Dual RLp-18 Sealed Sub - Input Please

[fireanimal]

I am in the middle of planning/constructing a Home Theater in my basement. I have studied multiple subwoofer designs including IB and LLT, but I feel that a sealed sub is best in my situation.

My room will be L14.5' W11.5' H7.5'. The room will be as isolated as possible from the rest of the house, that is why I can't do IB, I would have to isolate a secound room.

The enclosure needs to sit at the front/center of the room, under my projection screen, without sticking out to far. The Max height was 30" and depth was 16". Port diameters, length, and port noise all played into not being able to do a LLT.

I will be using a Crown Xti 1000 amp, but I am not sure which way would be better to wire up the subs. Each Channel at 4ohms 500 watts .5% THD or Bridge 2ohms 1400 watts 1% THD. I will be using the Dual 2 ohm voice coil RLP-18's.

I have modeled the Sub in Bassbox Pro, but I am really a newbie at this kind of stuff so it could be way off! Please have a look and let me know.

I have also factored in a room gain of 3 dB/octave rise @ 35Hz, and I am not sure if this is correct or not.

I can use the shelving filters and PQ in the crown if I have to, but I will also be getting a FBD, to tame all the peaks.

I have included some graphs as well as the original BassBox file, for anyone to play around with.

All your input would be great on this design.

Thanks

[jagman]

Hi,

Have you already purchased your amp? Just curious becuase Kevin at DIYCable.com is coming out with a new 1000 watt plate amp that has a defeatable LLT curcuit, a defeatable hi pass crossover and a couple bands of parametric EQ. I highly doubt that will alleviate the need for a parametric EQ (BFD), but at the same time it allows a lot of flexibility. Since your theater isn't finished and you plan on using sealed subs, this may be a nice alternative. I would at least check out his website and forum and/or give him a call.

Good luck!

[fireanimal]

Yeah, I already have the amp.

How does the design look?

Thanks

[fireanimal]

Scratch the 2 Ohm bridged the Xti won't work for that. If I need 1400 watts, I will need the 4 ohm version of the sub.

But 500 Watts per driver should be enough for my little room. If I need more after, I can always add a second amp...1000 watts per driver, that should push them to Xmax.

[fireanimal]

Really looking for some input from the pros, before I go ahead and call this design final.


Thanks

[brandonnash]

I'm not as familiar with bassbox, but if you could change your graphs to a max of say 100 hz it may help out with viewing it. Could you be a bit more specific about your reasons for not being able to do ported? There's (almost) always a way to work around your listed problems.

[fireanimal]

fireanimal wrote:

The enclosure needs to sit at the front/center of the room, under my projection screen, without sticking out to far. The Max height was 30" and depth was 16". Port diameters, length, and port noise all played into not being able to do a LLT.

With Bassbox there are no controls for graph size, at least I can't find any.

Thanks

[ISLAND1000]

Sound Splinter recommends 7 cubic feet for a sealed box. A 24x24x24 would yield approx. 7 cubic feet inside dimension including driver and bracing. You can change the dimensions of the boxes to suit your space just so long as you maintain the 7 cubic foot inside volume. Make two separate boxes rather than one big one. It will give you much more versatility and make moving the boxes much easier.
Your XTi 1000 will provide you with all the PEQ and filters you'll need. The XTi needs to be run through a computer to gain full advantage of the parametric equalizer and filter. You can make real time adjustments to all Crown functions with a computer mouse. It's amazing. One channel of the amp per speaker will easily load your room. The combination of Crown amp and sealed box with the Rlp-18s will be awesome!!!