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Dual opposed 12" Infinity Reference sealed subwoofer - Page 2

post #31 of 51
Quote:
Originally Posted by tlag View Post

Could be wrong, but that seems hard to beat for the money.

Well, other than quad-opposed 1260s? smile.gif
post #32 of 51
Thread Starter 
Quote:
Originally Posted by tlag View Post

Well, other than quad-opposed 1260s? smile.gif


Ah, but my Crown will only put out 550 W per channel @ 2ohms, so dual opposed would mean more power (I guess I'd get 3db/cab though) smile.gif

For the cost, overall, I think it's not too bad. I'm in Canada, so I'm waiting for a place in Buffalo to get my drivers from Amazon, then I'm good to go! The planned piano gloss black might have to wait until after the Canadian winter. Painting at 0F, no thanks.
post #33 of 51
Quote:
Originally Posted by apnea View Post


19.5" L/W/D would net out about 4 ft^3 -t.

My box dimensions are 19.5" external. 18X18X18 internal. 18^3 is 3.375 ft3 before bracing. So 3 ft3 after. 1.5 per driver.
post #34 of 51
Quote:
Originally Posted by tlag View Post

Could be wrong, but that seems hard to beat for the money.

You could be right biggrin.gif The dual opposed will do ~103Db at 20hz and max out at ~112 @ 55-60hz. That's just one ~$150 box. Imagine four of them ;-) $600 for drivers and $400-500 for the amp. So $1000 all in.There are $3K commercial offerings that can't touch this.
post #35 of 51
Quote:
Originally Posted by apnea View Post

Some output from winISD, plotting a single driver in 1.25 cubes (internal) with 500W (over the maximum specs given by Infinity, but we'll see about that.....)
I had to guess at some of the T/S specs, and I couldn't find a file for winISD - I hope I guessed right

Max SPL - not stellar, but I'm in this for the experience, so for < $100 a cab, I'm happy

Over-excursion of around 3mm - I'm not too concerned, should I be? I could wire the 2 voice coils in series to present 350W per driver, but I don't like leaving headroom on the table

I'm looking at putting a single 1262 into 1.2ft3 and saved my design in BassBox Pro. First, here's all the T/S specs on the 1262 straight from Infinity for you -
http://us.infinitysystems.com/tl_files/catalog//Infinity/Infinity-Car/Specsheets/Reference/Reference/1262w/REF1262W_PI_EN.pdf

Second, modeling in my 1.2 cu ft sealed file with 500w input, I'm showing xmax is not exceeded. Xmax does not exceed until 584 watts with coils wired in parallel for 2 ohms. You should be good. Of course, things are always a little different on paper then in reality, but I don't think I'd worry if I were you. You'll know if you exceed xmax and just back off the boom knob a bit.

Third, I don't see any issues with needing a hi-pass filter in a cab this size. My modeling shows it's not necessary.

Now, fourth. It's been a while since I've done sub design and setup. About 16 years to be exact when I was into car audio. But if memory serves, I want to say I remember something about damping and driver control not being as "tight" or "accurate" when we start to get into sub setups below 4ohms. Don't quote me on this, but if this is for an audiophile type setup, it may be worth looking into.

Out of curiosity, have you considered doing a isobaric setup with 2 1262's? Lower response, smaller cabinet, but a slight loss in dB.
post #36 of 51
Thread Starter 
Quote:
Originally Posted by zagnutty View Post

I'm looking at putting a single 1262 into 1.2ft3 and saved my design in BassBox Pro. First, here's all the T/S specs on the 1262 straight from Infinity for you -
http://us.infinitysystems.com/tl_files/catalog//Infinity/Infinity-Car/Specsheets/Reference/Reference/1262w/REF1262W_PI_EN.pdf
Second, modeling in my 1.2 cu ft sealed file with 500w input, I'm showing xmax is not exceeded. Xmax does not exceed until 584 watts with coils wired in parallel for 2 ohms. You should be good. Of course, things are always a little different on paper then in reality, but I don't think I'd worry if I were you. You'll know if you exceed xmax and just back off the boom knob a bit.
Third, I don't see any issues with needing a hi-pass filter in a cab this size. My modeling shows it's not necessary.
Now, fourth. It's been a while since I've done sub design and setup. About 16 years to be exact when I was into car audio. But if memory serves, I want to say I remember something about damping and driver control not being as "tight" or "accurate" when we start to get into sub setups below 4ohms. Don't quote me on this, but if this is for an audiophile type setup, it may be worth looking into.
Out of curiosity, have you considered doing a isobaric setup with 2 1262's? Lower response, smaller cabinet, but a slight loss in dB.

Thanks for the info: I picked it up off here, but as I haven't used winISD much I wasn't sure if I'd input everything correctly. I cheated a slightly larger box (1.5 cubes), but I think I'll keep to the stated specs. I want two smaller cabs to even out the response, and add significant WAF, all while keeping the costs low.

I got the drivers in Buffalo yesterday (go CBI!), and they look awesome. I plan on cutting wood starting this weekend.

I'd love to hear anyone else input on 2 ohms - I'm committed to that route now (unless I wire the VC for 8ohms, which I don't want to do with this amp).
post #37 of 51
Thread Starter 
Oh - I have another couple of questions. What wire are people using to connect from the binding posts to the driver? I've got a ton of 12 gauge, can I use that? I've seen people using 4 gauge etc, not sure if that's overkill?

In the same vein, is it 'ok' to use the 12 gauge between my amp (Crown XLS1000) and the subs? I plan on just using regular speaker wire, same stuff that drives my other speakers.

Thanks
post #38 of 51
post #39 of 51
4 gauge or lower is often used in high power car audio applications because to get a lot of power to the amplifier on a 12v system, you need a ton of current.

the voltage coming out of the amplifier to the subwoofer is higher or the power would be limited to 144 watts into a 1 ohm subwoofer. with the higher voltage, the current is less, so the wire can be smaller.

12 gauge from a home amp to a sub is fine. it wouldn't make any sense to have thicker cable running from your amp to your sub, then what is running in your wall from the panel box to the receptacle and that is likely 12 gauge.
Edited by LTD02 - 11/20/12 at 9:51am
post #40 of 51
Thread Starter 
Makes a lot of sense - thanks!
post #41 of 51
just scored a 2 pack of these on sonicelectronix for 106 bucks

between this and the PE yung plate amps probably the most bang buck deal of the year diy subwoofer
post #42 of 51
Ha. Actually just changed my order to two 1260W's. Scored a Behringer EPX2000 at a killer deal I couldn't pass up either. It'll give 600w/ch x2 @4 Ohms for these little beasts. I'm sure they'll put a smile on my parents faces when they come over for dinner and unwrap them Christmas.

Total for hardware is now $306. We have sheets of ply and osb all over since they are building a new house. Couldn't beat this deal with a stick cool.gif Thanks guys!!
post #43 of 51
Thread Starter 
I built a 1.25 cube test box (18*14*14 external) from 3/4 ply to view dimensions / gotchas through the build. Hooked it up last night, feeding the sub-out of my Denon 1712 right into a Crown XLS 1000 pro-amp.

It's a big space, and I'm building a pair of them, but even in a totally unbraced, potentially air-leaking box with no stuffing they sounded great - not too much below ~30Hz, but I hope stuffing and bracing will help with a lot of that.

I might get a miniDSP down the road, but as it stands, I'm spending < $100 a cabinet (excluding amplification), and I don't think it can get much better than that for under $100.
post #44 of 51
umm I'd feel bad if someone didn't get a deal on these eek.gif

amazon has the 1262W models on sale for only $34.40ea
1260W for $56.61ea
post #45 of 51
+ 30.49 shipping. Dam't man, you scared me there. They do have them for 50.52 w/ free shipping.
post #46 of 51
Doh! didn't add to cart lol I can't get to sonicelectronix at the moment but when changed my order to 1260W pair they honored it at $106/ w free shipping. Just saying in case amazon runs out of the 2 in stock. Basically they have both 1260/2 at equal pricing. My Dad is gonna love these.
post #47 of 51
Thread Starter 
Can I get someone to check my maths please? I keep on double checking and coming out with a new answer - never a good sign.

I want to put each of these drivers (1262w) in 1.25 cubes. I'm using 0.75" MDF, plus an internal baffle so the driver is flushmounted.

External dimension (inches):

W: 15.5
H: 19
D: 14

With 0.4 cubes for driver and bracing, I think I net out at 1.27 cubes - is that correct? The front ends up at 1.5" thick basically. My first test box was 14*14*18 and now I rethink it, with driver and bracing it should be 1 cu ft.

Also, if I recess the driver into the inner baffle, how should I compensate for the difference in volume? I'm subtracting for the entire baffle (17.5*14*0.74), but then there is a very large hole cut in the middle.....

Thanks!
post #48 of 51
Quote:
Originally Posted by apnea View Post

Can I get someone to check my maths please? I keep on double checking and coming out with a new answer - never a good sign.
I want to put each of these drivers (1262w) in 1.25 cubes. I'm using 0.75" MDF, plus an internal baffle so the driver is flushmounted.
External dimension (inches):
W: 15.5
H: 19
D: 14
With 0.4 cubes for driver and bracing, I think I net out at 1.27 cubes - is that correct? The front ends up at 1.5" thick basically. My first test box was 14*14*18 and now I rethink it, with driver and bracing it should be 1 cu ft.
Also, if I recess the driver into the inner baffle, how should I compensate for the difference in volume? I'm subtracting for the entire baffle (17.5*14*0.74), but then there is a very large hole cut in the middle.....
Thanks!

Treat the double baffle as if the outer piece of mdf wasn't there. In other words, you calc your internal depth by subracting 2.25" from external.

Your internal dim are 14 x 17.5 x 11.75 = 1.6659 cu ft. subtract your driver disp & bracing. You should still be in the 1.2-1.4 cu ft range.
post #49 of 51
Thread Starter 
Thanks for the fast reply, it makes sense now.

edit:

My cut-sheet - the dimensions are a little funky due to the space I have to work in (shallow), but might help anyone who is looking to build a 1.25 cubes box that has a similar requirement


Edited by apnea - 11/29/12 at 5:06pm
post #50 of 51
Quote:
Originally Posted by apnea View Post

I built a 1.25 cube test box (18*14*14 external) from 3/4 ply to view dimensions / gotchas through the build. Hooked it up last night, feeding the sub-out of my Denon 1712 right into a Crown XLS 1000 pro-amp.
It's a big space, and I'm building a pair of them, but even in a totally unbraced, potentially air-leaking box with no stuffing they sounded great - not too much below ~30Hz, but I hope stuffing and bracing will help with a lot of that.
I might get a miniDSP down the road, but as it stands, I'm spending < $100 a cabinet (excluding amplification), and I don't think it can get much better than that for under $100.

You do the dual opposed X 2 and you will see something below 30hz corner loaded and stacked. ~106-107 at 20Hz w/o hitting x-max. Four 12" drivers will do that biggrin.gif
post #51 of 51
So when do we get to see pics and your thoughts on how they are working out for you?
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