing something wrong. Is there a tutorial somewhere on here that I can read to learn how to use it better?

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WinISD can be tough to use in the beginning. Unfortunately I don't know of any good online tutorials, a google search may turn up some. I'm pretty good with WinISD and I'd be happy to help you if I can.

I have two tips I can give you that will making using it a lot easier. The first is to make sure you are running the newest version (most people aren't), you can download it here: http://www.linearteam.org/download/winisd-07x.exe

The second thing is to make sure you are entering in the driver parameters correctly. There is definitely a right and wrong way to do it. Here is the right way:

The suggested procedure for entering driver parameters is following (check first that "Auto calculate unknowns" option is checked):
1. Enter Mms and Cms
This gives fs. If either is not available, then enter fs and other parameter.
2. Enter Sd, Bl and Re
Now, you should get all but Qms (and Qts), Vas. Please note that Vas may not match exactly what is specified by manufacturer, because exact value of Vas depends on environmental parameters. See FAQ.
3. Enter Rms or Qms.
Either one will do, although I tend to prefer Qms over Rms, because it can usually be measured in driver measurement procedures.
4. Enter Hc, Hg and Pe.
If Hc or Hg or either is available, then enter Xmax and optionally either Hc or Hg if available.
5. Enter number of voicecoils.
This procedure is most accurate. Also note that it also calculates true SPL (1W/1m) value. So it might not match the marketing SPL value, which is generally somewhat vague. Not in all cases, though.
6. Correct Znom, if necessary.
If there are several voicecoils, then you must be careful when entering parameters in that case, because many manufacturers give Bl in voice coils in series, because it yields double value for Bl against parallel connection. If driver manufacturer gives Qes, Bl and Cms or Mms, then you can check how Bl is specified. For that, you can enter following parameters to calculate Re: Qes, Fs, Mms or Cms and Bl. Connection mode can be changed by changing the combobox selection. The driver editor then converts Bl and Re values accordingly.
Equivalently, you can check for Bl by entering:
Qes, Fs, Mms or Cms and Re (for desired connection mode).
If you enter resistance for parallel connection and get about half of advertised Bl, then you know, that Bl was specified that way.

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

Builds:

U7qkMTL.jpg  LgPgE9w.jpg  Od2G3u1.jpg  xMyLoO1.jpg  9pAlXUK.jpg

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