Help needed with Unibox

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I recently downloaded the unibox program to use for designing a sub-woofer/passive radiator set-up. Maybe perhaps a mentor that could help me choose the correct driver/radiator for building a pair of subwoofers. Any help or suggestions would be appreciated! :D

Thanks,

Emile
 
You could post this in Subwoofers, people would be glad to help.

You might want to define environment, size, and performance requirements as well as budget and associated equipment and then people could make driver suggestions.

There aren't a lot of 8" subwoofers out there - one I know of is made by Tangband W8... is the model number, IIRC.
 
Dayton makes both at parts express, or PE as most call them. There are a few others if you search around, but dayton stuff seems to be pretty good for the cost. They also have some projects all planned out for their products including subs, but not sure what size. They have plate amps too. It really depends on your budget with this kind of stuff. Madisound also carries some drivers.
 
Hi jol50, Thanks for the info, but it's not where I can purchase the drivers at this point, but rather designing the proper box using the unibox program. I would like someone to explain or answer some question I have pertaining to the program. Do you use or have knowledge of the unibox program?

Thanks,

Emile
 
I use winISD. I get the specs of prospective drivers and plug them in, model what I want, pick the best one and verify power handling/quality/etc to meet my needs and I'm all done. PE lists the specs of every driver they sell, or every one I've looked at. A lot of cheap car subs do not list them, in fact PE sells some pyramid subs where they (PE) measured the specs and list them I'm pretty sure. Nobody else lists them. PE sells the equipment to measure them. I'm not selling PE, just that there are not that many places that sell the PRs...I don't care what you buy. PE makes an effort like other bare driver sellers to show specs for DIY boxes.

If this is a car sub I would recommend if you can run a sub in the car to find out what frequencies are weak strong, this will help you to find a response curve that fits your vehicle better. ie: if you need more 30Hz than the test sub, (model the test sub and ) make sure your new sub shows more db at 30Hz. If it is for HT then you want a flatter/lower curve than a car. I would search up some info on that first to determine the response that is going to work well for you, unless you are familiar with that stuff. Note a port or PR does unload under its tuned frequency, if you tune it higher you should run a subsonic filter near tuning...if you are anywhere close to its max power handling.
 
I have another program I used a few times, it can take more variables like cabin/room gain/stuffing and such. I'll try to find it and see what it is. You might find those kinds of features more useful if you can measure things, I just adjust the box by ear if I must.
 
Thanks for trying to help! I reall do appreciate it! It's just a little difficult sometimes to learn about a program such as unibox, especially when they don't have a good manual/guide. I really can't complain as this is freeware. Just let me know if you find something I could use.

Thanks again,

Emile
 
I think I did use that a little, but doubt I used the extra stuff you are asking about. I'd go read some of this stuff, just google unibox+subwoofer and it comes up with a lot of stuff, and the forums they talk about it on. Something like this might get you started: http://www.s10forum.com/how_to_design_an_enclosure_for_your_subwoofer

Otherwise run winISD a little it is easier/simpler and you will get the idea of what it is doing. Most of the extra unibox stuff is modeling stuffing in the box, crossovers, and things like that however the core response of the speaker in the box will be close to winISD.

Some unibox info: http://home20.inet.tele.dk/kou/ubmodel.html
 
Thanks again jol50, I will look the links over and see if I can get a little more use out of unibox. Just for the record, I do have SoundEasy with boxcad, but haven't worked with it yet as it is complex. You had mentioned something about winISD and was wondering if this is freeware?

Thanks!
 
Hi
I can help you with the unibox SS. You want to use unibox esp. for passive radiator designs.... it provides very useful charts like drone cone excursion vs frequency.

Re passive radiator ...basic info link http://www.diysubwoofers.org/prd/

"Like their ported cousins, passive radiator systems are much more sensitive to misaligned parameters than sealed enclosure systems, which makes their construction more difficult for the beginning DIYer. I advise that you don't attempt to build these systems, unless you're certain that the T/S parameters for the driver that you want to use are correct. "

In my mind the only reason to use PRD designs over BassReflex is when the ports dimensions get too unwieldy for the box. But then you have the additional expense of the drone cone.


EDIT>
An idea to start with ...go to the Tymphany web site i.e. the XXLS application sheets, to reproduce their PR design stuff using Unibox.
http://www.tymphany.com/830842-app-note
 
Hi Infinia, Thanks again for the info! I was just trying to get a better understanding for using the Unibox program. I have the latest version-4.08. The woofer I have is a Dayton Audio 8" shown here: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-480 and the PR: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-492 I have loaded the parameters of the woofer into unibox to see what size box it recommends. I am using the WT3 program for the parameters. So after manually putting the values into the unibox Drive Unit Parameters, I then scroll down to the Passive Radiator Box and notice that they have two sections, Fictive No1- KO. Can you explain how I need to use this?

Thanks,

Emile
 
Hi
Struggle a little more first.. by entering the values for the peerless 10" design in the link above. Then you'll know when you get close.

EDIT> I would choose a larger passive radiator (have you read the primer in the link?)

" ALWAYS use a passive radiator that is larger in diameter than the active driver, as the displacement of the passive radiator usually has to be 1.5 to 2 times that of the driver. If it's not possible to use one large passive radiator, then you can use two or more smaller ones, and tune them by working out the effective diameter from the combined surface area of the radiators "

Looking at the peerless 10' example the chart of excursion vs freq. The passive is almost 3 times the actives excursion.



If you already have that PR part it'll mostably limit your design. You can proceed or double up on the PR or just try a vent instead.
 
FSHZ:42 said:
So after manually putting the values into the unibox Drive Unit Parameters, I then scroll down to the Passive Radiator Box and notice that they have two sections, Fictive No1- KO. Can you explain how I need to use this?

Thanks,

Emile


HI
Fictive No1 = name place holder (enter the passive rad part no. )

1st section enter PR parameters
2nd enter modified Vb info (optional)
 
Hi
Here's what I came up with. Looks like no problem with using an 8" PR no added mass. you could go small as 30 liter but PR excursion gets worse.
Looks much better BR with a 40 liter box and vent 7.6 cm x 31 cm yikes
 

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infinia said:
Hi
Tried it with a Dayton 10" PR with added mass of 30 grams. Looks like the optimum design, everything looks much better!

F-3dB is 36 Hz.
Hi Infinia, So basically that graph(Peak Cone Excursion) that shows the excursion of both the driver and the pr is what determines the outcome? In otherwords, the x-max on both drivers, should not exceed the red line? So, if that is correct, anything over the red line would be a no-no?
 
Each has it's own limit.
Depending on the PR construction it's limit is softer. For the Dayton PR it's limit is the front suspension ie going in the forward motion is stiffer than downward, so distortion results due to unsymetrical forces.

The driver can exceed Xmax but IM distortion goes up exponentially so its limit is firmer.

Then there is Xmax damage sometimes listed for higher end products. This is usually when the bottom of the voice coil former contacts the end plate, this is mostably a very bad result.
 
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