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Keager's Quad RE XXX 18 Underfloor IB Build

post #1 of 341
Thread Starter 
Well the title pretty much sums it up. Started with dual RE XXX 18's, and my better half came to my conclusion that the enclosures were going to be far too large. With my tail between my legs I looked for alternatives. That search brought me to thecultoftheinfinitelybaffled. A terrific forum all about infinite baffle subwoofers. I was instantly sold with the lack of a visible enclosure(but a hole in the floor), and from everybody that has heard one, says the sound quality is incredible.

I then thought, why just cut one hole in the floor of my house when I can cut two!?! I bought two more XXX 18's. This time they showed up with a different dust cap that said RE instead of XXX. I made a stink about it at first, then decided it didn't matter because nobody's gonna see them, and the company gave me a store credit for the inconvenience. I kinda like th RE caps better now

There will be two manifolds, each housing two drivers. this is going to be incredibly difficult to install due to the very tight crawlspace and wieght of the drivers, but I love a challenge. As I build, I will detail and photograph the hurdles I'll have to overcome. I start construction next weekend, post any questions or comments, and heres a few photos of the drivers, what they are replacing and the crazy packaging they are shipped in. have a great day!

Oh, and they will be powered by my LG clone FP14000!







post #2 of 341
Sick... Subscribed...

Nice choice of amps as well. Are your XXX dual 4ohm? Pushing anything lower that 2.8ohm per channel would be taking a risk on the clones. I'm sure you already knew that though.
post #3 of 341
Thread Starter 
They are dual 2ohm. Plan on running 4ohm stereo. Two drivers per channel. In infinite, the drivers require far less amp power. It is excursion limited, which in this case I have a.decent amount of excursion at my disposal.
post #4 of 341
Quote:
Originally Posted by keager View Post

They are dual 2ohm. Plan on running 4ohm stereo. Two drivers per channel. In infinite, the drivers require far less amp power. It is excursion limited, which in this case I have a.decent amount of excursion at my disposal.

Understood. Pushing out a little over 2k watts per channel should keep the amp safe for sure. I haven't researched IB setup as much as other people have, but are we sure feeding your XXX half of their rms in an IB setup would maximize their potential?
post #5 of 341
Thread Starter 
If for some reason it isn't enough power, I have a crown xls 5000 here on standby. I thought the lg does 4400x2 infour ohm stereo. Maybe thats 2 ohm stereo I'm thinking of.....
post #6 of 341
Quote:
Originally Posted by keager View Post

If for some reason it isn't enough power, I have a crown xls 5000 here on standby. I thought the lg does 4400x2 infour ohm stereo. Maybe thats 2 ohm stereo I'm thinking of.....

You are correct. However, that is why I asked if your XXX were dual 4 ohm, so you could wire a pair of them for your amp to see 4 ohm per channel. I forget if RE even offers a dual 4 ohm option for their XXX line. I think I remember one of their older competition lines (was it the MT series) offered more VC options.

Anyway, for 2 subs per channel your options would be as follows:

If you had dual 4 ohm your options would be:
1 ohm
4 ohm or
16 ohm

Since you have dual 2 ohm, your options will be:
0.5 ohm
2 ohm or
8 ohm

You could always get another Clone. Driving matching subs with different amps would personally drive me crazy...
post #7 of 341
Thread Starter 
So if i had two subs wired in series per channel, it would result in a 2 ohm load? I guess I'll cross that bridge when i get to it. Ifirc, even with 1kw per driver, they will do very well. They aren't having to work against the air pressure of an enclosure. Thanks for the heads up!
post #8 of 341
Take a serious look at the Ashly KLR amps. I have a pair of 3200s available pretty cheap.
post #9 of 341
Quote:
Originally Posted by keager View Post

So if i had two subs wired in series per channel, it would result in a 2 ohm load? I guess I'll cross that bridge when i get to it. Ifirc, even with 1kw per driver, they will do very well. They aren't having to work against the air pressure of an enclosure. Thanks for the heads up!

Given the limitations of the Clone, your only option is to wire each subs VC in series then series the subs together for a 8 ohm load.

In a sealed application, you would need more power. I can't comment on an IB install though. I'm sure there are many smarter than I that can weigh in on your specific application.
post #10 of 341
How much are the RE xxx these days
post #11 of 341
Thread Starter 
780 shipped
post #12 of 341
Wow. I don't remember ever seeing those drivers used in an IB. How much power does it take to reach xmax, free air?
post #13 of 341
Thread Starter 
Its the first I have seen an attempt at IB with them. Modeling them in winisd with 1kw each, stays well below xmax and about 117db at 10hz with no hpf. Nice natural curve. I recommend everybody curious about IB subs to visit thecultoftheinfinitelybaffled. Good stuff there, and great knowledgable help.
post #14 of 341
Quote:
Originally Posted by keager View Post

Its the first I have seen an attempt at IB with them. Modeling them in winisd with 1kw each, stays well below xmax and about 117db at 10hz with no hpf. Nice natural curve. I recommend everybody curious about IB subs to visit thecultoftheinfinitelybaffled. Good stuff there, and great knowledgable help.

That's serious man. Sounds great. I'll be checking back frequently for sure.

Hey, since you have winisd, have you tried modling them at their RMS? Seems to me the goal would be as close to xmax as possible to give you the headroom you need/want. Not sure about you, but the last thing I would want if I was undertaking such a feat is to still want more... Still have that itch.

Regardless, I know you are going to be happy and impressed.
post #15 of 341
Thread Starter 
I would get more power out of running the crown at 2 ohm stereo vs running the clone at 8 ohm stereo.
post #16 of 341
Quote:
Originally Posted by keager View Post

I would get more power out of running the crown at 2 ohm stereo vs running the clone at 8 ohm stereo.

So if you decided to take that avenue, you would be feeding each sub roughly:

Crown = 1,250 watts (2,500/2 @ 2 ohm Stereo)

vs.

Clone = 1,100 watts (2,200/2 @ 8 ohm Stereo)
(need a Clone owner to verify actual power output @ 8 ohms)

Looks like you might get slightly more power if you went that route, but your Crown would be working much much harder pushing a 2 ohm load.

Looking at your situation, it kinda sucks. If you were to try to implement both amps, you would have some major power differences.

For instance, if you ran a pair (2) of your XXX from your Crown for a 4 ohm load to each channel, you would be able to squeeze 1,800 watts to each sub. However, if you were to run the other pair from your Clone for a 4 ohm load to each channel, you would see 4,400 watts to each sub. That's a huge power variance. It might be something that wouldn't bother you, but I personally wouldn't mess with that.

I'm under the impression that you have already purchased the Clone. Is that the case? If not, it sounds like another XLS 5000 would be better suited for your application. On the other hand, if you already own the Clone, I would seriously consider purchasing another one for headroom/flexibility purposes. You know, just in case you get the itch to put those badboys in a sealed application. Either way, sounds like you might have "address" (throw more money at) your amp situation one way or another to maximize your XXX's potential.

My .02. Hope it helps, or at least gives you some other things to consider.
post #17 of 341
Thread Starter 
Yes, I already have everything, as I wasnt originally planning an IB. So I'll figure out a way to deal to deal with it. I do also have a mini dsp to EQ the two different manifolds. I appreciate you taking the time to point these things out.
post #18 of 341
Wow, just modelled these in WinISD, This is going to be an astonishing system! Those subs are insane in sheer size, its going to be a battle installing them, maybe you could fit in some sort of small hydraulic jack/trolley to get them in place in the manifold, and bolt them in, I would not like to imagine one of those coming through the ceiling!.

It seems you will have usable output down to 5Hz if the signal does not roll off through your various components.
post #19 of 341
Nice! Your mounting opposed right? I hope so!
post #20 of 341
Thread Starter 
Yup, two dual opposed drivers in each manifold under the floor of my bottom level. The crawl space isnt much taller than the drivers, so, I wont need to really lift them into position luckily.
post #21 of 341
Get another FP and use the crown for your LMS I'm subbed obviously!!! I wish I could go the IB route with my pair of those guys, that would greatly increase the efficiency of them. larger sealed boxes is where I think im headed though.
post #22 of 341
Thread Starter 
I'm selling the LMS so that I have no sub enclosures above ground and to help off set the cost of the XXX's. I might sell the clone and get another xls since the drivers will not need 4400 watts each and the clone will be easier to sell I think( and lighter to ship). Dunno, lots of ideas. Too bad the clone wont do 2ohm stereo. gonna focus on construction/installation this weekend because I'm wife/baby/10yr old free all weekend. Doesnt happen very often. If my closest neighbors can't handle a tablesaw at 6am, they definitely won't be cut out for the resulting subsonic assault. lol
post #23 of 341
Quote:
Originally Posted by keager View Post

I'm selling the LMS so that I have no sub enclosures above ground and to help off set the cost of the XXX's. I might sell the clone and get another xls since the drivers will not need 4400 watts each and the clone will be easier to sell I think( and lighter to ship). Dunno, lots of ideas. Too bad the clone wont do 2ohm stereo. gonna focus on construction/installation this weekend because I'm wife/baby/10yr old free all weekend. Doesnt happen very often. If my closest neighbors can't handle a tablesaw at 6am, they definitely won't be cut out for the resulting subsonic assault. lol

Dibbs! PM sent.

I didn't realize you already had a Ultra in your arsenal. If you already had one, why not just get three more vs. buying four new RE XXX?
I know the XXX has more xmax, but from what I have heard a lot of the other users post, the LMS is more linear, with less distortion and better response. Of course, I might not have read that verbatim, but the jest of my research points to the LMS being a better all around performer.

Maybe your IB install will put the two beasts on more of a level playing field. Interesting...
post #24 of 341
popalock,

I would agree with this as the efficiency of the RE's as you get above 40hz greatly diminishes and in a sealed alignment, I am sucking an aweful lot from the amp with demanding bass tracks (music actually)
post #25 of 341
Thread Starter 
I think they are on a more even playing field in an Ib with the main factor being displacement. Maybe I'm wrong, but thats what I picked up from the experts.
post #26 of 341
Quote:
Originally Posted by keager View Post

Yup, two dual opposed drivers in each manifold under the floor of my bottom level. The crawl space isnt much taller than the drivers, so, I wont need to really lift them into position luckily.

How big is your IB cutout going to be? Are you at least going to be able to slide the subs through the hole you cut in your floor?

I mean, I guess technically your only real option would be to build the box, then install the subs afterwards unless you want your subs to lay in the crawl space while you build the box?

I couldn't image trying to manuver those things in a small crawl space... Sounds, exhausting.

Hey, if your crawl space is large enough to accomodate the XXX shipping tube, it might make it easer to use that and roll the sub into position vs. trying to shimmey it to your floor cutout.
post #27 of 341
Thread Starter 
Ginna have to make a little plywood sled to pull the drivers to there location. Cutout is about 14x20, but the subs are 15 inches deep. Limited by floor joist spacing.
post #28 of 341
Quote:
Originally Posted by keager View Post

Ginna have to make a little plywood sled to pull the drivers to there location. Cutout is about 14x20, but the subs are 15 inches deep. Limited by floor joist spacing.

Sounds like this is going to be a true labor of love for you. I'll check back after this weekend. Expecting some major updates...

Let me know about your spare LMS and Clone when you get the chance.
post #29 of 341
Thread Starter 
Absolutely! Thanks for the advice and interest.
post #30 of 341
Quote:
Originally Posted by keager View Post

I think they are on a more even playing field in an Ib with the main factor being displacement. Maybe I'm wrong, but thats what I picked up from the experts.

have you tried to free air one of them yet? Mine havent left the boxes since I put them in so I dont know what they will do outside the box. What i do know is that I dont even get CLOSE to xmax in the box and im running the fp14k as well...
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