# ED 3.6 box design help



## soundstreamer (Jun 2, 2015)

I've had this Elemental Designs 3.6 subwoofer sitting around forever and I'm finally deciding to give it a try as part of my new PC speaker system. I'm not very experienced with winisd so I figure I'm doing something wrong but I need some help. I'm wanting to try to it out in a ported box but when I do I get some crazy long port lengths. Could someone help point me in the right direction for box size and port length to use?

These are the T/S parameters I have found.

Qts: .29
Qes: .30
Qms: 10.5
Fs: 28.00Hz
Re: 3.2
Vas: 22L
Mms: 50.0g
Bl: 13.30T*m
SPL: 85dB
Sd: 114cm²
Xmax: 13.0mm
Voice Coil: 38.0mm

Magnet Width: 5.000"
Cutout Diameter: 5.700"
Mounting Depth: 3.518"
Weight: 7lb
Total Height: 4.000"
Displacement: .04 ft³
Outside Diameter: 6.75"


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## dumdum (Feb 27, 2007)

If your getting crazy long port lengths the box volume is too small/port area too large/tuning too low... or a combination of these


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## WilliamS (Oct 1, 2016)

I remember these, I had 8 of these goofy little subwoofers in my Mazda 3. Did a great job on subwoofer duty.


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## Grinder (Dec 18, 2016)

soundstreamer said:


> I've had this Elemental Designs 3.6 subwoofer sitting around forever and I'm finally deciding to give it a try as part of my new PC speaker system. I'm not very experienced with winisd so I figure I'm doing something wrong but I need some help. I'm wanting to try to it out in a ported box but when I do I get some crazy long port lengths. Could someone help point me in the right direction for box size and port length to use?
> 
> These are the T/S parameters I have found.
> 
> ...


How much power (watts RMS) do you plan to give them?

Meanwhile, I'll see what I come up with in WinISD.


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## Grinder (Dec 18, 2016)

Based on response curve, it looks to me like your best bet might be 0.5 ft^3 at 40 Hz, with an F3 of 36 Hz. While I don't know the RMS rating of this driver, at 600 watts modeling shows 12.6 mm max excursion at 52.6 Hz ( exceeding 13 mm max excursion at 34 Hz and under, requiring the use of a suitable high-pass filter to prevent overexcursion), a vent velocity of 48 m/s at 39 Hz, with a 3" diameter vent tube 21.5 " in length.

48 m/s is rather high, but would probably be okay with a flared port. Trouble is, I can hardly imagine fitting 21.5" port length in .5 ft^3.

Also, it seems that 113 dB might be overkill for a computer sound system.

However, 100 watts yields 105.5 dB, at 44 m/s vent velocity through a 2" diameter vent tube at just over 9" length. This 2" flared vent tube should produce zero port noise at 44 m/s (*at a corrected length of 10.12").https://www.parts-express.com/precision-port-2-flared-speaker-cabinet-port-tube-kit--268-348

*Bear in mind that flared ports need to be a bit longer than non-flared. Use Precision Sound Products calculator to determine length of their ports: Products Menu

Alternatively, you could increase cabinet volume, in order to reduce the required vent length for a given Fb (tuning frequency), at the expense of a commensurate spike in response, in which case (or perhaps in any case) you might need/want EQ. 

Either of these processors could provide PEQ and HP/LP/BP filters for the sub and satellites:

https://www.parts-express.com/minidsp-2x4-digital-signal-processor--230-320

https://www.parts-express.com/dayto...nal-processor-for-home-and-car-audio--230-500


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## WilliamS (Oct 1, 2016)

Out of curiosity why does the port need to be in the box? Its for a PC setup, make something crazy with external ports!


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## Grinder (Dec 18, 2016)

WilliamS said:


> Out of curiosity why does the port need to be in the box? Its for a PC setup, make something crazy with external ports!


YES!!! Now, why didn't I think of that?!


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## dumdum (Feb 27, 2007)

If you do have the port outside the box try and bend it around with big radii and have the exit near the sub purely for phasing purposes


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## soundstreamer (Jun 2, 2015)

Grinder said:


> Based on response curve, it looks to me like your best bet might be 0.5 ft^3 at 40 Hz, with an F3 of 36 Hz. While I don't know the RMS rating of this driver, at 600 watts modeling shows 12.6 mm max excursion at 52.6 Hz ( exceeding 13 mm max excursion at 34 Hz and under, requiring the use of a suitable high-pass filter to prevent overexcursion), a vent velocity of 48 m/s at 39 Hz, with a 3" diameter vent tube 21.5 " in length.
> 
> 48 m/s is rather high, but would probably be okay with a flared port. Trouble is, I can hardly imagine fitting 21.5" port length in .5 ft^3.
> 
> ...


Thank you very much for all that information that really helps me out. I'm not exactly certain on RMS rating for it is either. But at least right now I will not be anywhere near that level as I will start off using this plate amplifier. 

https://www.parts-express.com/dayton-audio-mca2250e-21-channel-class-d-plate-amplifier--300-771

It only has 50 watts at 4 ohms. I havent decided on what speakers I want to use for the satellites but I have a number of options laying around my garage to choose from.

I never thought of running an external port either. I might give that a try as well.


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## WilliamS (Oct 1, 2016)

I only suggested external port as I know that the smaller enclosures become a nightmare for conventional ports, so why not take it outside! This allows you to tune it as well and Ive seen some neat external setups, such as rams horns and such. Bending PVC, at least smaller 2" is pretty simple with patience without kinks, Ill give you a hint "SAND"


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## Grinder (Dec 18, 2016)

If I were going external, I'd opt for something larger than 2" if I could, particularly in the absence of nicely flared ends (akin to those of Precision Ports).


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## WilliamS (Oct 1, 2016)

Grinder said:


> If I were going external, I'd opt for something larger than 2" if I could, particularly in the absence of nicely flared ends (akin to those of Precision Ports).


Only reason I said 2 was its easier to bend with hot sand method. 3 inch gets a bit tough. Tall Aero ports coming out would look cool.

Something like this is unique!


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## soundstreamer (Jun 2, 2015)

WilliamS said:


> Only reason I said 2 was its easier to bend with hot sand method. 3 inch gets a bit tough. Tall Aero ports coming out would look cool.
> 
> Something like this is unique!


Those look really cool but way above my ability level. I'm probably sticking with something simple for right now and maybe try something more extravagant at another time. Definitely has me thinking of some ideas to try though.


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