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Scott's Dual RL-p18 'LLT' design/build thread

post #1 of 398
Thread Starter 
Hi Everybody!

Some of you around here have seen me post from time to time. I have a fair amount of experience with 'Unibox' but not too much skills with wood working/tools. That is where I will need the the most help. I already know what I want in terms of performance. With two RLp18's, a EP2500 and a small-ass room. Yep, not worried about a "lack of performance"...heh.

So like I said, I know what I want and have modeled it in 'Unibox'. My problem is with coming up with a build guide for me so when I build this sucker, so I know what I am doing. Now, I have some wood working experience. I've built a Adire Tempest vented "Adire alignment" about 5 or so years ago when I was a Jr. in High School. Build the original Adire LCC and 281's the following year. That's about all my "experience" in woodworking. Did wood class in jr. high but I kinda slacked in that class and didn't really take-in what I was supposed to be learning.

Enough with the life story...

What I want is TWO large cabs, one each to house one RL-p18 and one 8" ID port. I originally wanted to build the whole thing with a 28" ID sonotube @ about 6ft in height but things like a small door and other circumstances have changed the build from sono to MDF. I want them to be pretty large because I am shooting for 650-800 effective liters per cab. Yep, pretty big. Spent plenty of time looking over this similar build over at HTS. http://www.hometheatershack.com/foru...llt-begun.html

I thought a 3ft9in tall by 2ft wide and 3ft9in - 4ft in length each would net me in that area. ***You can see my problem. I have no idea how to really get an accurate internal volume.*** I wanted to got with 4ftx2ftx4ft cab for each cause it sounded easy to design but quickly changed that so when I move out of the house and into a place with "normal" height ceiling I could still stack these suckers. Not that I would want to too often what with how much they will weigh...

So...here are the facts so far.

1) 650 liters minimum per cab, 700-800 liters optimal.
2) Tune will be 12-13hz approximately. Tune will move up if I feel I am not happy with this, the lowest tune. Easy to trim a port.
3) 8 inch ID sono will be used per cab for port. Length will change depending on internal volume and final tuning.
4) MDF will be used with two or three window braces. Front (and possibly) back baffles will be double layer.
5) Sub driver will be front firing with a rear firing port. This lets me stack them with no worries on clearance. (***UPDATE 5/18/07*** Possibly front firing port now.)
6) Behringer EP2500 will be used in "bridged mode" to deliver up to 2400w (1400w realistically) total to be distributed between them.
7) No finish has been decided on. Probably anything that is easy, durable and cheap.
8) Already have the two drivers just sitting, waiting to be used. Already have the EP2500. Bridged and running my center channel, atm. Just need to buy wood and the other stuff...

I already know that the driver only takes up a few liters and the port will be around the mid 20's into the 30's in liters of volume displaced. I just don't know how much the bracing and stuffing will take up in volume. I can only do the math on the volume of the whole box by simply entering the 4 x 3.75 x 2 into the windows calculator. Heh, not very good at math too, I guess.

***UPDATE 10/08/07 Changed this graph as I had them way out on page 8 or 9. Figured Id put them on the front page. More accurate graphs and the newest models.***

Unibox FR


Excursion


Port airspeed @ 650w each


Impedance



*********

If you want to model out what my finished project will be...Try: 1450liters, two RL-p18d4 in parallel, 11hz tune with a 20.3cm port each. Minimal leakage, walls lined, and one flush end for port.

*********

So what do you guys say...?

Give me some guidance and help a young man enter bass heaven?
post #2 of 398
ah man.........I thought you were gonna join the club!

post #3 of 398
Thread Starter 
Aww...maing, c'mon now. I'm still in the "Big-ass subwoofer" club. Just not two towers like I had originally wanted. Suppliers in town sucked ass. Nobody had nothing and I am not exaggerating. A 26" ID sono would have to be made special and would cost $300. No thanks.

At 800 liters a pop...I think I am still eligible for joining the club, sono or no sono.
post #4 of 398
God those things will be heavy.

Bad ass though!
post #5 of 398
Great another dual driver setup in a big box. The RL-p18 looks like a great choice for big ported cabinets!
post #6 of 398
Why not do them in separate boxes? You can get better in room response with co-location and they will portable with just two people, instead of...8. Right now you are looking at like 3x3x5', that is huge.
post #7 of 398
Merry X-Mas dude

718.9 liters, including .2cubic' for the driver
Port 8" id 3/16" wall 32 1/8" OAL
Holes in braces 19"ID
Braces 4" X .75"
Outside Dimms:
45" tall
50.5" long, saving you some cutting because MDF is 49" wide
24" wide



edited to adjust for 49" mdf
post #8 of 398
Thread Starter 
Quote:


Why not do them in separate boxes? You can get better in room response with co-location and they will portable with just two people, instead of...8. Right now you are looking at like 3x3x5', that is huge.

In the first post I said...

Quote:


What I want is TWO large cabs, one to house one RL-p18 and one 8" ID port.

I would like to stack them but if it proves to be too much of a back-breaking procedure, even with 3 or 4 of us. If I can't then one goes on the other side of the room.

Quote:


Merry X-Mas dude

Woah...

Thats.......perfect....wow!

Is that a little double brace section where the driver goes? In the CAD it looks like that. Cause I was gonna ask if I should be double layering at least the baffle. This a HUGE eightteen.

That CAD drawing will really help. Thanks!

How many sheet do you think each will use? My first estimate with my first "napkin design" was 2 - 3 sheets each. Not bad. Some nice heft but ....doable.

...Now I just need a cut-sheet and I am set!
post #9 of 398
Sorry, my post was in reference to TheEAR's post, not yours
post #10 of 398
If you are ok with the dimensions, I'll draw up the cut sheets
If you want it in a .pdf PM me your e-mail address
at least 3 sheets per enclosure, mabey 7 total
post #11 of 398
Thread Starter 
Quote:


Sorry, my post was in reference to TheEAR's post, not yours

Oops! Sorry. It was kinda late when I read your reply and didn't really notice...

Quote:


If you are ok with the dimensions, I'll draw up the cut sheets
If you want it in a .pdf PM me your e-mail address
at least 3 sheets per enclosure, mabey 7 total

Yes! That would be just great. PM sent.

Curious...I know Balitic Birch is more expensive but lighter. What do you guys think about using BB for the side panels and/or possibly the top and bottom? Save some weight but not spend too much since the whole thing wouldn't be made of it. Not too sure if mixing types of wood is bad. Ive seen some people use a little BB in a mostly MDF build before.

MDF for the baffle and braces and BB for the side panels??? Eh...eh?
post #12 of 398
BB is great, but the real BB is in 5' X 5' sheets. unless you stretch the boxes to ~61.5" OAL your gonna waste lots of wood=$$$$$$$$$


I'll get to work on the cut sheet documentation, might have it ready tonight
post #13 of 398
Thread Starter 
Maybe I can use the excess for the little braces. I would just need two sheets if I were to only use the BB for the biggest part, the side panels. Sound right? *EDIT* Whoops. Just read that BB was 5 x 5...really? Awww damn. That would be four sheets of BB then. Ouch. Ill have to check the prices for BB when I pick up the MDF. If it isn't too expensive then maybe Ill use it.

Quote:


I'll get to work on the cut sheet documentation, might have it ready tonight

Awesome! Thanks, again. The CAD and cut-sheet will make the (plz, plz PLZ) whole build a fast process.
post #14 of 398
This is a test of the High db Porting System, I repeat, This is olny a test



I have a lil more gluing to do, then it's back to your box


BB is not cheap, if your looking to save $$$ and weight I can switch out the internal bracing for 1/2". That is a reasonable alternative.
post #15 of 398
Thread Starter 
What's that you got going there, buddy?

Quote:


I have a lil more gluing to do, then it's back to your box

That's cool...whenever you have the time. I haven't even picked up any wood yet. I see you are working on something yourself...

Quote:


if your looking to save $$$ and weight I can switch out the internal bracing for 1/2". That is a reasonable alternative.

How much of a weight difference does that quarter of inch will make? Since the braces have such large cutouts...
post #16 of 398
For a sub box, 100% perfectly void-free birch ply isn't a requirement... I have found almost completely (but not quite) void free birch 13ply (18mm) at my local HD for the same cost as MDF...
post #17 of 398
End Tables for my Dad, I got tired of him hinting about how he liked some of the other stuff I built.


1/2" MDF is ~1/3 lighter than 3/4" MDF, not bad.

If there's decent BB at HD for similar $$$$ I'm all for that
I'm goin' in tomorrow to have a look for it, I just bought 3 sheets of 3/4" MDF last saturday, it ran me just under $70 including tax
post #18 of 398
Do you have access to a router?

What wood working tools you got to work with? Table Saw?
post #19 of 398








Click to go back to second page
post #20 of 398
Wow, that thing will weigh a ton!
post #21 of 398
Thread Starter 
Hello...

Holy cow!!! Wow...that...just about covers it, don't it?

Tools? Yes. Pretty much covered. Between my dad and my uncle that lives just two houses down the street, I have got: Table saw, router, circular saw, table press, drill. Pretty sure we have jigsaws and hacksaws and all that. Dunno on the quantity but we do have clamps. I think all I would need to buy would be a circle jig.

Those cutout/dimension CADs are so helpful, thank you very, VERY much NEO Dan. You even cover the port issue I was gonna bring up...I assumed that a 8" sono is thinner and lighter than the ones that are used for the full sized subs. That extra ring should do the trick. I need to make sure and not permanently seal it right away. Starting with a 12hz gives me an option to trim it away and increase the tune if I feel I am not satisfied with the SPL in the 14-30hz range.

That box you're building looks pretty nice. Gotta post some pics of that when you're done. I wanna see that, for sure.
post #22 of 398
Quote:
Originally Posted by cjd View Post

For a sub box, 100% perfectly void-free birch ply isn't a requirement... I have found almost completely (but not quite) void free birch 13ply (18mm) at my local HD for the same cost as MDF...

MDF, China's finest Cabinet Grade Hardwood ply , and Chineese Birch ply
If the Hardwood ply wasn't so fugly i'd seriously consider using it



Here is the first cab I built for my Dad, three fake ports due to me routering the wrong end of the box. No big deal though, I'm building him a matching pair now. They will be finished out as end tables.
Stats:
24"h X 18"w X 36"d
Just over 6cf @12.8hz


Here's why I get asked to design subwoofer cabs
8 sheets of MDF, some of it is 2.25" thick, 7'6" tall Beast, I did this ~6 years agao. Now i'm waiting for the TC LMS-2500 stuff to come out, so can build something like I did for you.
post #23 of 398
Nice job Dan. That's an awesome bass array.
post #24 of 398
Thread Starter 
Ahhh....so you're the one who built that sucker! I love that thing. Wish that was my first subwoofer, ever. Haha! Are those AV-15's in there. Holy cow! What's that tuned to?

That end table sub you made for your dad looks pretty nice. Lots of router work, looks like.

Nothing going on yet since I had to pay off a ticket I got almost a year ago. Better to pay it off than to pay an extra $300 or go to jail.

Anyhow...I took these about a month ago and I am not sure who has seen them.

teh box


Driver on top of my current vented Tempest






Logo


Amaray case on top for scale. Some people were using dvds/cds on their 15 inchers for scale but this just makes more sense for a large Sd driver such as this.
post #25 of 398
Neo Dan,

That is some serious sub you have there! The poor Sunfire looks so tiny next to the mighty goliath.


Scott,

Those Soundsplinter RL-p18 woofers look like serious business,definite eye candy for the sub fanatics.

I wonder if they have them in stock...

Sent them an email,I like ...I like.
post #26 of 398
Quote:
Originally Posted by TheEAR View Post

Neo Dan,

That is some serious sub you have there! The poor Sunfire looks so tiny next to the mighty goliath.


Scott,

Those Soundsplinter RL-p18 woofers look like serious business,definite eye candy for the sub fanatics.

I wonder if they have them in stock...

Sent them an email,I like ...I like.

Of course they do. www.soundsplinter.com
post #27 of 398
Quote:
Originally Posted by Scott Simonian View Post

Ahhh....so you're the one who built that sucker! I love that thing. Wish that was my first subwoofer, ever. Haha! Are those AV-15's in there. Holy cow! What's that tuned to?

That end table sub you made for your dad looks pretty nice. Lots of router work, looks like.

Nothing going on yet since I had to pay off a ticket I got almost a year ago. Better to pay it off than to pay an extra $300 or go to jail.

Anyhow...I took these about a month ago and I am not sure who has seen them.

teh box

Glad you guys like

the drivers are Eclipse 88 series, 3" VC, 19mm X-Max, QT .474, FS 21, VAS 201L, good stuff. Box is tuned around 14hz IIRC, I should check it with WT2.

The router work is almost all using bearing guided bits, super easy

Sometimes you have to pay before you play

Nice pictures, can't wait to see some of your build.

Will you promise to post a youtube vid of you attempting to pull the Jedi mind trick when the Police come to issue you a citation, that'd be great. "There is no loud noise here" LOL
post #28 of 398
Vitod,

Emailed SoundSplinter and Mike was couteous and answered my mails fast! I am ordering two RL-p18's starting next week!

Each driver in its own 14cu ft cabinet ,tuned to 14Hz. Slot porting of course,as it is easy to make them very long.
post #29 of 398
Thread Starter 
Quote:


Glad you guys like

the drivers are Eclipse 88 series, 3" VC, 19mm X-Max, QT .474, FS 21, VAS 201L, good stuff. Box is tuned around 14hz IIRC, I should check it with WT2.

The router work is almost all using bearing guided bits, super easy

Ah, nice! I am sure that baby rocks the house well. Even got a K2 strapped to it! Ahaha! Even with guides, Im pretty newb at routing so I guess it would have been daunting to me.


Quote:


Sometimes you have to pay before you play

Aint that the truth!

Quote:


Nice pictures, can't wait to see some of your build.

Will you promise to post a youtube vid of you attempting to pull the Jedi mind trick when the Police come to issue you a citation, that'd be great. "There is no loud noise here" LOL

Absolutely! Funny thing, there is a highway patrolman that lives just down the street. Although their house sure cause a lot more noise around the neighborhood than I will with these. My walls are surprisingly soundproof.

Quote:


Emailed SoundSplinter and Mike was couteous and answered my mails fast! I am ordering two RL-p18's starting next week!

Each driver in its own 14cu ft cabinet ,tuned to 14Hz. Slot porting of course,as it is easy to make them very long.

Hell yeah! Another with dual 18's...should be sweet!
post #30 of 398
TheEAR,
Why such a high tune, you going for SPL???

You should make something big enough to keep you from draging it back and fourth from room to room
You got a JL for that, right.

IMHO I think i'll end up with the box above but tuned between 7.5-10hz, BKA filter modded to bring up the low end and protect the driver
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