Rise of the Eighteens

**Sonnie** · **01-26-09, 12:28 AM**

Here's the scenario...

Dual 18's using an LLT design in a home theater (dedicated room) of approximately 3500 cubic feet.

Approximately 120ft^3 (3400 liters) to work with for an enclosure... maximum port diameter is 8"... no length restrictions.

I want to use two 18's. They can either be combined in one enclosure or two individual enclosures.

Power will be one Behringer EP2500 bridged 4 ohm, so drivers need to be setup for a 4 ohm load.

Figure using about 1800-1900 watts max (EP2500 tested at about 1950 watts).

What 18's would you use... what size enclosure or enclosures... what tune, etc... ???

I will only consider using drivers from one of our sponsors.

**atledreier** · **01-26-09, 12:36 AM**

And you're at it again!

Told you a single 15 was too small for you!

**Sonnie** · **01-26-09, 12:54 AM**

Well...

... this is for my new HT room. No way I can have just one sub in there... you know that.

I am going to open this up to sealed recommendations as well. With 120ft^3, I could do a sealed that would almost be an IB.

**atledreier** · **01-26-09, 01:48 AM**

Why sacrifice the headroom and extension when you can slap a pipe in the box and have ultimate bliss?

**Sonnie** · **01-26-09, 01:57 AM**

Just a thought... for those that might come up with a good reason to go sealed.

**atledreier** · **01-26-09, 03:12 AM**

Good luck with that..

**Mike P.** · **01-26-09, 08:15 AM**

Quote:

Power will be one Behringer EP2500 bridged 4 ohm, so drivers need to be setup for a 4 ohm load.

Then you only have 2 choices. Fi Q18-D1 or SoundSplinter RL-p18-D4. Here is A SPL model of one of each. Input power is 900 watts for both. Porting needs to be 10 inch diameter to keep the air speed acceptable.

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**looneybomber** · **01-26-09, 09:04 AM**

With that huge amount of space available, I vote for the Q18's

**Mike P.** · **01-26-09, 09:19 AM**

I do too. In a LLT application the Fi Q18 is the closest match to a Maelstrom-X.

**Sonnie** · **01-26-09, 10:44 AM**

I wish Kevin had those Maelstrom-X drivers in a single 2 ohm or dual 4. It looks like they are dual 6 ohm.

I can actually open up this area that I have available to gain another 3-400ft^3 for a total of about 500-600 cubic feet. The opening into that other space would only be about 10" x 24". Not sure if that would restrict it too much or not, but that would give me the possibility of an IB system, would it not? Of course I might want to consider 4 drivers instead of 2.

**Mike P.** · **01-26-09, 12:18 PM**

The latest batch of Maelstrom-X are dual 2-ohm.

**Ricci** · **01-26-09, 03:15 PM**

Quote:

Sonnie wrote:

Just a thought... for those that might come up with a good reason to go sealed.

A couple of questions...What is your budget for the drivers? Are you adverse to more than 2 drivers or other combinations of sizes of drivers?

I would say that the Mal-x would be the top choice for a big double 18 EBS, but there's no 2 or 8ohm model.

After that I personally like the RLP18 a bit better than the Q18, but that's just me. I think that Scott's design would be a good idea. His are 25cu ft each RLP's tuned to 11hz each with 8" ports and he also uses a bridged EP2500. If you tune to around 12-13hz each RLP should be fine with it's half of full power from the amp(figure 1000w each on peaks). Q18 is pretty similar really.

**Blaser** · **01-26-09, 03:26 PM**

Sonnie,

Is it possible to consider dual amps? A better experience and more headroom. Your room isn't small. I have dual LLTs in half the size of your room, and just enough. With that space I would consider some serious woofing and power.

**Blaser** · **01-26-09, 03:29 PM**

Quote:

Ricci wrote:

A couple of questions...What is your budget for the drivers? Are you adverse to more than 2 drivers or other combinations of sizes of drivers?

I would say that the Mal-x would be the top choice for a big double 18 EBS, but there's no 2 or 8ohm model.

After that I personally like the RLP18 a bit better than the Q18, but that's just me. I think that Scott's design would be a good idea. His are 25cu ft each RLP's tuned to 11hz each with 8" ports and he also uses a bridged EP2500. If you tune to around 12-13hz each RLP should be fine with it's half of full power from the amp(figure 1000w each on peaks). Q18 is pretty similar really.

I agree with you about the RL-P18. Pls note this sub takes 2000 W+ in my setup without any problem. I would even say it likes to be given some homework

**Sonnie** · **01-26-09, 03:41 PM**

If I went with dual amps then I could go with the dual Maelstrom-X's. That would be impressive indeed.

I would like to stay with just 2 drivers. I will already have a pair of 15's in the front. I have the one Audiopulse now and will probably do another one of those for the other sub in the front. So I am going to have 4 subs altogether. Of course then I am going to have the same dilemma with the dual fronts as I am the back... those are dual 2 ohm drivers.

I can't win here.

**Ricci** · **01-26-09, 03:48 PM**

That's going to be a lot of bass Sonnie. Well ... I vote for Mal-X's if you get more power and the RLP's if you stay with a single EP2500. Do you already have the EP2500 to use for this project?

**Blaser** · **01-26-09, 03:55 PM**

Do you have something to play with phase? You will certainly need to adjust subs phase since they will be far from each other

**Sonnie** · **01-26-09, 04:20 PM**

They will be right at equal distance from the main listening position, so phase should not be an issue. At least it wasn't in my last setup which had a very similar sub setup. I tried phase in 15 degree increments to 180 and 0 ended up being the best.

**Blaser** · **01-26-09, 04:32 PM**

At equal distance you should be fine, but but but if they are far apart (4ft+) from each other, they might not couple up to 80 Hz. Anyway give it a try and we'll see.

**Warpdrv** · **01-26-09, 05:47 PM**

Sonnie, I vote the Mal-X's, but hey I'm a bit partial.....

Just to be sure, this run of them is Single 4ohm VC, Kevin has stated the next run will be dual 2ohm for more flexibility. The upper bass response on these babies is spectacular... What mains will you be running with your new sub configuration....?

Any hints on what the size of your new HT will be... configuration...

**Blaser** · **01-26-09, 06:32 PM**

Sonnie. I don't want you to worry too much if you end up with a system that does not exactly give you 4 or 8 ohm. There won't be a huge difference between different loads (as opposed to what you might think) The EP 2500 power at 4 ohm is ~ power at 8 ohm.

**Sonnie** · **01-26-09, 09:42 PM**

If I bridge it 4 ohms... I get about 1950 watts. At 8 ohms bridged... it is about 1330 watts, still good power, just not taking advantage of all of its power.

**Sonnie** · **01-27-09, 02:24 AM**

**atledreier** · **01-27-09, 02:52 AM**

Figure another 8-9dB from teh 15s, plus roomgain, and you're looking at serious structural damage to you house, Sonnie. You are aware you can reach reference outdoors with that setup?

Pretty over the top!

**Sonnie** · **01-27-09, 09:44 AM**

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