Ported enclosure size for the 18" beast!

**Mongrel714** · **07-05-07, 07:14 PM**

Hey all, has anyone done a ported build with the RL-p18, I really dont want to do a 12 cu ft build, so what would be a good size??

**vitod** · **07-06-07, 09:09 AM**

To get the full potential of this driver is go big.

You'll lose some good low end output with, let say, 9cuft tuned to 15hz. This driver WANTS a big box. Up to you.

**Mongrel714** · **07-06-07, 09:47 AM**

My initial thoughts were 10 cu ft, i'de like to keep the box at about 6'-6'6" tall.

**vitod** · **07-06-07, 10:52 AM**

What do you have? D2 or D4?

**Mongrel714** · **07-06-07, 01:01 PM**

I have the D2, I'm going to put a QSC RMX 1450 on it, and I just started to work out the enclosure space on paper, should'nt have a prob with 12 cu ft.

**vitod** · **07-06-07, 01:08 PM**

12cuft tuned to either 12-15hz looks good.

**Mongrel714** · **07-06-07, 06:47 PM**

I picked up my amp today!!!!, 1400 watts @ 4 ohms!, hooked it up to my poor JL Audio 12",

it wont live long even at the reduced wattage,

heres some pics, and thanks for the info vitod, that sounds great to me!

**bob1029** · **07-07-07, 12:40 AM**

That amp looks awesome... Now I just got done going back and forth with steve on my enclosure and tuning, and it would seem that a ~520 liter (18 cu ft) enclosure tuned to ~15 hz is the best way to go with a ported setup. My enclosure (without feet) comes out to 6'-7" with a 24" diameter. This sounds like it might be right in your range.

**Sonnie** · **07-07-07, 12:59 AM**

Nice amp... it looks pretty similar to my EP2500, except yours is more power.

**Mongrel714** · **07-07-07, 04:20 AM**

Thanks for the info Bob, What are you covering your Sono with? and hows your caps going to be finished? and Thanks Sonnie, what is a EP 2500?? so far the amp is doing very well, allthough its not even breathing hard pushing a 8 ohm load, I about blew the JLs cone out a couple of times last night, scared my cocker spaniel in the kitchen, Had to dial the power down, its amazing how much fuller the bass is allready, My wife is worried!

EDIT:
Oh yeah, are there any rules on hooking up this amp to my reciever, (Onkyo 7.1 HT reciever) I'm just taking it out of my sub pre-out and into the barrier srtip input at the moment, what input would be best to use, balanced XLR, or 1/4' ??

**vitod** · **07-07-07, 04:47 AM**

Quote:

Mongrel714 wrote:

Thanks for the info Bob, What are you covering your Sono with? and hows your caps going to be finished? and Thanks Sonnie, what is a EP 2500??

Behringer EP2500 amp.

**bob1029** · **07-07-07, 08:10 AM**

I will be covering the tube with black marine carpet, which can be obtained from Home Depot. Also, I will most likely sand the caps (2 layers 3/4" mdf) and spray paint them black, possibly with a clearcoat.
The hookup would probably be ok with rca->1/4" from the sub-preout to the amp. I had some issues with my onkyo 901 that required an art cleanbox to convert the unbalanced 1/4" to balanced xlr, but the cleabox will cut off the lower subwoofer frequencies without modification. I would try the 1/4" and if you have issues with levels, we can address them as they arise.

**Mongrel714** · **07-07-07, 07:58 PM**

Quote:

bob1029 wrote:

I will be covering the tube with black marine carpet, which can be obtained from Home Depot. Also, I will most likely sand the caps (2 layers 3/4" mdf) and spray paint them black, possibly with a clearcoat.
The hookup would probably be ok with rca->1/4" from the sub-preout to the amp. I had some issues with my onkyo 901 that required an art cleanbox to convert the unbalanced 1/4" to balanced xlr, but the cleabox will cut off the lower subwoofer frequencies without modification. I would try the 1/4" and if you have issues with levels, we can address them as they arise.

Now I do have a couple of DOD direct boxes left over from the old days, would those work to convert to balanced inputs?? We always used them to run a 1/4" input tp XLR.

**Mongrel714** · **07-09-07, 08:30 PM**

Hey guys, heres a couple pics of the direct box, we used it when we had to run a bass or keyboard directly into a low imp input on a mixing board, the 1/4" input is listed as 50k ohms, the low imp side is listed as 600 ohms, it also has a o-40db boost pad and a ground lift, think it will work to hook up my amp?? also, will I be able to tell a diff between 14hz and 18hz?? 12.8 cu ft at 18 hz and 18 cu ft at 14 hz, (their recomended optimums) just wondering about tuning! thanks guys!

**Mongrel714** · **07-10-07, 06:11 PM**

I'm ready to start chopping wood, so I'm trying my luck with Win isd, looking to do a 17 cu ft enclosure at 14 hz, I'm not sure what Im doing here, so I hope someone will look over these for me, thanks guys!

**Mongrel714** · **07-10-07, 10:39 PM**

Heres some basic meas.

**Mongrel714** · **07-11-07, 04:37 AM**

R.I.P. JL Audio 12"
1997 ? - 2007, My 12" gave up the ghost last night

while watching "Dead Silence" (very scary movie, Ill do a short review later) I am amazed at how much good sound adds to a movie, I've never been on edge before watching a flik!

New driver is supposed to arrive today!!!

**Mongrel714** · **07-11-07, 05:58 PM**

IT"S HERE!!!! Wow, you don't realize how big these drivers are till you see them in person, this is a high quality product, thank you again guys!

**Mongrel714** · **07-11-07, 07:15 PM**

Cut list, looks like I'm gonna need 3 sheets of MDF.

**Jerm357** · **07-11-07, 07:22 PM**

Quote:

Mongrel714 wrote:

I'm ready to start chopping wood, so I'm trying my luck with Win isd, looking to do a 17 cu ft enclosure at 14 hz, I'm not sure what Im doing here, so I hope someone will look over these for me, thanks guys!

If it were me I would go 22cf with a 14-14.5hz tune. But your design plan is not too bad. Theres realy only about a 2db difference between the two designs in the low end.

**Mongrel714** · **07-11-07, 07:47 PM**

Thanks for the info jerm, I'm itching to start on this, I am about maxed out on space with this enclosure now, so I may stick with this size, I've enlisted the help of our carpenter at work tp help me cut this weekend. so here we go!

**Jerm357** · **07-11-07, 09:14 PM**

Your design shape looks realy cool, but I wonder if the port opening is going to have any ill effects cut like that. Wheres Steve C or Ilkka when you need them?

BTW... Cool avatar

**SteveCallas** · **07-12-07, 12:03 AM**

At 17 cubes, I'd personally tune the RL-p18 to ~15.5hz, which would be an 8" dameter port that is ~27" long. No sense in using a tuning lower than what will likely mesh well with room gain to keep you flat down low, as a rolled off low end isn't all that useful in my opinion.

Advertisement