Dual RL-p15 D2 driver DIY..

[steve nn]

Hey all,

I would first like to state what a nice resource this Forum has proven to be. Being that I have everything on order or it's already arrived..I thought it time to ask for a little critiquing. Any help that would come my way would be much appreciated and would greatly help me out on my first DIY project. I have had many subwoofers, but admittedly don't know squat about what I'm taking on. I sold my two SVS PB12-Ultra's to move forward or back, so I'll find out soon enough?

My thinking is if I go with the BASSIS http://www.marchandelec.com/wm8.html coupled with the EP2500 http://www.musiciansbuy.com/mb/item.asp?ic=EP2500 I should be able to build any sub I want with out breaking the $bank. I'm planning on my first unit coming in at 4.5 to 4.75... sealed enclosure with a RL-p15 D2 on the front and back (depends how you look at it) with the EP2500 delivering 600 20/20 rated watts to each driver at 4ohm. I was hoping to go with 3/4 MDF and then cover with Cherry veneer. The front and back (baffle) would be 1.5 thick as to inset the driver's. I had planned on lining the inside with acoustic foam http://www.partsexpress.com/pe/pshow...54&rak=260-515 and using the http://www.partsexpress.com/pe/showd...number=260-304 for the dual driver terminal.

Question one...It has been suggested that going with a driver on each side can aid in the SQ dept concerning resonance? Some might not think this is a good idea? I am willing to go with a taller design if need be.. so I can place both drivers on the same side..or go with two smaller units?

Question two...Would 3/4 with good bracing be adequate?

This sub or subs will be placed in a 24 X 12 X 10' room 11' away from seating and used pretty much exclusively for HT.

Image not available

You can see that I need a little hp from my leaky situation, but all in all since my seating is up against the back wall, it evens out to a degree.

[ThomasW]

Most of the concept sounds good. You really should have a 1.5" wall cabinet unless you're going to use Baltic Birch ply with multiple ladder/window bracing. 3/4" bracing is always fine.

If you want to recess/flush mount the driver, the baffle boards will need to be thicker than 1.5"

Opposing firing drivers is a great idea, since it won't walk around the room when you turn up the volume .... :T

I'm not sure what you're referring to when you say ..."It has been suggested that going with a driver on each side can aid in the SQ dept concerning resonance?"

I suggest you just start with a Behringer DSP1124P (ak BFD) and see how that works for your primary EQ. Add the LT circuit later if you don't get enough low bass from room-gain and the BFD.

For a sealed box I suggest using fiberglass batts as the primary damping material. Acoustic foam is fine for ported designs.

[steve nn]

Most of the concept sounds good. You really should have a 1.5" wall cabinet unless you're going to use Baltic Birch ply with multiple ladder/window bracing. 3/4" bracing is always fine.

That was my original plan suggested by Jack G, but then I deviated to the MDF when I decided to apply the veneer. I'll definitely revert back then.

I was planning on another type of bracing, but I'll run with your suggestion on the window bracing. Do you think two up and down would do the job or do you think I ought to go with three?

If you want to recess/flush mount the driver, the baffle boards will need to be thicker than 1.5"

Yes.. I think it was a post by yourself that I just came across suggesting to go with three 3/4" sheets for this? So I guess a guy would plan on mounting the driver on the bottom layer then as to give another 3/4" recess.? It keeps getting heavier but hey I want this to be right.:driving:

I'm not sure what you're referring to when you say ..."It has been suggested that going with a driver on each side can aid in the SQ dept concerning resonance?"

Well actually the sub walking around the room was brought up in the advice given me, but I took the suggestion as also aiding in smoother bass. I just re-read the advice and I'm pretty certain I misunderstood after correlating it with your advice.

I suggest you just start with a Behringer DSP1124P (ak BFD) and see how that works for your primary EQ. Add the LT circuit later if you don't get enough low bass from room-gain and the BFD.

I really like what has been said of the Bassis though. I do have the little Art 351 slider, but the Bassis seems like a very precision unit although quite spendy considering other options better than the Art. As long as I stay with the sealed design I think I'm pretty sold on the Bassis though.

For a sealed box I suggest using fiberglass batts as the primary damping material. Acoustic foam is fine for ported designs.

All be darn..What R would you recommend and would it matter if it's faced or unfaced? Another thought would be would this cause the driver to see the enclosure a little larger?

Thank you so much for your help ThomasW, I really appreciate your expertise and advice. ;x(

[ThomasW]

"R" value doesn't matter, sealed subs are stuffed at a rate of 0.5-1.5lbs/cu ft. Unfaced batts are used

If you want to do a inner layer of BB ply and an outer layer of MDF to veneer that works fine.

The number of braces depend on the dimensions of the box.

I have a Bassis and yes it nice. IMO it's a bit overpriced given what's really needed for a LT which is a set it and forget it device after the values are entered.

You might consider emailing Rob Cheng. He designed a really nice low buck LT circuit and was for a while selling stuff to make it. Here's a link to his website. Ask if he has anymore circuit boards or partial kits available. http://maxhawk.flagshiphosting.com/projects/Linkwitz/

[steve nn]

"R" value doesn't matter, sealed subs are stuffed at a rate of 0.5-1.5lbs/cu ft. Unfaced batts are used

Ok.. don't line, but stuff.

If you want to do a inner layer of BB ply and an outer layer of MDF to veneer that works fine.

Can a guy veneer over the BB ply then. I was thinking of going the screw and glue rout the first time around, so I was hoping that the veneer would give it a much more refined look. My thinking has been even if I didn't use screws, the edges of the ply would show with out getting into a more complicated design.

The number of braces depend on the dimensions of the box.

Now that I can go back to the cube and considering a single driver on each end.. it should come in around a 22.5" cube with the 3/4" ply. This is the outside diamiter.. I'll add to the depth,(baffles) but it wont need to be considered to the inside diameter. I'll extend the depth to factor for the three layers of ply.

I have a Bassis and yes it nice. IMO it's a bit overpriced given what's really needed for a LT which is a set it and forget it device after the values are entered.

I totally understand and I rather dislike shelling out so much $$ for the unit, but at least I got a $100 off due to the holyday special.:roll: For my situation, I think/hope it will serve me well? It'll most likely be incorporated with other options in the future.. so I would like to consider EQ a done deal along with the user adjustability it seems to present. You know far better than I with actually using one though.

[Paul H]

....
Can a guy veneer over the BB ply then. I was thinking of going the screw and glue rout the first time around, so I was hoping that the veneer would give it a much more refined look. My thinking has been even if I didn't use screws, the edges of the ply would show with out getting into a more complicated design.
...

You can certainly veneer over BB ply.

Personally I like the look of the BB ply edges, as the thin void-free layers give a decent look exposed and just stained - but like I said, personally ..

Paul

[steve nn]

Personally I like the look of the BB ply edges, as the thin void-free layers give a decent look exposed and just stained - but like I said, personally ..

You know Paul, I might have more of a preference in that direction than what I communicated. We made a little trip to my Folks last weekend (50th wedding anniversary) and I took a good look at what my father has been up to wood wise and noticed how the bands didn't look bad at all imo. Actually it looked rather interesting after stain and varnish. The thought came to mind how things would look with the rounded-over edges? Can a guy round-over the ply with out it splintering all to heck? I figured I would do a little practice with the router and see how it looked. Indeed it would be nice to consider it as a viable option with future projects.

I'm also wondering if a guy can inlay some veneer here and there throughout a project? Ah!.. Maybe I've watched Norm Abrams to much?ops: I do like the thought though. Thanks Paul

[ThomasW]

BB ply tends to tear-out on the edges unless you have VERY sharp tools.

The nice thing about using MDF is the ability to machine it and have a really flat surface without tear-out.

If you want to use BB ply as the finish layer be sure to seal it with sanding sealer before applying any stain. That helps avoid 'blotching' which frequently occurs when staining Birch.

[steve nn]

If you want to use BB ply as the finish layer be sure to seal it with sanding sealer before applying any stain. That helps avoid 'blotching' which frequently occurs when staining Birch.

I'll be sure to remember that.

Considering what I'm up to with the dual RL-p15 D2 drivers powered by the EP2500 at 600-750 watts per driver with the BASSIS included..would you go with a larger enclosure? The Fs (23.42) is admittedly a little high, but would you venture to say I'll have enough power on hand to get good response down to 16-18Hz with the 4.5 or so? I guess a few dB of protection is a good idea If its any help I can post a graph of what other subs have been able to achieve in my room for reference?.. minus THD of course. I really don't have a size limit per say, but I would like to go with the sealed design this first time around.

[---k---]

Steve,
I'll comment on the wall thickness. As many of you are aware, I was a doubter of needing greater than 3/4" MDF for the walls. I built my subs out of 3/4"+1/2" anyway, with one window brace. I thought that this would be overkill. Well i maybe it is, but when I had it cranking, I could put my hand on the walls of the sub and still feel vibration in the walls. It wasn't a lot of movement, it wasn't even visible, but it was something I could feel. grrrr.

Notice that Thomas said 3/4" BB w/ MULTIPLE window braces.

Another comment I have, is I did the one brace. I test fit my box with screws, cut the window brace so that it was a little large, and then sanded it until it just fit snug. Then, I assembled the box with glue and all, and wouldn't you know that the window brace was too big in some spots, and gaps in others. I had everything layed out exactly the same, so I'm not sure how this happened. I think some of it could have been because I was doing things outside, then moved inside and maybe the temperature. I was also trying to do the bracing flush inside, so this kindof sucked.

If I had to do it over, I would probably again go with 3/4"+1/2" because I can lift the box without the driver and move it around, but I would add more bracing, and I would build the box like Thomas had suggested. Don't laminate before assembly, but build the outer box first, then line the inside with the second layer and add the bracing as you go, so you get like dado joints.

Two boxes will allow you to have two boxes about the same size as your old Ultras. One box, would have to be very big to have the same Q as two boxes. You also have the benifits of dual placement. One box would definitely be easier to construct.
FYI, your 4.5 cu feet is about 130L. My boxes are about 100L NET each.

[ThomasW]

Steve,

Bigger is always bigger as far as sealed boxes are concerned. The obvious down side to bigger boxes is of course weight.

And no I don't need to see the plots, after 40 yrs of this DIY stuff I have a pretty good idea of what a driver can and can't do in a standard alignment....

[---k---]

Steve,
this is a model of 2 RL-p15 in a single box:



While the scale doesn't really show it, there is around a 2db swing from a 4cuft to a 6.0cuft box at 20HZ. This is big differance, no?. Just so you know, two of my boxes will equal 200L.

So, +6db @20hz from a BFD and a little room gain should bring me at most -3 at 20hz.

[steve nn]

Thank you Ryan. I'm off to work at this time but I really appreciate your input and the time you took to make this post. I'll definitely chew on this today along with your other communicate.

And no I don't need to see the plots, after 40 yrs of this DIY stuff I have a pretty good idea of what a driver can and can't do in a standard alignment....

That's why I made reference to the plot or what my room response is. I have no idea what to expect while you have made many DIY projects. Sorry if I offended it was not my intention. ops:

[---k---]

Steve,
I wouldn't sweat it too much. I think no matter what you do, your sub will turn out great. Could it be better, probably -- but what couldn't. I finally made my decision based on what would look good in my room, which just happened to be a 100L box. I could have made it a little deeper and added 20-30L, and it would have been even better, but...

I can't comment on how SQ will differ from one size to the next, but Thomas keeps saying, build the biggest box you can.

I just keep thinking that you had 2 Ultras before, why not replace them with two new subs about the same size?

[ThomasW]

Here are the basics, the bigger the box = higher efficiency, a lower tuning and a lower "Q".

So pick your poison and go for it....

[steve nn]

You know I think your reasoning is getting to me Ryan. I never have liked the idea of opposing the drivers corner loaded anyway. Building up doesn't really appeal to me either..mmm So that leaves me with building dual units that I can stack or load side-by-side like I have been.

My one concern about going to large is frying the drivers, but I think I'll be fine with the 6-750 watts per driver in dual 4.25 cu ft enclosures. On the other hand it'll take less EQ and cut the risk of adding distortion by introducing to much juice. Maybe I should use what I have on hand to get a feel for things before I step out and finalize the BASSIS? Heck I could fund another project with the savings.

Anyway.. Thank you for allowing me to visualize by modeling out the different options. That was very gracious of you and I appreciate the time it took.

[---k---]

Steve,
Dual opposing drivers does have it's advantages. Thomas originally recommended it to me, but because of room placement options, it went out. So, don't rely on my recomendations, I'm a real rookie at this. Trust Thomas, and build whatever fits in your room better and looks the best to you.

I don't think you'll be anywhere near frying the drying if you keep the amp around 3/4 open, and based on my initial trial, this will be more than enough.

Also, don't worry about the BASSIS. That is easy to add later. Start with a BFD, see what it can do and then go from there.

The modeling took about 10 minutes. You should give it a try sometime. It is fun.

[ssabripo]

Steve...sorry for the delay..I haven't forgotten about you...I will post those FR's for you shorlty!

[steve nn]

Dual opposing drivers does have it's advantages. Thomas originally recommended it to me, but because of room placement options, it went out. So, don't rely on my recomendations, I'm a real rookie at this. Trust Thomas, and build whatever fits in your room better and looks the best to you.

It was in your Thread that I noticed Thomas advised against it. My sub/s will be corner loaded and the idea of the other driver facing the wall didn't totally sit well. I have FR plotted both loading options with front firing units and there are minor differences..I don't want to tall a sub, nor can the sub be to wide. The loading space I have to work with is about a 33" block. I can still fudge up a little further though.

Image not available

Steve...sorry for the delay..I haven't forgotten about you...I will post those FR's for you shorlty!

Hey no problem Sherv....you have your own project going and I totally understand. Isn't it odd all the help we have given others and now here we sit. Character builder yes?

I went to go ship my Ultra's yesterday and wouldn't you know, as I was getting into the vehicle to position it for loading, I noticed the B L tire was about flat. So off I go to less-shwab. :sos: Well I got it done today and I'm glad I don't have that hanging over my head anymore. It looks as though everything is going to be here this week and I'm on vacation next week. Stop talkin and start chalking! :W

[steve nn]

If you want to do a inner layer of BB ply and an outer layer of MDF to veneer that works fine.

"R" value doesn't matter, sealed subs are stuffed at a rate of 0.5-1.5lbs/cu ft. Unfaced batts are used

BB ply tends to tear-out on the edges unless you have VERY sharp tools.

The nice thing about using MDF is the ability to machine it and have a really flat surface without tear-out.

I can't comment on how SQ will differ from one size to the next, but Thomas keeps saying, build the biggest box you can.

I guess I better go pick up a table saw and a router. I do have a circular so I can use that to rip and keep from having to spend to much $$ on the table saw. I'll most likely need to buy a 60 tooth blade?? Well if I'm going to veneer I'll probably not need the 60 tooth to start out then??

Since I'll be going with the BB ply with the suggested window bracing, can I use wood screws for the driver? and do I need some kind of rubber seal or the like for the driver/s? From all the subs I have taken apart it would seem that I can use the wood screws and no extra seal material is needed.

Glue? Any recommendations on a wood glue I can pick up at HD. I will be using the glue and screw method since I'll be covering it up. I guess clamps are still going to be needed? A few small ones for the use of holding things in place for sure.

I still need to figure out whether to built up or go with two sep units. Im sort of leaning with the one larger enclosure now I think. I guess if I go this rout I ought to go with the 1/2 MDF wrapped around the ply along with using the ply for the window bracing. Now the bracing will go up against the MDF (outer shell) with the ply butting up against it yes? I'll put the back on last so the braces wont be able to be slot loaded like the other three sides, unless I'm corrected. Since I'll have the table saw,.. I could cut a groove into the ply to accept the bracing instead. The back (last side to go on) would be hard to get right though.

I know there there's more than a few questions here, but I'm trying to finalize this to a certain extent in the old noggin.

Thanks guys/Thomas

[ThomasW]

Separate units give the option of using 2 locations in the future. And they'll be MUCH lighter to move around.

60 or 80 tooth blades are good...

I use Titebond II, Gorilla glue is a hassle IMO.

Don't cut all the way through the ply for attaching the window braces. A dado 3/8" deep is fine if you want to go to all work involved with dados. I'm lazy so I'd just use butt joints to attach the bracing to the inner walls.

[steve nn]

I'm lazy so I'd just use butt joints to attach the bracing to the inner walls.

That sounds good to me. Do you mean I should screw some blocks inside as something to screw the braces to or do you mean the braces are put together with the but joints? I had planned on using a solid sheet and cutting out the inside as to keep the brace in one solid piece?? If I go this rout.. could I have your blessing on using reg 3/4 ply? :B

[ThomasW]

The window braces are made from a single sheet of material.

If I go this rout.. could I have your blessing on using reg 3/4 ply?

For the enclosure? No way that stuff is riddled with voids. BB ply is almost void-free. That why we use it.

If you happen to live near a Rockler Woodworking store they're having a 1/2 price sale on BB ply until Jan 29th

[steve nn]

Your a beautiful man Thomas. I just goggled it and there happens to be one here in the NW about eight miles away. You just saved me a %^%#$ load of $$.. Who needs Geico.

[---k---]

Steve,
I used just a circular saw, and my cuts tended to be all over the place. A friend said that I could borrow his table saw after he finished a project he was working on, and I never got around to taking him up on it. I really regretted it. If I had to do it over, I would cut the ply down to w/in 1" or so of the final cut and then use the table saw to make the precision cuts.

With all my cuts not being straight and off by 1/8" here and there, I found a router and trim bit to be my best friend! I picked up a Hitachi combo and loved it. It really helped me fix several booh-boohs.

I used 4 36" long bar clamps for most of my build. I felt I could have used more. This was mainly to hold the box together until I could get the screws in. The clamps also held the joints in contact, because I tried not to use too many screws. The more screws I put in, the more of a tendancy I had to split the wood. Get the real bar clamps, not the Irwin Quick Clamps. Real bar clamps are cheaper and hold tighter. I had a pair of each. The Irwin Quick Clamps wouldn't hold as tight, and after a while began to slip (and are way to expensive).

You'll notice on the SS drivers that there is a peice of rubber around the perimeter. CJD told me when I was up at his place that I could either leave it on and not use the weather stripping, or take it off and use weather stripping. I choose to take it off, thinking that I could get a better seal. Not sure if this is true or not, but... If you leave it on, your hole will need to be slightly bigger.

I used both Tightbond II and Gorilla. I used the Tightbond II on all my joints and it worked out really well. Easy to use, cleaned up easily, and appears to be very strong. I screwed around with the Gorilla glue. People talk about how it is expansive, so it fills in any holes you may have. Well, I had some small holes around my perimeter that I tried to just fill up with Gorilla, yeah it expanded but it wasn't very dense and I'm not sure how well it worked. Probably a mixture of saw dust and Tightbond to make a putty would be much better. Don't know.

Thomas brings up a good point about weight/size. I always forget that. My boxes are ~80lbs w/o the driver. I can just barly pick them up and carry them in and out of the garage by myself. If they were any bigger in size or weighed any more, I would definitely need help carrying them around. And since my garage isn't heated, mine went in and out several times.

I think Thomas described in my thread how he builds his boxes with 2 layers. After not having done it that way, I think if I ever re-did it, I would try his way. Basically, he said that he builds the outer box, then lenght of inner layer, then bracing, then the next length of inner layer, ect. You might want to give it a thought.

I think I understand what your thinking with the bracing touching the back panel. I struggled with this. I glued up three sides of my box and the back at once, with the other side just screwed. This allowed me to set a weight on the bracing to make sure it was in firm contact with the back panel. And, I could take the side off and get a caulk gun in all the corners easily.

Also, a router will make the groove in the panels for bracing better than any other tool. That is what it is made for. But, if you find that post where Thomas describes how he builds them, and do it this way, you won't have to groove anything.

[steve nn]

Well I missed the boat on the BB ply. It looks as though its not included in the sale. If I did go with it including using the BB for the braces and baffles.. it's going to go way over budget factoring the router, table saw and BASSIS to get me started.

Also, a router will make the groove in the panels for bracing better than any other tool. That is what it is made for. But, if you find that post where Thomas describes how he builds them, and do it this way, you won't have to groove anything.

My motto is overbuild. Doubled 3/4" MDF is 8 times more resistant to flexing then a single 3/4" layer........I used a form of window bracing when I built the AS-15. There I made the outer layer and the braces were spaced by gluing in separate pieces of wood that also formed a complete second layer for the cabinet. That way I didn't have to deal with lining up dado cuts made in 1.5" thick material.......

I picked up the wood and I elected to go with 3/4 MDF for the outer shell and use the 1/2 MDF for the inner shell. I'll use 3/4 MDF for the window braces and try to go about it as Thomas suggested piecing it together as I go. The ends/sides of the bracing butts up against the outer wall correct??..with the inner shell butting up against the sides of the bracing correct? That would mean the inner shell is done in two to three shortened up sheets per side, top, bottom with the back (last to go on) just doubled up and screwed and glued.

I went with the Ryobi table saw http://www.ryobitools.com/index.php/catalog/tool/bts15/ which I'm sure will do a hacker like me ok, but I have concern on the router I picked up.. http://www.ryobitools.com/index.php/.../tool/r162rta/ ..It isn't the plunge type that I read about in your Thread Ryan. Do you think I ought to return it and go with the plunge? I would be giving up the table, but I would be gaining the plunge capability. As a option, I can also use the router with out the table.

Get the real bar clamps

Advice taken. Thank you for your help guys. It looks like I'll be out in the garage from Tuesday on building my first project. Since I'm on vacation, I hope to finish it by the end of the week minus veneer. I'll hold off on that and the second unit until I see how the first one fairs with BASSIS and without. I guess I'm looking at about a 4.25 cu ft enclosure with fill. I picked up some batts, but it has the backing. So I'll pull it off and stuff.. not like I originally planned.

[ThomasW]

You don't need a Bassis to start with. And if you need a LT circuit there are significantly lower cost units available. The Bassis is fun because it's adjustable. However once dialed in the settings never change unless you get a different sub. So the normal thing is a little LT where a couple of components on the circuit board are change when one changes design. These can be built for a fraction the price of the Bassis.

Also everyone needs a BFD those are $100, but there's another option. If instead of the BFD you buy the Behringer DEQ 2496, your get all the functionality of the BFD, plus the ability to make a LT circuit, and you get built-in measurement capability all for $300.

[steve nn]

Also everyone needs a BFD those are $100, but there's another option. If instead of the BFD you buy the Behringer DEQ 2496, your get all the functionality of the BFD, plus the ability to make a LT circuit, and you get built-in measurement capability all for $300.

AH! I think I understand your frustration concerning me and the BASSIS now? I thought the BASSIS had the EQ functionality along with the other user adjustability LT benefits. So your telling me I would still need the EQ (if I went that rout) with the BASSIS to utilize it????????????

[ThomasW]

Right, the Bassis is only a really fancy LT circuit, it has no other EQ functions.

So even if you buy a Bassis you'll still need EQ to flatten the in-room response or create a 'house-curve'.

[---k---]

Steve,

You need a Plunge Router to make the circle cuts. A plunge router basically has the bit on a spring so you can push it down into the wood. To make the circle holes, you can use a jig saw if you want, but if you're buying a router (and you will love it once you get it), get a plunge/fix combo, and it will be easy as pie. You'll also need to make a jig for the router, or buy the Jasper Jig. Thomas has on one of his websites how to make a driver hole with a router. It might help you to visualize things.

You'll need a couple of bits for that router. A 2" Trim bits (the ones with the bearing on the bottom) came in real handy for me. I picked it up at a woodworking store. But once my box was assembled, it allowed me to trace all the edges and make sure they were perfectly flush. I hope that is making sense. I got a couple woodworking books from the library before I stated, and it helped me out a bit. I could have used more help, but....

Good luck, have fun, don't worry about screwing up little details because most things are fixable one way or another.

[steve nn]

Right, the Bassis is only a really fancy LT circuit, it has no other EQ functions.

Well that takes care of that then. I would much rather upgrade my Art to the DEQ and then take things from there. For $5-600 I took for granted it had EQ capability. My dumb...Thanks for Qing me in.

You need a Plunge Router to make the circle cuts. Good luck, have fun, don't worry about screwing up little details

There are two things I've learned in the last 12 hrs..Routers are no fun and I always like taking the line out regardless how hard I try not to.. (Table saw or router) I now measure a 1/16 over and quit fighting it.

Been out of town for a few days but we're moving forward now. Every thing has been dry fitted including the braces. I think I'll go out and put the terminal cup in and then screw, glue and clamp. I'll still need to wrap the 1/2" outer shell around it along with the veneer.

[---k---]

Looks real good! Did you go with 22x22x22 (pure guess)?

[steve nn]

Did you go with 22x22x22 (pure guess)?

Pretty close!...actually 21.5 at 1.25". I guess I should come in around 3.6 cu ft or there abouts. I was going to go 4.25 but Mike talked me out of it. I'll try this out first and see where it takes me?

Looks real good!

That's nice of you to say Ryan, but we can see the baffle needed rounded over. Free hand didn't work to well, but I made up a jig out of a old yard-stick that had been laying around. Nothing like high tech tools you know?



I might be able to fire this thing up tomorrow if I keep the pace and don't get lazy?? The outer shell is ready to go (been dry fitted) so all the cutting and router work is done.

[---k---]

I keep seeing people post progress photos after like two days they got thiers subs done. Mine took me almost a month to do!

I don't see anything wrong in your photos. Once you get it glued up and then take your router to the edges and clean everything up, and a coat of paint, I think it will look darn impressive. :T :T

[steve nn]

I keep seeing people post progress photos after like two days they got thiers subs done. Mine took me almost a month to do!

You came to mind when I ripping a sheet.. did Ryan actually build his whole sub with out a table saw? I guess many have and will, but what a time saver! I don't question the validity of having one around now that's for sure.. No I spent the better part of the last few days looking at a piece of paper with a square box drawn on it visualizing what to do right before I started. The one thing I didn't have figured out was the baffle and making it a perfect round circle. Scribing it out was no problem of course, but trying to freehand it with the router was a the pits! When it turned out so bad, I was forced to come up with a solution. I at least could see what I had to work with at that point. This Forum (you and Thomas) have been my saving grace though.

I don't see anything wrong in your photos. Once you get it glued up and then take your router to the edges and clean everything up, and a coat of paint, I think it will look darn impressive.

The inside layer of the baffle is still freehand, but that's ok because it'll be covered up. I might save my veneer for the next project and do the paint or some other form of finishing it off? I'll determine that after I see what kind of response I get with EQ. My seating is up against the back boundary along with the sub being corner loaded, so I'll keep my fingers crossed.

Yes that edging bit with the guide at the end is a God send for a Ultra DIY beginner like myself..worth it's weight in gold no? That was a good suggestion on your part and one I was sure to take.

[---k---]

If your inner peice of the baffle being free hand is the worse thing you did, I think you're doing pretty good. :T Of course, I'm the guy you cut both of his front baffles about 1/2" too narrow and didn't realize it untill the everything else was glued up!

How thick is your baffle? I actually ended up making my 1/2"+3/4"+3/4"=2" . Maybe overkill, but overkill was recommended. I guess there is concern because the driver pounds the piss out of the baffle.

Also, you got any photos of your bracing. Just curious what you came up with.


Are you having fun?

[steve nn]

Of course, I'm the guy you cut both of his front baffles about 1/2" too narrow and didn't realize it untill the everything else was glued up!

Yikes! I thought I heard a loud noise the other day. I'm surprised I haven't done the same though... when I seat the driver today, I'll let you know.

How thick is your baffle? I actually ended up making my 1/2"+3/4"+3/4"=2" .

1/2 + 3/4 + 3/4 = 2" :lol:

Also, you got any photos of your bracing. Just curious what you came up with.

Nothing fancy or pretty, but I hope functional with the 1 1/4 shell? It seems to be passing the rap test anyway except for the back. I'm hoping the extra 1/2" will square that away with out chewing up any more volume. I still might put a band across the back though?

Are you having fun?

OH yeah..I'm having to fight the temptation to plop the driver in and give it a run though. I really like subwoofers so this gives me a opportunity to get very involved without costing a arm and a leg. I actually always came out fine $$ wise come to think of it, but I'm not noted for my longevity with any certain sub although maybe a certain company.

[ssabripo]

Hey Steve...looking good man!!! :T

My AV15 is still pending (they said another 2 weeks, because of backordered magnets for the MKII motors) .... I'm jelous you already are almost finished and I still dont even have my driver here :M

by the way, I apologize for not sending you that design....I guess you dont need it now ops: ...I'll make it up next time!

good job man....keep it up

[steve nn]

My AV15 is still pending (they said another 2 weeks, because of backordered magnets for the MKII motors) .... I'm jelous you already are almost finished and I still dont even have my driver here

Hey Sherv,
Well your sitting good then. Two weeks will go fast as you know all to well with us getting older by the day. Easy for me to say though right. The AV15 is a nice driver to be sure. I think I mentioned to you in another communicate that I had one built when they first came out by Brian Bunge? Now that the first generation AV is history all is well. Your going to like it I'm sure.

by the way, I apologize for not sending you that design....I guess you dont need it now ...I'll make it up next time!

Please don't give it a second thought..I totally understand. Hey it's been nothing short of a marathon around here. 53 hrs and she's up and running. I had a little problem today that actually worked out well in the end. I guess my writing on the panels were a bit confusing after the dry fit, so when the real deal went down, I wound up with a side panel for the bottom that wouldn't fit. I re-cut (the panel) and wound up with a 22" cube instead of the 21.5". I'm coming in at + - 6 from 18 to 99Hz. If I cut my 30-40Hz hump, I could easily come in at + - 3. I admittedly like a little curve for HT though. No weak spots at all.

Plopped in the EAGLES (hell freezes) over in DTS and it was as good as I have ever had it SQ wise. I then viewed in part the GLADIATOR, SW II and THE INCREDIBLES. Yip!.. it's all there..SPL along with great SQ. I was so afraid this was going to turn out to be some kind of car boom box (no slam towards car woofs)..Went back and looked at a few of my graphs and I think it should hold up very well considering SPL from the preliminary test I ran with no compression setting in from -17 to -5.

Sorry if I'm ranting or coming across as a bragger. That's really not the case..(I am ranting all right :blah: ) I give the credit to all who helped me along the way and the SS RL-p15 driver. I was really starting to doubt this driver, but no more. I guess I will use the Cherry veneer on this sub.

[---k---]

So, I take it that the corner loading gives you plenty of extension? Just a little boost from the BFD and you'll be there? Do you just have one done or both?

Looking real good. I'm thinking that your's turned out better than mine! Grrrr

[SteveCallas]

Good work, glad to hear it turned out so well. Is the second one on the way?

[ThomasW]

I was so afraid this was going to turn out to be some kind of car boom box

We don't let people build that kind of box....

[steve nn]

So, I take it that the corner loading gives you plenty of extension?

Generally I refer to the to the RF corner as corner 1 and my NF corner as corner 2. Both corners can and do work out well response wise, but I do favor corner 1 eleven feet away even though NF corner 2 provides a little more gain including low end response. Loading by the screen (as in your case) isn't a option in my situation FR wise or ascetically.

Just a little boost from the BFD and you'll be there?

I'll have to play around with that..I usually suffer a dip around the 20Hz mark when I do so though. Even the provided onboard EQ in a plate amp will cause this with many subs.

Do you just have one done or both?

Just the one except the veneer, staining and varnish. From what I can tell so far, I think just the one will be just fine. I could do the second unit and pull one of the drivers for a ported option in the future or just do the vented without ever building the second sealed unit.

Looking real good. I'm thinking that your's turned out better than mine! Grrrr

I don't know Ryan? What I can tell you it's a 22" cube 1.25" thick with 5.75' of R-13 stuffed into it. I lightly fluffed the panels of R-13. If there is anybody who is deserving of a good DIY sub...your the one who comes to my mind. You've been there all the way br.

[steve nn]

Good work, glad to hear it turned out so well. Is the second one on the way?

Hey Steve good to see you and Thanks! Who can really say. I'm going to sit back for a month or so and think about it. The wife is due to take off any moment and I'm on vacation with a brandnew sub that I really like. arty:

Since I'm all setup now with the tools and amp including the second driver (that I have full confidence in now)..only time will tell. I cut the legs off a corner table that hasn't been replaced yet, so maybe I'll build a larger vented enclosure that will double as the corner table. One of the Ultra's was actually being used for this purpose most of the time. Now that I have a little idea of the subs capability,.. going the option rout seams pretty appealing.

We don't let people build that kind of box....

That's funny Thomas. You sure as ^%$% have my attention. I was out there on a limb going about things the way that I did, but I now totally agree and had the best nights sleep that I've had in the past two months since I started all this. It was Ilkka who originally got me to thinking about this driver along with Jack G modeling it up for me. Couple that with all your help here on the Forum with the actual building process..it turned out very well with a driver to spare.

[SteveCallas]

Is it too early to ask how you think it compares to the pair of Ultras or perhaps a single Ultra? This is the DIY section, so you won't have to worry about being attacked