New sub need help designing enclosure.

[ThomasW]

Unibox will only work with the real MS Office version of Excel. It won't work with OpenOffice, StarOffice, etc.

I've put that much weight on PR's, but they were 15" not 10"

You can model PR based subs using WinISD Pro.

[Hdale85]

Ok I got WinISD working but when I try and add the driver it keeps giving me this!

Image not available

What am I missing Thomas?

[Dennis H]

Just like it says, see the help file for how to enter the T/S params. If you enter numbers that don't add up, it will give you an error. So add the basic numbers and let it calculate the rest.

[Hdale85]

Hmm viewing the help file is going to take some extra work with Wine (windows emulator). What are the basic parameters?

[Hdale85]

Ok I put these in and it lets me save the Driver now :B Is this enough specs?

Image not available

[Hdale85]

Ok WinISD is not working at all now...Won't plot anything hmm....

[ThomasW]

Don't have a clue about the Linux/Wine thing

Here's a good WinISD tutorial

[Hdale85]

I got Excel working in linux no worries unibox works perfectly now.

[Dennis H]

Here's the WinISD help file minus the pics. Scroll down to "Important note for 0.50a7 and above:"

Edit: Okay, I see you got Unibox working (better than I can do with Excel 97 on Windoze) so it's all good.

-------------------------------------

If you want to create your own drivers, open the New Project window (CTRL-N is a shortcut), click on the "New" button next to the down arrow of the drop down on the New Project window. This opens up the Driver Editor window:


Again, driver editor is split into several tabs, which we will discuss now. Let's begin with first "General"-Tab.

Most of the parameters in "General"-tab are self-explanatory, but perhaps short explanation is in place anyway.


Manufacturer is the name of the company who actually made the physical driver, e.g. name of the OEM factory.
Brand is the marketing name of the driver.
Model is type marking on the driver.
Data provided by field is by default filled by user name.
For comment field, you can enter your own findings about particular driver.
At bottom of the driver editor window, there is a "Auto calculate unknowns" option. As you'll later notice, it is very great help when entering parameters. In fact, it is recommended that you enter as few parameters as possible, because then Driver editor will ensure, that your data is in perfect accordance with Thiele/Small-model.


In Parameters tab, you enter the Thiele/Small Parameters of the driver that you wish to add to your database. If you wish to change the mathematical units in which your parameters are given in, simply click on the unit and WinISD will toggle through the available units and make the conversion for you. For instance, if you put a speaker diameter of 8.0 in., and you'd rather have that value in cm, mm, etc., simply click on the value (in. in this case), and watch as WinISD converts it over for you. The area and distance systems are used for Ports and 1w/1m (SPL) measurements.

All of the drivers that you create are automatically saved in the \drivers subdirectory (folder) of your \WinISD directory (folder) and, as such, will not be deleted or overwritten when you update the WinISD database from the WinISD home page. The driver name that you provide will be the actual name of the file in the \drivers directory, so don't include any \'s or anything else in the driver name that would be illegal as a Windows file name.

The bare minimum information that must be entered is the last three fields of first subsection (Qts, Vas, and Fs). Note that you won't get anything else but minimum set of graphs with these three parameters, so be sure to enter all relevant parameters. As you enter the parameters, driver editor will continuously check if new parameters can be calculated from parameters, which you have so far entered.

Parameter status is indicated by different colors. Green means user entered parameter, Blue means calculated parameter. Black means not entered nor calculated parameter. You can change entered parameters anytime, and the editor will re-calculate all calculated parameters all over again.

Important note for 0.50a7 and above:
The driver editor won't accept erraneous entries anymore. Your data must be perfect (i.e. not over-defined by entering "too much" parameters), for you to be able to save it. If you try to enter too many of them, editor will display an error dialog when you try to save the data.


In above tab, you can enter dimensional information of your driver. It shows then approximate displacement volume DVol. It is probably most accurate that can be obtained using just these dimensions. Most evident neglected volume is the driver frame. On the right, there is illustration for what most dimensions mean. Only one which is not illustrated, is the voice coil diameter, VCd. See also Thiele/Small-parameters section in articles.


--------------------------------------------------------------------------------

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.

Like in Driver-tab in project window, you'll probably noticed the driver icon in bottom of the driver editor window. you can drag the driver object into some project by just dragging the icon.


--------------------------------------------------------------------------------

Worked example of entering driver data into program
For example, Let's enter a entry for Scan-Speak 21W/8555-00 driver, which has following specs:

Characteristic sensitivity (2.83V / 1m) 87 dB
Recommended frequency range 20 - 600 Hz
Free air resonance frequency, fs 20 Hz
DC resistance, Re 5.5 ohm
Voice coil inductance, Le 0.4 mH
Effective piston area, Sd 220 cm²
Moving mass incl. air, md 32 g
Mechanical loss, Rm 0.9 Ns/m
Force factor, BL 8.2 Tm
Equivalent volume, Vas 136 ltr.
Mechanical Q-factor, Qms 4.5
Electrical Q-factor, Qes 0.33
Total Q-factor, Qts 0.31
Excursion, lin./max. ±6.5 / ±12 mm
Voice coil diameter 42 mm
Rated power handling 100 W
Net weight 2.4 kg

So what specs should be entered?
Based on guidelines given above, let's enter fs, Mms, Qms, Re, Bl, Sd, Le, Xmax and Pe. If you have incorrect unit displayed, just click on it until it matches with driver data units. As you enter the values, note how driver editor continuously calculates missing fields.
After entering those specs as suggested above, we obtain following entries in editor window:


As you can see, we got ourselves some of the specs what weren't even specified by the manufacturer. Calculated SPL 1w/1m spec matches also quite well, which is not the case with some of the brands. If you compare calculated Vas against manufacturer's spec, you'll notice that it matches quite well. So we can be quite confident that our data is reasonably correct.

When you have entered all the specs, you can check the "Advanced parameters"-tab, and see some statistics of your entered driver (calculated from the parameters we just entered):


There, we can see, that this driver is definitely not suitable for horizontal mounting, Gloss is almost 10 percent! Also, using single woofer like this doesn't certainly be an SPL subwoofer, maximum predicted closed box SPL at 20 Hz at maximum excursion is only 83.7 dB. You can also see the air properties, which WinISD used when it calculated missing fields.

Finally, you can click "Save"-button to save the entered data. Driver editor suggests a filename for our driver.


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This page originally written by JJ Richard (JJRichard@linearteam.org) and revised by Janne Ahonen (janne@linearteam.org)

[Hdale85]

Well unibox still wasn't working quite right. I forgot that I reinstalled windows on my laptop. So I loaded up WinISD. I can't seem to make anything look very good with the PR its a very steep slope. I don't really know what I'm doing though but I'm playing with it.

[---k---]

I've ran FreeBSD and Linux for over 10 years. This past winter my last Linux box got unplugged. It just wasn't worth it to me anymore. To me, it had become more complicated than it was 10 years ago.

I wonder if it is better to load Unibox up on a thumbdrive and just go to a library or something for the 1 hour it will probably take you to model the thing. Save your stress for when you actually begin building.

[Dennis H]

The thing about PRs, as you add mass, the box gets more like a sealed one. Infinite mass is like a stiff wall. 2.5 kg sounds way to heavy to me. Might as well build a sealed box. Just try the driver in some different boxes - sealed, vented, PR - and let WinISD pick the alignment. Then tune from there.

[Hdale85]

I think I'm going to send the PR's back and exchange for another OEM10 and just do 2 sealed boxes for them one for each side of the front speakers. This PR stuff is just seeming a little too much effort and not enough benefit.

[ThomasW]

A PR is just a version of a vented box. Modeling one in a software program requires a bit more data, (see attachment)

What's gained with PR's in the ability to tune a small box to a low Fb, something problematic with a port unless you want it to stick out like a stove pipe.

PR's don't increase the overall output like adding a second driver. And given their cost, I find them of limited value.

[dyazdani]

What's gained with PR's in the ability to tune a small box to a low Fb, something problematic with a port unless you want it to stick out like a stove pipe.

PR's don't increase the overall output like adding a second driver. And given their cost, I find them of limited value.

I've got a test sub in a vehicle with two "stove pipes," looks funny

You might just model a vented sub and do a quick, preliminary design to see how big an enclosure you'll need. If you think it will be too big then you can go sealed.

[theskuh]

Bringing this thread back.. I have an oem 10 and one matching PR. I modeled it in winisd and could get a decent tune at around 24hz and about 1.2 cubic foot box. Any other size the output was real close to a sealed box. I pmed kyle about this becasue they suggest a .5 box with a pr? It didn't seem to make much sense to me to put it in that small of a box when it wasn't modeling any better. He responded "better to keep it under 1 cubic foot with the pr" and that was it UGG..

So I am building my box now. I am making it out of 12" sono. I have the endcaps almost finished. I get my amp in a couple of days. I cut one section of sono to .8 cubic feet, why? Because it was between what I thought was right and what kyle thought was correct. I think I am going to cut another section of tube to 1.2 cu ft. and clamp the thing together. So I will test with both and see. With the smaller boxes I was also finding with winisd I couldn't add any weight to tune lower. the 1.2 actually modeled with some weight IIRC like 700grams.

Ideally I wanted to do a small sub for my house but I might relegate this to car duty and do a big sonosub for the house. I bought these without knowing enough but I will see this project through.

What do you think about the 1.2 cu ft box? why would it model better yet they suggest that it HAS to be under 1 cubic feet?

[ThomasW]

Without seeing Kyle's or your complete sim data it's impossible to comment about performance.

You know of course that PR's can't be used in either up or down firing orientations?

I wouldn't think PR's would work very well in a car. Seems like the inertial effects created when driving would have a negative impact on their operation.

[theskuh]

Yeah. My small sono is horizontal. the PR is stiff. I am not sure that driving would affect it. but I hear ya. I will only drive in the direction the pr is not facing. lol.

I will grab all the sim data and post it. I am on intel mac so I have to switch to the darkside to capture it.

[theskuh]

here is some of my spl graphs. I am not sure if this is what you are looking for but I am blindly going forward.

Here is a closed tc-10 and a tc-10 and a pr with 500 grams on it both in a .5 box.

[theskuh]

here are both in a 1.2 cubic foot box.








I would think that this size box would be more advantageous since the base goes lower and has a flatter curve? Maybe he is designing for a higher spl?

I dunno

[ThomasW]

Kyle's a car audio kind of guy, as a result he may like the 'boom' inherent in his design.

Given the effects of room gain on either alignment, I'd go with the bigger box and lower tuning

[theskuh]

Cool thats what I will do!! Should be able to put it roughly together today. Get my amp in a couple days to test it.

thanks for the help!

[Hdale85]

Well this is old I know but I just got off the phone with Mike and as soon as he gets these passive radiators back he's shipping me out a DVC TC3000 15". Very happy about that. Now I have to figure out if I want to use it or sell it...hmm It's been so long since I ordered it I didn't even bother asking about a refund. Not to mention our paypal account got messed up due to someone hacking the password or something and spending to much money so it would complicate things because it would have to be a check or something. Oh well shouldn't be hard to sell the driver if I decide as they are no longer available and if they ever are again they are going to be like twice as much money. They are charging something like 500 for the TC2000 15" now.