Dirt cheap DIY sub

[Brandon B]

A (non HT) friend mentioned he was going to go buy a cheap sub for $150 at some local store. I said I thought we could put one together for that which would kick its ass.

Given spending about $90 on a parts express plate amp, anything better in drivers than one of these to get down to 30Hz for under $50?

BB

[ThomasW]

Let me look in my driver stash the basement. I probably have something better than that PE driver.

Nothing I have will be shielded, is that necessary?

[Brandon B]

Probably not.

Thanks for checking.

BB

[ThomasW]

Brandon,

I have a NOS 12" Gold Sound 1240 DVC driver

$35+shipping

I shot some pics of it but my CompactFlash reader died, so I can't get them loaded into the PC

Driver has a dual 2 layer 2.5" VC's, black poly cone, very heavy gauge chrome plated stamped steel frame. Although brand new this is a older driver than the ones listed on the website. It has a foam surround and felt dust cap.

Should be used in a ported cab given the low Xmax

[Brandon B]

Looks like a good deal to me. I'll talk to my friend today and get back to you.

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[Brandon B]

Friend says yes please, thank you very much. Send you a check? Check can be from me since your are better acquainted with me than him.

He's gonna go with this for the amp. Unless he opts to spend $20 more for the 200 watt one.

Happen to know offhand what the optimal vented box volume and vent length/diameter are, or if they are on the mfr site? Found a reference to a 2 cubic foot cabinet for the current model, but nothing for the port.

Or remind me the name of the free/demo sub modelling program and I'll go find it.

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[Brandon B]

Where'd you go, Thomas?

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[ThomasW]

I'm around it's just been a very busy last couple of days.

Send me his address and I'll send out the driver

Unibox is our choice for freeware.

If you want a quick and dirty online calculator use these links

http://www.carstereo.com/help/Articles.cfm?id=17

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

Their referencing the 18X18X16 box because that's preassembled box size they sell.

Bigger is better for the box size for low excursion drivers. Tune it around 25Hz, use a 4" diameter flared port (PE 268-352) if he can afford it. If the added cost is a big deal then use 4" dia PVC.

For the $20 difference I opt for the bigger PE amp. It's a good long term investment for a time when he can afford a better driver

[Brandon B]

Looks like we'll be doing about a 7.9 cu. ft box with a 4"x4" (approx.) port to get about a 25 Hz box. Won't get him to reference, but in his house plenty of thumping.

I'll post pics when we build.

Thanks for all your help Thomas, he's pretty jazzed.

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[ThomasW]

Wow, that's pretty big box!

Remind him that's a low Xmax woofer, not a Shiva :wink:

Line the inside of the box with some fiberglass insulation, or polyester batting.

[Brandon B]

Was gonna line it.

The numbers were run with .6" as the Xmax. Should that have been cut in half? Assumed it was 1 way, not p2p.

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[ThomasW]

An Adire Shiva is 1.29" P-P (16.6mm Xmax, one-way). The Gold Sound driver is about 1/2 that.

Not to worry, if he blows it up; I'll have a bunch of lightly used Shiva's available in a month or so. It will drop in the same cutout as the Gold Sound

As a reference you might want to checkout the ported Shiva applications papers

http://www.adireaudio.com/Files/VentedShivaApplications.PDF

[Pat]

I'll have a bunch of lightly used Shiva's available in a month or so.

:E Uh Oh...what do you have up your sleeve now Tom?? 8O

[ThomasW]

Hi Pat,

Last year Adire offered a preorder sale for their DPL12"s. I bought quite a few drivers with the intent of replacing the Shiva's in both my IB's. I meant to do this exchange quite a while ago, but got side tracked with other projects.

When time permits (probably mid to late fall) I'll put in the DLP12"s, then have a fire sale on used, but not abused Shiva's..... :wink:

[Andrew Pratt]

What do you hope to gain with the DPL12's over the shiva in your IB install?

[Ten 99]

storage space that they're taking up!

[ThomasW]

Andrew,

They'll just play slightly lower with less EQ. Not a really big difference, the price on the DPL12"s was too good to pass up.

Originally I planned on using them for dipole projects like the Arvo Design. But we went with the TC-Sounds drivers there, so the fall back plan is to use them to populate the IB's

[Pat]

Slightly lower with less EQ...umkay

IIRC wasn't big IB putting out a useable 4hz :E

LOL...who am I to question the ways of the the poohba

;x( ;x( ;x( ;x( ;x( ;x( ;x(

[ThomasW]

Hey guys, what's happening with this project?

[Brandon B]

I am in Tokyo this week. Left Chris with a bottle of Gorilla glue and a bunch of rectangles of MDF and all my longer bar clamps.

In theory when I get home he'll have a box of sorts. And stained fingertips.

I'll post then.

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[David Meek]

In theory when I get home he'll have a box of sorts. And stained fingertips.

:rofl:

Hehe, another soul lost. . .

[Brandon B]

Well, I am going to his hyouse to see this tonight. I will make sure I get a pic or two to post.

He also bought the Parts Express $140/pair monitor kits and is pleased as punch with them compared to his old Costco bargain speakers. Let you know what I think of those as well.

BB